Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

40 files changed, 22800 insertions, 0 deletions

diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig
new file mode 100644
index 000000000..606a9d07f
--- /dev/null
+++ b/drivers/android/Kconfig
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: GPL-2.0
+menu "Android"
+
+config ANDROID_BINDER_IPC
+	bool "Android Binder IPC Driver"
+	depends on MMU
+	depends on NET
+	default n
+	help
+	  Binder is used in Android for both communication between processes,
+	  and remote method invocation.
+
+	  This means one Android process can call a method/routine in another
+	  Android process, using Binder to identify, invoke and pass arguments
+	  between said processes.
+
+config ANDROID_BINDER_IPC_RUST
+	bool "Rust version of Android Binder IPC Driver"
+	depends on RUST && MMU && NET && !ANDROID_BINDER_IPC
+	help
+	  This enables the Rust implementation of the Binder driver.
+
+	  Binder is used in Android for both communication between processes,
+	  and remote method invocation.
+
+	  This means one Android process can call a method/routine in another
+	  Android process, using Binder to identify, invoke and pass arguments
+	  between said processes.
+
+config ANDROID_BINDERFS
+	bool "Android Binderfs filesystem"
+	depends on ANDROID_BINDER_IPC
+	default n
+	help
+	  Binderfs is a pseudo-filesystem for the Android Binder IPC driver
+	  which can be mounted per-ipc namespace allowing to run multiple
+	  instances of Android.
+	  Each binderfs mount initially only contains a binder-control device.
+	  It can be used to dynamically allocate new binder IPC devices via
+	  ioctls.
+
+config ANDROID_BINDER_DEVICES
+	string "Android Binder devices"
+	depends on ANDROID_BINDER_IPC || ANDROID_BINDER_IPC_RUST
+	default "binder,hwbinder,vndbinder"
+	help
+	  Default value for the binder.devices parameter.
+
+	  The binder.devices parameter is a comma-separated list of strings
+	  that specifies the names of the binder device nodes that will be
+	  created. Each binder device has its own context manager, and is
+	  therefore logically separated from the other devices.
+
+config ANDROID_BINDER_ALLOC_KUNIT_TEST
+	tristate "KUnit Tests for Android Binder Alloc" if !KUNIT_ALL_TESTS
+	depends on ANDROID_BINDER_IPC && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This feature builds the binder alloc KUnit tests.
+
+	  Each test case runs using a pared-down binder_alloc struct and
+	  test-specific freelist, which allows this KUnit module to be loaded
+	  for testing without interfering with a running system.
+
+endmenu
diff --git a/drivers/android/Makefile b/drivers/android/Makefile
new file mode 100644
index 000000000..e0c650d38
--- /dev/null
+++ b/drivers/android/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+ccflags-y += -I$(src)			# needed for trace events
+
+obj-$(CONFIG_ANDROID_BINDERFS)		+= binderfs.o
+obj-$(CONFIG_ANDROID_BINDER_IPC)	+= binder.o binder_alloc.o binder_netlink.o
+obj-$(CONFIG_ANDROID_BINDER_ALLOC_KUNIT_TEST)	+= tests/
+obj-$(CONFIG_ANDROID_BINDER_IPC_RUST)	+= binder/
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
new file mode 100644
index 000000000..8f2ef1bd5
--- /dev/null
+++ b/drivers/android/binder.c
@@ -0,0 +1,7186 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* binder.c
+ *
+ * Android IPC Subsystem
+ *
+ * Copyright (C) 2007-2008 Google, Inc.
+ */
+
+/*
+ * Locking overview
+ *
+ * There are 3 main spinlocks which must be acquired in the
+ * order shown:
+ *
+ * 1) proc->outer_lock : protects binder_ref
+ *    binder_proc_lock() and binder_proc_unlock() are
+ *    used to acq/rel.
+ * 2) node->lock : protects most fields of binder_node.
+ *    binder_node_lock() and binder_node_unlock() are
+ *    used to acq/rel
+ * 3) proc->inner_lock : protects the thread and node lists
+ *    (proc->threads, proc->waiting_threads, proc->nodes)
+ *    and all todo lists associated with the binder_proc
+ *    (proc->todo, thread->todo, proc->delivered_death and
+ *    node->async_todo), as well as thread->transaction_stack
+ *    binder_inner_proc_lock() and binder_inner_proc_unlock()
+ *    are used to acq/rel
+ *
+ * Any lock under procA must never be nested under any lock at the same
+ * level or below on procB.
+ *
+ * Functions that require a lock held on entry indicate which lock
+ * in the suffix of the function name:
+ *
+ * foo_olocked() : requires node->outer_lock
+ * foo_nlocked() : requires node->lock
+ * foo_ilocked() : requires proc->inner_lock
+ * foo_oilocked(): requires proc->outer_lock and proc->inner_lock
+ * foo_nilocked(): requires node->lock and proc->inner_lock
+ * ...
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/fdtable.h>
+#include <linux/file.h>
+#include <linux/freezer.h>
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/nsproxy.h>
+#include <linux/poll.h>
+#include <linux/debugfs.h>
+#include <linux/rbtree.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/mm.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/pid_namespace.h>
+#include <linux/security.h>
+#include <linux/spinlock.h>
+#include <linux/ratelimit.h>
+#include <linux/syscalls.h>
+#include <linux/task_work.h>
+#include <linux/sizes.h>
+#include <linux/ktime.h>
+
+#include <kunit/visibility.h>
+
+#include <uapi/linux/android/binder.h>
+
+#include <linux/cacheflush.h>
+
+#include "binder_netlink.h"
+#include "binder_internal.h"
+#include "binder_trace.h"
+
+static HLIST_HEAD(binder_deferred_list);
+static DEFINE_MUTEX(binder_deferred_lock);
+
+static HLIST_HEAD(binder_devices);
+static DEFINE_SPINLOCK(binder_devices_lock);
+
+static HLIST_HEAD(binder_procs);
+static DEFINE_MUTEX(binder_procs_lock);
+
+static HLIST_HEAD(binder_dead_nodes);
+static DEFINE_SPINLOCK(binder_dead_nodes_lock);
+
+static struct dentry *binder_debugfs_dir_entry_root;
+static struct dentry *binder_debugfs_dir_entry_proc;
+static atomic_t binder_last_id;
+
+static int proc_show(struct seq_file *m, void *unused);
+DEFINE_SHOW_ATTRIBUTE(proc);
+
+#define FORBIDDEN_MMAP_FLAGS                (VM_WRITE)
+
+enum {
+	BINDER_DEBUG_USER_ERROR             = 1U << 0,
+	BINDER_DEBUG_FAILED_TRANSACTION     = 1U << 1,
+	BINDER_DEBUG_DEAD_TRANSACTION       = 1U << 2,
+	BINDER_DEBUG_OPEN_CLOSE             = 1U << 3,
+	BINDER_DEBUG_DEAD_BINDER            = 1U << 4,
+	BINDER_DEBUG_DEATH_NOTIFICATION     = 1U << 5,
+	BINDER_DEBUG_READ_WRITE             = 1U << 6,
+	BINDER_DEBUG_USER_REFS              = 1U << 7,
+	BINDER_DEBUG_THREADS                = 1U << 8,
+	BINDER_DEBUG_TRANSACTION            = 1U << 9,
+	BINDER_DEBUG_TRANSACTION_COMPLETE   = 1U << 10,
+	BINDER_DEBUG_FREE_BUFFER            = 1U << 11,
+	BINDER_DEBUG_INTERNAL_REFS          = 1U << 12,
+	BINDER_DEBUG_PRIORITY_CAP           = 1U << 13,
+	BINDER_DEBUG_SPINLOCKS              = 1U << 14,
+};
+static uint32_t binder_debug_mask = BINDER_DEBUG_USER_ERROR |
+	BINDER_DEBUG_FAILED_TRANSACTION | BINDER_DEBUG_DEAD_TRANSACTION;
+module_param_named(debug_mask, binder_debug_mask, uint, 0644);
+
+char *binder_devices_param = CONFIG_ANDROID_BINDER_DEVICES;
+module_param_named(devices, binder_devices_param, charp, 0444);
+
+static DECLARE_WAIT_QUEUE_HEAD(binder_user_error_wait);
+static int binder_stop_on_user_error;
+
+static int binder_set_stop_on_user_error(const char *val,
+					 const struct kernel_param *kp)
+{
+	int ret;
+
+	ret = param_set_int(val, kp);
+	if (binder_stop_on_user_error < 2)
+		wake_up(&binder_user_error_wait);
+	return ret;
+}
+module_param_call(stop_on_user_error, binder_set_stop_on_user_error,
+	param_get_int, &binder_stop_on_user_error, 0644);
+
+static __printf(2, 3) void binder_debug(int mask, const char *format, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	if (binder_debug_mask & mask) {
+		va_start(args, format);
+		vaf.va = &args;
+		vaf.fmt = format;
+		pr_info_ratelimited("%pV", &vaf);
+		va_end(args);
+	}
+}
+
+#define binder_txn_error(x...) \
+	binder_debug(BINDER_DEBUG_FAILED_TRANSACTION, x)
+
+static __printf(1, 2) void binder_user_error(const char *format, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	if (binder_debug_mask & BINDER_DEBUG_USER_ERROR) {
+		va_start(args, format);
+		vaf.va = &args;
+		vaf.fmt = format;
+		pr_info_ratelimited("%pV", &vaf);
+		va_end(args);
+	}
+
+	if (binder_stop_on_user_error)
+		binder_stop_on_user_error = 2;
+}
+
+#define binder_set_extended_error(ee, _id, _command, _param) \
+	do { \
+		(ee)->id = _id; \
+		(ee)->command = _command; \
+		(ee)->param = _param; \
+	} while (0)
+
+#define to_flat_binder_object(hdr) \
+	container_of(hdr, struct flat_binder_object, hdr)
+
+#define to_binder_fd_object(hdr) container_of(hdr, struct binder_fd_object, hdr)
+
+#define to_binder_buffer_object(hdr) \
+	container_of(hdr, struct binder_buffer_object, hdr)
+
+#define to_binder_fd_array_object(hdr) \
+	container_of(hdr, struct binder_fd_array_object, hdr)
+
+static struct binder_stats binder_stats;
+
+static inline void binder_stats_deleted(enum binder_stat_types type)
+{
+	atomic_inc(&binder_stats.obj_deleted[type]);
+}
+
+static inline void binder_stats_created(enum binder_stat_types type)
+{
+	atomic_inc(&binder_stats.obj_created[type]);
+}
+
+struct binder_transaction_log_entry {
+	int debug_id;
+	int debug_id_done;
+	int call_type;
+	int from_proc;
+	int from_thread;
+	int target_handle;
+	int to_proc;
+	int to_thread;
+	int to_node;
+	int data_size;
+	int offsets_size;
+	int return_error_line;
+	uint32_t return_error;
+	uint32_t return_error_param;
+	char context_name[BINDERFS_MAX_NAME + 1];
+};
+
+struct binder_transaction_log {
+	atomic_t cur;
+	bool full;
+	struct binder_transaction_log_entry entry[32];
+};
+
+static struct binder_transaction_log binder_transaction_log;
+static struct binder_transaction_log binder_transaction_log_failed;
+
+static struct binder_transaction_log_entry *binder_transaction_log_add(
+	struct binder_transaction_log *log)
+{
+	struct binder_transaction_log_entry *e;
+	unsigned int cur = atomic_inc_return(&log->cur);
+
+	if (cur >= ARRAY_SIZE(log->entry))
+		log->full = true;
+	e = &log->entry[cur % ARRAY_SIZE(log->entry)];
+	WRITE_ONCE(e->debug_id_done, 0);
+	/*
+	 * write-barrier to synchronize access to e->debug_id_done.
+	 * We make sure the initialized 0 value is seen before
+	 * memset() other fields are zeroed by memset.
+	 */
+	smp_wmb();
+	memset(e, 0, sizeof(*e));
+	return e;
+}
+
+enum binder_deferred_state {
+	BINDER_DEFERRED_FLUSH        = 0x01,
+	BINDER_DEFERRED_RELEASE      = 0x02,
+};
+
+enum {
+	BINDER_LOOPER_STATE_REGISTERED  = 0x01,
+	BINDER_LOOPER_STATE_ENTERED     = 0x02,
+	BINDER_LOOPER_STATE_EXITED      = 0x04,
+	BINDER_LOOPER_STATE_INVALID     = 0x08,
+	BINDER_LOOPER_STATE_WAITING     = 0x10,
+	BINDER_LOOPER_STATE_POLL        = 0x20,
+};
+
+/**
+ * binder_proc_lock() - Acquire outer lock for given binder_proc
+ * @proc:         struct binder_proc to acquire
+ *
+ * Acquires proc->outer_lock. Used to protect binder_ref
+ * structures associated with the given proc.
+ */
+#define binder_proc_lock(proc) _binder_proc_lock(proc, __LINE__)
+static void
+_binder_proc_lock(struct binder_proc *proc, int line)
+	__acquires(&proc->outer_lock)
+{
+	binder_debug(BINDER_DEBUG_SPINLOCKS,
+		     "%s: line=%d\n", __func__, line);
+	spin_lock(&proc->outer_lock);
+}
+
+/**
+ * binder_proc_unlock() - Release outer lock for given binder_proc
+ * @proc:                struct binder_proc to acquire
+ *
+ * Release lock acquired via binder_proc_lock()
+ */
+#define binder_proc_unlock(proc) _binder_proc_unlock(proc, __LINE__)
+static void
+_binder_proc_unlock(struct binder_proc *proc, int line)
+	__releases(&proc->outer_lock)
+{
+	binder_debug(BINDER_DEBUG_SPINLOCKS,
+		     "%s: line=%d\n", __func__, line);
+	spin_unlock(&proc->outer_lock);
+}
+
+/**
+ * binder_inner_proc_lock() - Acquire inner lock for given binder_proc
+ * @proc:         struct binder_proc to acquire
+ *
+ * Acquires proc->inner_lock. Used to protect todo lists
+ */
+#define binder_inner_proc_lock(proc) _binder_inner_proc_lock(proc, __LINE__)
+static void
+_binder_inner_proc_lock(struct binder_proc *proc, int line)
+	__acquires(&proc->inner_lock)
+{
+	binder_debug(BINDER_DEBUG_SPINLOCKS,
+		     "%s: line=%d\n", __func__, line);
+	spin_lock(&proc->inner_lock);
+}
+
+/**
+ * binder_inner_proc_unlock() - Release inner lock for given binder_proc
+ * @proc:         struct binder_proc to acquire
+ *
+ * Release lock acquired via binder_inner_proc_lock()
+ */
+#define binder_inner_proc_unlock(proc) _binder_inner_proc_unlock(proc, __LINE__)
+static void
+_binder_inner_proc_unlock(struct binder_proc *proc, int line)
+	__releases(&proc->inner_lock)
+{
+	binder_debug(BINDER_DEBUG_SPINLOCKS,
+		     "%s: line=%d\n", __func__, line);
+	spin_unlock(&proc->inner_lock);
+}
+
+/**
+ * binder_node_lock() - Acquire spinlock for given binder_node
+ * @node:         struct binder_node to acquire
+ *
+ * Acquires node->lock. Used to protect binder_node fields
+ */
+#define binder_node_lock(node) _binder_node_lock(node, __LINE__)
+static void
+_binder_node_lock(struct binder_node *node, int line)
+	__acquires(&node->lock)
+{
+	binder_debug(BINDER_DEBUG_SPINLOCKS,
+		     "%s: line=%d\n", __func__, line);
+	spin_lock(&node->lock);
+}
+
+/**
+ * binder_node_unlock() - Release spinlock for given binder_proc
+ * @node:         struct binder_node to acquire
+ *
+ * Release lock acquired via binder_node_lock()
+ */
+#define binder_node_unlock(node) _binder_node_unlock(node, __LINE__)
+static void
+_binder_node_unlock(struct binder_node *node, int line)
+	__releases(&node->lock)
+{
+	binder_debug(BINDER_DEBUG_SPINLOCKS,
+		     "%s: line=%d\n", __func__, line);
+	spin_unlock(&node->lock);
+}
+
+/**
+ * binder_node_inner_lock() - Acquire node and inner locks
+ * @node:         struct binder_node to acquire
+ *
+ * Acquires node->lock. If node->proc also acquires
+ * proc->inner_lock. Used to protect binder_node fields
+ */
+#define binder_node_inner_lock(node) _binder_node_inner_lock(node, __LINE__)
+static void
+_binder_node_inner_lock(struct binder_node *node, int line)
+	__acquires(&node->lock) __acquires(&node->proc->inner_lock)
+{
+	binder_debug(BINDER_DEBUG_SPINLOCKS,
+		     "%s: line=%d\n", __func__, line);
+	spin_lock(&node->lock);
+	if (node->proc)
+		binder_inner_proc_lock(node->proc);
+	else
+		/* annotation for sparse */
+		__acquire(&node->proc->inner_lock);
+}
+
+/**
+ * binder_node_inner_unlock() - Release node and inner locks
+ * @node:         struct binder_node to acquire
+ *
+ * Release lock acquired via binder_node_lock()
+ */
+#define binder_node_inner_unlock(node) _binder_node_inner_unlock(node, __LINE__)
+static void
+_binder_node_inner_unlock(struct binder_node *node, int line)
+	__releases(&node->lock) __releases(&node->proc->inner_lock)
+{
+	struct binder_proc *proc = node->proc;
+
+	binder_debug(BINDER_DEBUG_SPINLOCKS,
+		     "%s: line=%d\n", __func__, line);
+	if (proc)
+		binder_inner_proc_unlock(proc);
+	else
+		/* annotation for sparse */
+		__release(&node->proc->inner_lock);
+	spin_unlock(&node->lock);
+}
+
+static bool binder_worklist_empty_ilocked(struct list_head *list)
+{
+	return list_empty(list);
+}
+
+/**
+ * binder_worklist_empty() - Check if no items on the work list
+ * @proc:       binder_proc associated with list
+ * @list:	list to check
+ *
+ * Return: true if there are no items on list, else false
+ */
+static bool binder_worklist_empty(struct binder_proc *proc,
+				  struct list_head *list)
+{
+	bool ret;
+
+	binder_inner_proc_lock(proc);
+	ret = binder_worklist_empty_ilocked(list);
+	binder_inner_proc_unlock(proc);
+	return ret;
+}
+
+/**
+ * binder_enqueue_work_ilocked() - Add an item to the work list
+ * @work:         struct binder_work to add to list
+ * @target_list:  list to add work to
+ *
+ * Adds the work to the specified list. Asserts that work
+ * is not already on a list.
+ *
+ * Requires the proc->inner_lock to be held.
+ */
+static void
+binder_enqueue_work_ilocked(struct binder_work *work,
+			   struct list_head *target_list)
+{
+	BUG_ON(target_list == NULL);
+	BUG_ON(work->entry.next && !list_empty(&work->entry));
+	list_add_tail(&work->entry, target_list);
+}
+
+/**
+ * binder_enqueue_deferred_thread_work_ilocked() - Add deferred thread work
+ * @thread:       thread to queue work to
+ * @work:         struct binder_work to add to list
+ *
+ * Adds the work to the todo list of the thread. Doesn't set the process_todo
+ * flag, which means that (if it wasn't already set) the thread will go to
+ * sleep without handling this work when it calls read.
+ *
+ * Requires the proc->inner_lock to be held.
+ */
+static void
+binder_enqueue_deferred_thread_work_ilocked(struct binder_thread *thread,
+					    struct binder_work *work)
+{
+	WARN_ON(!list_empty(&thread->waiting_thread_node));
+	binder_enqueue_work_ilocked(work, &thread->todo);
+}
+
+/**
+ * binder_enqueue_thread_work_ilocked() - Add an item to the thread work list
+ * @thread:       thread to queue work to
+ * @work:         struct binder_work to add to list
+ *
+ * Adds the work to the todo list of the thread, and enables processing
+ * of the todo queue.
+ *
+ * Requires the proc->inner_lock to be held.
+ */
+static void
+binder_enqueue_thread_work_ilocked(struct binder_thread *thread,
+				   struct binder_work *work)
+{
+	WARN_ON(!list_empty(&thread->waiting_thread_node));
+	binder_enqueue_work_ilocked(work, &thread->todo);
+
+	/* (e)poll-based threads require an explicit wakeup signal when
+	 * queuing their own work; they rely on these events to consume
+	 * messages without I/O block. Without it, threads risk waiting
+	 * indefinitely without handling the work.
+	 */
+	if (thread->looper & BINDER_LOOPER_STATE_POLL &&
+	    thread->pid == current->pid && !thread->process_todo)
+		wake_up_interruptible_sync(&thread->wait);
+
+	thread->process_todo = true;
+}
+
+/**
+ * binder_enqueue_thread_work() - Add an item to the thread work list
+ * @thread:       thread to queue work to
+ * @work:         struct binder_work to add to list
+ *
+ * Adds the work to the todo list of the thread, and enables processing
+ * of the todo queue.
+ */
+static void
+binder_enqueue_thread_work(struct binder_thread *thread,
+			   struct binder_work *work)
+{
+	binder_inner_proc_lock(thread->proc);
+	binder_enqueue_thread_work_ilocked(thread, work);
+	binder_inner_proc_unlock(thread->proc);
+}
+
+static void
+binder_dequeue_work_ilocked(struct binder_work *work)
+{
+	list_del_init(&work->entry);
+}
+
+/**
+ * binder_dequeue_work() - Removes an item from the work list
+ * @proc:         binder_proc associated with list
+ * @work:         struct binder_work to remove from list
+ *
+ * Removes the specified work item from whatever list it is on.
+ * Can safely be called if work is not on any list.
+ */
+static void
+binder_dequeue_work(struct binder_proc *proc, struct binder_work *work)
+{
+	binder_inner_proc_lock(proc);
+	binder_dequeue_work_ilocked(work);
+	binder_inner_proc_unlock(proc);
+}
+
+static struct binder_work *binder_dequeue_work_head_ilocked(
+					struct list_head *list)
+{
+	struct binder_work *w;
+
+	w = list_first_entry_or_null(list, struct binder_work, entry);
+	if (w)
+		list_del_init(&w->entry);
+	return w;
+}
+
+static void
+binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer);
+static void binder_free_thread(struct binder_thread *thread);
+static void binder_free_proc(struct binder_proc *proc);
+static void binder_inc_node_tmpref_ilocked(struct binder_node *node);
+
+static bool binder_has_work_ilocked(struct binder_thread *thread,
+				    bool do_proc_work)
+{
+	return thread->process_todo ||
+		thread->looper_need_return ||
+		(do_proc_work &&
+		 !binder_worklist_empty_ilocked(&thread->proc->todo));
+}
+
+static bool binder_has_work(struct binder_thread *thread, bool do_proc_work)
+{
+	bool has_work;
+
+	binder_inner_proc_lock(thread->proc);
+	has_work = binder_has_work_ilocked(thread, do_proc_work);
+	binder_inner_proc_unlock(thread->proc);
+
+	return has_work;
+}
+
+static bool binder_available_for_proc_work_ilocked(struct binder_thread *thread)
+{
+	return !thread->transaction_stack &&
+		binder_worklist_empty_ilocked(&thread->todo);
+}
+
+static void binder_wakeup_poll_threads_ilocked(struct binder_proc *proc,
+					       bool sync)
+{
+	struct rb_node *n;
+	struct binder_thread *thread;
+
+	for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) {
+		thread = rb_entry(n, struct binder_thread, rb_node);
+		if (thread->looper & BINDER_LOOPER_STATE_POLL &&
+		    binder_available_for_proc_work_ilocked(thread)) {
+			if (sync)
+				wake_up_interruptible_sync(&thread->wait);
+			else
+				wake_up_interruptible(&thread->wait);
+		}
+	}
+}
+
+/**
+ * binder_select_thread_ilocked() - selects a thread for doing proc work.
+ * @proc:	process to select a thread from
+ *
+ * Note that calling this function moves the thread off the waiting_threads
+ * list, so it can only be woken up by the caller of this function, or a
+ * signal. Therefore, callers *should* always wake up the thread this function
+ * returns.
+ *
+ * Return:	If there's a thread currently waiting for process work,
+ *		returns that thread. Otherwise returns NULL.
+ */
+static struct binder_thread *
+binder_select_thread_ilocked(struct binder_proc *proc)
+{
+	struct binder_thread *thread;
+
+	assert_spin_locked(&proc->inner_lock);
+	thread = list_first_entry_or_null(&proc->waiting_threads,
+					  struct binder_thread,
+					  waiting_thread_node);
+
+	if (thread)
+		list_del_init(&thread->waiting_thread_node);
+
+	return thread;
+}
+
+/**
+ * binder_wakeup_thread_ilocked() - wakes up a thread for doing proc work.
+ * @proc:	process to wake up a thread in
+ * @thread:	specific thread to wake-up (may be NULL)
+ * @sync:	whether to do a synchronous wake-up
+ *
+ * This function wakes up a thread in the @proc process.
+ * The caller may provide a specific thread to wake-up in
+ * the @thread parameter. If @thread is NULL, this function
+ * will wake up threads that have called poll().
+ *
+ * Note that for this function to work as expected, callers
+ * should first call binder_select_thread() to find a thread
+ * to handle the work (if they don't have a thread already),
+ * and pass the result into the @thread parameter.
+ */
+static void binder_wakeup_thread_ilocked(struct binder_proc *proc,
+					 struct binder_thread *thread,
+					 bool sync)
+{
+	assert_spin_locked(&proc->inner_lock);
+
+	if (thread) {
+		if (sync)
+			wake_up_interruptible_sync(&thread->wait);
+		else
+			wake_up_interruptible(&thread->wait);
+		return;
+	}
+
+	/* Didn't find a thread waiting for proc work; this can happen
+	 * in two scenarios:
+	 * 1. All threads are busy handling transactions
+	 *    In that case, one of those threads should call back into
+	 *    the kernel driver soon and pick up this work.
+	 * 2. Threads are using the (e)poll interface, in which case
+	 *    they may be blocked on the waitqueue without having been
+	 *    added to waiting_threads. For this case, we just iterate
+	 *    over all threads not handling transaction work, and
+	 *    wake them all up. We wake all because we don't know whether
+	 *    a thread that called into (e)poll is handling non-binder
+	 *    work currently.
+	 */
+	binder_wakeup_poll_threads_ilocked(proc, sync);
+}
+
+static void binder_wakeup_proc_ilocked(struct binder_proc *proc)
+{
+	struct binder_thread *thread = binder_select_thread_ilocked(proc);
+
+	binder_wakeup_thread_ilocked(proc, thread, /* sync = */false);
+}
+
+static void binder_set_nice(long nice)
+{
+	long min_nice;
+
+	if (can_nice(current, nice)) {
+		set_user_nice(current, nice);
+		return;
+	}
+	min_nice = rlimit_to_nice(rlimit(RLIMIT_NICE));
+	binder_debug(BINDER_DEBUG_PRIORITY_CAP,
+		     "%d: nice value %ld not allowed use %ld instead\n",
+		      current->pid, nice, min_nice);
+	set_user_nice(current, min_nice);
+	if (min_nice <= MAX_NICE)
+		return;
+	binder_user_error("%d RLIMIT_NICE not set\n", current->pid);
+}
+
+static struct binder_node *binder_get_node_ilocked(struct binder_proc *proc,
+						   binder_uintptr_t ptr)
+{
+	struct rb_node *n = proc->nodes.rb_node;
+	struct binder_node *node;
+
+	assert_spin_locked(&proc->inner_lock);
+
+	while (n) {
+		node = rb_entry(n, struct binder_node, rb_node);
+
+		if (ptr < node->ptr)
+			n = n->rb_left;
+		else if (ptr > node->ptr)
+			n = n->rb_right;
+		else {
+			/*
+			 * take an implicit weak reference
+			 * to ensure node stays alive until
+			 * call to binder_put_node()
+			 */
+			binder_inc_node_tmpref_ilocked(node);
+			return node;
+		}
+	}
+	return NULL;
+}
+
+static struct binder_node *binder_get_node(struct binder_proc *proc,
+					   binder_uintptr_t ptr)
+{
+	struct binder_node *node;
+
+	binder_inner_proc_lock(proc);
+	node = binder_get_node_ilocked(proc, ptr);
+	binder_inner_proc_unlock(proc);
+	return node;
+}
+
+static struct binder_node *binder_init_node_ilocked(
+						struct binder_proc *proc,
+						struct binder_node *new_node,
+						struct flat_binder_object *fp)
+{
+	struct rb_node **p = &proc->nodes.rb_node;
+	struct rb_node *parent = NULL;
+	struct binder_node *node;
+	binder_uintptr_t ptr = fp ? fp->binder : 0;
+	binder_uintptr_t cookie = fp ? fp->cookie : 0;
+	__u32 flags = fp ? fp->flags : 0;
+
+	assert_spin_locked(&proc->inner_lock);
+
+	while (*p) {
+
+		parent = *p;
+		node = rb_entry(parent, struct binder_node, rb_node);
+
+		if (ptr < node->ptr)
+			p = &(*p)->rb_left;
+		else if (ptr > node->ptr)
+			p = &(*p)->rb_right;
+		else {
+			/*
+			 * A matching node is already in
+			 * the rb tree. Abandon the init
+			 * and return it.
+			 */
+			binder_inc_node_tmpref_ilocked(node);
+			return node;
+		}
+	}
+	node = new_node;
+	binder_stats_created(BINDER_STAT_NODE);
+	node->tmp_refs++;
+	rb_link_node(&node->rb_node, parent, p);
+	rb_insert_color(&node->rb_node, &proc->nodes);
+	node->debug_id = atomic_inc_return(&binder_last_id);
+	node->proc = proc;
+	node->ptr = ptr;
+	node->cookie = cookie;
+	node->work.type = BINDER_WORK_NODE;
+	node->min_priority = flags & FLAT_BINDER_FLAG_PRIORITY_MASK;
+	node->accept_fds = !!(flags & FLAT_BINDER_FLAG_ACCEPTS_FDS);
+	node->txn_security_ctx = !!(flags & FLAT_BINDER_FLAG_TXN_SECURITY_CTX);
+	spin_lock_init(&node->lock);
+	INIT_LIST_HEAD(&node->work.entry);
+	INIT_LIST_HEAD(&node->async_todo);
+	binder_debug(BINDER_DEBUG_INTERNAL_REFS,
+		     "%d:%d node %d u%016llx c%016llx created\n",
+		     proc->pid, current->pid, node->debug_id,
+		     (u64)node->ptr, (u64)node->cookie);
+
+	return node;
+}
+
+static struct binder_node *binder_new_node(struct binder_proc *proc,
+					   struct flat_binder_object *fp)
+{
+	struct binder_node *node;
+	struct binder_node *new_node = kzalloc_obj(*node);
+
+	if (!new_node)
+		return NULL;
+	binder_inner_proc_lock(proc);
+	node = binder_init_node_ilocked(proc, new_node, fp);
+	binder_inner_proc_unlock(proc);
+	if (node != new_node)
+		/*
+		 * The node was already added by another thread
+		 */
+		kfree(new_node);
+
+	return node;
+}
+
+static void binder_free_node(struct binder_node *node)
+{
+	kfree(node);
+	binder_stats_deleted(BINDER_STAT_NODE);
+}
+
+static int binder_inc_node_nilocked(struct binder_node *node, int strong,
+				    int internal,
+				    struct list_head *target_list)
+{
+	struct binder_proc *proc = node->proc;
+
+	assert_spin_locked(&node->lock);
+	if (proc)
+		assert_spin_locked(&proc->inner_lock);
+	if (strong) {
+		if (internal) {
+			if (target_list == NULL &&
+			    node->internal_strong_refs == 0 &&
+			    !(node->proc &&
+			      node == node->proc->context->binder_context_mgr_node &&
+			      node->has_strong_ref)) {
+				pr_err("invalid inc strong node for %d\n",
+					node->debug_id);
+				return -EINVAL;
+			}
+			node->internal_strong_refs++;
+		} else
+			node->local_strong_refs++;
+		if (!node->has_strong_ref && target_list) {
+			struct binder_thread *thread = container_of(target_list,
+						    struct binder_thread, todo);
+			binder_dequeue_work_ilocked(&node->work);
+			BUG_ON(&thread->todo != target_list);
+			binder_enqueue_deferred_thread_work_ilocked(thread,
+								   &node->work);
+		}
+	} else {
+		if (!internal)
+			node->local_weak_refs++;
+		if (!node->has_weak_ref && target_list && list_empty(&node->work.entry))
+			binder_enqueue_work_ilocked(&node->work, target_list);
+	}
+	return 0;
+}
+
+static int binder_inc_node(struct binder_node *node, int strong, int internal,
+			   struct list_head *target_list)
+{
+	int ret;
+
+	binder_node_inner_lock(node);
+	ret = binder_inc_node_nilocked(node, strong, internal, target_list);
+	binder_node_inner_unlock(node);
+
+	return ret;
+}
+
+static bool binder_dec_node_nilocked(struct binder_node *node,
+				     int strong, int internal)
+{
+	struct binder_proc *proc = node->proc;
+
+	assert_spin_locked(&node->lock);
+	if (proc)
+		assert_spin_locked(&proc->inner_lock);
+	if (strong) {
+		if (internal)
+			node->internal_strong_refs--;
+		else
+			node->local_strong_refs--;
+		if (node->local_strong_refs || node->internal_strong_refs)
+			return false;
+	} else {
+		if (!internal)
+			node->local_weak_refs--;
+		if (node->local_weak_refs || node->tmp_refs ||
+				!hlist_empty(&node->refs))
+			return false;
+	}
+
+	if (proc && (node->has_strong_ref || node->has_weak_ref)) {
+		if (list_empty(&node->work.entry)) {
+			binder_enqueue_work_ilocked(&node->work, &proc->todo);
+			binder_wakeup_proc_ilocked(proc);
+		}
+	} else {
+		if (hlist_empty(&node->refs) && !node->local_strong_refs &&
+		    !node->local_weak_refs && !node->tmp_refs) {
+			if (proc) {
+				binder_dequeue_work_ilocked(&node->work);
+				rb_erase(&node->rb_node, &proc->nodes);
+				binder_debug(BINDER_DEBUG_INTERNAL_REFS,
+					     "refless node %d deleted\n",
+					     node->debug_id);
+			} else {
+				BUG_ON(!list_empty(&node->work.entry));
+				spin_lock(&binder_dead_nodes_lock);
+				/*
+				 * tmp_refs could have changed so
+				 * check it again
+				 */
+				if (node->tmp_refs) {
+					spin_unlock(&binder_dead_nodes_lock);
+					return false;
+				}
+				hlist_del(&node->dead_node);
+				spin_unlock(&binder_dead_nodes_lock);
+				binder_debug(BINDER_DEBUG_INTERNAL_REFS,
+					     "dead node %d deleted\n",
+					     node->debug_id);
+			}
+			return true;
+		}
+	}
+	return false;
+}
+
+static void binder_dec_node(struct binder_node *node, int strong, int internal)
+{
+	bool free_node;
+
+	binder_node_inner_lock(node);
+	free_node = binder_dec_node_nilocked(node, strong, internal);
+	binder_node_inner_unlock(node);
+	if (free_node)
+		binder_free_node(node);
+}
+
+static void binder_inc_node_tmpref_ilocked(struct binder_node *node)
+{
+	/*
+	 * No call to binder_inc_node() is needed since we
+	 * don't need to inform userspace of any changes to
+	 * tmp_refs
+	 */
+	node->tmp_refs++;
+}
+
+/**
+ * binder_inc_node_tmpref() - take a temporary reference on node
+ * @node:	node to reference
+ *
+ * Take reference on node to prevent the node from being freed
+ * while referenced only by a local variable. The inner lock is
+ * needed to serialize with the node work on the queue (which
+ * isn't needed after the node is dead). If the node is dead
+ * (node->proc is NULL), use binder_dead_nodes_lock to protect
+ * node->tmp_refs against dead-node-only cases where the node
+ * lock cannot be acquired (eg traversing the dead node list to
+ * print nodes)
+ */
+static void binder_inc_node_tmpref(struct binder_node *node)
+{
+	binder_node_lock(node);
+	if (node->proc)
+		binder_inner_proc_lock(node->proc);
+	else
+		spin_lock(&binder_dead_nodes_lock);
+	binder_inc_node_tmpref_ilocked(node);
+	if (node->proc)
+		binder_inner_proc_unlock(node->proc);
+	else
+		spin_unlock(&binder_dead_nodes_lock);
+	binder_node_unlock(node);
+}
+
+/**
+ * binder_dec_node_tmpref() - remove a temporary reference on node
+ * @node:	node to reference
+ *
+ * Release temporary reference on node taken via binder_inc_node_tmpref()
+ */
+static void binder_dec_node_tmpref(struct binder_node *node)
+{
+	bool free_node;
+
+	binder_node_inner_lock(node);
+	if (!node->proc)
+		spin_lock(&binder_dead_nodes_lock);
+	else
+		__acquire(&binder_dead_nodes_lock);
+	node->tmp_refs--;
+	BUG_ON(node->tmp_refs < 0);
+	if (!node->proc)
+		spin_unlock(&binder_dead_nodes_lock);
+	else
+		__release(&binder_dead_nodes_lock);
+	/*
+	 * Call binder_dec_node() to check if all refcounts are 0
+	 * and cleanup is needed. Calling with strong=0 and internal=1
+	 * causes no actual reference to be released in binder_dec_node().
+	 * If that changes, a change is needed here too.
+	 */
+	free_node = binder_dec_node_nilocked(node, 0, 1);
+	binder_node_inner_unlock(node);
+	if (free_node)
+		binder_free_node(node);
+}
+
+static void binder_put_node(struct binder_node *node)
+{
+	binder_dec_node_tmpref(node);
+}
+
+static struct binder_ref *binder_get_ref_olocked(struct binder_proc *proc,
+						 u32 desc, bool need_strong_ref)
+{
+	struct rb_node *n = proc->refs_by_desc.rb_node;
+	struct binder_ref *ref;
+
+	while (n) {
+		ref = rb_entry(n, struct binder_ref, rb_node_desc);
+
+		if (desc < ref->data.desc) {
+			n = n->rb_left;
+		} else if (desc > ref->data.desc) {
+			n = n->rb_right;
+		} else if (need_strong_ref && !ref->data.strong) {
+			binder_user_error("tried to use weak ref as strong ref\n");
+			return NULL;
+		} else {
+			return ref;
+		}
+	}
+	return NULL;
+}
+
+/* Find the smallest unused descriptor the "slow way" */
+static u32 slow_desc_lookup_olocked(struct binder_proc *proc, u32 offset)
+{
+	struct binder_ref *ref;
+	struct rb_node *n;
+	u32 desc;
+
+	desc = offset;
+	for (n = rb_first(&proc->refs_by_desc); n; n = rb_next(n)) {
+		ref = rb_entry(n, struct binder_ref, rb_node_desc);
+		if (ref->data.desc > desc)
+			break;
+		desc = ref->data.desc + 1;
+	}
+
+	return desc;
+}
+
+/*
+ * Find an available reference descriptor ID. The proc->outer_lock might
+ * be released in the process, in which case -EAGAIN is returned and the
+ * @desc should be considered invalid.
+ */
+static int get_ref_desc_olocked(struct binder_proc *proc,
+				struct binder_node *node,
+				u32 *desc)
+{
+	struct dbitmap *dmap = &proc->dmap;
+	unsigned int nbits, offset;
+	unsigned long *new, bit;
+
+	/* 0 is reserved for the context manager */
+	offset = (node == proc->context->binder_context_mgr_node) ? 0 : 1;
+
+	if (!dbitmap_enabled(dmap)) {
+		*desc = slow_desc_lookup_olocked(proc, offset);
+		return 0;
+	}
+
+	if (dbitmap_acquire_next_zero_bit(dmap, offset, &bit) == 0) {
+		*desc = bit;
+		return 0;
+	}
+
+	/*
+	 * The dbitmap is full and needs to grow. The proc->outer_lock
+	 * is briefly released to allocate the new bitmap safely.
+	 */
+	nbits = dbitmap_grow_nbits(dmap);
+	binder_proc_unlock(proc);
+	new = bitmap_zalloc(nbits, GFP_KERNEL);
+	binder_proc_lock(proc);
+	dbitmap_grow(dmap, new, nbits);
+
+	return -EAGAIN;
+}
+
+/**
+ * binder_get_ref_for_node_olocked() - get the ref associated with given node
+ * @proc:	binder_proc that owns the ref
+ * @node:	binder_node of target
+ * @new_ref:	newly allocated binder_ref to be initialized or %NULL
+ *
+ * Look up the ref for the given node and return it if it exists
+ *
+ * If it doesn't exist and the caller provides a newly allocated
+ * ref, initialize the fields of the newly allocated ref and insert
+ * into the given proc rb_trees and node refs list.
+ *
+ * Return:	the ref for node. It is possible that another thread
+ *		allocated/initialized the ref first in which case the
+ *		returned ref would be different than the passed-in
+ *		new_ref. new_ref must be kfree'd by the caller in
+ *		this case.
+ */
+static struct binder_ref *binder_get_ref_for_node_olocked(
+					struct binder_proc *proc,
+					struct binder_node *node,
+					struct binder_ref *new_ref)
+{
+	struct binder_ref *ref;
+	struct rb_node *parent;
+	struct rb_node **p;
+	u32 desc;
+
+retry:
+	p = &proc->refs_by_node.rb_node;
+	parent = NULL;
+	while (*p) {
+		parent = *p;
+		ref = rb_entry(parent, struct binder_ref, rb_node_node);
+
+		if (node < ref->node)
+			p = &(*p)->rb_left;
+		else if (node > ref->node)
+			p = &(*p)->rb_right;
+		else
+			return ref;
+	}
+	if (!new_ref)
+		return NULL;
+
+	/* might release the proc->outer_lock */
+	if (get_ref_desc_olocked(proc, node, &desc) == -EAGAIN)
+		goto retry;
+
+	binder_stats_created(BINDER_STAT_REF);
+	new_ref->data.debug_id = atomic_inc_return(&binder_last_id);
+	new_ref->proc = proc;
+	new_ref->node = node;
+	rb_link_node(&new_ref->rb_node_node, parent, p);
+	rb_insert_color(&new_ref->rb_node_node, &proc->refs_by_node);
+
+	new_ref->data.desc = desc;
+	p = &proc->refs_by_desc.rb_node;
+	while (*p) {
+		parent = *p;
+		ref = rb_entry(parent, struct binder_ref, rb_node_desc);
+
+		if (new_ref->data.desc < ref->data.desc)
+			p = &(*p)->rb_left;
+		else if (new_ref->data.desc > ref->data.desc)
+			p = &(*p)->rb_right;
+		else
+			BUG();
+	}
+	rb_link_node(&new_ref->rb_node_desc, parent, p);
+	rb_insert_color(&new_ref->rb_node_desc, &proc->refs_by_desc);
+
+	binder_node_lock(node);
+	hlist_add_head(&new_ref->node_entry, &node->refs);
+
+	binder_debug(BINDER_DEBUG_INTERNAL_REFS,
+		     "%d new ref %d desc %d for node %d\n",
+		      proc->pid, new_ref->data.debug_id, new_ref->data.desc,
+		      node->debug_id);
+	binder_node_unlock(node);
+	return new_ref;
+}
+
+static void binder_cleanup_ref_olocked(struct binder_ref *ref)
+{
+	struct dbitmap *dmap = &ref->proc->dmap;
+	bool delete_node = false;
+
+	binder_debug(BINDER_DEBUG_INTERNAL_REFS,
+		     "%d delete ref %d desc %d for node %d\n",
+		      ref->proc->pid, ref->data.debug_id, ref->data.desc,
+		      ref->node->debug_id);
+
+	if (dbitmap_enabled(dmap))
+		dbitmap_clear_bit(dmap, ref->data.desc);
+	rb_erase(&ref->rb_node_desc, &ref->proc->refs_by_desc);
+	rb_erase(&ref->rb_node_node, &ref->proc->refs_by_node);
+
+	binder_node_inner_lock(ref->node);
+	if (ref->data.strong)
+		binder_dec_node_nilocked(ref->node, 1, 1);
+
+	hlist_del(&ref->node_entry);
+	delete_node = binder_dec_node_nilocked(ref->node, 0, 1);
+	binder_node_inner_unlock(ref->node);
+	/*
+	 * Clear ref->node unless we want the caller to free the node
+	 */
+	if (!delete_node) {
+		/*
+		 * The caller uses ref->node to determine
+		 * whether the node needs to be freed. Clear
+		 * it since the node is still alive.
+		 */
+		ref->node = NULL;
+	}
+
+	if (ref->death) {
+		binder_debug(BINDER_DEBUG_DEAD_BINDER,
+			     "%d delete ref %d desc %d has death notification\n",
+			      ref->proc->pid, ref->data.debug_id,
+			      ref->data.desc);
+		binder_dequeue_work(ref->proc, &ref->death->work);
+		binder_stats_deleted(BINDER_STAT_DEATH);
+	}
+
+	if (ref->freeze) {
+		binder_dequeue_work(ref->proc, &ref->freeze->work);
+		binder_stats_deleted(BINDER_STAT_FREEZE);
+	}
+
+	binder_stats_deleted(BINDER_STAT_REF);
+}
+
+/**
+ * binder_inc_ref_olocked() - increment the ref for given handle
+ * @ref:         ref to be incremented
+ * @strong:      if true, strong increment, else weak
+ * @target_list: list to queue node work on
+ *
+ * Increment the ref. @ref->proc->outer_lock must be held on entry
+ *
+ * Return: 0, if successful, else errno
+ */
+static int binder_inc_ref_olocked(struct binder_ref *ref, int strong,
+				  struct list_head *target_list)
+{
+	int ret;
+
+	if (strong) {
+		if (ref->data.strong == 0) {
+			ret = binder_inc_node(ref->node, 1, 1, target_list);
+			if (ret)
+				return ret;
+		}
+		ref->data.strong++;
+	} else {
+		if (ref->data.weak == 0) {
+			ret = binder_inc_node(ref->node, 0, 1, target_list);
+			if (ret)
+				return ret;
+		}
+		ref->data.weak++;
+	}
+	return 0;
+}
+
+/**
+ * binder_dec_ref_olocked() - dec the ref for given handle
+ * @ref:	ref to be decremented
+ * @strong:	if true, strong decrement, else weak
+ *
+ * Decrement the ref.
+ *
+ * Return: %true if ref is cleaned up and ready to be freed.
+ */
+static bool binder_dec_ref_olocked(struct binder_ref *ref, int strong)
+{
+	if (strong) {
+		if (ref->data.strong == 0) {
+			binder_user_error("%d invalid dec strong, ref %d desc %d s %d w %d\n",
+					  ref->proc->pid, ref->data.debug_id,
+					  ref->data.desc, ref->data.strong,
+					  ref->data.weak);
+			return false;
+		}
+		ref->data.strong--;
+		if (ref->data.strong == 0)
+			binder_dec_node(ref->node, strong, 1);
+	} else {
+		if (ref->data.weak == 0) {
+			binder_user_error("%d invalid dec weak, ref %d desc %d s %d w %d\n",
+					  ref->proc->pid, ref->data.debug_id,
+					  ref->data.desc, ref->data.strong,
+					  ref->data.weak);
+			return false;
+		}
+		ref->data.weak--;
+	}
+	if (ref->data.strong == 0 && ref->data.weak == 0) {
+		binder_cleanup_ref_olocked(ref);
+		return true;
+	}
+	return false;
+}
+
+/**
+ * binder_get_node_from_ref() - get the node from the given proc/desc
+ * @proc:	proc containing the ref
+ * @desc:	the handle associated with the ref
+ * @need_strong_ref: if true, only return node if ref is strong
+ * @rdata:	the id/refcount data for the ref
+ *
+ * Given a proc and ref handle, return the associated binder_node
+ *
+ * Return: a binder_node or NULL if not found or not strong when strong required
+ */
+static struct binder_node *binder_get_node_from_ref(
+		struct binder_proc *proc,
+		u32 desc, bool need_strong_ref,
+		struct binder_ref_data *rdata)
+{
+	struct binder_node *node;
+	struct binder_ref *ref;
+
+	binder_proc_lock(proc);
+	ref = binder_get_ref_olocked(proc, desc, need_strong_ref);
+	if (!ref)
+		goto err_no_ref;
+	node = ref->node;
+	/*
+	 * Take an implicit reference on the node to ensure
+	 * it stays alive until the call to binder_put_node()
+	 */
+	binder_inc_node_tmpref(node);
+	if (rdata)
+		*rdata = ref->data;
+	binder_proc_unlock(proc);
+
+	return node;
+
+err_no_ref:
+	binder_proc_unlock(proc);
+	return NULL;
+}
+
+/**
+ * binder_free_ref() - free the binder_ref
+ * @ref:	ref to free
+ *
+ * Free the binder_ref. Free the binder_node indicated by ref->node
+ * (if non-NULL) and the binder_ref_death indicated by ref->death.
+ */
+static void binder_free_ref(struct binder_ref *ref)
+{
+	if (ref->node)
+		binder_free_node(ref->node);
+	kfree(ref->death);
+	kfree(ref->freeze);
+	kfree(ref);
+}
+
+/* shrink descriptor bitmap if needed */
+static void try_shrink_dmap(struct binder_proc *proc)
+{
+	unsigned long *new;
+	int nbits;
+
+	binder_proc_lock(proc);
+	nbits = dbitmap_shrink_nbits(&proc->dmap);
+	binder_proc_unlock(proc);
+
+	if (!nbits)
+		return;
+
+	new = bitmap_zalloc(nbits, GFP_KERNEL);
+	binder_proc_lock(proc);
+	dbitmap_shrink(&proc->dmap, new, nbits);
+	binder_proc_unlock(proc);
+}
+
+/**
+ * binder_update_ref_for_handle() - inc/dec the ref for given handle
+ * @proc:	proc containing the ref
+ * @desc:	the handle associated with the ref
+ * @increment:	true=inc reference, false=dec reference
+ * @strong:	true=strong reference, false=weak reference
+ * @rdata:	the id/refcount data for the ref
+ *
+ * Given a proc and ref handle, increment or decrement the ref
+ * according to "increment" arg.
+ *
+ * Return: 0 if successful, else errno
+ */
+static int binder_update_ref_for_handle(struct binder_proc *proc,
+		uint32_t desc, bool increment, bool strong,
+		struct binder_ref_data *rdata)
+{
+	int ret = 0;
+	struct binder_ref *ref;
+	bool delete_ref = false;
+
+	binder_proc_lock(proc);
+	ref = binder_get_ref_olocked(proc, desc, strong);
+	if (!ref) {
+		ret = -EINVAL;
+		goto err_no_ref;
+	}
+	if (increment)
+		ret = binder_inc_ref_olocked(ref, strong, NULL);
+	else
+		delete_ref = binder_dec_ref_olocked(ref, strong);
+
+	if (rdata)
+		*rdata = ref->data;
+	binder_proc_unlock(proc);
+
+	if (delete_ref) {
+		binder_free_ref(ref);
+		try_shrink_dmap(proc);
+	}
+	return ret;
+
+err_no_ref:
+	binder_proc_unlock(proc);
+	return ret;
+}
+
+/**
+ * binder_dec_ref_for_handle() - dec the ref for given handle
+ * @proc:	proc containing the ref
+ * @desc:	the handle associated with the ref
+ * @strong:	true=strong reference, false=weak reference
+ * @rdata:	the id/refcount data for the ref
+ *
+ * Just calls binder_update_ref_for_handle() to decrement the ref.
+ *
+ * Return: 0 if successful, else errno
+ */
+static int binder_dec_ref_for_handle(struct binder_proc *proc,
+		uint32_t desc, bool strong, struct binder_ref_data *rdata)
+{
+	return binder_update_ref_for_handle(proc, desc, false, strong, rdata);
+}
+
+
+/**
+ * binder_inc_ref_for_node() - increment the ref for given proc/node
+ * @proc:	 proc containing the ref
+ * @node:	 target node
+ * @strong:	 true=strong reference, false=weak reference
+ * @target_list: worklist to use if node is incremented
+ * @rdata:	 the id/refcount data for the ref
+ *
+ * Given a proc and node, increment the ref. Create the ref if it
+ * doesn't already exist
+ *
+ * Return: 0 if successful, else errno
+ */
+static int binder_inc_ref_for_node(struct binder_proc *proc,
+			struct binder_node *node,
+			bool strong,
+			struct list_head *target_list,
+			struct binder_ref_data *rdata)
+{
+	struct binder_ref *ref;
+	struct binder_ref *new_ref = NULL;
+	int ret = 0;
+
+	binder_proc_lock(proc);
+	ref = binder_get_ref_for_node_olocked(proc, node, NULL);
+	if (!ref) {
+		binder_proc_unlock(proc);
+		new_ref = kzalloc_obj(*ref);
+		if (!new_ref)
+			return -ENOMEM;
+		binder_proc_lock(proc);
+		ref = binder_get_ref_for_node_olocked(proc, node, new_ref);
+	}
+	ret = binder_inc_ref_olocked(ref, strong, target_list);
+	*rdata = ref->data;
+	if (ret && ref == new_ref) {
+		/*
+		 * Cleanup the failed reference here as the target
+		 * could now be dead and have already released its
+		 * references by now. Calling on the new reference
+		 * with strong=0 and a tmp_refs will not decrement
+		 * the node. The new_ref gets kfree'd below.
+		 */
+		binder_cleanup_ref_olocked(new_ref);
+		ref = NULL;
+	}
+
+	binder_proc_unlock(proc);
+	if (new_ref && ref != new_ref)
+		/*
+		 * Another thread created the ref first so
+		 * free the one we allocated
+		 */
+		kfree(new_ref);
+	return ret;
+}
+
+static void binder_pop_transaction_ilocked(struct binder_thread *target_thread,
+					   struct binder_transaction *t)
+{
+	BUG_ON(!target_thread);
+	assert_spin_locked(&target_thread->proc->inner_lock);
+	BUG_ON(target_thread->transaction_stack != t);
+	BUG_ON(target_thread->transaction_stack->from != target_thread);
+	target_thread->transaction_stack =
+		target_thread->transaction_stack->from_parent;
+	t->from = NULL;
+}
+
+/**
+ * binder_thread_dec_tmpref() - decrement thread->tmp_ref
+ * @thread:	thread to decrement
+ *
+ * A thread needs to be kept alive while being used to create or
+ * handle a transaction. binder_get_txn_from() is used to safely
+ * extract t->from from a binder_transaction and keep the thread
+ * indicated by t->from from being freed. When done with that
+ * binder_thread, this function is called to decrement the
+ * tmp_ref and free if appropriate (thread has been released
+ * and no transaction being processed by the driver)
+ */
+static void binder_thread_dec_tmpref(struct binder_thread *thread)
+{
+	/*
+	 * atomic is used to protect the counter value while
+	 * it cannot reach zero or thread->is_dead is false
+	 */
+	binder_inner_proc_lock(thread->proc);
+	atomic_dec(&thread->tmp_ref);
+	if (thread->is_dead && !atomic_read(&thread->tmp_ref)) {
+		binder_inner_proc_unlock(thread->proc);
+		binder_free_thread(thread);
+		return;
+	}
+	binder_inner_proc_unlock(thread->proc);
+}
+
+/**
+ * binder_proc_dec_tmpref() - decrement proc->tmp_ref
+ * @proc:	proc to decrement
+ *
+ * A binder_proc needs to be kept alive while being used to create or
+ * handle a transaction. proc->tmp_ref is incremented when
+ * creating a new transaction or the binder_proc is currently in-use
+ * by threads that are being released. When done with the binder_proc,
+ * this function is called to decrement the counter and free the
+ * proc if appropriate (proc has been released, all threads have
+ * been released and not currently in-use to process a transaction).
+ */
+static void binder_proc_dec_tmpref(struct binder_proc *proc)
+{
+	binder_inner_proc_lock(proc);
+	proc->tmp_ref--;
+	if (proc->is_dead && RB_EMPTY_ROOT(&proc->threads) &&
+			!proc->tmp_ref) {
+		binder_inner_proc_unlock(proc);
+		binder_free_proc(proc);
+		return;
+	}
+	binder_inner_proc_unlock(proc);
+}
+
+/**
+ * binder_get_txn_from() - safely extract the "from" thread in transaction
+ * @t:	binder transaction for t->from
+ *
+ * Atomically return the "from" thread and increment the tmp_ref
+ * count for the thread to ensure it stays alive until
+ * binder_thread_dec_tmpref() is called.
+ *
+ * Return: the value of t->from
+ */
+static struct binder_thread *binder_get_txn_from(
+		struct binder_transaction *t)
+{
+	struct binder_thread *from;
+
+	guard(spinlock)(&t->lock);
+	from = t->from;
+	if (from)
+		atomic_inc(&from->tmp_ref);
+	return from;
+}
+
+/**
+ * binder_get_txn_from_and_acq_inner() - get t->from and acquire inner lock
+ * @t:	binder transaction for t->from
+ *
+ * Same as binder_get_txn_from() except it also acquires the proc->inner_lock
+ * to guarantee that the thread cannot be released while operating on it.
+ * The caller must call binder_inner_proc_unlock() to release the inner lock
+ * as well as call binder_dec_thread_txn() to release the reference.
+ *
+ * Return: the value of t->from
+ */
+static struct binder_thread *binder_get_txn_from_and_acq_inner(
+		struct binder_transaction *t)
+	__acquires(&t->from->proc->inner_lock)
+{
+	struct binder_thread *from;
+
+	from = binder_get_txn_from(t);
+	if (!from) {
+		__acquire(&from->proc->inner_lock);
+		return NULL;
+	}
+	binder_inner_proc_lock(from->proc);
+	if (t->from) {
+		BUG_ON(from != t->from);
+		return from;
+	}
+	binder_inner_proc_unlock(from->proc);
+	__acquire(&from->proc->inner_lock);
+	binder_thread_dec_tmpref(from);
+	return NULL;
+}
+
+/**
+ * binder_free_txn_fixups() - free unprocessed fd fixups
+ * @t:	binder transaction for t->from
+ *
+ * If the transaction is being torn down prior to being
+ * processed by the target process, free all of the
+ * fd fixups and fput the file structs. It is safe to
+ * call this function after the fixups have been
+ * processed -- in that case, the list will be empty.
+ */
+static void binder_free_txn_fixups(struct binder_transaction *t)
+{
+	struct binder_txn_fd_fixup *fixup, *tmp;
+
+	list_for_each_entry_safe(fixup, tmp, &t->fd_fixups, fixup_entry) {
+		fput(fixup->file);
+		if (fixup->target_fd >= 0)
+			put_unused_fd(fixup->target_fd);
+		list_del(&fixup->fixup_entry);
+		kfree(fixup);
+	}
+}
+
+static void binder_txn_latency_free(struct binder_transaction *t)
+{
+	int from_proc, from_thread, to_proc, to_thread;
+
+	spin_lock(&t->lock);
+	from_proc = t->from ? t->from->proc->pid : 0;
+	from_thread = t->from ? t->from->pid : 0;
+	to_proc = t->to_proc ? t->to_proc->pid : 0;
+	to_thread = t->to_thread ? t->to_thread->pid : 0;
+	spin_unlock(&t->lock);
+
+	trace_binder_txn_latency_free(t, from_proc, from_thread, to_proc, to_thread);
+}
+
+static void binder_free_transaction(struct binder_transaction *t)
+{
+	struct binder_thread *target_thread;
+	struct binder_proc *target_proc;
+
+	spin_lock(&t->lock);
+	target_proc = t->to_proc;
+	target_thread = t->to_thread;
+	/*
+	 * Pin target_thread to keep target_proc alive. Undelivered
+	 * transactions with !target_thread are safe, as target_proc
+	 * can only be the current context there.
+	 */
+	if (target_thread)
+		atomic_inc(&target_thread->tmp_ref);
+	spin_unlock(&t->lock);
+
+	if (target_proc) {
+		binder_inner_proc_lock(target_proc);
+		target_proc->outstanding_txns--;
+		if (target_proc->outstanding_txns < 0)
+			pr_warn("%s: Unexpected outstanding_txns %d\n",
+				__func__, target_proc->outstanding_txns);
+		if (!target_proc->outstanding_txns && target_proc->is_frozen)
+			wake_up_interruptible_all(&target_proc->freeze_wait);
+		if (t->buffer)
+			t->buffer->transaction = NULL;
+		binder_inner_proc_unlock(target_proc);
+	}
+
+	if (target_thread)
+		binder_thread_dec_tmpref(target_thread);
+
+	if (trace_binder_txn_latency_free_enabled())
+		binder_txn_latency_free(t);
+	/*
+	 * If the transaction has no target_proc, then
+	 * t->buffer->transaction has already been cleared.
+	 */
+	binder_free_txn_fixups(t);
+	kfree(t);
+	binder_stats_deleted(BINDER_STAT_TRANSACTION);
+}
+
+static void binder_send_failed_reply(struct binder_transaction *t,
+				     uint32_t error_code)
+{
+	struct binder_thread *target_thread;
+	struct binder_transaction *next;
+
+	BUG_ON(t->flags & TF_ONE_WAY);
+	while (1) {
+		target_thread = binder_get_txn_from_and_acq_inner(t);
+		if (target_thread) {
+			binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
+				     "send failed reply for transaction %d to %d:%d\n",
+				      t->debug_id,
+				      target_thread->proc->pid,
+				      target_thread->pid);
+
+			binder_pop_transaction_ilocked(target_thread, t);
+			if (target_thread->reply_error.cmd == BR_OK) {
+				target_thread->reply_error.cmd = error_code;
+				binder_enqueue_thread_work_ilocked(
+					target_thread,
+					&target_thread->reply_error.work);
+				wake_up_interruptible(&target_thread->wait);
+			} else {
+				/*
+				 * Cannot get here for normal operation, but
+				 * we can if multiple synchronous transactions
+				 * are sent without blocking for responses.
+				 * Just ignore the 2nd error in this case.
+				 */
+				pr_warn("Unexpected reply error: %u\n",
+					target_thread->reply_error.cmd);
+			}
+			binder_inner_proc_unlock(target_thread->proc);
+			binder_thread_dec_tmpref(target_thread);
+			binder_free_transaction(t);
+			return;
+		}
+		__release(&target_thread->proc->inner_lock);
+		next = t->from_parent;
+
+		binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
+			     "send failed reply for transaction %d, target dead\n",
+			     t->debug_id);
+
+		binder_free_transaction(t);
+		if (next == NULL) {
+			binder_debug(BINDER_DEBUG_DEAD_BINDER,
+				     "reply failed, no target thread at root\n");
+			return;
+		}
+		t = next;
+		binder_debug(BINDER_DEBUG_DEAD_BINDER,
+			     "reply failed, no target thread -- retry %d\n",
+			      t->debug_id);
+	}
+}
+
+/**
+ * binder_cleanup_transaction() - cleans up undelivered transaction
+ * @t:		transaction that needs to be cleaned up
+ * @reason:	reason the transaction wasn't delivered
+ * @error_code:	error to return to caller (if synchronous call)
+ */
+static void binder_cleanup_transaction(struct binder_transaction *t,
+				       const char *reason,
+				       uint32_t error_code)
+{
+	if (t->buffer->target_node && !(t->flags & TF_ONE_WAY)) {
+		binder_send_failed_reply(t, error_code);
+	} else {
+		binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
+			"undelivered transaction %d, %s\n",
+			t->debug_id, reason);
+		binder_free_transaction(t);
+	}
+}
+
+/**
+ * binder_get_object() - gets object and checks for valid metadata
+ * @proc:	binder_proc owning the buffer
+ * @u:		sender's user pointer to base of buffer
+ * @buffer:	binder_buffer that we're parsing.
+ * @offset:	offset in the @buffer at which to validate an object.
+ * @object:	struct binder_object to read into
+ *
+ * Copy the binder object at the given offset into @object. If @u is
+ * provided then the copy is from the sender's buffer. If not, then
+ * it is copied from the target's @buffer.
+ *
+ * Return:	If there's a valid metadata object at @offset, the
+ *		size of that object. Otherwise, it returns zero. The object
+ *		is read into the struct binder_object pointed to by @object.
+ */
+static size_t binder_get_object(struct binder_proc *proc,
+				const void __user *u,
+				struct binder_buffer *buffer,
+				unsigned long offset,
+				struct binder_object *object)
+{
+	size_t read_size;
+	struct binder_object_header *hdr;
+	size_t object_size = 0;
+
+	read_size = min_t(size_t, sizeof(*object), buffer->data_size - offset);
+	if (offset > buffer->data_size || read_size < sizeof(*hdr) ||
+	    !IS_ALIGNED(offset, sizeof(u32)))
+		return 0;
+
+	if (u) {
+		if (copy_from_user(object, u + offset, read_size))
+			return 0;
+	} else {
+		if (binder_alloc_copy_from_buffer(&proc->alloc, object, buffer,
+						  offset, read_size))
+			return 0;
+	}
+
+	/* Ok, now see if we read a complete object. */
+	hdr = &object->hdr;
+	switch (hdr->type) {
+	case BINDER_TYPE_BINDER:
+	case BINDER_TYPE_WEAK_BINDER:
+	case BINDER_TYPE_HANDLE:
+	case BINDER_TYPE_WEAK_HANDLE:
+		object_size = sizeof(struct flat_binder_object);
+		break;
+	case BINDER_TYPE_FD:
+		object_size = sizeof(struct binder_fd_object);
+		break;
+	case BINDER_TYPE_PTR:
+		object_size = sizeof(struct binder_buffer_object);
+		break;
+	case BINDER_TYPE_FDA:
+		object_size = sizeof(struct binder_fd_array_object);
+		break;
+	default:
+		return 0;
+	}
+	if (offset <= buffer->data_size - object_size &&
+	    buffer->data_size >= object_size)
+		return object_size;
+	else
+		return 0;
+}
+
+/**
+ * binder_validate_ptr() - validates binder_buffer_object in a binder_buffer.
+ * @proc:	binder_proc owning the buffer
+ * @b:		binder_buffer containing the object
+ * @object:	struct binder_object to read into
+ * @index:	index in offset array at which the binder_buffer_object is
+ *		located
+ * @start_offset: points to the start of the offset array
+ * @object_offsetp: offset of @object read from @b
+ * @num_valid:	the number of valid offsets in the offset array
+ *
+ * Return:	If @index is within the valid range of the offset array
+ *		described by @start and @num_valid, and if there's a valid
+ *		binder_buffer_object at the offset found in index @index
+ *		of the offset array, that object is returned. Otherwise,
+ *		%NULL is returned.
+ *		Note that the offset found in index @index itself is not
+ *		verified; this function assumes that @num_valid elements
+ *		from @start were previously verified to have valid offsets.
+ *		If @object_offsetp is non-NULL, then the offset within
+ *		@b is written to it.
+ */
+static struct binder_buffer_object *binder_validate_ptr(
+						struct binder_proc *proc,
+						struct binder_buffer *b,
+						struct binder_object *object,
+						binder_size_t index,
+						binder_size_t start_offset,
+						binder_size_t *object_offsetp,
+						binder_size_t num_valid)
+{
+	size_t object_size;
+	binder_size_t object_offset;
+	unsigned long buffer_offset;
+
+	if (index >= num_valid)
+		return NULL;
+
+	buffer_offset = start_offset + sizeof(binder_size_t) * index;
+	if (binder_alloc_copy_from_buffer(&proc->alloc, &object_offset,
+					  b, buffer_offset,
+					  sizeof(object_offset)))
+		return NULL;
+	object_size = binder_get_object(proc, NULL, b, object_offset, object);
+	if (!object_size || object->hdr.type != BINDER_TYPE_PTR)
+		return NULL;
+	if (object_offsetp)
+		*object_offsetp = object_offset;
+
+	return &object->bbo;
+}
+
+/**
+ * binder_validate_fixup() - validates pointer/fd fixups happen in order.
+ * @proc:		binder_proc owning the buffer
+ * @b:			transaction buffer
+ * @objects_start_offset: offset to start of objects buffer
+ * @buffer_obj_offset:	offset to binder_buffer_object in which to fix up
+ * @fixup_offset:	start offset in @buffer to fix up
+ * @last_obj_offset:	offset to last binder_buffer_object that we fixed
+ * @last_min_offset:	minimum fixup offset in object at @last_obj_offset
+ *
+ * Return:		%true if a fixup in buffer @buffer at offset @offset is
+ *			allowed.
+ *
+ * For safety reasons, we only allow fixups inside a buffer to happen
+ * at increasing offsets; additionally, we only allow fixup on the last
+ * buffer object that was verified, or one of its parents.
+ *
+ * Example of what is allowed:
+ *
+ * A
+ *   B (parent = A, offset = 0)
+ *   C (parent = A, offset = 16)
+ *     D (parent = C, offset = 0)
+ *   E (parent = A, offset = 32) // min_offset is 16 (C.parent_offset)
+ *
+ * Examples of what is not allowed:
+ *
+ * Decreasing offsets within the same parent:
+ * A
+ *   C (parent = A, offset = 16)
+ *   B (parent = A, offset = 0) // decreasing offset within A
+ *
+ * Referring to a parent that wasn't the last object or any of its parents:
+ * A
+ *   B (parent = A, offset = 0)
+ *   C (parent = A, offset = 0)
+ *   C (parent = A, offset = 16)
+ *     D (parent = B, offset = 0) // B is not A or any of A's parents
+ */
+static bool binder_validate_fixup(struct binder_proc *proc,
+				  struct binder_buffer *b,
+				  binder_size_t objects_start_offset,
+				  binder_size_t buffer_obj_offset,
+				  binder_size_t fixup_offset,
+				  binder_size_t last_obj_offset,
+				  binder_size_t last_min_offset)
+{
+	if (!last_obj_offset) {
+		/* Nothing to fix up in */
+		return false;
+	}
+
+	while (last_obj_offset != buffer_obj_offset) {
+		unsigned long buffer_offset;
+		struct binder_object last_object;
+		struct binder_buffer_object *last_bbo;
+		size_t object_size = binder_get_object(proc, NULL, b,
+						       last_obj_offset,
+						       &last_object);
+		if (object_size != sizeof(*last_bbo))
+			return false;
+
+		last_bbo = &last_object.bbo;
+		/*
+		 * Safe to retrieve the parent of last_obj, since it
+		 * was already previously verified by the driver.
+		 */
+		if ((last_bbo->flags & BINDER_BUFFER_FLAG_HAS_PARENT) == 0)
+			return false;
+		last_min_offset = last_bbo->parent_offset + sizeof(uintptr_t);
+		buffer_offset = objects_start_offset +
+			sizeof(binder_size_t) * last_bbo->parent;
+		if (binder_alloc_copy_from_buffer(&proc->alloc,
+						  &last_obj_offset,
+						  b, buffer_offset,
+						  sizeof(last_obj_offset)))
+			return false;
+	}
+	return (fixup_offset >= last_min_offset);
+}
+
+/**
+ * struct binder_task_work_cb - for deferred close
+ *
+ * @twork:                callback_head for task work
+ * @file:                 file to close
+ *
+ * Structure to pass task work to be handled after
+ * returning from binder_ioctl() via task_work_add().
+ */
+struct binder_task_work_cb {
+	struct callback_head twork;
+	struct file *file;
+};
+
+/**
+ * binder_do_fd_close() - close list of file descriptors
+ * @twork:	callback head for task work
+ *
+ * It is not safe to call ksys_close() during the binder_ioctl()
+ * function if there is a chance that binder's own file descriptor
+ * might be closed. This is to meet the requirements for using
+ * fdget() (see comments for __fget_light()). Therefore use
+ * task_work_add() to schedule the close operation once we have
+ * returned from binder_ioctl(). This function is a callback
+ * for that mechanism and does the actual ksys_close() on the
+ * given file descriptor.
+ */
+static void binder_do_fd_close(struct callback_head *twork)
+{
+	struct binder_task_work_cb *twcb = container_of(twork,
+			struct binder_task_work_cb, twork);
+
+	fput(twcb->file);
+	kfree(twcb);
+}
+
+/**
+ * binder_deferred_fd_close() - schedule a close for the given file-descriptor
+ * @fd:		file-descriptor to close
+ *
+ * See comments in binder_do_fd_close(). This function is used to schedule
+ * a file-descriptor to be closed after returning from binder_ioctl().
+ */
+static void binder_deferred_fd_close(int fd)
+{
+	struct binder_task_work_cb *twcb;
+
+	twcb = kzalloc_obj(*twcb);
+	if (!twcb)
+		return;
+	init_task_work(&twcb->twork, binder_do_fd_close);
+	twcb->file = file_close_fd(fd);
+	if (twcb->file) {
+		// pin it until binder_do_fd_close(); see comments there
+		get_file(twcb->file);
+		filp_close(twcb->file, current->files);
+		task_work_add(current, &twcb->twork, TWA_RESUME);
+	} else {
+		kfree(twcb);
+	}
+}
+
+static void binder_transaction_buffer_release(struct binder_proc *proc,
+					      struct binder_thread *thread,
+					      struct binder_buffer *buffer,
+					      binder_size_t off_end_offset,
+					      bool is_failure)
+{
+	int debug_id = buffer->debug_id;
+	binder_size_t off_start_offset, buffer_offset;
+
+	binder_debug(BINDER_DEBUG_TRANSACTION,
+		     "%d buffer release %d, size %zd-%zd, failed at %llx\n",
+		     proc->pid, buffer->debug_id,
+		     buffer->data_size, buffer->offsets_size,
+		     (unsigned long long)off_end_offset);
+
+	if (buffer->target_node)
+		binder_dec_node(buffer->target_node, 1, 0);
+
+	off_start_offset = ALIGN(buffer->data_size, sizeof(void *));
+
+	for (buffer_offset = off_start_offset; buffer_offset < off_end_offset;
+	     buffer_offset += sizeof(binder_size_t)) {
+		struct binder_object_header *hdr;
+		size_t object_size = 0;
+		struct binder_object object;
+		binder_size_t object_offset;
+
+		if (!binder_alloc_copy_from_buffer(&proc->alloc, &object_offset,
+						   buffer, buffer_offset,
+						   sizeof(object_offset)))
+			object_size = binder_get_object(proc, NULL, buffer,
+							object_offset, &object);
+		if (object_size == 0) {
+			pr_err("transaction release %d bad object at offset %lld, size %zd\n",
+			       debug_id, (u64)object_offset, buffer->data_size);
+			continue;
+		}
+		hdr = &object.hdr;
+		switch (hdr->type) {
+		case BINDER_TYPE_BINDER:
+		case BINDER_TYPE_WEAK_BINDER: {
+			struct flat_binder_object *fp;
+			struct binder_node *node;
+
+			fp = to_flat_binder_object(hdr);
+			node = binder_get_node(proc, fp->binder);
+			if (node == NULL) {
+				pr_err("transaction release %d bad node %016llx\n",
+				       debug_id, (u64)fp->binder);
+				break;
+			}
+			binder_debug(BINDER_DEBUG_TRANSACTION,
+				     "        node %d u%016llx\n",
+				     node->debug_id, (u64)node->ptr);
+			binder_dec_node(node, hdr->type == BINDER_TYPE_BINDER,
+					0);
+			binder_put_node(node);
+		} break;
+		case BINDER_TYPE_HANDLE:
+		case BINDER_TYPE_WEAK_HANDLE: {
+			struct flat_binder_object *fp;
+			struct binder_ref_data rdata;
+			int ret;
+
+			fp = to_flat_binder_object(hdr);
+			ret = binder_dec_ref_for_handle(proc, fp->handle,
+				hdr->type == BINDER_TYPE_HANDLE, &rdata);
+
+			if (ret) {
+				pr_err("transaction release %d bad handle %d, ret = %d\n",
+				 debug_id, fp->handle, ret);
+				break;
+			}
+			binder_debug(BINDER_DEBUG_TRANSACTION,
+				     "        ref %d desc %d\n",
+				     rdata.debug_id, rdata.desc);
+		} break;
+
+		case BINDER_TYPE_FD: {
+			/*
+			 * No need to close the file here since user-space
+			 * closes it for successfully delivered
+			 * transactions. For transactions that weren't
+			 * delivered, the new fd was never allocated so
+			 * there is no need to close and the fput on the
+			 * file is done when the transaction is torn
+			 * down.
+			 */
+		} break;
+		case BINDER_TYPE_PTR:
+			/*
+			 * Nothing to do here, this will get cleaned up when the
+			 * transaction buffer gets freed
+			 */
+			break;
+		case BINDER_TYPE_FDA: {
+			struct binder_fd_array_object *fda;
+			struct binder_buffer_object *parent;
+			struct binder_object ptr_object;
+			binder_size_t fda_offset;
+			size_t fd_index;
+			binder_size_t fd_buf_size;
+			binder_size_t num_valid;
+
+			if (is_failure) {
+				/*
+				 * The fd fixups have not been applied so no
+				 * fds need to be closed.
+				 */
+				continue;
+			}
+
+			num_valid = (buffer_offset - off_start_offset) /
+						sizeof(binder_size_t);
+			fda = to_binder_fd_array_object(hdr);
+			parent = binder_validate_ptr(proc, buffer, &ptr_object,
+						     fda->parent,
+						     off_start_offset,
+						     NULL,
+						     num_valid);
+			if (!parent) {
+				pr_err("transaction release %d bad parent offset\n",
+				       debug_id);
+				continue;
+			}
+			fd_buf_size = sizeof(u32) * fda->num_fds;
+			if (fda->num_fds >= SIZE_MAX / sizeof(u32)) {
+				pr_err("transaction release %d invalid number of fds (%lld)\n",
+				       debug_id, (u64)fda->num_fds);
+				continue;
+			}
+			if (fd_buf_size > parent->length ||
+			    fda->parent_offset > parent->length - fd_buf_size) {
+				/* No space for all file descriptors here. */
+				pr_err("transaction release %d not enough space for %lld fds in buffer\n",
+				       debug_id, (u64)fda->num_fds);
+				continue;
+			}
+			/*
+			 * the source data for binder_buffer_object is visible
+			 * to user-space and the @buffer element is the user
+			 * pointer to the buffer_object containing the fd_array.
+			 * Convert the address to an offset relative to
+			 * the base of the transaction buffer.
+			 */
+			fda_offset = parent->buffer - buffer->user_data +
+				fda->parent_offset;
+			for (fd_index = 0; fd_index < fda->num_fds;
+			     fd_index++) {
+				u32 fd;
+				int err;
+				binder_size_t offset = fda_offset +
+					fd_index * sizeof(fd);
+
+				err = binder_alloc_copy_from_buffer(
+						&proc->alloc, &fd, buffer,
+						offset, sizeof(fd));
+				WARN_ON(err);
+				if (!err) {
+					binder_deferred_fd_close(fd);
+					/*
+					 * Need to make sure the thread goes
+					 * back to userspace to complete the
+					 * deferred close
+					 */
+					if (thread)
+						thread->looper_need_return = true;
+				}
+			}
+		} break;
+		default:
+			pr_err("transaction release %d bad object type %x\n",
+				debug_id, hdr->type);
+			break;
+		}
+	}
+}
+
+/* Clean up all the objects in the buffer */
+static inline void binder_release_entire_buffer(struct binder_proc *proc,
+						struct binder_thread *thread,
+						struct binder_buffer *buffer,
+						bool is_failure)
+{
+	binder_size_t off_end_offset;
+
+	off_end_offset = ALIGN(buffer->data_size, sizeof(void *));
+	off_end_offset += buffer->offsets_size;
+
+	binder_transaction_buffer_release(proc, thread, buffer,
+					  off_end_offset, is_failure);
+}
+
+static int binder_translate_binder(struct flat_binder_object *fp,
+				   struct binder_transaction *t,
+				   struct binder_thread *thread)
+{
+	struct binder_node *node;
+	struct binder_proc *proc = thread->proc;
+	struct binder_proc *target_proc = t->to_proc;
+	struct binder_ref_data rdata;
+	int ret = 0;
+
+	node = binder_get_node(proc, fp->binder);
+	if (!node) {
+		node = binder_new_node(proc, fp);
+		if (!node)
+			return -ENOMEM;
+	}
+	if (fp->cookie != node->cookie) {
+		binder_user_error("%d:%d sending u%016llx node %d, cookie mismatch %016llx != %016llx\n",
+				  proc->pid, thread->pid, (u64)fp->binder,
+				  node->debug_id, (u64)fp->cookie,
+				  (u64)node->cookie);
+		ret = -EINVAL;
+		goto done;
+	}
+	if (security_binder_transfer_binder(proc->cred, target_proc->cred)) {
+		ret = -EPERM;
+		goto done;
+	}
+
+	ret = binder_inc_ref_for_node(target_proc, node,
+			fp->hdr.type == BINDER_TYPE_BINDER,
+			&thread->todo, &rdata);
+	if (ret)
+		goto done;
+
+	if (fp->hdr.type == BINDER_TYPE_BINDER)
+		fp->hdr.type = BINDER_TYPE_HANDLE;
+	else
+		fp->hdr.type = BINDER_TYPE_WEAK_HANDLE;
+	fp->binder = 0;
+	fp->handle = rdata.desc;
+	fp->cookie = 0;
+
+	trace_binder_transaction_node_to_ref(t, node, &rdata);
+	binder_debug(BINDER_DEBUG_TRANSACTION,
+		     "        node %d u%016llx -> ref %d desc %d\n",
+		     node->debug_id, (u64)node->ptr,
+		     rdata.debug_id, rdata.desc);
+done:
+	binder_put_node(node);
+	return ret;
+}
+
+static int binder_translate_handle(struct flat_binder_object *fp,
+				   struct binder_transaction *t,
+				   struct binder_thread *thread)
+{
+	struct binder_proc *proc = thread->proc;
+	struct binder_proc *target_proc = t->to_proc;
+	struct binder_node *node;
+	struct binder_ref_data src_rdata;
+	int ret = 0;
+
+	node = binder_get_node_from_ref(proc, fp->handle,
+			fp->hdr.type == BINDER_TYPE_HANDLE, &src_rdata);
+	if (!node) {
+		binder_user_error("%d:%d got transaction with invalid handle, %d\n",
+				  proc->pid, thread->pid, fp->handle);
+		return -EINVAL;
+	}
+	if (security_binder_transfer_binder(proc->cred, target_proc->cred)) {
+		ret = -EPERM;
+		goto done;
+	}
+
+	binder_node_lock(node);
+	if (node->proc == target_proc) {
+		if (fp->hdr.type == BINDER_TYPE_HANDLE)
+			fp->hdr.type = BINDER_TYPE_BINDER;
+		else
+			fp->hdr.type = BINDER_TYPE_WEAK_BINDER;
+		fp->binder = node->ptr;
+		fp->cookie = node->cookie;
+		if (node->proc)
+			binder_inner_proc_lock(node->proc);
+		else
+			__acquire(&node->proc->inner_lock);
+		binder_inc_node_nilocked(node,
+					 fp->hdr.type == BINDER_TYPE_BINDER,
+					 0, NULL);
+		if (node->proc)
+			binder_inner_proc_unlock(node->proc);
+		else
+			__release(&node->proc->inner_lock);
+		trace_binder_transaction_ref_to_node(t, node, &src_rdata);
+		binder_debug(BINDER_DEBUG_TRANSACTION,
+			     "        ref %d desc %d -> node %d u%016llx\n",
+			     src_rdata.debug_id, src_rdata.desc, node->debug_id,
+			     (u64)node->ptr);
+		binder_node_unlock(node);
+	} else {
+		struct binder_ref_data dest_rdata;
+
+		binder_node_unlock(node);
+		ret = binder_inc_ref_for_node(target_proc, node,
+				fp->hdr.type == BINDER_TYPE_HANDLE,
+				NULL, &dest_rdata);
+		if (ret)
+			goto done;
+
+		fp->binder = 0;
+		fp->handle = dest_rdata.desc;
+		fp->cookie = 0;
+		trace_binder_transaction_ref_to_ref(t, node, &src_rdata,
+						    &dest_rdata);
+		binder_debug(BINDER_DEBUG_TRANSACTION,
+			     "        ref %d desc %d -> ref %d desc %d (node %d)\n",
+			     src_rdata.debug_id, src_rdata.desc,
+			     dest_rdata.debug_id, dest_rdata.desc,
+			     node->debug_id);
+	}
+done:
+	binder_put_node(node);
+	return ret;
+}
+
+static int binder_translate_fd(u32 fd, binder_size_t fd_offset,
+			       struct binder_transaction *t,
+			       struct binder_thread *thread,
+			       struct binder_transaction *in_reply_to)
+{
+	struct binder_proc *proc = thread->proc;
+	struct binder_proc *target_proc = t->to_proc;
+	struct binder_txn_fd_fixup *fixup;
+	struct file *file;
+	int ret = 0;
+	bool target_allows_fd;
+
+	if (in_reply_to)
+		target_allows_fd = !!(in_reply_to->flags & TF_ACCEPT_FDS);
+	else
+		target_allows_fd = t->buffer->target_node->accept_fds;
+	if (!target_allows_fd) {
+		binder_user_error("%d:%d got %s with fd, %d, but target does not allow fds\n",
+				  proc->pid, thread->pid,
+				  in_reply_to ? "reply" : "transaction",
+				  fd);
+		ret = -EPERM;
+		goto err_fd_not_accepted;
+	}
+
+	file = fget(fd);
+	if (!file) {
+		binder_user_error("%d:%d got transaction with invalid fd, %d\n",
+				  proc->pid, thread->pid, fd);
+		ret = -EBADF;
+		goto err_fget;
+	}
+	ret = security_binder_transfer_file(proc->cred, target_proc->cred, file);
+	if (ret < 0) {
+		ret = -EPERM;
+		goto err_security;
+	}
+
+	/*
+	 * Add fixup record for this transaction. The allocation
+	 * of the fd in the target needs to be done from a
+	 * target thread.
+	 */
+	fixup = kzalloc_obj(*fixup);
+	if (!fixup) {
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+	fixup->file = file;
+	fixup->offset = fd_offset;
+	fixup->target_fd = -1;
+	trace_binder_transaction_fd_send(t, fd, fixup->offset);
+	list_add_tail(&fixup->fixup_entry, &t->fd_fixups);
+
+	return ret;
+
+err_alloc:
+err_security:
+	fput(file);
+err_fget:
+err_fd_not_accepted:
+	return ret;
+}
+
+/**
+ * struct binder_ptr_fixup - data to be fixed-up in target buffer
+ * @offset:      offset in target buffer to fixup
+ * @skip_size:   bytes to skip in copy (fixup will be written later)
+ * @fixup_data:  data to write at fixup offset
+ * @node:        list node
+ *
+ * This is used for the pointer fixup list (pf) which is created and consumed
+ * during binder_transaction() and is only accessed locally. No
+ * locking is necessary.
+ *
+ * The list is ordered by @offset.
+ */
+struct binder_ptr_fixup {
+	binder_size_t offset;
+	size_t skip_size;
+	binder_uintptr_t fixup_data;
+	struct list_head node;
+};
+
+/**
+ * struct binder_sg_copy - scatter-gather data to be copied
+ * @offset:        offset in target buffer
+ * @sender_uaddr:  user address in source buffer
+ * @length:        bytes to copy
+ * @node:          list node
+ *
+ * This is used for the sg copy list (sgc) which is created and consumed
+ * during binder_transaction() and is only accessed locally. No
+ * locking is necessary.
+ *
+ * The list is ordered by @offset.
+ */
+struct binder_sg_copy {
+	binder_size_t offset;
+	const void __user *sender_uaddr;
+	size_t length;
+	struct list_head node;
+};
+
+/**
+ * binder_do_deferred_txn_copies() - copy and fixup scatter-gather data
+ * @alloc:	binder_alloc associated with @buffer
+ * @buffer:	binder buffer in target process
+ * @sgc_head:	list_head of scatter-gather copy list
+ * @pf_head:	list_head of pointer fixup list
+ *
+ * Processes all elements of @sgc_head, applying fixups from @pf_head
+ * and copying the scatter-gather data from the source process' user
+ * buffer to the target's buffer. It is expected that the list creation
+ * and processing all occurs during binder_transaction() so these lists
+ * are only accessed in local context.
+ *
+ * Return: 0=success, else -errno
+ */
+static int binder_do_deferred_txn_copies(struct binder_alloc *alloc,
+					 struct binder_buffer *buffer,
+					 struct list_head *sgc_head,
+					 struct list_head *pf_head)
+{
+	int ret = 0;
+	struct binder_sg_copy *sgc, *tmpsgc;
+	struct binder_ptr_fixup *tmppf;
+	struct binder_ptr_fixup *pf =
+		list_first_entry_or_null(pf_head, struct binder_ptr_fixup,
+					 node);
+
+	list_for_each_entry_safe(sgc, tmpsgc, sgc_head, node) {
+		size_t bytes_copied = 0;
+
+		while (bytes_copied < sgc->length) {
+			size_t copy_size;
+			size_t bytes_left = sgc->length - bytes_copied;
+			size_t offset = sgc->offset + bytes_copied;
+
+			/*
+			 * We copy up to the fixup (pointed to by pf)
+			 */
+			copy_size = pf ? min(bytes_left, (size_t)pf->offset - offset)
+				       : bytes_left;
+			if (!ret && copy_size)
+				ret = binder_alloc_copy_user_to_buffer(
+						alloc, buffer,
+						offset,
+						sgc->sender_uaddr + bytes_copied,
+						copy_size);
+			bytes_copied += copy_size;
+			if (copy_size != bytes_left) {
+				BUG_ON(!pf);
+				/* we stopped at a fixup offset */
+				if (pf->skip_size) {
+					/*
+					 * we are just skipping. This is for
+					 * BINDER_TYPE_FDA where the translated
+					 * fds will be fixed up when we get
+					 * to target context.
+					 */
+					bytes_copied += pf->skip_size;
+				} else {
+					/* apply the fixup indicated by pf */
+					if (!ret)
+						ret = binder_alloc_copy_to_buffer(
+							alloc, buffer,
+							pf->offset,
+							&pf->fixup_data,
+							sizeof(pf->fixup_data));
+					bytes_copied += sizeof(pf->fixup_data);
+				}
+				list_del(&pf->node);
+				kfree(pf);
+				pf = list_first_entry_or_null(pf_head,
+						struct binder_ptr_fixup, node);
+			}
+		}
+		list_del(&sgc->node);
+		kfree(sgc);
+	}
+	list_for_each_entry_safe(pf, tmppf, pf_head, node) {
+		BUG_ON(pf->skip_size == 0);
+		list_del(&pf->node);
+		kfree(pf);
+	}
+	BUG_ON(!list_empty(sgc_head));
+
+	return ret > 0 ? -EINVAL : ret;
+}
+
+/**
+ * binder_cleanup_deferred_txn_lists() - free specified lists
+ * @sgc_head:	list_head of scatter-gather copy list
+ * @pf_head:	list_head of pointer fixup list
+ *
+ * Called to clean up @sgc_head and @pf_head if there is an
+ * error.
+ */
+static void binder_cleanup_deferred_txn_lists(struct list_head *sgc_head,
+					      struct list_head *pf_head)
+{
+	struct binder_sg_copy *sgc, *tmpsgc;
+	struct binder_ptr_fixup *pf, *tmppf;
+
+	list_for_each_entry_safe(sgc, tmpsgc, sgc_head, node) {
+		list_del(&sgc->node);
+		kfree(sgc);
+	}
+	list_for_each_entry_safe(pf, tmppf, pf_head, node) {
+		list_del(&pf->node);
+		kfree(pf);
+	}
+}
+
+/**
+ * binder_defer_copy() - queue a scatter-gather buffer for copy
+ * @sgc_head:		list_head of scatter-gather copy list
+ * @offset:		binder buffer offset in target process
+ * @sender_uaddr:	user address in source process
+ * @length:		bytes to copy
+ *
+ * Specify a scatter-gather block to be copied. The actual copy must
+ * be deferred until all the needed fixups are identified and queued.
+ * Then the copy and fixups are done together so un-translated values
+ * from the source are never visible in the target buffer.
+ *
+ * We are guaranteed that repeated calls to this function will have
+ * monotonically increasing @offset values so the list will naturally
+ * be ordered.
+ *
+ * Return: 0=success, else -errno
+ */
+static int binder_defer_copy(struct list_head *sgc_head, binder_size_t offset,
+			     const void __user *sender_uaddr, size_t length)
+{
+	struct binder_sg_copy *bc = kzalloc_obj(*bc);
+
+	if (!bc)
+		return -ENOMEM;
+
+	bc->offset = offset;
+	bc->sender_uaddr = sender_uaddr;
+	bc->length = length;
+	INIT_LIST_HEAD(&bc->node);
+
+	/*
+	 * We are guaranteed that the deferred copies are in-order
+	 * so just add to the tail.
+	 */
+	list_add_tail(&bc->node, sgc_head);
+
+	return 0;
+}
+
+/**
+ * binder_add_fixup() - queue a fixup to be applied to sg copy
+ * @pf_head:	list_head of binder ptr fixup list
+ * @offset:	binder buffer offset in target process
+ * @fixup:	bytes to be copied for fixup
+ * @skip_size:	bytes to skip when copying (fixup will be applied later)
+ *
+ * Add the specified fixup to a list ordered by @offset. When copying
+ * the scatter-gather buffers, the fixup will be copied instead of
+ * data from the source buffer. For BINDER_TYPE_FDA fixups, the fixup
+ * will be applied later (in target process context), so we just skip
+ * the bytes specified by @skip_size. If @skip_size is 0, we copy the
+ * value in @fixup.
+ *
+ * This function is called *mostly* in @offset order, but there are
+ * exceptions. Since out-of-order inserts are relatively uncommon,
+ * we insert the new element by searching backward from the tail of
+ * the list.
+ *
+ * Return: 0=success, else -errno
+ */
+static int binder_add_fixup(struct list_head *pf_head, binder_size_t offset,
+			    binder_uintptr_t fixup, size_t skip_size)
+{
+	struct binder_ptr_fixup *pf = kzalloc_obj(*pf);
+	struct binder_ptr_fixup *tmppf;
+
+	if (!pf)
+		return -ENOMEM;
+
+	pf->offset = offset;
+	pf->fixup_data = fixup;
+	pf->skip_size = skip_size;
+	INIT_LIST_HEAD(&pf->node);
+
+	/* Fixups are *mostly* added in-order, but there are some
+	 * exceptions. Look backwards through list for insertion point.
+	 */
+	list_for_each_entry_reverse(tmppf, pf_head, node) {
+		if (tmppf->offset < pf->offset) {
+			list_add(&pf->node, &tmppf->node);
+			return 0;
+		}
+	}
+	/*
+	 * if we get here, then the new offset is the lowest so
+	 * insert at the head
+	 */
+	list_add(&pf->node, pf_head);
+	return 0;
+}
+
+static int binder_translate_fd_array(struct list_head *pf_head,
+				     struct binder_fd_array_object *fda,
+				     const void __user *sender_ubuffer,
+				     struct binder_buffer_object *parent,
+				     struct binder_buffer_object *sender_uparent,
+				     struct binder_transaction *t,
+				     struct binder_thread *thread,
+				     struct binder_transaction *in_reply_to)
+{
+	binder_size_t fdi, fd_buf_size;
+	binder_size_t fda_offset;
+	const void __user *sender_ufda_base;
+	struct binder_proc *proc = thread->proc;
+	int ret;
+
+	if (fda->num_fds == 0)
+		return 0;
+
+	fd_buf_size = sizeof(u32) * fda->num_fds;
+	if (fda->num_fds >= SIZE_MAX / sizeof(u32)) {
+		binder_user_error("%d:%d got transaction with invalid number of fds (%lld)\n",
+				  proc->pid, thread->pid, (u64)fda->num_fds);
+		return -EINVAL;
+	}
+	if (fd_buf_size > parent->length ||
+	    fda->parent_offset > parent->length - fd_buf_size) {
+		/* No space for all file descriptors here. */
+		binder_user_error("%d:%d not enough space to store %lld fds in buffer\n",
+				  proc->pid, thread->pid, (u64)fda->num_fds);
+		return -EINVAL;
+	}
+	/*
+	 * the source data for binder_buffer_object is visible
+	 * to user-space and the @buffer element is the user
+	 * pointer to the buffer_object containing the fd_array.
+	 * Convert the address to an offset relative to
+	 * the base of the transaction buffer.
+	 */
+	fda_offset = parent->buffer - t->buffer->user_data +
+		fda->parent_offset;
+	sender_ufda_base = (void __user *)(uintptr_t)sender_uparent->buffer +
+				fda->parent_offset;
+
+	if (!IS_ALIGNED((unsigned long)fda_offset, sizeof(u32)) ||
+	    !IS_ALIGNED((unsigned long)sender_ufda_base, sizeof(u32))) {
+		binder_user_error("%d:%d parent offset not aligned correctly.\n",
+				  proc->pid, thread->pid);
+		return -EINVAL;
+	}
+	ret = binder_add_fixup(pf_head, fda_offset, 0, fda->num_fds * sizeof(u32));
+	if (ret)
+		return ret;
+
+	for (fdi = 0; fdi < fda->num_fds; fdi++) {
+		u32 fd;
+		binder_size_t offset = fda_offset + fdi * sizeof(fd);
+		binder_size_t sender_uoffset = fdi * sizeof(fd);
+
+		ret = copy_from_user(&fd, sender_ufda_base + sender_uoffset, sizeof(fd));
+		if (!ret)
+			ret = binder_translate_fd(fd, offset, t, thread,
+						  in_reply_to);
+		if (ret)
+			return ret > 0 ? -EINVAL : ret;
+	}
+	return 0;
+}
+
+static int binder_fixup_parent(struct list_head *pf_head,
+			       struct binder_transaction *t,
+			       struct binder_thread *thread,
+			       struct binder_buffer_object *bp,
+			       binder_size_t off_start_offset,
+			       binder_size_t num_valid,
+			       binder_size_t last_fixup_obj_off,
+			       binder_size_t last_fixup_min_off)
+{
+	struct binder_buffer_object *parent;
+	struct binder_buffer *b = t->buffer;
+	struct binder_proc *proc = thread->proc;
+	struct binder_proc *target_proc = t->to_proc;
+	struct binder_object object;
+	binder_size_t buffer_offset;
+	binder_size_t parent_offset;
+
+	if (!(bp->flags & BINDER_BUFFER_FLAG_HAS_PARENT))
+		return 0;
+
+	parent = binder_validate_ptr(target_proc, b, &object, bp->parent,
+				     off_start_offset, &parent_offset,
+				     num_valid);
+	if (!parent) {
+		binder_user_error("%d:%d got transaction with invalid parent offset or type\n",
+				  proc->pid, thread->pid);
+		return -EINVAL;
+	}
+
+	if (!binder_validate_fixup(target_proc, b, off_start_offset,
+				   parent_offset, bp->parent_offset,
+				   last_fixup_obj_off,
+				   last_fixup_min_off)) {
+		binder_user_error("%d:%d got transaction with out-of-order buffer fixup\n",
+				  proc->pid, thread->pid);
+		return -EINVAL;
+	}
+
+	if (parent->length < sizeof(binder_uintptr_t) ||
+	    bp->parent_offset > parent->length - sizeof(binder_uintptr_t)) {
+		/* No space for a pointer here! */
+		binder_user_error("%d:%d got transaction with invalid parent offset\n",
+				  proc->pid, thread->pid);
+		return -EINVAL;
+	}
+
+	buffer_offset = bp->parent_offset + parent->buffer - b->user_data;
+
+	return binder_add_fixup(pf_head, buffer_offset, bp->buffer, 0);
+}
+
+/**
+ * binder_can_update_transaction() - Can a txn be superseded by an updated one?
+ * @t1: the pending async txn in the frozen process
+ * @t2: the new async txn to supersede the outdated pending one
+ *
+ * Return:  true if t2 can supersede t1
+ *          false if t2 can not supersede t1
+ */
+static bool binder_can_update_transaction(struct binder_transaction *t1,
+					  struct binder_transaction *t2)
+{
+	if ((t1->flags & t2->flags & (TF_ONE_WAY | TF_UPDATE_TXN)) !=
+	    (TF_ONE_WAY | TF_UPDATE_TXN) || !t1->to_proc || !t2->to_proc)
+		return false;
+	if (t1->to_proc->tsk == t2->to_proc->tsk && t1->code == t2->code &&
+	    t1->flags == t2->flags && t1->buffer->pid == t2->buffer->pid &&
+	    t1->buffer->target_node->ptr == t2->buffer->target_node->ptr &&
+	    t1->buffer->target_node->cookie == t2->buffer->target_node->cookie)
+		return true;
+	return false;
+}
+
+/**
+ * binder_find_outdated_transaction_ilocked() - Find the outdated transaction
+ * @t:		 new async transaction
+ * @target_list: list to find outdated transaction
+ *
+ * Return: the outdated transaction if found
+ *         NULL if no outdated transacton can be found
+ *
+ * Requires the proc->inner_lock to be held.
+ */
+static struct binder_transaction *
+binder_find_outdated_transaction_ilocked(struct binder_transaction *t,
+					 struct list_head *target_list)
+{
+	struct binder_work *w;
+
+	list_for_each_entry(w, target_list, entry) {
+		struct binder_transaction *t_queued;
+
+		if (w->type != BINDER_WORK_TRANSACTION)
+			continue;
+		t_queued = container_of(w, struct binder_transaction, work);
+		if (binder_can_update_transaction(t_queued, t))
+			return t_queued;
+	}
+	return NULL;
+}
+
+/**
+ * binder_proc_transaction() - sends a transaction to a process and wakes it up
+ * @t:		transaction to send
+ * @proc:	process to send the transaction to
+ * @thread:	thread in @proc to send the transaction to (may be NULL)
+ *
+ * This function queues a transaction to the specified process. It will try
+ * to find a thread in the target process to handle the transaction and
+ * wake it up. If no thread is found, the work is queued to the proc
+ * waitqueue.
+ *
+ * If the @thread parameter is not NULL, the transaction is always queued
+ * to the waitlist of that specific thread.
+ *
+ * Return:	0 if the transaction was successfully queued
+ *		BR_DEAD_REPLY if the target process or thread is dead
+ *		BR_FROZEN_REPLY if the target process or thread is frozen and
+ *			the sync transaction was rejected
+ *		BR_TRANSACTION_PENDING_FROZEN if the target process is frozen
+ *		and the async transaction was successfully queued
+ */
+static int binder_proc_transaction(struct binder_transaction *t,
+				    struct binder_proc *proc,
+				    struct binder_thread *thread)
+{
+	struct binder_node *node = t->buffer->target_node;
+	bool oneway = !!(t->flags & TF_ONE_WAY);
+	bool pending_async = false;
+	struct binder_transaction *t_outdated = NULL;
+	bool frozen = false;
+
+	BUG_ON(!node);
+	binder_node_lock(node);
+	if (oneway) {
+		BUG_ON(thread);
+		if (node->has_async_transaction)
+			pending_async = true;
+		else
+			node->has_async_transaction = true;
+	}
+
+	binder_inner_proc_lock(proc);
+	if (proc->is_frozen) {
+		frozen = true;
+		proc->sync_recv |= !oneway;
+		proc->async_recv |= oneway;
+	}
+
+	if ((frozen && !oneway) || proc->is_dead ||
+			(thread && thread->is_dead)) {
+		binder_inner_proc_unlock(proc);
+		binder_node_unlock(node);
+		return frozen ? BR_FROZEN_REPLY : BR_DEAD_REPLY;
+	}
+
+	if (!thread && !pending_async)
+		thread = binder_select_thread_ilocked(proc);
+
+	if (thread) {
+		binder_enqueue_thread_work_ilocked(thread, &t->work);
+	} else if (!pending_async) {
+		binder_enqueue_work_ilocked(&t->work, &proc->todo);
+	} else {
+		if ((t->flags & TF_UPDATE_TXN) && frozen) {
+			t_outdated = binder_find_outdated_transaction_ilocked(t,
+									      &node->async_todo);
+			if (t_outdated) {
+				binder_debug(BINDER_DEBUG_TRANSACTION,
+					     "txn %d supersedes %d\n",
+					     t->debug_id, t_outdated->debug_id);
+				list_del_init(&t_outdated->work.entry);
+				proc->outstanding_txns--;
+			}
+		}
+		binder_enqueue_work_ilocked(&t->work, &node->async_todo);
+	}
+
+	if (!pending_async)
+		binder_wakeup_thread_ilocked(proc, thread, !oneway /* sync */);
+
+	proc->outstanding_txns++;
+	binder_inner_proc_unlock(proc);
+	binder_node_unlock(node);
+
+	/*
+	 * To reduce potential contention, free the outdated transaction and
+	 * buffer after releasing the locks.
+	 */
+	if (t_outdated) {
+		struct binder_buffer *buffer = t_outdated->buffer;
+
+		t_outdated->buffer = NULL;
+		buffer->transaction = NULL;
+		trace_binder_transaction_update_buffer_release(buffer);
+		binder_release_entire_buffer(proc, NULL, buffer, false);
+		binder_alloc_free_buf(&proc->alloc, buffer);
+		kfree(t_outdated);
+		binder_stats_deleted(BINDER_STAT_TRANSACTION);
+	}
+
+	if (oneway && frozen)
+		return BR_TRANSACTION_PENDING_FROZEN;
+
+	return 0;
+}
+
+/**
+ * binder_get_node_refs_for_txn() - Get required refs on node for txn
+ * @node:         struct binder_node for which to get refs
+ * @procp:        returns @node->proc if valid
+ * @error:        if no @procp then returns BR_DEAD_REPLY
+ *
+ * User-space normally keeps the node alive when creating a transaction
+ * since it has a reference to the target. The local strong ref keeps it
+ * alive if the sending process dies before the target process processes
+ * the transaction. If the source process is malicious or has a reference
+ * counting bug, relying on the local strong ref can fail.
+ *
+ * Since user-space can cause the local strong ref to go away, we also take
+ * a tmpref on the node to ensure it survives while we are constructing
+ * the transaction. We also need a tmpref on the proc while we are
+ * constructing the transaction, so we take that here as well.
+ *
+ * Return: The target_node with refs taken or NULL if no @node->proc is NULL.
+ * Also sets @procp if valid. If the @node->proc is NULL indicating that the
+ * target proc has died, @error is set to BR_DEAD_REPLY.
+ */
+static struct binder_node *binder_get_node_refs_for_txn(
+		struct binder_node *node,
+		struct binder_proc **procp,
+		uint32_t *error)
+{
+	struct binder_node *target_node = NULL;
+
+	binder_node_inner_lock(node);
+	if (node->proc) {
+		target_node = node;
+		binder_inc_node_nilocked(node, 1, 0, NULL);
+		binder_inc_node_tmpref_ilocked(node);
+		node->proc->tmp_ref++;
+		*procp = node->proc;
+	} else
+		*error = BR_DEAD_REPLY;
+	binder_node_inner_unlock(node);
+
+	return target_node;
+}
+
+static void binder_set_txn_from_error(struct binder_transaction *t, int id,
+				      uint32_t command, int32_t param)
+{
+	struct binder_thread *from = binder_get_txn_from_and_acq_inner(t);
+
+	if (!from) {
+		/* annotation for sparse */
+		__release(&from->proc->inner_lock);
+		return;
+	}
+
+	/* don't override existing errors */
+	if (from->ee.command == BR_OK)
+		binder_set_extended_error(&from->ee, id, command, param);
+	binder_inner_proc_unlock(from->proc);
+	binder_thread_dec_tmpref(from);
+}
+
+/**
+ * binder_netlink_report() - report a transaction failure via netlink
+ * @proc:	the binder proc sending the transaction
+ * @t:		the binder transaction that failed
+ * @data_size:	the user provided data size for the transaction
+ * @error:	enum binder_driver_return_protocol returned to sender
+ *
+ * Note that t->buffer is not safe to access here, as it may have been
+ * released (or not yet allocated). Callers should guarantee all the
+ * transaction items used here are safe to access.
+ */
+static void binder_netlink_report(struct binder_proc *proc,
+				  struct binder_transaction *t,
+				  u32 data_size,
+				  u32 error)
+{
+	const char *context = proc->context->name;
+	struct sk_buff *skb;
+	void *hdr;
+
+	if (!genl_has_listeners(&binder_nl_family, &init_net,
+				BINDER_NLGRP_REPORT))
+		return;
+
+	trace_binder_netlink_report(context, t, data_size, error);
+
+	skb = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!skb)
+		return;
+
+	hdr = genlmsg_put(skb, 0, 0, &binder_nl_family, 0, BINDER_CMD_REPORT);
+	if (!hdr)
+		goto free_skb;
+
+	if (nla_put_u32(skb, BINDER_A_REPORT_ERROR, error) ||
+	    nla_put_string(skb, BINDER_A_REPORT_CONTEXT, context) ||
+	    nla_put_u32(skb, BINDER_A_REPORT_FROM_PID, t->from_pid) ||
+	    nla_put_u32(skb, BINDER_A_REPORT_FROM_TID, t->from_tid))
+		goto cancel_skb;
+
+	if (t->to_proc &&
+	    nla_put_u32(skb, BINDER_A_REPORT_TO_PID, t->to_proc->pid))
+		goto cancel_skb;
+
+	if (t->to_thread &&
+	    nla_put_u32(skb, BINDER_A_REPORT_TO_TID, t->to_thread->pid))
+		goto cancel_skb;
+
+	if (t->is_reply && nla_put_flag(skb, BINDER_A_REPORT_IS_REPLY))
+		goto cancel_skb;
+
+	if (nla_put_u32(skb, BINDER_A_REPORT_FLAGS, t->flags) ||
+	    nla_put_u32(skb, BINDER_A_REPORT_CODE, t->code) ||
+	    nla_put_u32(skb, BINDER_A_REPORT_DATA_SIZE, data_size))
+		goto cancel_skb;
+
+	genlmsg_end(skb, hdr);
+	genlmsg_multicast(&binder_nl_family, skb, 0, BINDER_NLGRP_REPORT,
+			  GFP_KERNEL);
+	return;
+
+cancel_skb:
+	genlmsg_cancel(skb, hdr);
+free_skb:
+	nlmsg_free(skb);
+}
+
+static void binder_transaction(struct binder_proc *proc,
+			       struct binder_thread *thread,
+			       struct binder_transaction_data *tr, int reply,
+			       binder_size_t extra_buffers_size)
+{
+	int ret;
+	struct binder_transaction *t;
+	struct binder_work *w;
+	struct binder_work *tcomplete;
+	binder_size_t buffer_offset = 0;
+	binder_size_t off_start_offset, off_end_offset;
+	binder_size_t off_min;
+	binder_size_t sg_buf_offset, sg_buf_end_offset;
+	binder_size_t user_offset = 0;
+	struct binder_proc *target_proc = NULL;
+	struct binder_thread *target_thread = NULL;
+	struct binder_node *target_node = NULL;
+	struct binder_transaction *in_reply_to = NULL;
+	struct binder_transaction_log_entry *e;
+	uint32_t return_error = 0;
+	uint32_t return_error_param = 0;
+	uint32_t return_error_line = 0;
+	binder_size_t last_fixup_obj_off = 0;
+	binder_size_t last_fixup_min_off = 0;
+	struct binder_context *context = proc->context;
+	int t_debug_id = atomic_inc_return(&binder_last_id);
+	ktime_t t_start_time = ktime_get();
+	struct lsm_context lsmctx = { };
+	size_t lsmctx_aligned_size = 0;
+	LIST_HEAD(sgc_head);
+	LIST_HEAD(pf_head);
+	const void __user *user_buffer = (const void __user *)
+				(uintptr_t)tr->data.ptr.buffer;
+
+	e = binder_transaction_log_add(&binder_transaction_log);
+	e->debug_id = t_debug_id;
+	e->call_type = reply ? 2 : !!(tr->flags & TF_ONE_WAY);
+	e->from_proc = proc->pid;
+	e->from_thread = thread->pid;
+	e->target_handle = tr->target.handle;
+	e->data_size = tr->data_size;
+	e->offsets_size = tr->offsets_size;
+	strscpy(e->context_name, proc->context->name, BINDERFS_MAX_NAME);
+
+	binder_inner_proc_lock(proc);
+	binder_set_extended_error(&thread->ee, t_debug_id, BR_OK, 0);
+	binder_inner_proc_unlock(proc);
+
+	t = kzalloc_obj(*t);
+	if (!t) {
+		binder_txn_error("%d:%d cannot allocate transaction\n",
+				 thread->pid, proc->pid);
+		return_error = BR_FAILED_REPLY;
+		return_error_param = -ENOMEM;
+		return_error_line = __LINE__;
+		goto err_alloc_t_failed;
+	}
+	INIT_LIST_HEAD(&t->fd_fixups);
+	binder_stats_created(BINDER_STAT_TRANSACTION);
+	spin_lock_init(&t->lock);
+	t->debug_id = t_debug_id;
+	t->start_time = t_start_time;
+	t->from_pid = proc->pid;
+	t->from_tid = thread->pid;
+	t->sender_euid = current_euid();
+	t->code = tr->code;
+	t->flags = tr->flags;
+	t->priority = task_nice(current);
+	t->work.type = BINDER_WORK_TRANSACTION;
+	t->is_async = !reply && (tr->flags & TF_ONE_WAY);
+	t->is_reply = reply;
+	if (!reply && !(tr->flags & TF_ONE_WAY))
+		t->from = thread;
+
+	if (reply) {
+		binder_inner_proc_lock(proc);
+		in_reply_to = thread->transaction_stack;
+		if (in_reply_to == NULL) {
+			binder_inner_proc_unlock(proc);
+			binder_user_error("%d:%d got reply transaction with no transaction stack\n",
+					  proc->pid, thread->pid);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EPROTO;
+			return_error_line = __LINE__;
+			goto err_empty_call_stack;
+		}
+		if (in_reply_to->to_thread != thread) {
+			spin_lock(&in_reply_to->lock);
+			binder_user_error("%d:%d got reply transaction with bad transaction stack, transaction %d has target %d:%d\n",
+				proc->pid, thread->pid, in_reply_to->debug_id,
+				in_reply_to->to_proc ?
+				in_reply_to->to_proc->pid : 0,
+				in_reply_to->to_thread ?
+				in_reply_to->to_thread->pid : 0);
+			spin_unlock(&in_reply_to->lock);
+			binder_inner_proc_unlock(proc);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EPROTO;
+			return_error_line = __LINE__;
+			in_reply_to = NULL;
+			goto err_bad_call_stack;
+		}
+		thread->transaction_stack = in_reply_to->to_parent;
+		binder_inner_proc_unlock(proc);
+		binder_set_nice(in_reply_to->saved_priority);
+		target_thread = binder_get_txn_from_and_acq_inner(in_reply_to);
+		if (target_thread == NULL) {
+			/* annotation for sparse */
+			__release(&target_thread->proc->inner_lock);
+			binder_txn_error("%d:%d reply target not found\n",
+				thread->pid, proc->pid);
+			return_error = BR_DEAD_REPLY;
+			return_error_line = __LINE__;
+			goto err_dead_binder;
+		}
+		if (target_thread->transaction_stack != in_reply_to) {
+			binder_user_error("%d:%d got reply transaction with bad target transaction stack %d, expected %d\n",
+				proc->pid, thread->pid,
+				target_thread->transaction_stack ?
+				target_thread->transaction_stack->debug_id : 0,
+				in_reply_to->debug_id);
+			binder_inner_proc_unlock(target_thread->proc);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EPROTO;
+			return_error_line = __LINE__;
+			in_reply_to = NULL;
+			target_thread = NULL;
+			goto err_dead_binder;
+		}
+		target_proc = target_thread->proc;
+		target_proc->tmp_ref++;
+		binder_inner_proc_unlock(target_thread->proc);
+	} else {
+		if (tr->target.handle) {
+			struct binder_ref *ref;
+
+			/*
+			 * There must already be a strong ref
+			 * on this node. If so, do a strong
+			 * increment on the node to ensure it
+			 * stays alive until the transaction is
+			 * done.
+			 */
+			binder_proc_lock(proc);
+			ref = binder_get_ref_olocked(proc, tr->target.handle,
+						     true);
+			if (ref) {
+				target_node = binder_get_node_refs_for_txn(
+						ref->node, &target_proc,
+						&return_error);
+			} else {
+				binder_user_error("%d:%d got transaction to invalid handle, %u\n",
+						  proc->pid, thread->pid, tr->target.handle);
+				return_error = BR_FAILED_REPLY;
+			}
+			binder_proc_unlock(proc);
+		} else {
+			mutex_lock(&context->context_mgr_node_lock);
+			target_node = context->binder_context_mgr_node;
+			if (target_node)
+				target_node = binder_get_node_refs_for_txn(
+						target_node, &target_proc,
+						&return_error);
+			else
+				return_error = BR_DEAD_REPLY;
+			mutex_unlock(&context->context_mgr_node_lock);
+			if (target_node && target_proc->pid == proc->pid) {
+				binder_user_error("%d:%d got transaction to context manager from process owning it\n",
+						  proc->pid, thread->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = -EINVAL;
+				return_error_line = __LINE__;
+				goto err_invalid_target_handle;
+			}
+		}
+		if (!target_node) {
+			binder_txn_error("%d:%d cannot find target node\n",
+					 proc->pid, thread->pid);
+			/* return_error is set above */
+			return_error_param = -EINVAL;
+			return_error_line = __LINE__;
+			goto err_dead_binder;
+		}
+		e->to_node = target_node->debug_id;
+		if (WARN_ON(proc == target_proc)) {
+			binder_txn_error("%d:%d self transactions not allowed\n",
+				thread->pid, proc->pid);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EINVAL;
+			return_error_line = __LINE__;
+			goto err_invalid_target_handle;
+		}
+		if (security_binder_transaction(proc->cred,
+						target_proc->cred) < 0) {
+			binder_txn_error("%d:%d transaction credentials failed\n",
+				thread->pid, proc->pid);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EPERM;
+			return_error_line = __LINE__;
+			goto err_invalid_target_handle;
+		}
+		binder_inner_proc_lock(proc);
+
+		w = list_first_entry_or_null(&thread->todo,
+					     struct binder_work, entry);
+		if (!(tr->flags & TF_ONE_WAY) && w &&
+		    w->type == BINDER_WORK_TRANSACTION) {
+			/*
+			 * Do not allow new outgoing transaction from a
+			 * thread that has a transaction at the head of
+			 * its todo list. Only need to check the head
+			 * because binder_select_thread_ilocked picks a
+			 * thread from proc->waiting_threads to enqueue
+			 * the transaction, and nothing is queued to the
+			 * todo list while the thread is on waiting_threads.
+			 */
+			binder_user_error("%d:%d new transaction not allowed when there is a transaction on thread todo\n",
+					  proc->pid, thread->pid);
+			binder_inner_proc_unlock(proc);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EPROTO;
+			return_error_line = __LINE__;
+			goto err_bad_todo_list;
+		}
+
+		if (!(tr->flags & TF_ONE_WAY) && thread->transaction_stack) {
+			struct binder_transaction *tmp;
+
+			tmp = thread->transaction_stack;
+			if (tmp->to_thread != thread) {
+				spin_lock(&tmp->lock);
+				binder_user_error("%d:%d got new transaction with bad transaction stack, transaction %d has target %d:%d\n",
+					proc->pid, thread->pid, tmp->debug_id,
+					tmp->to_proc ? tmp->to_proc->pid : 0,
+					tmp->to_thread ?
+					tmp->to_thread->pid : 0);
+				spin_unlock(&tmp->lock);
+				binder_inner_proc_unlock(proc);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = -EPROTO;
+				return_error_line = __LINE__;
+				goto err_bad_call_stack;
+			}
+			while (tmp) {
+				struct binder_thread *from;
+
+				spin_lock(&tmp->lock);
+				from = tmp->from;
+				if (from && from->proc == target_proc) {
+					atomic_inc(&from->tmp_ref);
+					target_thread = from;
+					spin_unlock(&tmp->lock);
+					break;
+				}
+				spin_unlock(&tmp->lock);
+				tmp = tmp->from_parent;
+			}
+		}
+		binder_inner_proc_unlock(proc);
+	}
+
+	t->to_proc = target_proc;
+	t->to_thread = target_thread;
+	if (target_thread)
+		e->to_thread = target_thread->pid;
+	e->to_proc = target_proc->pid;
+
+	tcomplete = kzalloc_obj(*tcomplete);
+	if (tcomplete == NULL) {
+		binder_txn_error("%d:%d cannot allocate work for transaction\n",
+			thread->pid, proc->pid);
+		return_error = BR_FAILED_REPLY;
+		return_error_param = -ENOMEM;
+		return_error_line = __LINE__;
+		goto err_alloc_tcomplete_failed;
+	}
+	binder_stats_created(BINDER_STAT_TRANSACTION_COMPLETE);
+
+	if (reply)
+		binder_debug(BINDER_DEBUG_TRANSACTION,
+			     "%d:%d BC_REPLY %d -> %d:%d, data size %lld-%lld-%lld\n",
+			     proc->pid, thread->pid, t->debug_id,
+			     target_proc->pid, target_thread->pid,
+			     (u64)tr->data_size, (u64)tr->offsets_size,
+			     (u64)extra_buffers_size);
+	else
+		binder_debug(BINDER_DEBUG_TRANSACTION,
+			     "%d:%d BC_TRANSACTION %d -> %d - node %d, data size %lld-%lld-%lld\n",
+			     proc->pid, thread->pid, t->debug_id,
+			     target_proc->pid, target_node->debug_id,
+			     (u64)tr->data_size, (u64)tr->offsets_size,
+			     (u64)extra_buffers_size);
+
+	if (target_node && target_node->txn_security_ctx) {
+		u32 secid;
+
+		security_cred_getsecid(proc->cred, &secid);
+		ret = security_secid_to_secctx(secid, &lsmctx);
+		if (ret < 0) {
+			binder_txn_error("%d:%d failed to get security context\n",
+				thread->pid, proc->pid);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = ret;
+			return_error_line = __LINE__;
+			goto err_get_secctx_failed;
+		}
+		lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64));
+		extra_buffers_size += lsmctx_aligned_size;
+		if (extra_buffers_size < lsmctx_aligned_size) {
+			binder_txn_error("%d:%d integer overflow of extra_buffers_size\n",
+				thread->pid, proc->pid);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EINVAL;
+			return_error_line = __LINE__;
+			goto err_bad_extra_size;
+		}
+	}
+
+	trace_binder_transaction(reply, t, target_node);
+
+	t->buffer = binder_alloc_new_buf(&target_proc->alloc, tr->data_size,
+		tr->offsets_size, extra_buffers_size,
+		!reply && (t->flags & TF_ONE_WAY));
+	if (IS_ERR(t->buffer)) {
+		char *s;
+
+		ret = PTR_ERR(t->buffer);
+		s = (ret == -ESRCH) ? ": vma cleared, target dead or dying"
+			: (ret == -ENOSPC) ? ": no space left"
+			: (ret == -ENOMEM) ? ": memory allocation failed"
+			: "";
+		binder_txn_error("cannot allocate buffer%s", s);
+
+		return_error_param = PTR_ERR(t->buffer);
+		return_error = return_error_param == -ESRCH ?
+			BR_DEAD_REPLY : BR_FAILED_REPLY;
+		return_error_line = __LINE__;
+		t->buffer = NULL;
+		goto err_binder_alloc_buf_failed;
+	}
+	if (lsmctx.context) {
+		int err;
+		size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
+				    ALIGN(tr->offsets_size, sizeof(void *)) +
+				    ALIGN(extra_buffers_size, sizeof(void *)) -
+				    lsmctx_aligned_size;
+
+		t->security_ctx = t->buffer->user_data + buf_offset;
+		err = binder_alloc_copy_to_buffer(&target_proc->alloc,
+						  t->buffer, buf_offset,
+						  lsmctx.context, lsmctx.len);
+		if (err) {
+			t->security_ctx = 0;
+			WARN_ON(1);
+		}
+		security_release_secctx(&lsmctx);
+		lsmctx.context = NULL;
+	}
+	t->buffer->debug_id = t->debug_id;
+	t->buffer->transaction = t;
+	t->buffer->target_node = target_node;
+	t->buffer->clear_on_free = !!(t->flags & TF_CLEAR_BUF);
+	trace_binder_transaction_alloc_buf(t->buffer);
+
+	if (binder_alloc_copy_user_to_buffer(
+				&target_proc->alloc,
+				t->buffer,
+				ALIGN(tr->data_size, sizeof(void *)),
+				(const void __user *)
+					(uintptr_t)tr->data.ptr.offsets,
+				tr->offsets_size)) {
+		binder_user_error("%d:%d got transaction with invalid offsets ptr\n",
+				proc->pid, thread->pid);
+		return_error = BR_FAILED_REPLY;
+		return_error_param = -EFAULT;
+		return_error_line = __LINE__;
+		goto err_copy_data_failed;
+	}
+	if (!IS_ALIGNED(tr->offsets_size, sizeof(binder_size_t))) {
+		binder_user_error("%d:%d got transaction with invalid offsets size, %lld\n",
+				proc->pid, thread->pid, (u64)tr->offsets_size);
+		return_error = BR_FAILED_REPLY;
+		return_error_param = -EINVAL;
+		return_error_line = __LINE__;
+		goto err_bad_offset;
+	}
+	if (!IS_ALIGNED(extra_buffers_size, sizeof(u64))) {
+		binder_user_error("%d:%d got transaction with unaligned buffers size, %lld\n",
+				  proc->pid, thread->pid,
+				  (u64)extra_buffers_size);
+		return_error = BR_FAILED_REPLY;
+		return_error_param = -EINVAL;
+		return_error_line = __LINE__;
+		goto err_bad_offset;
+	}
+	off_start_offset = ALIGN(tr->data_size, sizeof(void *));
+	buffer_offset = off_start_offset;
+	off_end_offset = off_start_offset + tr->offsets_size;
+	sg_buf_offset = ALIGN(off_end_offset, sizeof(void *));
+	sg_buf_end_offset = sg_buf_offset + extra_buffers_size -
+		lsmctx_aligned_size;
+	off_min = 0;
+	for (buffer_offset = off_start_offset; buffer_offset < off_end_offset;
+	     buffer_offset += sizeof(binder_size_t)) {
+		struct binder_object_header *hdr;
+		size_t object_size;
+		struct binder_object object;
+		binder_size_t object_offset;
+		binder_size_t copy_size;
+
+		if (binder_alloc_copy_from_buffer(&target_proc->alloc,
+						  &object_offset,
+						  t->buffer,
+						  buffer_offset,
+						  sizeof(object_offset))) {
+			binder_txn_error("%d:%d copy offset from buffer failed\n",
+				thread->pid, proc->pid);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EINVAL;
+			return_error_line = __LINE__;
+			goto err_bad_offset;
+		}
+
+		/*
+		 * Copy the source user buffer up to the next object
+		 * that will be processed.
+		 */
+		copy_size = object_offset - user_offset;
+		if (copy_size && (user_offset > object_offset ||
+				object_offset > tr->data_size ||
+				binder_alloc_copy_user_to_buffer(
+					&target_proc->alloc,
+					t->buffer, user_offset,
+					user_buffer + user_offset,
+					copy_size))) {
+			binder_user_error("%d:%d got transaction with invalid data ptr\n",
+					proc->pid, thread->pid);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EFAULT;
+			return_error_line = __LINE__;
+			goto err_copy_data_failed;
+		}
+		object_size = binder_get_object(target_proc, user_buffer,
+				t->buffer, object_offset, &object);
+		if (object_size == 0 || object_offset < off_min) {
+			binder_user_error("%d:%d got transaction with invalid offset (%lld, min %lld max %lld) or object.\n",
+					  proc->pid, thread->pid,
+					  (u64)object_offset,
+					  (u64)off_min,
+					  (u64)t->buffer->data_size);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EINVAL;
+			return_error_line = __LINE__;
+			goto err_bad_offset;
+		}
+		/*
+		 * Set offset to the next buffer fragment to be
+		 * copied
+		 */
+		user_offset = object_offset + object_size;
+
+		hdr = &object.hdr;
+		off_min = object_offset + object_size;
+		switch (hdr->type) {
+		case BINDER_TYPE_BINDER:
+		case BINDER_TYPE_WEAK_BINDER: {
+			struct flat_binder_object *fp;
+
+			fp = to_flat_binder_object(hdr);
+			ret = binder_translate_binder(fp, t, thread);
+
+			if (ret < 0 ||
+			    binder_alloc_copy_to_buffer(&target_proc->alloc,
+							t->buffer,
+							object_offset,
+							fp, sizeof(*fp))) {
+				binder_txn_error("%d:%d translate binder failed\n",
+					thread->pid, proc->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = ret;
+				return_error_line = __LINE__;
+				goto err_translate_failed;
+			}
+		} break;
+		case BINDER_TYPE_HANDLE:
+		case BINDER_TYPE_WEAK_HANDLE: {
+			struct flat_binder_object *fp;
+
+			fp = to_flat_binder_object(hdr);
+			ret = binder_translate_handle(fp, t, thread);
+			if (ret < 0 ||
+			    binder_alloc_copy_to_buffer(&target_proc->alloc,
+							t->buffer,
+							object_offset,
+							fp, sizeof(*fp))) {
+				binder_txn_error("%d:%d translate handle failed\n",
+					thread->pid, proc->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = ret;
+				return_error_line = __LINE__;
+				goto err_translate_failed;
+			}
+		} break;
+
+		case BINDER_TYPE_FD: {
+			struct binder_fd_object *fp = to_binder_fd_object(hdr);
+			binder_size_t fd_offset = object_offset +
+				(uintptr_t)&fp->fd - (uintptr_t)fp;
+			int ret = binder_translate_fd(fp->fd, fd_offset, t,
+						      thread, in_reply_to);
+
+			fp->pad_binder = 0;
+			if (ret < 0 ||
+			    binder_alloc_copy_to_buffer(&target_proc->alloc,
+							t->buffer,
+							object_offset,
+							fp, sizeof(*fp))) {
+				binder_txn_error("%d:%d translate fd failed\n",
+					thread->pid, proc->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = ret;
+				return_error_line = __LINE__;
+				goto err_translate_failed;
+			}
+		} break;
+		case BINDER_TYPE_FDA: {
+			struct binder_object ptr_object;
+			binder_size_t parent_offset;
+			struct binder_object user_object;
+			size_t user_parent_size;
+			struct binder_fd_array_object *fda =
+				to_binder_fd_array_object(hdr);
+			size_t num_valid = (buffer_offset - off_start_offset) /
+						sizeof(binder_size_t);
+			struct binder_buffer_object *parent =
+				binder_validate_ptr(target_proc, t->buffer,
+						    &ptr_object, fda->parent,
+						    off_start_offset,
+						    &parent_offset,
+						    num_valid);
+			if (!parent) {
+				binder_user_error("%d:%d got transaction with invalid parent offset or type\n",
+						  proc->pid, thread->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = -EINVAL;
+				return_error_line = __LINE__;
+				goto err_bad_parent;
+			}
+			if (!binder_validate_fixup(target_proc, t->buffer,
+						   off_start_offset,
+						   parent_offset,
+						   fda->parent_offset,
+						   last_fixup_obj_off,
+						   last_fixup_min_off)) {
+				binder_user_error("%d:%d got transaction with out-of-order buffer fixup\n",
+						  proc->pid, thread->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = -EINVAL;
+				return_error_line = __LINE__;
+				goto err_bad_parent;
+			}
+			/*
+			 * We need to read the user version of the parent
+			 * object to get the original user offset
+			 */
+			user_parent_size =
+				binder_get_object(proc, user_buffer, t->buffer,
+						  parent_offset, &user_object);
+			if (user_parent_size != sizeof(user_object.bbo)) {
+				binder_user_error("%d:%d invalid ptr object size: %zd vs %zd\n",
+						  proc->pid, thread->pid,
+						  user_parent_size,
+						  sizeof(user_object.bbo));
+				return_error = BR_FAILED_REPLY;
+				return_error_param = -EINVAL;
+				return_error_line = __LINE__;
+				goto err_bad_parent;
+			}
+			ret = binder_translate_fd_array(&pf_head, fda,
+							user_buffer, parent,
+							&user_object.bbo, t,
+							thread, in_reply_to);
+			if (!ret)
+				ret = binder_alloc_copy_to_buffer(&target_proc->alloc,
+								  t->buffer,
+								  object_offset,
+								  fda, sizeof(*fda));
+			if (ret) {
+				binder_txn_error("%d:%d translate fd array failed\n",
+					thread->pid, proc->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = ret > 0 ? -EINVAL : ret;
+				return_error_line = __LINE__;
+				goto err_translate_failed;
+			}
+			last_fixup_obj_off = parent_offset;
+			last_fixup_min_off =
+				fda->parent_offset + sizeof(u32) * fda->num_fds;
+		} break;
+		case BINDER_TYPE_PTR: {
+			struct binder_buffer_object *bp =
+				to_binder_buffer_object(hdr);
+			size_t buf_left = sg_buf_end_offset - sg_buf_offset;
+			size_t num_valid;
+
+			if (bp->length > buf_left) {
+				binder_user_error("%d:%d got transaction with too large buffer\n",
+						  proc->pid, thread->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = -EINVAL;
+				return_error_line = __LINE__;
+				goto err_bad_offset;
+			}
+			ret = binder_defer_copy(&sgc_head, sg_buf_offset,
+				(const void __user *)(uintptr_t)bp->buffer,
+				bp->length);
+			if (ret) {
+				binder_txn_error("%d:%d deferred copy failed\n",
+					thread->pid, proc->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = ret;
+				return_error_line = __LINE__;
+				goto err_translate_failed;
+			}
+			/* Fixup buffer pointer to target proc address space */
+			bp->buffer = t->buffer->user_data + sg_buf_offset;
+			sg_buf_offset += ALIGN(bp->length, sizeof(u64));
+
+			num_valid = (buffer_offset - off_start_offset) /
+					sizeof(binder_size_t);
+			ret = binder_fixup_parent(&pf_head, t,
+						  thread, bp,
+						  off_start_offset,
+						  num_valid,
+						  last_fixup_obj_off,
+						  last_fixup_min_off);
+			if (ret < 0 ||
+			    binder_alloc_copy_to_buffer(&target_proc->alloc,
+							t->buffer,
+							object_offset,
+							bp, sizeof(*bp))) {
+				binder_txn_error("%d:%d failed to fixup parent\n",
+					thread->pid, proc->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = ret;
+				return_error_line = __LINE__;
+				goto err_translate_failed;
+			}
+			last_fixup_obj_off = object_offset;
+			last_fixup_min_off = 0;
+		} break;
+		default:
+			binder_user_error("%d:%d got transaction with invalid object type, %x\n",
+				proc->pid, thread->pid, hdr->type);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EINVAL;
+			return_error_line = __LINE__;
+			goto err_bad_object_type;
+		}
+	}
+	/* Done processing objects, copy the rest of the buffer */
+	if (binder_alloc_copy_user_to_buffer(
+				&target_proc->alloc,
+				t->buffer, user_offset,
+				user_buffer + user_offset,
+				tr->data_size - user_offset)) {
+		binder_user_error("%d:%d got transaction with invalid data ptr\n",
+				proc->pid, thread->pid);
+		return_error = BR_FAILED_REPLY;
+		return_error_param = -EFAULT;
+		return_error_line = __LINE__;
+		goto err_copy_data_failed;
+	}
+
+	ret = binder_do_deferred_txn_copies(&target_proc->alloc, t->buffer,
+					    &sgc_head, &pf_head);
+	if (ret) {
+		binder_user_error("%d:%d got transaction with invalid offsets ptr\n",
+				  proc->pid, thread->pid);
+		return_error = BR_FAILED_REPLY;
+		return_error_param = ret;
+		return_error_line = __LINE__;
+		goto err_copy_data_failed;
+	}
+	if (t->buffer->oneway_spam_suspect) {
+		tcomplete->type = BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT;
+		binder_netlink_report(proc, t, tr->data_size,
+				      BR_ONEWAY_SPAM_SUSPECT);
+	} else {
+		tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE;
+	}
+
+	if (reply) {
+		binder_enqueue_thread_work(thread, tcomplete);
+		binder_inner_proc_lock(target_proc);
+		if (target_thread->is_dead) {
+			return_error = BR_DEAD_REPLY;
+			binder_inner_proc_unlock(target_proc);
+			goto err_dead_proc_or_thread;
+		}
+		BUG_ON(t->buffer->async_transaction != 0);
+		binder_pop_transaction_ilocked(target_thread, in_reply_to);
+		binder_enqueue_thread_work_ilocked(target_thread, &t->work);
+		target_proc->outstanding_txns++;
+		binder_inner_proc_unlock(target_proc);
+		wake_up_interruptible_sync(&target_thread->wait);
+		binder_free_transaction(in_reply_to);
+	} else if (!(t->flags & TF_ONE_WAY)) {
+		BUG_ON(t->buffer->async_transaction != 0);
+		binder_inner_proc_lock(proc);
+		/*
+		 * Defer the TRANSACTION_COMPLETE, so we don't return to
+		 * userspace immediately; this allows the target process to
+		 * immediately start processing this transaction, reducing
+		 * latency. We will then return the TRANSACTION_COMPLETE when
+		 * the target replies (or there is an error).
+		 */
+		binder_enqueue_deferred_thread_work_ilocked(thread, tcomplete);
+		t->from_parent = thread->transaction_stack;
+		thread->transaction_stack = t;
+		binder_inner_proc_unlock(proc);
+		return_error = binder_proc_transaction(t,
+				target_proc, target_thread);
+		if (return_error) {
+			binder_inner_proc_lock(proc);
+			binder_pop_transaction_ilocked(thread, t);
+			binder_inner_proc_unlock(proc);
+			goto err_dead_proc_or_thread;
+		}
+	} else {
+		/*
+		 * Make a transaction copy. It is not safe to access 't' after
+		 * binder_proc_transaction() reported a pending frozen. The
+		 * target could thaw and consume the transaction at any point.
+		 * Instead, use a safe 't_copy' for binder_netlink_report().
+		 */
+		struct binder_transaction t_copy = *t;
+
+		BUG_ON(target_node == NULL);
+		BUG_ON(t->buffer->async_transaction != 1);
+		return_error = binder_proc_transaction(t, target_proc, NULL);
+		/*
+		 * Let the caller know when async transaction reaches a frozen
+		 * process and is put in a pending queue, waiting for the target
+		 * process to be unfrozen.
+		 */
+		if (return_error == BR_TRANSACTION_PENDING_FROZEN) {
+			tcomplete->type = BINDER_WORK_TRANSACTION_PENDING;
+			binder_netlink_report(proc, &t_copy, tr->data_size,
+					      return_error);
+		}
+		binder_enqueue_thread_work(thread, tcomplete);
+		if (return_error &&
+		    return_error != BR_TRANSACTION_PENDING_FROZEN)
+			goto err_dead_proc_or_thread;
+	}
+	if (target_thread)
+		binder_thread_dec_tmpref(target_thread);
+	binder_proc_dec_tmpref(target_proc);
+	if (target_node)
+		binder_dec_node_tmpref(target_node);
+	/*
+	 * write barrier to synchronize with initialization
+	 * of log entry
+	 */
+	smp_wmb();
+	WRITE_ONCE(e->debug_id_done, t_debug_id);
+	return;
+
+err_dead_proc_or_thread:
+	binder_txn_error("%d:%d %s process or thread\n",
+			 proc->pid, thread->pid,
+			 return_error == BR_FROZEN_REPLY ? "frozen" : "dead");
+	return_error_line = __LINE__;
+	binder_dequeue_work(proc, tcomplete);
+err_translate_failed:
+err_bad_object_type:
+err_bad_offset:
+err_bad_parent:
+err_copy_data_failed:
+	binder_cleanup_deferred_txn_lists(&sgc_head, &pf_head);
+	binder_free_txn_fixups(t);
+	trace_binder_transaction_failed_buffer_release(t->buffer);
+	binder_transaction_buffer_release(target_proc, NULL, t->buffer,
+					  buffer_offset, true);
+	if (target_node)
+		binder_dec_node_tmpref(target_node);
+	target_node = NULL;
+	t->buffer->transaction = NULL;
+	binder_alloc_free_buf(&target_proc->alloc, t->buffer);
+err_binder_alloc_buf_failed:
+err_bad_extra_size:
+	if (lsmctx.context)
+		security_release_secctx(&lsmctx);
+err_get_secctx_failed:
+	kfree(tcomplete);
+	binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
+err_alloc_tcomplete_failed:
+	if (trace_binder_txn_latency_free_enabled())
+		binder_txn_latency_free(t);
+err_bad_todo_list:
+err_bad_call_stack:
+err_empty_call_stack:
+err_dead_binder:
+err_invalid_target_handle:
+	if (target_node) {
+		binder_dec_node(target_node, 1, 0);
+		binder_dec_node_tmpref(target_node);
+	}
+
+	binder_netlink_report(proc, t, tr->data_size, return_error);
+	kfree(t);
+	binder_stats_deleted(BINDER_STAT_TRANSACTION);
+err_alloc_t_failed:
+
+	binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
+		     "%d:%d transaction %s to %d:%d failed %d/%d/%d, code %u size %lld-%lld line %d\n",
+		     proc->pid, thread->pid, reply ? "reply" :
+		     (tr->flags & TF_ONE_WAY ? "async" : "call"),
+		     target_proc ? target_proc->pid : 0,
+		     target_thread ? target_thread->pid : 0,
+		     t_debug_id, return_error, return_error_param,
+		     tr->code, (u64)tr->data_size, (u64)tr->offsets_size,
+		     return_error_line);
+
+	if (target_thread)
+		binder_thread_dec_tmpref(target_thread);
+	if (target_proc)
+		binder_proc_dec_tmpref(target_proc);
+
+	{
+		struct binder_transaction_log_entry *fe;
+
+		e->return_error = return_error;
+		e->return_error_param = return_error_param;
+		e->return_error_line = return_error_line;
+		fe = binder_transaction_log_add(&binder_transaction_log_failed);
+		*fe = *e;
+		/*
+		 * write barrier to synchronize with initialization
+		 * of log entry
+		 */
+		smp_wmb();
+		WRITE_ONCE(e->debug_id_done, t_debug_id);
+		WRITE_ONCE(fe->debug_id_done, t_debug_id);
+	}
+
+	BUG_ON(thread->return_error.cmd != BR_OK);
+	if (in_reply_to) {
+		binder_set_txn_from_error(in_reply_to, t_debug_id,
+				return_error, return_error_param);
+		thread->return_error.cmd = BR_TRANSACTION_COMPLETE;
+		binder_enqueue_thread_work(thread, &thread->return_error.work);
+		binder_send_failed_reply(in_reply_to, return_error);
+	} else {
+		binder_inner_proc_lock(proc);
+		binder_set_extended_error(&thread->ee, t_debug_id,
+				return_error, return_error_param);
+		binder_inner_proc_unlock(proc);
+		thread->return_error.cmd = return_error;
+		binder_enqueue_thread_work(thread, &thread->return_error.work);
+	}
+}
+
+static int
+binder_request_freeze_notification(struct binder_proc *proc,
+				   struct binder_thread *thread,
+				   struct binder_handle_cookie *handle_cookie)
+{
+	struct binder_ref_freeze *freeze;
+	struct binder_ref *ref;
+
+	freeze = kzalloc_obj(*freeze);
+	if (!freeze)
+		return -ENOMEM;
+	binder_proc_lock(proc);
+	ref = binder_get_ref_olocked(proc, handle_cookie->handle, false);
+	if (!ref) {
+		binder_user_error("%d:%d BC_REQUEST_FREEZE_NOTIFICATION invalid ref %d\n",
+				  proc->pid, thread->pid, handle_cookie->handle);
+		binder_proc_unlock(proc);
+		kfree(freeze);
+		return -EINVAL;
+	}
+
+	binder_node_lock(ref->node);
+	if (ref->freeze) {
+		binder_user_error("%d:%d BC_REQUEST_FREEZE_NOTIFICATION already set\n",
+				  proc->pid, thread->pid);
+		binder_node_unlock(ref->node);
+		binder_proc_unlock(proc);
+		kfree(freeze);
+		return -EINVAL;
+	}
+
+	binder_stats_created(BINDER_STAT_FREEZE);
+	INIT_LIST_HEAD(&freeze->work.entry);
+	freeze->cookie = handle_cookie->cookie;
+	freeze->work.type = BINDER_WORK_FROZEN_BINDER;
+	ref->freeze = freeze;
+
+	if (ref->node->proc) {
+		binder_inner_proc_lock(ref->node->proc);
+		freeze->is_frozen = ref->node->proc->is_frozen;
+		binder_inner_proc_unlock(ref->node->proc);
+
+		binder_inner_proc_lock(proc);
+		binder_enqueue_work_ilocked(&freeze->work, &proc->todo);
+		binder_wakeup_proc_ilocked(proc);
+		binder_inner_proc_unlock(proc);
+	}
+
+	binder_node_unlock(ref->node);
+	binder_proc_unlock(proc);
+	return 0;
+}
+
+static int
+binder_clear_freeze_notification(struct binder_proc *proc,
+				 struct binder_thread *thread,
+				 struct binder_handle_cookie *handle_cookie)
+{
+	struct binder_ref_freeze *freeze;
+	struct binder_ref *ref;
+
+	binder_proc_lock(proc);
+	ref = binder_get_ref_olocked(proc, handle_cookie->handle, false);
+	if (!ref) {
+		binder_user_error("%d:%d BC_CLEAR_FREEZE_NOTIFICATION invalid ref %d\n",
+				  proc->pid, thread->pid, handle_cookie->handle);
+		binder_proc_unlock(proc);
+		return -EINVAL;
+	}
+
+	binder_node_lock(ref->node);
+
+	if (!ref->freeze) {
+		binder_user_error("%d:%d BC_CLEAR_FREEZE_NOTIFICATION freeze notification not active\n",
+				  proc->pid, thread->pid);
+		binder_node_unlock(ref->node);
+		binder_proc_unlock(proc);
+		return -EINVAL;
+	}
+	freeze = ref->freeze;
+	binder_inner_proc_lock(proc);
+	if (freeze->cookie != handle_cookie->cookie) {
+		binder_user_error("%d:%d BC_CLEAR_FREEZE_NOTIFICATION freeze notification cookie mismatch %016llx != %016llx\n",
+				  proc->pid, thread->pid, (u64)freeze->cookie,
+				  (u64)handle_cookie->cookie);
+		binder_inner_proc_unlock(proc);
+		binder_node_unlock(ref->node);
+		binder_proc_unlock(proc);
+		return -EINVAL;
+	}
+	ref->freeze = NULL;
+	/*
+	 * Take the existing freeze object and overwrite its work type. There are three cases here:
+	 * 1. No pending notification. In this case just add the work to the queue.
+	 * 2. A notification was sent and is pending an ack from userspace. Once an ack arrives, we
+	 *    should resend with the new work type.
+	 * 3. A notification is pending to be sent. Since the work is already in the queue, nothing
+	 *    needs to be done here.
+	 */
+	freeze->work.type = BINDER_WORK_CLEAR_FREEZE_NOTIFICATION;
+	if (list_empty(&freeze->work.entry)) {
+		binder_enqueue_work_ilocked(&freeze->work, &proc->todo);
+		binder_wakeup_proc_ilocked(proc);
+	} else if (freeze->sent) {
+		freeze->resend = true;
+	}
+	binder_inner_proc_unlock(proc);
+	binder_node_unlock(ref->node);
+	binder_proc_unlock(proc);
+	return 0;
+}
+
+static int
+binder_freeze_notification_done(struct binder_proc *proc,
+				struct binder_thread *thread,
+				binder_uintptr_t cookie)
+{
+	struct binder_ref_freeze *freeze = NULL;
+	struct binder_work *w;
+
+	binder_inner_proc_lock(proc);
+	list_for_each_entry(w, &proc->delivered_freeze, entry) {
+		struct binder_ref_freeze *tmp_freeze =
+			container_of(w, struct binder_ref_freeze, work);
+
+		if (tmp_freeze->cookie == cookie) {
+			freeze = tmp_freeze;
+			break;
+		}
+	}
+	if (!freeze) {
+		binder_user_error("%d:%d BC_FREEZE_NOTIFICATION_DONE %016llx not found\n",
+				  proc->pid, thread->pid, (u64)cookie);
+		binder_inner_proc_unlock(proc);
+		return -EINVAL;
+	}
+	binder_dequeue_work_ilocked(&freeze->work);
+	freeze->sent = false;
+	if (freeze->resend) {
+		freeze->resend = false;
+		binder_enqueue_work_ilocked(&freeze->work, &proc->todo);
+		binder_wakeup_proc_ilocked(proc);
+	}
+	binder_inner_proc_unlock(proc);
+	return 0;
+}
+
+/**
+ * binder_free_buf() - free the specified buffer
+ * @proc:       binder proc that owns buffer
+ * @thread:     binder thread performing the buffer release
+ * @buffer:     buffer to be freed
+ * @is_failure: failed to send transaction
+ *
+ * If the buffer is for an async transaction, enqueue the next async
+ * transaction from the node.
+ *
+ * Cleanup the buffer and free it.
+ */
+static void
+binder_free_buf(struct binder_proc *proc,
+		struct binder_thread *thread,
+		struct binder_buffer *buffer, bool is_failure)
+{
+	binder_inner_proc_lock(proc);
+	if (buffer->transaction) {
+		buffer->transaction->buffer = NULL;
+		buffer->transaction = NULL;
+	}
+	binder_inner_proc_unlock(proc);
+	if (buffer->async_transaction && buffer->target_node) {
+		struct binder_node *buf_node;
+		struct binder_work *w;
+
+		buf_node = buffer->target_node;
+		binder_node_inner_lock(buf_node);
+		BUG_ON(!buf_node->has_async_transaction);
+		BUG_ON(buf_node->proc != proc);
+		w = binder_dequeue_work_head_ilocked(
+				&buf_node->async_todo);
+		if (!w) {
+			buf_node->has_async_transaction = false;
+		} else {
+			binder_enqueue_work_ilocked(
+					w, &proc->todo);
+			binder_wakeup_proc_ilocked(proc);
+		}
+		binder_node_inner_unlock(buf_node);
+	}
+	trace_binder_transaction_buffer_release(buffer);
+	binder_release_entire_buffer(proc, thread, buffer, is_failure);
+	binder_alloc_free_buf(&proc->alloc, buffer);
+}
+
+static int binder_thread_write(struct binder_proc *proc,
+			struct binder_thread *thread,
+			binder_uintptr_t binder_buffer, size_t size,
+			binder_size_t *consumed)
+{
+	uint32_t cmd;
+	struct binder_context *context = proc->context;
+	void __user *buffer = (void __user *)(uintptr_t)binder_buffer;
+	void __user *ptr = buffer + *consumed;
+	void __user *end = buffer + size;
+
+	while (ptr < end && thread->return_error.cmd == BR_OK) {
+		int ret;
+
+		if (get_user(cmd, (uint32_t __user *)ptr))
+			return -EFAULT;
+		ptr += sizeof(uint32_t);
+		trace_binder_command(cmd);
+		if (_IOC_NR(cmd) < ARRAY_SIZE(binder_stats.bc)) {
+			atomic_inc(&binder_stats.bc[_IOC_NR(cmd)]);
+			atomic_inc(&proc->stats.bc[_IOC_NR(cmd)]);
+			atomic_inc(&thread->stats.bc[_IOC_NR(cmd)]);
+		}
+		switch (cmd) {
+		case BC_INCREFS:
+		case BC_ACQUIRE:
+		case BC_RELEASE:
+		case BC_DECREFS: {
+			uint32_t target;
+			const char *debug_string;
+			bool strong = cmd == BC_ACQUIRE || cmd == BC_RELEASE;
+			bool increment = cmd == BC_INCREFS || cmd == BC_ACQUIRE;
+			struct binder_ref_data rdata;
+
+			if (get_user(target, (uint32_t __user *)ptr))
+				return -EFAULT;
+
+			ptr += sizeof(uint32_t);
+			ret = -1;
+			if (increment && !target) {
+				struct binder_node *ctx_mgr_node;
+
+				mutex_lock(&context->context_mgr_node_lock);
+				ctx_mgr_node = context->binder_context_mgr_node;
+				if (ctx_mgr_node) {
+					if (ctx_mgr_node->proc == proc) {
+						binder_user_error("%d:%d context manager tried to acquire desc 0\n",
+								  proc->pid, thread->pid);
+						mutex_unlock(&context->context_mgr_node_lock);
+						return -EINVAL;
+					}
+					ret = binder_inc_ref_for_node(
+							proc, ctx_mgr_node,
+							strong, NULL, &rdata);
+				}
+				mutex_unlock(&context->context_mgr_node_lock);
+			}
+			if (ret)
+				ret = binder_update_ref_for_handle(
+						proc, target, increment, strong,
+						&rdata);
+			if (!ret && rdata.desc != target) {
+				binder_user_error("%d:%d tried to acquire reference to desc %d, got %d instead\n",
+					proc->pid, thread->pid,
+					target, rdata.desc);
+			}
+			switch (cmd) {
+			case BC_INCREFS:
+				debug_string = "IncRefs";
+				break;
+			case BC_ACQUIRE:
+				debug_string = "Acquire";
+				break;
+			case BC_RELEASE:
+				debug_string = "Release";
+				break;
+			case BC_DECREFS:
+			default:
+				debug_string = "DecRefs";
+				break;
+			}
+			if (ret) {
+				binder_user_error("%d:%d %s %d refcount change on invalid ref %d ret %d\n",
+					proc->pid, thread->pid, debug_string,
+					strong, target, ret);
+				break;
+			}
+			binder_debug(BINDER_DEBUG_USER_REFS,
+				     "%d:%d %s ref %d desc %d s %d w %d\n",
+				     proc->pid, thread->pid, debug_string,
+				     rdata.debug_id, rdata.desc, rdata.strong,
+				     rdata.weak);
+			break;
+		}
+		case BC_INCREFS_DONE:
+		case BC_ACQUIRE_DONE: {
+			binder_uintptr_t node_ptr;
+			binder_uintptr_t cookie;
+			struct binder_node *node;
+			bool free_node;
+
+			if (get_user(node_ptr, (binder_uintptr_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(binder_uintptr_t);
+			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(binder_uintptr_t);
+			node = binder_get_node(proc, node_ptr);
+			if (node == NULL) {
+				binder_user_error("%d:%d %s u%016llx no match\n",
+					proc->pid, thread->pid,
+					cmd == BC_INCREFS_DONE ?
+					"BC_INCREFS_DONE" :
+					"BC_ACQUIRE_DONE",
+					(u64)node_ptr);
+				break;
+			}
+			if (cookie != node->cookie) {
+				binder_user_error("%d:%d %s u%016llx node %d cookie mismatch %016llx != %016llx\n",
+					proc->pid, thread->pid,
+					cmd == BC_INCREFS_DONE ?
+					"BC_INCREFS_DONE" : "BC_ACQUIRE_DONE",
+					(u64)node_ptr, node->debug_id,
+					(u64)cookie, (u64)node->cookie);
+				binder_put_node(node);
+				break;
+			}
+			binder_node_inner_lock(node);
+			if (cmd == BC_ACQUIRE_DONE) {
+				if (node->pending_strong_ref == 0) {
+					binder_user_error("%d:%d BC_ACQUIRE_DONE node %d has no pending acquire request\n",
+						proc->pid, thread->pid,
+						node->debug_id);
+					binder_node_inner_unlock(node);
+					binder_put_node(node);
+					break;
+				}
+				node->pending_strong_ref = 0;
+			} else {
+				if (node->pending_weak_ref == 0) {
+					binder_user_error("%d:%d BC_INCREFS_DONE node %d has no pending increfs request\n",
+						proc->pid, thread->pid,
+						node->debug_id);
+					binder_node_inner_unlock(node);
+					binder_put_node(node);
+					break;
+				}
+				node->pending_weak_ref = 0;
+			}
+			free_node = binder_dec_node_nilocked(node,
+					cmd == BC_ACQUIRE_DONE, 0);
+			WARN_ON(free_node);
+			binder_debug(BINDER_DEBUG_USER_REFS,
+				     "%d:%d %s node %d ls %d lw %d tr %d\n",
+				     proc->pid, thread->pid,
+				     cmd == BC_INCREFS_DONE ? "BC_INCREFS_DONE" : "BC_ACQUIRE_DONE",
+				     node->debug_id, node->local_strong_refs,
+				     node->local_weak_refs, node->tmp_refs);
+			binder_node_inner_unlock(node);
+			binder_put_node(node);
+			break;
+		}
+		case BC_ATTEMPT_ACQUIRE:
+			pr_err("BC_ATTEMPT_ACQUIRE not supported\n");
+			return -EINVAL;
+		case BC_ACQUIRE_RESULT:
+			pr_err("BC_ACQUIRE_RESULT not supported\n");
+			return -EINVAL;
+
+		case BC_FREE_BUFFER: {
+			binder_uintptr_t data_ptr;
+			struct binder_buffer *buffer;
+
+			if (get_user(data_ptr, (binder_uintptr_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(binder_uintptr_t);
+
+			buffer = binder_alloc_prepare_to_free(&proc->alloc,
+							      data_ptr);
+			if (IS_ERR_OR_NULL(buffer)) {
+				if (PTR_ERR(buffer) == -EPERM) {
+					binder_user_error(
+						"%d:%d BC_FREE_BUFFER matched unreturned or currently freeing buffer at offset %lx\n",
+						proc->pid, thread->pid,
+						(unsigned long)data_ptr - proc->alloc.vm_start);
+				} else {
+					binder_user_error(
+						"%d:%d BC_FREE_BUFFER no match for buffer at offset %lx\n",
+						proc->pid, thread->pid,
+						(unsigned long)data_ptr - proc->alloc.vm_start);
+				}
+				break;
+			}
+			binder_debug(BINDER_DEBUG_FREE_BUFFER,
+				     "%d:%d BC_FREE_BUFFER at offset %lx found buffer %d for %s transaction\n",
+				     proc->pid, thread->pid,
+				     (unsigned long)data_ptr - proc->alloc.vm_start,
+				     buffer->debug_id,
+				     buffer->transaction ? "active" : "finished");
+			binder_free_buf(proc, thread, buffer, false);
+			break;
+		}
+
+		case BC_TRANSACTION_SG:
+		case BC_REPLY_SG: {
+			struct binder_transaction_data_sg tr;
+
+			if (copy_from_user(&tr, ptr, sizeof(tr)))
+				return -EFAULT;
+			ptr += sizeof(tr);
+			binder_transaction(proc, thread, &tr.transaction_data,
+					   cmd == BC_REPLY_SG, tr.buffers_size);
+			break;
+		}
+		case BC_TRANSACTION:
+		case BC_REPLY: {
+			struct binder_transaction_data tr;
+
+			if (copy_from_user(&tr, ptr, sizeof(tr)))
+				return -EFAULT;
+			ptr += sizeof(tr);
+			binder_transaction(proc, thread, &tr,
+					   cmd == BC_REPLY, 0);
+			break;
+		}
+
+		case BC_REGISTER_LOOPER:
+			binder_debug(BINDER_DEBUG_THREADS,
+				     "%d:%d BC_REGISTER_LOOPER\n",
+				     proc->pid, thread->pid);
+			binder_inner_proc_lock(proc);
+			if (thread->looper & BINDER_LOOPER_STATE_ENTERED) {
+				thread->looper |= BINDER_LOOPER_STATE_INVALID;
+				binder_user_error("%d:%d ERROR: BC_REGISTER_LOOPER called after BC_ENTER_LOOPER\n",
+					proc->pid, thread->pid);
+			} else if (proc->requested_threads == 0) {
+				thread->looper |= BINDER_LOOPER_STATE_INVALID;
+				binder_user_error("%d:%d ERROR: BC_REGISTER_LOOPER called without request\n",
+					proc->pid, thread->pid);
+			} else {
+				proc->requested_threads--;
+				proc->requested_threads_started++;
+			}
+			thread->looper |= BINDER_LOOPER_STATE_REGISTERED;
+			binder_inner_proc_unlock(proc);
+			break;
+		case BC_ENTER_LOOPER:
+			binder_debug(BINDER_DEBUG_THREADS,
+				     "%d:%d BC_ENTER_LOOPER\n",
+				     proc->pid, thread->pid);
+			if (thread->looper & BINDER_LOOPER_STATE_REGISTERED) {
+				thread->looper |= BINDER_LOOPER_STATE_INVALID;
+				binder_user_error("%d:%d ERROR: BC_ENTER_LOOPER called after BC_REGISTER_LOOPER\n",
+					proc->pid, thread->pid);
+			}
+			thread->looper |= BINDER_LOOPER_STATE_ENTERED;
+			break;
+		case BC_EXIT_LOOPER:
+			binder_debug(BINDER_DEBUG_THREADS,
+				     "%d:%d BC_EXIT_LOOPER\n",
+				     proc->pid, thread->pid);
+			thread->looper |= BINDER_LOOPER_STATE_EXITED;
+			break;
+
+		case BC_REQUEST_DEATH_NOTIFICATION:
+		case BC_CLEAR_DEATH_NOTIFICATION: {
+			uint32_t target;
+			binder_uintptr_t cookie;
+			struct binder_ref *ref;
+			struct binder_ref_death *death = NULL;
+
+			if (get_user(target, (uint32_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(uint32_t);
+			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(binder_uintptr_t);
+			if (cmd == BC_REQUEST_DEATH_NOTIFICATION) {
+				/*
+				 * Allocate memory for death notification
+				 * before taking lock
+				 */
+				death = kzalloc_obj(*death);
+				if (death == NULL) {
+					WARN_ON(thread->return_error.cmd !=
+						BR_OK);
+					thread->return_error.cmd = BR_ERROR;
+					binder_enqueue_thread_work(
+						thread,
+						&thread->return_error.work);
+					binder_debug(
+						BINDER_DEBUG_FAILED_TRANSACTION,
+						"%d:%d BC_REQUEST_DEATH_NOTIFICATION failed\n",
+						proc->pid, thread->pid);
+					break;
+				}
+			}
+			binder_proc_lock(proc);
+			ref = binder_get_ref_olocked(proc, target, false);
+			if (ref == NULL) {
+				binder_user_error("%d:%d %s invalid ref %d\n",
+					proc->pid, thread->pid,
+					cmd == BC_REQUEST_DEATH_NOTIFICATION ?
+					"BC_REQUEST_DEATH_NOTIFICATION" :
+					"BC_CLEAR_DEATH_NOTIFICATION",
+					target);
+				binder_proc_unlock(proc);
+				kfree(death);
+				break;
+			}
+
+			binder_debug(BINDER_DEBUG_DEATH_NOTIFICATION,
+				     "%d:%d %s %016llx ref %d desc %d s %d w %d for node %d\n",
+				     proc->pid, thread->pid,
+				     cmd == BC_REQUEST_DEATH_NOTIFICATION ?
+				     "BC_REQUEST_DEATH_NOTIFICATION" :
+				     "BC_CLEAR_DEATH_NOTIFICATION",
+				     (u64)cookie, ref->data.debug_id,
+				     ref->data.desc, ref->data.strong,
+				     ref->data.weak, ref->node->debug_id);
+
+			binder_node_lock(ref->node);
+			if (cmd == BC_REQUEST_DEATH_NOTIFICATION) {
+				if (ref->death) {
+					binder_user_error("%d:%d BC_REQUEST_DEATH_NOTIFICATION death notification already set\n",
+						proc->pid, thread->pid);
+					binder_node_unlock(ref->node);
+					binder_proc_unlock(proc);
+					kfree(death);
+					break;
+				}
+				binder_stats_created(BINDER_STAT_DEATH);
+				INIT_LIST_HEAD(&death->work.entry);
+				death->cookie = cookie;
+				ref->death = death;
+				if (ref->node->proc == NULL) {
+					ref->death->work.type = BINDER_WORK_DEAD_BINDER;
+
+					binder_inner_proc_lock(proc);
+					binder_enqueue_work_ilocked(
+						&ref->death->work, &proc->todo);
+					binder_wakeup_proc_ilocked(proc);
+					binder_inner_proc_unlock(proc);
+				}
+			} else {
+				if (ref->death == NULL) {
+					binder_user_error("%d:%d BC_CLEAR_DEATH_NOTIFICATION death notification not active\n",
+						proc->pid, thread->pid);
+					binder_node_unlock(ref->node);
+					binder_proc_unlock(proc);
+					break;
+				}
+				death = ref->death;
+				if (death->cookie != cookie) {
+					binder_user_error("%d:%d BC_CLEAR_DEATH_NOTIFICATION death notification cookie mismatch %016llx != %016llx\n",
+						proc->pid, thread->pid,
+						(u64)death->cookie,
+						(u64)cookie);
+					binder_node_unlock(ref->node);
+					binder_proc_unlock(proc);
+					break;
+				}
+				ref->death = NULL;
+				binder_inner_proc_lock(proc);
+				if (list_empty(&death->work.entry)) {
+					death->work.type = BINDER_WORK_CLEAR_DEATH_NOTIFICATION;
+					if (thread->looper &
+					    (BINDER_LOOPER_STATE_REGISTERED |
+					     BINDER_LOOPER_STATE_ENTERED))
+						binder_enqueue_thread_work_ilocked(
+								thread,
+								&death->work);
+					else {
+						binder_enqueue_work_ilocked(
+								&death->work,
+								&proc->todo);
+						binder_wakeup_proc_ilocked(
+								proc);
+					}
+				} else {
+					BUG_ON(death->work.type != BINDER_WORK_DEAD_BINDER);
+					death->work.type = BINDER_WORK_DEAD_BINDER_AND_CLEAR;
+				}
+				binder_inner_proc_unlock(proc);
+			}
+			binder_node_unlock(ref->node);
+			binder_proc_unlock(proc);
+		} break;
+		case BC_DEAD_BINDER_DONE: {
+			struct binder_work *w;
+			binder_uintptr_t cookie;
+			struct binder_ref_death *death = NULL;
+
+			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
+				return -EFAULT;
+
+			ptr += sizeof(cookie);
+			binder_inner_proc_lock(proc);
+			list_for_each_entry(w, &proc->delivered_death,
+					    entry) {
+				struct binder_ref_death *tmp_death =
+					container_of(w,
+						     struct binder_ref_death,
+						     work);
+
+				if (tmp_death->cookie == cookie) {
+					death = tmp_death;
+					break;
+				}
+			}
+			binder_debug(BINDER_DEBUG_DEAD_BINDER,
+				     "%d:%d BC_DEAD_BINDER_DONE %016llx found %p\n",
+				     proc->pid, thread->pid, (u64)cookie,
+				     death);
+			if (death == NULL) {
+				binder_user_error("%d:%d BC_DEAD_BINDER_DONE %016llx not found\n",
+					proc->pid, thread->pid, (u64)cookie);
+				binder_inner_proc_unlock(proc);
+				break;
+			}
+			binder_dequeue_work_ilocked(&death->work);
+			if (death->work.type == BINDER_WORK_DEAD_BINDER_AND_CLEAR) {
+				death->work.type = BINDER_WORK_CLEAR_DEATH_NOTIFICATION;
+				if (thread->looper &
+					(BINDER_LOOPER_STATE_REGISTERED |
+					 BINDER_LOOPER_STATE_ENTERED))
+					binder_enqueue_thread_work_ilocked(
+						thread, &death->work);
+				else {
+					binder_enqueue_work_ilocked(
+							&death->work,
+							&proc->todo);
+					binder_wakeup_proc_ilocked(proc);
+				}
+			}
+			binder_inner_proc_unlock(proc);
+		} break;
+
+		case BC_REQUEST_FREEZE_NOTIFICATION: {
+			struct binder_handle_cookie handle_cookie;
+			int error;
+
+			if (copy_from_user(&handle_cookie, ptr, sizeof(handle_cookie)))
+				return -EFAULT;
+			ptr += sizeof(handle_cookie);
+			error = binder_request_freeze_notification(proc, thread,
+								   &handle_cookie);
+			if (error)
+				return error;
+		} break;
+
+		case BC_CLEAR_FREEZE_NOTIFICATION: {
+			struct binder_handle_cookie handle_cookie;
+			int error;
+
+			if (copy_from_user(&handle_cookie, ptr, sizeof(handle_cookie)))
+				return -EFAULT;
+			ptr += sizeof(handle_cookie);
+			error = binder_clear_freeze_notification(proc, thread, &handle_cookie);
+			if (error)
+				return error;
+		} break;
+
+		case BC_FREEZE_NOTIFICATION_DONE: {
+			binder_uintptr_t cookie;
+			int error;
+
+			if (get_user(cookie, (binder_uintptr_t __user *)ptr))
+				return -EFAULT;
+
+			ptr += sizeof(cookie);
+			error = binder_freeze_notification_done(proc, thread, cookie);
+			if (error)
+				return error;
+		} break;
+
+		default:
+			pr_err("%d:%d unknown command %u\n",
+			       proc->pid, thread->pid, cmd);
+			return -EINVAL;
+		}
+		*consumed = ptr - buffer;
+	}
+	return 0;
+}
+
+static void binder_stat_br(struct binder_proc *proc,
+			   struct binder_thread *thread, uint32_t cmd)
+{
+	trace_binder_return(cmd);
+	if (_IOC_NR(cmd) < ARRAY_SIZE(binder_stats.br)) {
+		atomic_inc(&binder_stats.br[_IOC_NR(cmd)]);
+		atomic_inc(&proc->stats.br[_IOC_NR(cmd)]);
+		atomic_inc(&thread->stats.br[_IOC_NR(cmd)]);
+	}
+}
+
+static int binder_put_node_cmd(struct binder_proc *proc,
+			       struct binder_thread *thread,
+			       void __user **ptrp,
+			       binder_uintptr_t node_ptr,
+			       binder_uintptr_t node_cookie,
+			       int node_debug_id,
+			       uint32_t cmd, const char *cmd_name)
+{
+	void __user *ptr = *ptrp;
+
+	if (put_user(cmd, (uint32_t __user *)ptr))
+		return -EFAULT;
+	ptr += sizeof(uint32_t);
+
+	if (put_user(node_ptr, (binder_uintptr_t __user *)ptr))
+		return -EFAULT;
+	ptr += sizeof(binder_uintptr_t);
+
+	if (put_user(node_cookie, (binder_uintptr_t __user *)ptr))
+		return -EFAULT;
+	ptr += sizeof(binder_uintptr_t);
+
+	binder_stat_br(proc, thread, cmd);
+	binder_debug(BINDER_DEBUG_USER_REFS, "%d:%d %s %d u%016llx c%016llx\n",
+		     proc->pid, thread->pid, cmd_name, node_debug_id,
+		     (u64)node_ptr, (u64)node_cookie);
+
+	*ptrp = ptr;
+	return 0;
+}
+
+static int binder_wait_for_work(struct binder_thread *thread,
+				bool do_proc_work)
+{
+	DEFINE_WAIT(wait);
+	struct binder_proc *proc = thread->proc;
+	int ret = 0;
+
+	binder_inner_proc_lock(proc);
+	for (;;) {
+		prepare_to_wait(&thread->wait, &wait, TASK_INTERRUPTIBLE|TASK_FREEZABLE);
+		if (binder_has_work_ilocked(thread, do_proc_work))
+			break;
+		if (do_proc_work)
+			list_add(&thread->waiting_thread_node,
+				 &proc->waiting_threads);
+		binder_inner_proc_unlock(proc);
+		schedule();
+		binder_inner_proc_lock(proc);
+		list_del_init(&thread->waiting_thread_node);
+		if (signal_pending(current)) {
+			ret = -EINTR;
+			break;
+		}
+	}
+	finish_wait(&thread->wait, &wait);
+	binder_inner_proc_unlock(proc);
+
+	return ret;
+}
+
+/**
+ * binder_apply_fd_fixups() - finish fd translation
+ * @proc:         binder_proc associated @t->buffer
+ * @t:	binder transaction with list of fd fixups
+ *
+ * Now that we are in the context of the transaction target
+ * process, we can allocate and install fds. Process the
+ * list of fds to translate and fixup the buffer with the
+ * new fds first and only then install the files.
+ *
+ * If we fail to allocate an fd, skip the install and release
+ * any fds that have already been allocated.
+ *
+ * Return: 0 on success, a negative errno code on failure.
+ */
+static int binder_apply_fd_fixups(struct binder_proc *proc,
+				  struct binder_transaction *t)
+{
+	struct binder_txn_fd_fixup *fixup, *tmp;
+	int ret = 0;
+
+	list_for_each_entry(fixup, &t->fd_fixups, fixup_entry) {
+		int fd = get_unused_fd_flags(O_CLOEXEC);
+
+		if (fd < 0) {
+			binder_debug(BINDER_DEBUG_TRANSACTION,
+				     "failed fd fixup txn %d fd %d\n",
+				     t->debug_id, fd);
+			ret = -ENOMEM;
+			goto err;
+		}
+		binder_debug(BINDER_DEBUG_TRANSACTION,
+			     "fd fixup txn %d fd %d\n",
+			     t->debug_id, fd);
+		trace_binder_transaction_fd_recv(t, fd, fixup->offset);
+		fixup->target_fd = fd;
+		if (binder_alloc_copy_to_buffer(&proc->alloc, t->buffer,
+						fixup->offset, &fd,
+						sizeof(u32))) {
+			ret = -EINVAL;
+			goto err;
+		}
+	}
+	list_for_each_entry_safe(fixup, tmp, &t->fd_fixups, fixup_entry) {
+		fd_install(fixup->target_fd, fixup->file);
+		list_del(&fixup->fixup_entry);
+		kfree(fixup);
+	}
+
+	return ret;
+
+err:
+	binder_free_txn_fixups(t);
+	return ret;
+}
+
+static int binder_thread_read(struct binder_proc *proc,
+			      struct binder_thread *thread,
+			      binder_uintptr_t binder_buffer, size_t size,
+			      binder_size_t *consumed, int non_block)
+{
+	void __user *buffer = (void __user *)(uintptr_t)binder_buffer;
+	void __user *ptr = buffer + *consumed;
+	void __user *end = buffer + size;
+
+	int ret = 0;
+	int wait_for_proc_work;
+
+	if (*consumed == 0) {
+		if (put_user(BR_NOOP, (uint32_t __user *)ptr))
+			return -EFAULT;
+		ptr += sizeof(uint32_t);
+	}
+
+retry:
+	binder_inner_proc_lock(proc);
+	wait_for_proc_work = binder_available_for_proc_work_ilocked(thread);
+	binder_inner_proc_unlock(proc);
+
+	thread->looper |= BINDER_LOOPER_STATE_WAITING;
+
+	trace_binder_wait_for_work(wait_for_proc_work,
+				   !!thread->transaction_stack,
+				   !binder_worklist_empty(proc, &thread->todo));
+	if (wait_for_proc_work) {
+		if (!(thread->looper & (BINDER_LOOPER_STATE_REGISTERED |
+					BINDER_LOOPER_STATE_ENTERED))) {
+			binder_user_error("%d:%d ERROR: Thread waiting for process work before calling BC_REGISTER_LOOPER or BC_ENTER_LOOPER (state %x)\n",
+				proc->pid, thread->pid, thread->looper);
+			wait_event_interruptible(binder_user_error_wait,
+						 binder_stop_on_user_error < 2);
+		}
+		binder_set_nice(proc->default_priority);
+	}
+
+	if (non_block) {
+		if (!binder_has_work(thread, wait_for_proc_work))
+			ret = -EAGAIN;
+	} else {
+		ret = binder_wait_for_work(thread, wait_for_proc_work);
+	}
+
+	thread->looper &= ~BINDER_LOOPER_STATE_WAITING;
+
+	if (ret)
+		return ret;
+
+	while (1) {
+		uint32_t cmd;
+		struct binder_transaction_data_secctx tr;
+		struct binder_transaction_data *trd = &tr.transaction_data;
+		struct binder_work *w = NULL;
+		struct list_head *list = NULL;
+		struct binder_transaction *t = NULL;
+		struct binder_thread *t_from;
+		size_t trsize = sizeof(*trd);
+
+		binder_inner_proc_lock(proc);
+		if (!binder_worklist_empty_ilocked(&thread->todo))
+			list = &thread->todo;
+		else if (!binder_worklist_empty_ilocked(&proc->todo) &&
+			   wait_for_proc_work)
+			list = &proc->todo;
+		else {
+			binder_inner_proc_unlock(proc);
+
+			/* no data added */
+			if (ptr - buffer == 4 && !thread->looper_need_return)
+				goto retry;
+			break;
+		}
+
+		if (end - ptr < sizeof(tr) + 4) {
+			binder_inner_proc_unlock(proc);
+			break;
+		}
+		w = binder_dequeue_work_head_ilocked(list);
+		if (binder_worklist_empty_ilocked(&thread->todo))
+			thread->process_todo = false;
+
+		switch (w->type) {
+		case BINDER_WORK_TRANSACTION: {
+			binder_inner_proc_unlock(proc);
+			t = container_of(w, struct binder_transaction, work);
+		} break;
+		case BINDER_WORK_RETURN_ERROR: {
+			struct binder_error *e = container_of(
+					w, struct binder_error, work);
+
+			WARN_ON(e->cmd == BR_OK);
+			binder_inner_proc_unlock(proc);
+			if (put_user(e->cmd, (uint32_t __user *)ptr))
+				return -EFAULT;
+			cmd = e->cmd;
+			e->cmd = BR_OK;
+			ptr += sizeof(uint32_t);
+
+			binder_stat_br(proc, thread, cmd);
+		} break;
+		case BINDER_WORK_TRANSACTION_COMPLETE:
+		case BINDER_WORK_TRANSACTION_PENDING:
+		case BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT: {
+			if (proc->oneway_spam_detection_enabled &&
+				   w->type == BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT)
+				cmd = BR_ONEWAY_SPAM_SUSPECT;
+			else if (w->type == BINDER_WORK_TRANSACTION_PENDING)
+				cmd = BR_TRANSACTION_PENDING_FROZEN;
+			else
+				cmd = BR_TRANSACTION_COMPLETE;
+			binder_inner_proc_unlock(proc);
+			kfree(w);
+			binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
+			if (put_user(cmd, (uint32_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(uint32_t);
+
+			binder_stat_br(proc, thread, cmd);
+			binder_debug(BINDER_DEBUG_TRANSACTION_COMPLETE,
+				     "%d:%d BR_TRANSACTION_COMPLETE\n",
+				     proc->pid, thread->pid);
+		} break;
+		case BINDER_WORK_NODE: {
+			struct binder_node *node = container_of(w, struct binder_node, work);
+			int strong, weak;
+			binder_uintptr_t node_ptr = node->ptr;
+			binder_uintptr_t node_cookie = node->cookie;
+			int node_debug_id = node->debug_id;
+			int has_weak_ref;
+			int has_strong_ref;
+			void __user *orig_ptr = ptr;
+
+			BUG_ON(proc != node->proc);
+			strong = node->internal_strong_refs ||
+					node->local_strong_refs;
+			weak = !hlist_empty(&node->refs) ||
+					node->local_weak_refs ||
+					node->tmp_refs || strong;
+			has_strong_ref = node->has_strong_ref;
+			has_weak_ref = node->has_weak_ref;
+
+			if (weak && !has_weak_ref) {
+				node->has_weak_ref = 1;
+				node->pending_weak_ref = 1;
+				node->local_weak_refs++;
+			}
+			if (strong && !has_strong_ref) {
+				node->has_strong_ref = 1;
+				node->pending_strong_ref = 1;
+				node->local_strong_refs++;
+			}
+			if (!strong && has_strong_ref)
+				node->has_strong_ref = 0;
+			if (!weak && has_weak_ref)
+				node->has_weak_ref = 0;
+			if (!weak && !strong) {
+				binder_debug(BINDER_DEBUG_INTERNAL_REFS,
+					     "%d:%d node %d u%016llx c%016llx deleted\n",
+					     proc->pid, thread->pid,
+					     node_debug_id,
+					     (u64)node_ptr,
+					     (u64)node_cookie);
+				rb_erase(&node->rb_node, &proc->nodes);
+				binder_inner_proc_unlock(proc);
+				binder_node_lock(node);
+				/*
+				 * Acquire the node lock before freeing the
+				 * node to serialize with other threads that
+				 * may have been holding the node lock while
+				 * decrementing this node (avoids race where
+				 * this thread frees while the other thread
+				 * is unlocking the node after the final
+				 * decrement)
+				 */
+				binder_node_unlock(node);
+				binder_free_node(node);
+			} else
+				binder_inner_proc_unlock(proc);
+
+			if (weak && !has_weak_ref)
+				ret = binder_put_node_cmd(
+						proc, thread, &ptr, node_ptr,
+						node_cookie, node_debug_id,
+						BR_INCREFS, "BR_INCREFS");
+			if (!ret && strong && !has_strong_ref)
+				ret = binder_put_node_cmd(
+						proc, thread, &ptr, node_ptr,
+						node_cookie, node_debug_id,
+						BR_ACQUIRE, "BR_ACQUIRE");
+			if (!ret && !strong && has_strong_ref)
+				ret = binder_put_node_cmd(
+						proc, thread, &ptr, node_ptr,
+						node_cookie, node_debug_id,
+						BR_RELEASE, "BR_RELEASE");
+			if (!ret && !weak && has_weak_ref)
+				ret = binder_put_node_cmd(
+						proc, thread, &ptr, node_ptr,
+						node_cookie, node_debug_id,
+						BR_DECREFS, "BR_DECREFS");
+			if (orig_ptr == ptr)
+				binder_debug(BINDER_DEBUG_INTERNAL_REFS,
+					     "%d:%d node %d u%016llx c%016llx state unchanged\n",
+					     proc->pid, thread->pid,
+					     node_debug_id,
+					     (u64)node_ptr,
+					     (u64)node_cookie);
+			if (ret)
+				return ret;
+		} break;
+		case BINDER_WORK_DEAD_BINDER:
+		case BINDER_WORK_DEAD_BINDER_AND_CLEAR:
+		case BINDER_WORK_CLEAR_DEATH_NOTIFICATION: {
+			struct binder_ref_death *death;
+			uint32_t cmd;
+			binder_uintptr_t cookie;
+
+			death = container_of(w, struct binder_ref_death, work);
+			if (w->type == BINDER_WORK_CLEAR_DEATH_NOTIFICATION)
+				cmd = BR_CLEAR_DEATH_NOTIFICATION_DONE;
+			else
+				cmd = BR_DEAD_BINDER;
+			cookie = death->cookie;
+
+			binder_debug(BINDER_DEBUG_DEATH_NOTIFICATION,
+				     "%d:%d %s %016llx\n",
+				      proc->pid, thread->pid,
+				      cmd == BR_DEAD_BINDER ?
+				      "BR_DEAD_BINDER" :
+				      "BR_CLEAR_DEATH_NOTIFICATION_DONE",
+				      (u64)cookie);
+			if (w->type == BINDER_WORK_CLEAR_DEATH_NOTIFICATION) {
+				binder_inner_proc_unlock(proc);
+				kfree(death);
+				binder_stats_deleted(BINDER_STAT_DEATH);
+			} else {
+				binder_enqueue_work_ilocked(
+						w, &proc->delivered_death);
+				binder_inner_proc_unlock(proc);
+			}
+			if (put_user(cmd, (uint32_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(uint32_t);
+			if (put_user(cookie,
+				     (binder_uintptr_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(binder_uintptr_t);
+			binder_stat_br(proc, thread, cmd);
+			if (cmd == BR_DEAD_BINDER)
+				goto done; /* DEAD_BINDER notifications can cause transactions */
+		} break;
+
+		case BINDER_WORK_FROZEN_BINDER: {
+			struct binder_ref_freeze *freeze;
+			struct binder_frozen_state_info info;
+
+			memset(&info, 0, sizeof(info));
+			freeze = container_of(w, struct binder_ref_freeze, work);
+			info.is_frozen = freeze->is_frozen;
+			info.cookie = freeze->cookie;
+			freeze->sent = true;
+			binder_enqueue_work_ilocked(w, &proc->delivered_freeze);
+			binder_inner_proc_unlock(proc);
+
+			if (put_user(BR_FROZEN_BINDER, (uint32_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(uint32_t);
+			if (copy_to_user(ptr, &info, sizeof(info)))
+				return -EFAULT;
+			ptr += sizeof(info);
+			binder_stat_br(proc, thread, BR_FROZEN_BINDER);
+			goto done; /* BR_FROZEN_BINDER notifications can cause transactions */
+		} break;
+
+		case BINDER_WORK_CLEAR_FREEZE_NOTIFICATION: {
+			struct binder_ref_freeze *freeze =
+			    container_of(w, struct binder_ref_freeze, work);
+			binder_uintptr_t cookie = freeze->cookie;
+
+			binder_inner_proc_unlock(proc);
+			kfree(freeze);
+			binder_stats_deleted(BINDER_STAT_FREEZE);
+			if (put_user(BR_CLEAR_FREEZE_NOTIFICATION_DONE, (uint32_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(uint32_t);
+			if (put_user(cookie, (binder_uintptr_t __user *)ptr))
+				return -EFAULT;
+			ptr += sizeof(binder_uintptr_t);
+			binder_stat_br(proc, thread, BR_CLEAR_FREEZE_NOTIFICATION_DONE);
+		} break;
+
+		default:
+			binder_inner_proc_unlock(proc);
+			pr_err("%d:%d: bad work type %d\n",
+			       proc->pid, thread->pid, w->type);
+			break;
+		}
+
+		if (!t)
+			continue;
+
+		BUG_ON(t->buffer == NULL);
+		if (t->buffer->target_node) {
+			struct binder_node *target_node = t->buffer->target_node;
+
+			trd->target.ptr = target_node->ptr;
+			trd->cookie =  target_node->cookie;
+			t->saved_priority = task_nice(current);
+			if (t->priority < target_node->min_priority &&
+			    !(t->flags & TF_ONE_WAY))
+				binder_set_nice(t->priority);
+			else if (!(t->flags & TF_ONE_WAY) ||
+				 t->saved_priority > target_node->min_priority)
+				binder_set_nice(target_node->min_priority);
+			cmd = BR_TRANSACTION;
+		} else {
+			trd->target.ptr = 0;
+			trd->cookie = 0;
+			cmd = BR_REPLY;
+		}
+		trd->code = t->code;
+		trd->flags = t->flags;
+		trd->sender_euid = from_kuid(current_user_ns(), t->sender_euid);
+
+		t_from = binder_get_txn_from(t);
+		if (t_from) {
+			struct task_struct *sender = t_from->proc->tsk;
+
+			trd->sender_pid =
+				task_tgid_nr_ns(sender,
+						task_active_pid_ns(current));
+		} else {
+			trd->sender_pid = 0;
+		}
+
+		ret = binder_apply_fd_fixups(proc, t);
+		if (ret) {
+			struct binder_buffer *buffer = t->buffer;
+			bool oneway = !!(t->flags & TF_ONE_WAY);
+			int tid = t->debug_id;
+
+			if (t_from)
+				binder_thread_dec_tmpref(t_from);
+			buffer->transaction = NULL;
+			binder_cleanup_transaction(t, "fd fixups failed",
+						   BR_FAILED_REPLY);
+			binder_free_buf(proc, thread, buffer, true);
+			binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
+				     "%d:%d %stransaction %d fd fixups failed %d/%d, line %d\n",
+				     proc->pid, thread->pid,
+				     oneway ? "async " :
+					(cmd == BR_REPLY ? "reply " : ""),
+				     tid, BR_FAILED_REPLY, ret, __LINE__);
+			if (cmd == BR_REPLY) {
+				cmd = BR_FAILED_REPLY;
+				if (put_user(cmd, (uint32_t __user *)ptr))
+					return -EFAULT;
+				ptr += sizeof(uint32_t);
+				binder_stat_br(proc, thread, cmd);
+				break;
+			}
+			continue;
+		}
+		trd->data_size = t->buffer->data_size;
+		trd->offsets_size = t->buffer->offsets_size;
+		trd->data.ptr.buffer = t->buffer->user_data;
+		trd->data.ptr.offsets = trd->data.ptr.buffer +
+					ALIGN(t->buffer->data_size,
+					    sizeof(void *));
+
+		tr.secctx = t->security_ctx;
+		if (t->security_ctx) {
+			cmd = BR_TRANSACTION_SEC_CTX;
+			trsize = sizeof(tr);
+		}
+		if (put_user(cmd, (uint32_t __user *)ptr)) {
+			if (t_from)
+				binder_thread_dec_tmpref(t_from);
+
+			binder_cleanup_transaction(t, "put_user failed",
+						   BR_FAILED_REPLY);
+
+			return -EFAULT;
+		}
+		ptr += sizeof(uint32_t);
+		if (copy_to_user(ptr, &tr, trsize)) {
+			if (t_from)
+				binder_thread_dec_tmpref(t_from);
+
+			binder_cleanup_transaction(t, "copy_to_user failed",
+						   BR_FAILED_REPLY);
+
+			return -EFAULT;
+		}
+		ptr += trsize;
+
+		trace_binder_transaction_received(t);
+		binder_stat_br(proc, thread, cmd);
+		binder_debug(BINDER_DEBUG_TRANSACTION,
+			     "%d:%d %s %d %d:%d, cmd %u size %zd-%zd\n",
+			     proc->pid, thread->pid,
+			     (cmd == BR_TRANSACTION) ? "BR_TRANSACTION" :
+				(cmd == BR_TRANSACTION_SEC_CTX) ?
+				     "BR_TRANSACTION_SEC_CTX" : "BR_REPLY",
+			     t->debug_id, t_from ? t_from->proc->pid : 0,
+			     t_from ? t_from->pid : 0, cmd,
+			     t->buffer->data_size, t->buffer->offsets_size);
+
+		if (t_from)
+			binder_thread_dec_tmpref(t_from);
+		t->buffer->allow_user_free = 1;
+		if (cmd != BR_REPLY && !(t->flags & TF_ONE_WAY)) {
+			binder_inner_proc_lock(thread->proc);
+			t->to_parent = thread->transaction_stack;
+			t->to_thread = thread;
+			thread->transaction_stack = t;
+			binder_inner_proc_unlock(thread->proc);
+		} else {
+			binder_free_transaction(t);
+		}
+		break;
+	}
+
+done:
+
+	*consumed = ptr - buffer;
+	binder_inner_proc_lock(proc);
+	if (proc->requested_threads == 0 &&
+	    list_empty(&thread->proc->waiting_threads) &&
+	    proc->requested_threads_started < proc->max_threads &&
+	    (thread->looper & (BINDER_LOOPER_STATE_REGISTERED |
+	     BINDER_LOOPER_STATE_ENTERED)) /* the user-space code fails to */
+	     /*spawn a new thread if we leave this out */) {
+		proc->requested_threads++;
+		binder_inner_proc_unlock(proc);
+		binder_debug(BINDER_DEBUG_THREADS,
+			     "%d:%d BR_SPAWN_LOOPER\n",
+			     proc->pid, thread->pid);
+		if (put_user(BR_SPAWN_LOOPER, (uint32_t __user *)buffer))
+			return -EFAULT;
+		binder_stat_br(proc, thread, BR_SPAWN_LOOPER);
+	} else
+		binder_inner_proc_unlock(proc);
+	return 0;
+}
+
+static void binder_release_work(struct binder_proc *proc,
+				struct list_head *list)
+{
+	struct binder_work *w;
+	enum binder_work_type wtype;
+
+	while (1) {
+		binder_inner_proc_lock(proc);
+		w = binder_dequeue_work_head_ilocked(list);
+		wtype = w ? w->type : 0;
+		binder_inner_proc_unlock(proc);
+		if (!w)
+			return;
+
+		switch (wtype) {
+		case BINDER_WORK_TRANSACTION: {
+			struct binder_transaction *t;
+
+			t = container_of(w, struct binder_transaction, work);
+
+			binder_cleanup_transaction(t, "process died.",
+						   BR_DEAD_REPLY);
+		} break;
+		case BINDER_WORK_RETURN_ERROR: {
+			struct binder_error *e = container_of(
+					w, struct binder_error, work);
+
+			binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
+				"undelivered TRANSACTION_ERROR: %u\n",
+				e->cmd);
+		} break;
+		case BINDER_WORK_TRANSACTION_PENDING:
+		case BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT:
+		case BINDER_WORK_TRANSACTION_COMPLETE: {
+			binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
+				"undelivered TRANSACTION_COMPLETE\n");
+			kfree(w);
+			binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
+		} break;
+		case BINDER_WORK_DEAD_BINDER_AND_CLEAR:
+		case BINDER_WORK_CLEAR_DEATH_NOTIFICATION: {
+			struct binder_ref_death *death;
+
+			death = container_of(w, struct binder_ref_death, work);
+			binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
+				"undelivered death notification, %016llx\n",
+				(u64)death->cookie);
+			kfree(death);
+			binder_stats_deleted(BINDER_STAT_DEATH);
+		} break;
+		case BINDER_WORK_NODE:
+			break;
+		case BINDER_WORK_CLEAR_FREEZE_NOTIFICATION: {
+			struct binder_ref_freeze *freeze;
+
+			freeze = container_of(w, struct binder_ref_freeze, work);
+			binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
+				     "undelivered freeze notification, %016llx\n",
+				     (u64)freeze->cookie);
+			kfree(freeze);
+			binder_stats_deleted(BINDER_STAT_FREEZE);
+		} break;
+		default:
+			pr_err("unexpected work type, %d, not freed\n",
+			       wtype);
+			break;
+		}
+	}
+
+}
+
+static struct binder_thread *binder_get_thread_ilocked(
+		struct binder_proc *proc, struct binder_thread *new_thread)
+{
+	struct binder_thread *thread = NULL;
+	struct rb_node *parent = NULL;
+	struct rb_node **p = &proc->threads.rb_node;
+
+	while (*p) {
+		parent = *p;
+		thread = rb_entry(parent, struct binder_thread, rb_node);
+
+		if (current->pid < thread->pid)
+			p = &(*p)->rb_left;
+		else if (current->pid > thread->pid)
+			p = &(*p)->rb_right;
+		else
+			return thread;
+	}
+	if (!new_thread)
+		return NULL;
+	thread = new_thread;
+	binder_stats_created(BINDER_STAT_THREAD);
+	thread->proc = proc;
+	thread->pid = current->pid;
+	atomic_set(&thread->tmp_ref, 0);
+	init_waitqueue_head(&thread->wait);
+	INIT_LIST_HEAD(&thread->todo);
+	rb_link_node(&thread->rb_node, parent, p);
+	rb_insert_color(&thread->rb_node, &proc->threads);
+	thread->looper_need_return = true;
+	thread->return_error.work.type = BINDER_WORK_RETURN_ERROR;
+	thread->return_error.cmd = BR_OK;
+	thread->reply_error.work.type = BINDER_WORK_RETURN_ERROR;
+	thread->reply_error.cmd = BR_OK;
+	thread->ee.command = BR_OK;
+	INIT_LIST_HEAD(&new_thread->waiting_thread_node);
+	return thread;
+}
+
+static struct binder_thread *binder_get_thread(struct binder_proc *proc)
+{
+	struct binder_thread *thread;
+	struct binder_thread *new_thread;
+
+	binder_inner_proc_lock(proc);
+	thread = binder_get_thread_ilocked(proc, NULL);
+	binder_inner_proc_unlock(proc);
+	if (!thread) {
+		new_thread = kzalloc_obj(*thread);
+		if (new_thread == NULL)
+			return NULL;
+		binder_inner_proc_lock(proc);
+		thread = binder_get_thread_ilocked(proc, new_thread);
+		binder_inner_proc_unlock(proc);
+		if (thread != new_thread)
+			kfree(new_thread);
+	}
+	return thread;
+}
+
+static void binder_free_proc(struct binder_proc *proc)
+{
+	struct binder_device *device;
+
+	BUG_ON(!list_empty(&proc->todo));
+	BUG_ON(!list_empty(&proc->delivered_death));
+	if (proc->outstanding_txns)
+		pr_warn("%s: Unexpected outstanding_txns %d\n",
+			__func__, proc->outstanding_txns);
+	device = container_of(proc->context, struct binder_device, context);
+	if (refcount_dec_and_test(&device->ref)) {
+		binder_remove_device(device);
+		kfree(proc->context->name);
+		kfree(device);
+	}
+	binder_alloc_deferred_release(&proc->alloc);
+	put_task_struct(proc->tsk);
+	put_cred(proc->cred);
+	binder_stats_deleted(BINDER_STAT_PROC);
+	dbitmap_free(&proc->dmap);
+	kfree(proc);
+}
+
+static void binder_free_thread(struct binder_thread *thread)
+{
+	BUG_ON(!list_empty(&thread->todo));
+	binder_stats_deleted(BINDER_STAT_THREAD);
+	binder_proc_dec_tmpref(thread->proc);
+	kfree(thread);
+}
+
+static int binder_thread_release(struct binder_proc *proc,
+				 struct binder_thread *thread)
+{
+	struct binder_transaction *t;
+	struct binder_transaction *send_reply = NULL;
+	int active_transactions = 0;
+	struct binder_transaction *last_t = NULL;
+
+	binder_inner_proc_lock(thread->proc);
+	/*
+	 * take a ref on the proc so it survives
+	 * after we remove this thread from proc->threads.
+	 * The corresponding dec is when we actually
+	 * free the thread in binder_free_thread()
+	 */
+	proc->tmp_ref++;
+	/*
+	 * take a ref on this thread to ensure it
+	 * survives while we are releasing it
+	 */
+	atomic_inc(&thread->tmp_ref);
+	rb_erase(&thread->rb_node, &proc->threads);
+	t = thread->transaction_stack;
+	if (t) {
+		spin_lock(&t->lock);
+		if (t->to_thread == thread)
+			send_reply = t;
+	} else {
+		__acquire(&t->lock);
+	}
+	thread->is_dead = true;
+
+	while (t) {
+		last_t = t;
+		active_transactions++;
+		binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
+			     "release %d:%d transaction %d %s, still active\n",
+			      proc->pid, thread->pid,
+			     t->debug_id,
+			     (t->to_thread == thread) ? "in" : "out");
+
+		if (t->to_thread == thread) {
+			thread->proc->outstanding_txns--;
+			t->to_proc = NULL;
+			t->to_thread = NULL;
+			if (t->buffer) {
+				t->buffer->transaction = NULL;
+				t->buffer = NULL;
+			}
+			t = t->to_parent;
+		} else if (t->from == thread) {
+			t->from = NULL;
+			t = t->from_parent;
+		} else
+			BUG();
+		spin_unlock(&last_t->lock);
+		if (t)
+			spin_lock(&t->lock);
+		else
+			__acquire(&t->lock);
+	}
+	/* annotation for sparse, lock not acquired in last iteration above */
+	__release(&t->lock);
+
+	/*
+	 * If this thread used poll, make sure we remove the waitqueue from any
+	 * poll data structures holding it.
+	 */
+	if (thread->looper & BINDER_LOOPER_STATE_POLL)
+		wake_up_pollfree(&thread->wait);
+
+	binder_inner_proc_unlock(thread->proc);
+
+	/*
+	 * This is needed to avoid races between wake_up_pollfree() above and
+	 * someone else removing the last entry from the queue for other reasons
+	 * (e.g. ep_remove_wait_queue() being called due to an epoll file
+	 * descriptor being closed).  Such other users hold an RCU read lock, so
+	 * we can be sure they're done after we call synchronize_rcu().
+	 */
+	if (thread->looper & BINDER_LOOPER_STATE_POLL)
+		synchronize_rcu();
+
+	if (send_reply)
+		binder_send_failed_reply(send_reply, BR_DEAD_REPLY);
+	binder_release_work(proc, &thread->todo);
+	binder_thread_dec_tmpref(thread);
+	return active_transactions;
+}
+
+static __poll_t binder_poll(struct file *filp,
+				struct poll_table_struct *wait)
+{
+	struct binder_proc *proc = filp->private_data;
+	struct binder_thread *thread = NULL;
+	bool wait_for_proc_work;
+
+	thread = binder_get_thread(proc);
+	if (!thread)
+		return EPOLLERR;
+
+	binder_inner_proc_lock(thread->proc);
+	thread->looper |= BINDER_LOOPER_STATE_POLL;
+	wait_for_proc_work = binder_available_for_proc_work_ilocked(thread);
+
+	binder_inner_proc_unlock(thread->proc);
+
+	poll_wait(filp, &thread->wait, wait);
+
+	if (binder_has_work(thread, wait_for_proc_work))
+		return EPOLLIN;
+
+	return 0;
+}
+
+static int binder_ioctl_write_read(struct file *filp, unsigned long arg,
+				struct binder_thread *thread)
+{
+	int ret = 0;
+	struct binder_proc *proc = filp->private_data;
+	void __user *ubuf = (void __user *)arg;
+	struct binder_write_read bwr;
+
+	if (copy_from_user(&bwr, ubuf, sizeof(bwr)))
+		return -EFAULT;
+
+	binder_debug(BINDER_DEBUG_READ_WRITE,
+		     "%d:%d write %lld at %016llx, read %lld at %016llx\n",
+		     proc->pid, thread->pid,
+		     (u64)bwr.write_size, (u64)bwr.write_buffer,
+		     (u64)bwr.read_size, (u64)bwr.read_buffer);
+
+	if (bwr.write_size > 0) {
+		ret = binder_thread_write(proc, thread,
+					  bwr.write_buffer,
+					  bwr.write_size,
+					  &bwr.write_consumed);
+		trace_binder_write_done(ret);
+		if (ret < 0) {
+			bwr.read_consumed = 0;
+			goto out;
+		}
+	}
+	if (bwr.read_size > 0) {
+		ret = binder_thread_read(proc, thread, bwr.read_buffer,
+					 bwr.read_size,
+					 &bwr.read_consumed,
+					 filp->f_flags & O_NONBLOCK);
+		trace_binder_read_done(ret);
+		binder_inner_proc_lock(proc);
+		if (!binder_worklist_empty_ilocked(&proc->todo))
+			binder_wakeup_proc_ilocked(proc);
+		binder_inner_proc_unlock(proc);
+		if (ret < 0)
+			goto out;
+	}
+	binder_debug(BINDER_DEBUG_READ_WRITE,
+		     "%d:%d wrote %lld of %lld, read return %lld of %lld\n",
+		     proc->pid, thread->pid,
+		     (u64)bwr.write_consumed, (u64)bwr.write_size,
+		     (u64)bwr.read_consumed, (u64)bwr.read_size);
+out:
+	if (copy_to_user(ubuf, &bwr, sizeof(bwr)))
+		ret = -EFAULT;
+	return ret;
+}
+
+static int binder_ioctl_set_ctx_mgr(struct file *filp,
+				    struct flat_binder_object *fbo)
+{
+	int ret = 0;
+	struct binder_proc *proc = filp->private_data;
+	struct binder_context *context = proc->context;
+	struct binder_node *new_node;
+	kuid_t curr_euid = current_euid();
+
+	guard(mutex)(&context->context_mgr_node_lock);
+	if (context->binder_context_mgr_node) {
+		pr_err("BINDER_SET_CONTEXT_MGR already set\n");
+		return -EBUSY;
+	}
+	ret = security_binder_set_context_mgr(proc->cred);
+	if (ret < 0)
+		return ret;
+	if (uid_valid(context->binder_context_mgr_uid)) {
+		if (!uid_eq(context->binder_context_mgr_uid, curr_euid)) {
+			pr_err("BINDER_SET_CONTEXT_MGR bad uid %d != %d\n",
+			       from_kuid(&init_user_ns, curr_euid),
+			       from_kuid(&init_user_ns,
+					 context->binder_context_mgr_uid));
+			return -EPERM;
+		}
+	} else {
+		context->binder_context_mgr_uid = curr_euid;
+	}
+	new_node = binder_new_node(proc, fbo);
+	if (!new_node)
+		return -ENOMEM;
+	binder_node_lock(new_node);
+	new_node->local_weak_refs++;
+	new_node->local_strong_refs++;
+	new_node->has_strong_ref = 1;
+	new_node->has_weak_ref = 1;
+	context->binder_context_mgr_node = new_node;
+	binder_node_unlock(new_node);
+	binder_put_node(new_node);
+	return ret;
+}
+
+static int binder_ioctl_get_node_info_for_ref(struct binder_proc *proc,
+		struct binder_node_info_for_ref *info)
+{
+	struct binder_node *node;
+	struct binder_context *context = proc->context;
+	__u32 handle = info->handle;
+
+	if (info->strong_count || info->weak_count || info->reserved1 ||
+	    info->reserved2 || info->reserved3) {
+		binder_user_error("%d BINDER_GET_NODE_INFO_FOR_REF: only handle may be non-zero.",
+				  proc->pid);
+		return -EINVAL;
+	}
+
+	/* This ioctl may only be used by the context manager */
+	mutex_lock(&context->context_mgr_node_lock);
+	if (!context->binder_context_mgr_node ||
+		context->binder_context_mgr_node->proc != proc) {
+		mutex_unlock(&context->context_mgr_node_lock);
+		return -EPERM;
+	}
+	mutex_unlock(&context->context_mgr_node_lock);
+
+	node = binder_get_node_from_ref(proc, handle, true, NULL);
+	if (!node)
+		return -EINVAL;
+
+	info->strong_count = node->local_strong_refs +
+		node->internal_strong_refs;
+	info->weak_count = node->local_weak_refs;
+
+	binder_put_node(node);
+
+	return 0;
+}
+
+static int binder_ioctl_get_node_debug_info(struct binder_proc *proc,
+				struct binder_node_debug_info *info)
+{
+	struct rb_node *n;
+	binder_uintptr_t ptr = info->ptr;
+
+	memset(info, 0, sizeof(*info));
+
+	binder_inner_proc_lock(proc);
+	for (n = rb_first(&proc->nodes); n != NULL; n = rb_next(n)) {
+		struct binder_node *node = rb_entry(n, struct binder_node,
+						    rb_node);
+		if (node->ptr > ptr) {
+			info->ptr = node->ptr;
+			info->cookie = node->cookie;
+			info->has_strong_ref = node->has_strong_ref;
+			info->has_weak_ref = node->has_weak_ref;
+			break;
+		}
+	}
+	binder_inner_proc_unlock(proc);
+
+	return 0;
+}
+
+static bool binder_txns_pending_ilocked(struct binder_proc *proc)
+{
+	struct rb_node *n;
+	struct binder_thread *thread;
+
+	if (proc->outstanding_txns > 0)
+		return true;
+
+	for (n = rb_first(&proc->threads); n; n = rb_next(n)) {
+		thread = rb_entry(n, struct binder_thread, rb_node);
+		if (thread->transaction_stack)
+			return true;
+	}
+	return false;
+}
+
+static void binder_add_freeze_work(struct binder_proc *proc, bool is_frozen)
+{
+	struct binder_node *prev = NULL;
+	struct rb_node *n;
+	struct binder_ref *ref;
+
+	binder_inner_proc_lock(proc);
+	for (n = rb_first(&proc->nodes); n; n = rb_next(n)) {
+		struct binder_node *node;
+
+		node = rb_entry(n, struct binder_node, rb_node);
+		binder_inc_node_tmpref_ilocked(node);
+		binder_inner_proc_unlock(proc);
+		if (prev)
+			binder_put_node(prev);
+		binder_node_lock(node);
+		hlist_for_each_entry(ref, &node->refs, node_entry) {
+			/*
+			 * Need the node lock to synchronize
+			 * with new notification requests and the
+			 * inner lock to synchronize with queued
+			 * freeze notifications.
+			 */
+			binder_inner_proc_lock(ref->proc);
+			if (!ref->freeze) {
+				binder_inner_proc_unlock(ref->proc);
+				continue;
+			}
+			ref->freeze->work.type = BINDER_WORK_FROZEN_BINDER;
+			if (list_empty(&ref->freeze->work.entry)) {
+				ref->freeze->is_frozen = is_frozen;
+				binder_enqueue_work_ilocked(&ref->freeze->work, &ref->proc->todo);
+				binder_wakeup_proc_ilocked(ref->proc);
+			} else {
+				if (ref->freeze->sent && ref->freeze->is_frozen != is_frozen)
+					ref->freeze->resend = true;
+				ref->freeze->is_frozen = is_frozen;
+			}
+			binder_inner_proc_unlock(ref->proc);
+		}
+		prev = node;
+		binder_node_unlock(node);
+		binder_inner_proc_lock(proc);
+		if (proc->is_dead)
+			break;
+	}
+	binder_inner_proc_unlock(proc);
+	if (prev)
+		binder_put_node(prev);
+}
+
+static int binder_ioctl_freeze(struct binder_freeze_info *info,
+			       struct binder_proc *target_proc)
+{
+	int ret = 0;
+
+	if (!info->enable) {
+		binder_inner_proc_lock(target_proc);
+		target_proc->sync_recv = false;
+		target_proc->async_recv = false;
+		target_proc->is_frozen = false;
+		binder_inner_proc_unlock(target_proc);
+		binder_add_freeze_work(target_proc, false);
+		return 0;
+	}
+
+	/*
+	 * Freezing the target. Prevent new transactions by
+	 * setting frozen state. If timeout specified, wait
+	 * for transactions to drain.
+	 */
+	binder_inner_proc_lock(target_proc);
+	target_proc->sync_recv = false;
+	target_proc->async_recv = false;
+	target_proc->is_frozen = true;
+	binder_inner_proc_unlock(target_proc);
+
+	if (info->timeout_ms > 0)
+		ret = wait_event_interruptible_timeout(
+			target_proc->freeze_wait,
+			(!target_proc->outstanding_txns),
+			msecs_to_jiffies(info->timeout_ms));
+
+	/* Check pending transactions that wait for reply */
+	if (ret >= 0) {
+		binder_inner_proc_lock(target_proc);
+		if (binder_txns_pending_ilocked(target_proc))
+			ret = -EAGAIN;
+		binder_inner_proc_unlock(target_proc);
+	}
+
+	if (ret < 0) {
+		binder_inner_proc_lock(target_proc);
+		target_proc->is_frozen = false;
+		binder_inner_proc_unlock(target_proc);
+	} else {
+		binder_add_freeze_work(target_proc, true);
+	}
+
+	return ret;
+}
+
+static int binder_ioctl_get_freezer_info(
+				struct binder_frozen_status_info *info)
+{
+	struct binder_proc *target_proc;
+	bool found = false;
+	__u32 txns_pending;
+
+	info->sync_recv = 0;
+	info->async_recv = 0;
+
+	mutex_lock(&binder_procs_lock);
+	hlist_for_each_entry(target_proc, &binder_procs, proc_node) {
+		if (target_proc->pid == info->pid) {
+			found = true;
+			binder_inner_proc_lock(target_proc);
+			txns_pending = binder_txns_pending_ilocked(target_proc);
+			info->sync_recv |= target_proc->sync_recv |
+					(txns_pending << 1);
+			info->async_recv |= target_proc->async_recv;
+			binder_inner_proc_unlock(target_proc);
+		}
+	}
+	mutex_unlock(&binder_procs_lock);
+
+	if (!found)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int binder_ioctl_get_extended_error(struct binder_thread *thread,
+					   void __user *ubuf)
+{
+	struct binder_extended_error ee;
+
+	binder_inner_proc_lock(thread->proc);
+	ee = thread->ee;
+	binder_set_extended_error(&thread->ee, 0, BR_OK, 0);
+	binder_inner_proc_unlock(thread->proc);
+
+	if (copy_to_user(ubuf, &ee, sizeof(ee)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	int ret;
+	struct binder_proc *proc = filp->private_data;
+	struct binder_thread *thread;
+	void __user *ubuf = (void __user *)arg;
+
+	trace_binder_ioctl(cmd, arg);
+
+	ret = wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2);
+	if (ret)
+		goto err_unlocked;
+
+	thread = binder_get_thread(proc);
+	if (thread == NULL) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	switch (cmd) {
+	case BINDER_WRITE_READ:
+		ret = binder_ioctl_write_read(filp, arg, thread);
+		if (ret)
+			goto err;
+		break;
+	case BINDER_SET_MAX_THREADS: {
+		u32 max_threads;
+
+		if (copy_from_user(&max_threads, ubuf,
+				   sizeof(max_threads))) {
+			ret = -EINVAL;
+			goto err;
+		}
+		binder_inner_proc_lock(proc);
+		proc->max_threads = max_threads;
+		binder_inner_proc_unlock(proc);
+		break;
+	}
+	case BINDER_SET_CONTEXT_MGR_EXT: {
+		struct flat_binder_object fbo;
+
+		if (copy_from_user(&fbo, ubuf, sizeof(fbo))) {
+			ret = -EINVAL;
+			goto err;
+		}
+		ret = binder_ioctl_set_ctx_mgr(filp, &fbo);
+		if (ret)
+			goto err;
+		break;
+	}
+	case BINDER_SET_CONTEXT_MGR:
+		ret = binder_ioctl_set_ctx_mgr(filp, NULL);
+		if (ret)
+			goto err;
+		break;
+	case BINDER_THREAD_EXIT:
+		binder_debug(BINDER_DEBUG_THREADS, "%d:%d exit\n",
+			     proc->pid, thread->pid);
+		binder_thread_release(proc, thread);
+		thread = NULL;
+		break;
+	case BINDER_VERSION: {
+		struct binder_version __user *ver = ubuf;
+
+		if (put_user(BINDER_CURRENT_PROTOCOL_VERSION,
+			     &ver->protocol_version)) {
+			ret = -EINVAL;
+			goto err;
+		}
+		break;
+	}
+	case BINDER_GET_NODE_INFO_FOR_REF: {
+		struct binder_node_info_for_ref info;
+
+		if (copy_from_user(&info, ubuf, sizeof(info))) {
+			ret = -EFAULT;
+			goto err;
+		}
+
+		ret = binder_ioctl_get_node_info_for_ref(proc, &info);
+		if (ret < 0)
+			goto err;
+
+		if (copy_to_user(ubuf, &info, sizeof(info))) {
+			ret = -EFAULT;
+			goto err;
+		}
+
+		break;
+	}
+	case BINDER_GET_NODE_DEBUG_INFO: {
+		struct binder_node_debug_info info;
+
+		if (copy_from_user(&info, ubuf, sizeof(info))) {
+			ret = -EFAULT;
+			goto err;
+		}
+
+		ret = binder_ioctl_get_node_debug_info(proc, &info);
+		if (ret < 0)
+			goto err;
+
+		if (copy_to_user(ubuf, &info, sizeof(info))) {
+			ret = -EFAULT;
+			goto err;
+		}
+		break;
+	}
+	case BINDER_FREEZE: {
+		struct binder_freeze_info info;
+		struct binder_proc **target_procs = NULL, *target_proc;
+		int target_procs_count = 0, i = 0;
+
+		ret = 0;
+
+		if (copy_from_user(&info, ubuf, sizeof(info))) {
+			ret = -EFAULT;
+			goto err;
+		}
+
+		mutex_lock(&binder_procs_lock);
+		hlist_for_each_entry(target_proc, &binder_procs, proc_node) {
+			if (target_proc->pid == info.pid)
+				target_procs_count++;
+		}
+
+		if (target_procs_count == 0) {
+			mutex_unlock(&binder_procs_lock);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		target_procs = kzalloc_objs(struct binder_proc *,
+					    target_procs_count);
+
+		if (!target_procs) {
+			mutex_unlock(&binder_procs_lock);
+			ret = -ENOMEM;
+			goto err;
+		}
+
+		hlist_for_each_entry(target_proc, &binder_procs, proc_node) {
+			if (target_proc->pid != info.pid)
+				continue;
+
+			binder_inner_proc_lock(target_proc);
+			target_proc->tmp_ref++;
+			binder_inner_proc_unlock(target_proc);
+
+			target_procs[i++] = target_proc;
+		}
+		mutex_unlock(&binder_procs_lock);
+
+		for (i = 0; i < target_procs_count; i++) {
+			if (ret >= 0)
+				ret = binder_ioctl_freeze(&info,
+							  target_procs[i]);
+
+			binder_proc_dec_tmpref(target_procs[i]);
+		}
+
+		kfree(target_procs);
+
+		if (ret < 0)
+			goto err;
+		break;
+	}
+	case BINDER_GET_FROZEN_INFO: {
+		struct binder_frozen_status_info info;
+
+		if (copy_from_user(&info, ubuf, sizeof(info))) {
+			ret = -EFAULT;
+			goto err;
+		}
+
+		ret = binder_ioctl_get_freezer_info(&info);
+		if (ret < 0)
+			goto err;
+
+		if (copy_to_user(ubuf, &info, sizeof(info))) {
+			ret = -EFAULT;
+			goto err;
+		}
+		break;
+	}
+	case BINDER_ENABLE_ONEWAY_SPAM_DETECTION: {
+		uint32_t enable;
+
+		if (copy_from_user(&enable, ubuf, sizeof(enable))) {
+			ret = -EFAULT;
+			goto err;
+		}
+		binder_inner_proc_lock(proc);
+		proc->oneway_spam_detection_enabled = (bool)enable;
+		binder_inner_proc_unlock(proc);
+		break;
+	}
+	case BINDER_GET_EXTENDED_ERROR:
+		ret = binder_ioctl_get_extended_error(thread, ubuf);
+		if (ret < 0)
+			goto err;
+		break;
+	default:
+		ret = -EINVAL;
+		goto err;
+	}
+	ret = 0;
+err:
+	if (thread)
+		thread->looper_need_return = false;
+	wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2);
+	if (ret && ret != -EINTR)
+		pr_info("%d:%d ioctl %x %lx returned %d\n", proc->pid, current->pid, cmd, arg, ret);
+err_unlocked:
+	trace_binder_ioctl_done(ret);
+	return ret;
+}
+
+static void binder_vma_open(struct vm_area_struct *vma)
+{
+	struct binder_proc *proc = vma->vm_private_data;
+
+	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
+		     "%d open vm area %lx-%lx (%ld K) vma %lx pagep %lx\n",
+		     proc->pid, vma->vm_start, vma->vm_end,
+		     (vma->vm_end - vma->vm_start) / SZ_1K, vma->vm_flags,
+		     (unsigned long)pgprot_val(vma->vm_page_prot));
+}
+
+static void binder_vma_close(struct vm_area_struct *vma)
+{
+	struct binder_proc *proc = vma->vm_private_data;
+
+	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
+		     "%d close vm area %lx-%lx (%ld K) vma %lx pagep %lx\n",
+		     proc->pid, vma->vm_start, vma->vm_end,
+		     (vma->vm_end - vma->vm_start) / SZ_1K, vma->vm_flags,
+		     (unsigned long)pgprot_val(vma->vm_page_prot));
+	binder_alloc_vma_close(&proc->alloc);
+}
+
+VISIBLE_IF_KUNIT vm_fault_t binder_vm_fault(struct vm_fault *vmf)
+{
+	return VM_FAULT_SIGBUS;
+}
+EXPORT_SYMBOL_IF_KUNIT(binder_vm_fault);
+
+static const struct vm_operations_struct binder_vm_ops = {
+	.open = binder_vma_open,
+	.close = binder_vma_close,
+	.fault = binder_vm_fault,
+};
+
+static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct binder_proc *proc = filp->private_data;
+
+	if (!same_thread_group(proc->tsk, current))
+		return -EINVAL;
+
+	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
+		     "%s: %d %lx-%lx (%ld K) vma %lx pagep %lx\n",
+		     __func__, proc->pid, vma->vm_start, vma->vm_end,
+		     (vma->vm_end - vma->vm_start) / SZ_1K, vma->vm_flags,
+		     (unsigned long)pgprot_val(vma->vm_page_prot));
+
+	if (vma->vm_flags & FORBIDDEN_MMAP_FLAGS) {
+		pr_err("%s: %d %lx-%lx %s failed %d\n", __func__,
+		       proc->pid, vma->vm_start, vma->vm_end, "bad vm_flags", -EPERM);
+		return -EPERM;
+	}
+	vm_flags_mod(vma, VM_DONTCOPY | VM_MIXEDMAP, VM_MAYWRITE);
+
+	vma->vm_ops = &binder_vm_ops;
+	vma->vm_private_data = proc;
+
+	return binder_alloc_mmap_handler(&proc->alloc, vma);
+}
+
+static int binder_open(struct inode *nodp, struct file *filp)
+{
+	struct binder_proc *proc, *itr;
+	struct binder_device *binder_dev;
+	struct binderfs_info *info;
+	struct dentry *binder_binderfs_dir_entry_proc = NULL;
+	bool existing_pid = false;
+
+	binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d:%d\n", __func__,
+		     current->tgid, current->pid);
+
+	proc = kzalloc_obj(*proc);
+	if (proc == NULL)
+		return -ENOMEM;
+
+	dbitmap_init(&proc->dmap);
+	spin_lock_init(&proc->inner_lock);
+	spin_lock_init(&proc->outer_lock);
+	proc->tsk = get_task_struct(current->group_leader);
+	proc->pid = current->tgid;
+	proc->cred = get_cred(filp->f_cred);
+	INIT_LIST_HEAD(&proc->todo);
+	init_waitqueue_head(&proc->freeze_wait);
+	proc->default_priority = task_nice(current);
+	/* binderfs stashes devices in i_private */
+	if (is_binderfs_device(nodp)) {
+		binder_dev = nodp->i_private;
+		info = nodp->i_sb->s_fs_info;
+		binder_binderfs_dir_entry_proc = info->proc_log_dir;
+	} else {
+		binder_dev = container_of(filp->private_data,
+					  struct binder_device, miscdev);
+	}
+	refcount_inc(&binder_dev->ref);
+	proc->context = &binder_dev->context;
+	binder_alloc_init(&proc->alloc);
+
+	binder_stats_created(BINDER_STAT_PROC);
+	INIT_LIST_HEAD(&proc->delivered_death);
+	INIT_LIST_HEAD(&proc->delivered_freeze);
+	INIT_LIST_HEAD(&proc->waiting_threads);
+	filp->private_data = proc;
+
+	mutex_lock(&binder_procs_lock);
+	hlist_for_each_entry(itr, &binder_procs, proc_node) {
+		if (itr->pid == proc->pid) {
+			existing_pid = true;
+			break;
+		}
+	}
+	hlist_add_head(&proc->proc_node, &binder_procs);
+	mutex_unlock(&binder_procs_lock);
+
+	if (binder_debugfs_dir_entry_proc && !existing_pid) {
+		char strbuf[11];
+
+		snprintf(strbuf, sizeof(strbuf), "%u", proc->pid);
+		/*
+		 * proc debug entries are shared between contexts.
+		 * Only create for the first PID to avoid debugfs log spamming
+		 * The printing code will anyway print all contexts for a given
+		 * PID so this is not a problem.
+		 */
+		proc->debugfs_entry = debugfs_create_file(strbuf, 0444,
+			binder_debugfs_dir_entry_proc,
+			(void *)(unsigned long)proc->pid,
+			&proc_fops);
+	}
+
+	if (binder_binderfs_dir_entry_proc && !existing_pid) {
+		char strbuf[11];
+		struct dentry *binderfs_entry;
+
+		snprintf(strbuf, sizeof(strbuf), "%u", proc->pid);
+		/*
+		 * Similar to debugfs, the process specific log file is shared
+		 * between contexts. Only create for the first PID.
+		 * This is ok since same as debugfs, the log file will contain
+		 * information on all contexts of a given PID.
+		 */
+		binderfs_entry = binderfs_create_file(binder_binderfs_dir_entry_proc,
+			strbuf, &proc_fops, (void *)(unsigned long)proc->pid);
+		if (!IS_ERR(binderfs_entry)) {
+			proc->binderfs_entry = binderfs_entry;
+		} else {
+			int error;
+
+			error = PTR_ERR(binderfs_entry);
+			pr_warn("Unable to create file %s in binderfs (error %d)\n",
+				strbuf, error);
+		}
+	}
+
+	return 0;
+}
+
+static int binder_flush(struct file *filp, fl_owner_t id)
+{
+	struct binder_proc *proc = filp->private_data;
+
+	binder_defer_work(proc, BINDER_DEFERRED_FLUSH);
+
+	return 0;
+}
+
+static void binder_deferred_flush(struct binder_proc *proc)
+{
+	struct rb_node *n;
+	int wake_count = 0;
+
+	binder_inner_proc_lock(proc);
+	for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) {
+		struct binder_thread *thread = rb_entry(n, struct binder_thread, rb_node);
+
+		thread->looper_need_return = true;
+		if (thread->looper & BINDER_LOOPER_STATE_WAITING) {
+			wake_up_interruptible(&thread->wait);
+			wake_count++;
+		}
+	}
+	binder_inner_proc_unlock(proc);
+
+	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
+		     "binder_flush: %d woke %d threads\n", proc->pid,
+		     wake_count);
+}
+
+static int binder_release(struct inode *nodp, struct file *filp)
+{
+	struct binder_proc *proc = filp->private_data;
+
+	debugfs_remove(proc->debugfs_entry);
+
+	if (proc->binderfs_entry) {
+		simple_recursive_removal(proc->binderfs_entry, NULL);
+		proc->binderfs_entry = NULL;
+	}
+
+	binder_defer_work(proc, BINDER_DEFERRED_RELEASE);
+
+	return 0;
+}
+
+static int binder_node_release(struct binder_node *node, int refs)
+{
+	struct binder_ref *ref;
+	int death = 0;
+	struct binder_proc *proc = node->proc;
+
+	binder_release_work(proc, &node->async_todo);
+
+	binder_node_lock(node);
+	binder_inner_proc_lock(proc);
+	binder_dequeue_work_ilocked(&node->work);
+	/*
+	 * The caller must have taken a temporary ref on the node,
+	 */
+	BUG_ON(!node->tmp_refs);
+	if (hlist_empty(&node->refs) && node->tmp_refs == 1) {
+		binder_inner_proc_unlock(proc);
+		binder_node_unlock(node);
+		binder_free_node(node);
+
+		return refs;
+	}
+
+	node->proc = NULL;
+	node->local_strong_refs = 0;
+	node->local_weak_refs = 0;
+	binder_inner_proc_unlock(proc);
+
+	spin_lock(&binder_dead_nodes_lock);
+	hlist_add_head(&node->dead_node, &binder_dead_nodes);
+	spin_unlock(&binder_dead_nodes_lock);
+
+	hlist_for_each_entry(ref, &node->refs, node_entry) {
+		refs++;
+		/*
+		 * Need the node lock to synchronize
+		 * with new notification requests and the
+		 * inner lock to synchronize with queued
+		 * death notifications.
+		 */
+		binder_inner_proc_lock(ref->proc);
+		if (!ref->death) {
+			binder_inner_proc_unlock(ref->proc);
+			continue;
+		}
+
+		death++;
+
+		BUG_ON(!list_empty(&ref->death->work.entry));
+		ref->death->work.type = BINDER_WORK_DEAD_BINDER;
+		binder_enqueue_work_ilocked(&ref->death->work,
+					    &ref->proc->todo);
+		binder_wakeup_proc_ilocked(ref->proc);
+		binder_inner_proc_unlock(ref->proc);
+	}
+
+	binder_debug(BINDER_DEBUG_DEAD_BINDER,
+		     "node %d now dead, refs %d, death %d\n",
+		     node->debug_id, refs, death);
+	binder_node_unlock(node);
+	binder_put_node(node);
+
+	return refs;
+}
+
+static void binder_deferred_release(struct binder_proc *proc)
+{
+	struct binder_context *context = proc->context;
+	struct rb_node *n;
+	int threads, nodes, incoming_refs, outgoing_refs, active_transactions;
+
+	mutex_lock(&binder_procs_lock);
+	hlist_del(&proc->proc_node);
+	mutex_unlock(&binder_procs_lock);
+
+	mutex_lock(&context->context_mgr_node_lock);
+	if (context->binder_context_mgr_node &&
+	    context->binder_context_mgr_node->proc == proc) {
+		binder_debug(BINDER_DEBUG_DEAD_BINDER,
+			     "%s: %d context_mgr_node gone\n",
+			     __func__, proc->pid);
+		context->binder_context_mgr_node = NULL;
+	}
+	mutex_unlock(&context->context_mgr_node_lock);
+	binder_inner_proc_lock(proc);
+	/*
+	 * Make sure proc stays alive after we
+	 * remove all the threads
+	 */
+	proc->tmp_ref++;
+
+	proc->is_dead = true;
+	proc->is_frozen = false;
+	proc->sync_recv = false;
+	proc->async_recv = false;
+	threads = 0;
+	active_transactions = 0;
+	while ((n = rb_first(&proc->threads))) {
+		struct binder_thread *thread;
+
+		thread = rb_entry(n, struct binder_thread, rb_node);
+		binder_inner_proc_unlock(proc);
+		threads++;
+		active_transactions += binder_thread_release(proc, thread);
+		binder_inner_proc_lock(proc);
+	}
+
+	nodes = 0;
+	incoming_refs = 0;
+	while ((n = rb_first(&proc->nodes))) {
+		struct binder_node *node;
+
+		node = rb_entry(n, struct binder_node, rb_node);
+		nodes++;
+		/*
+		 * take a temporary ref on the node before
+		 * calling binder_node_release() which will either
+		 * kfree() the node or call binder_put_node()
+		 */
+		binder_inc_node_tmpref_ilocked(node);
+		rb_erase(&node->rb_node, &proc->nodes);
+		binder_inner_proc_unlock(proc);
+		incoming_refs = binder_node_release(node, incoming_refs);
+		binder_inner_proc_lock(proc);
+	}
+	binder_inner_proc_unlock(proc);
+
+	outgoing_refs = 0;
+	binder_proc_lock(proc);
+	while ((n = rb_first(&proc->refs_by_desc))) {
+		struct binder_ref *ref;
+
+		ref = rb_entry(n, struct binder_ref, rb_node_desc);
+		outgoing_refs++;
+		binder_cleanup_ref_olocked(ref);
+		binder_proc_unlock(proc);
+		binder_free_ref(ref);
+		binder_proc_lock(proc);
+	}
+	binder_proc_unlock(proc);
+
+	binder_release_work(proc, &proc->todo);
+	binder_release_work(proc, &proc->delivered_death);
+	binder_release_work(proc, &proc->delivered_freeze);
+
+	binder_debug(BINDER_DEBUG_OPEN_CLOSE,
+		     "%s: %d threads %d, nodes %d (ref %d), refs %d, active transactions %d\n",
+		     __func__, proc->pid, threads, nodes, incoming_refs,
+		     outgoing_refs, active_transactions);
+
+	binder_proc_dec_tmpref(proc);
+}
+
+static void binder_deferred_func(struct work_struct *work)
+{
+	struct binder_proc *proc;
+
+	int defer;
+
+	do {
+		mutex_lock(&binder_deferred_lock);
+		if (!hlist_empty(&binder_deferred_list)) {
+			proc = hlist_entry(binder_deferred_list.first,
+					struct binder_proc, deferred_work_node);
+			hlist_del_init(&proc->deferred_work_node);
+			defer = proc->deferred_work;
+			proc->deferred_work = 0;
+		} else {
+			proc = NULL;
+			defer = 0;
+		}
+		mutex_unlock(&binder_deferred_lock);
+
+		if (defer & BINDER_DEFERRED_FLUSH)
+			binder_deferred_flush(proc);
+
+		if (defer & BINDER_DEFERRED_RELEASE)
+			binder_deferred_release(proc); /* frees proc */
+	} while (proc);
+}
+static DECLARE_WORK(binder_deferred_work, binder_deferred_func);
+
+static void
+binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer)
+{
+	guard(mutex)(&binder_deferred_lock);
+	proc->deferred_work |= defer;
+	if (hlist_unhashed(&proc->deferred_work_node)) {
+		hlist_add_head(&proc->deferred_work_node,
+				&binder_deferred_list);
+		schedule_work(&binder_deferred_work);
+	}
+}
+
+static void print_binder_transaction_ilocked(struct seq_file *m,
+					     struct binder_proc *proc,
+					     const char *prefix,
+					     struct binder_transaction *t)
+{
+	struct binder_proc *to_proc;
+	struct binder_buffer *buffer = t->buffer;
+	ktime_t current_time = ktime_get();
+
+	spin_lock(&t->lock);
+	to_proc = t->to_proc;
+	seq_printf(m,
+		   "%s %d: %pK from %d:%d to %d:%d code %x flags %x pri %ld a%d r%d elapsed %lldms",
+		   prefix, t->debug_id, t,
+		   t->from_pid,
+		   t->from_tid,
+		   to_proc ? to_proc->pid : 0,
+		   t->to_thread ? t->to_thread->pid : 0,
+		   t->code, t->flags, t->priority, t->is_async, t->is_reply,
+		   ktime_ms_delta(current_time, t->start_time));
+	spin_unlock(&t->lock);
+
+	if (proc != to_proc) {
+		/*
+		 * Can only safely deref buffer if we are holding the
+		 * correct proc inner lock for this node
+		 */
+		seq_puts(m, "\n");
+		return;
+	}
+
+	if (buffer == NULL) {
+		seq_puts(m, " buffer free\n");
+		return;
+	}
+	if (buffer->target_node)
+		seq_printf(m, " node %d", buffer->target_node->debug_id);
+	seq_printf(m, " size %zd:%zd offset %lx\n",
+		   buffer->data_size, buffer->offsets_size,
+		   buffer->user_data - proc->alloc.vm_start);
+}
+
+static void print_binder_work_ilocked(struct seq_file *m,
+				      struct binder_proc *proc,
+				      const char *prefix,
+				      const char *transaction_prefix,
+				      struct binder_work *w, bool hash_ptrs)
+{
+	struct binder_node *node;
+	struct binder_transaction *t;
+
+	switch (w->type) {
+	case BINDER_WORK_TRANSACTION:
+		t = container_of(w, struct binder_transaction, work);
+		print_binder_transaction_ilocked(
+				m, proc, transaction_prefix, t);
+		break;
+	case BINDER_WORK_RETURN_ERROR: {
+		struct binder_error *e = container_of(
+				w, struct binder_error, work);
+
+		seq_printf(m, "%stransaction error: %u\n",
+			   prefix, e->cmd);
+	} break;
+	case BINDER_WORK_TRANSACTION_COMPLETE:
+		seq_printf(m, "%stransaction complete\n", prefix);
+		break;
+	case BINDER_WORK_NODE:
+		node = container_of(w, struct binder_node, work);
+		if (hash_ptrs)
+			seq_printf(m, "%snode work %d: u%p c%p\n",
+				   prefix, node->debug_id,
+				   (void *)(long)node->ptr,
+				   (void *)(long)node->cookie);
+		else
+			seq_printf(m, "%snode work %d: u%016llx c%016llx\n",
+				   prefix, node->debug_id,
+				   (u64)node->ptr, (u64)node->cookie);
+		break;
+	case BINDER_WORK_DEAD_BINDER:
+		seq_printf(m, "%shas dead binder\n", prefix);
+		break;
+	case BINDER_WORK_DEAD_BINDER_AND_CLEAR:
+		seq_printf(m, "%shas cleared dead binder\n", prefix);
+		break;
+	case BINDER_WORK_CLEAR_DEATH_NOTIFICATION:
+		seq_printf(m, "%shas cleared death notification\n", prefix);
+		break;
+	case BINDER_WORK_FROZEN_BINDER:
+		seq_printf(m, "%shas frozen binder\n", prefix);
+		break;
+	case BINDER_WORK_CLEAR_FREEZE_NOTIFICATION:
+		seq_printf(m, "%shas cleared freeze notification\n", prefix);
+		break;
+	default:
+		seq_printf(m, "%sunknown work: type %d\n", prefix, w->type);
+		break;
+	}
+}
+
+static void print_binder_thread_ilocked(struct seq_file *m,
+					struct binder_thread *thread,
+					bool print_always, bool hash_ptrs)
+{
+	struct binder_transaction *t;
+	struct binder_work *w;
+	size_t start_pos = m->count;
+	size_t header_pos;
+
+	seq_printf(m, "  thread %d: l %02x need_return %d tr %d\n",
+			thread->pid, thread->looper,
+			thread->looper_need_return,
+			atomic_read(&thread->tmp_ref));
+	header_pos = m->count;
+	t = thread->transaction_stack;
+	while (t) {
+		if (t->from == thread) {
+			print_binder_transaction_ilocked(m, thread->proc,
+					"    outgoing transaction", t);
+			t = t->from_parent;
+		} else if (t->to_thread == thread) {
+			print_binder_transaction_ilocked(m, thread->proc,
+						 "    incoming transaction", t);
+			t = t->to_parent;
+		} else {
+			print_binder_transaction_ilocked(m, thread->proc,
+					"    bad transaction", t);
+			t = NULL;
+		}
+	}
+	list_for_each_entry(w, &thread->todo, entry) {
+		print_binder_work_ilocked(m, thread->proc, "    ",
+					  "    pending transaction",
+					  w, hash_ptrs);
+	}
+	if (!print_always && m->count == header_pos)
+		m->count = start_pos;
+}
+
+static void print_binder_node_nilocked(struct seq_file *m,
+				       struct binder_node *node,
+				       bool hash_ptrs)
+{
+	struct binder_ref *ref;
+	struct binder_work *w;
+	int count;
+
+	count = hlist_count_nodes(&node->refs);
+
+	if (hash_ptrs)
+		seq_printf(m, "  node %d: u%p c%p", node->debug_id,
+			   (void *)(long)node->ptr, (void *)(long)node->cookie);
+	else
+		seq_printf(m, "  node %d: u%016llx c%016llx", node->debug_id,
+			   (u64)node->ptr, (u64)node->cookie);
+	seq_printf(m, " hs %d hw %d ls %d lw %d is %d iw %d tr %d",
+		   node->has_strong_ref, node->has_weak_ref,
+		   node->local_strong_refs, node->local_weak_refs,
+		   node->internal_strong_refs, count, node->tmp_refs);
+	if (count) {
+		seq_puts(m, " proc");
+		hlist_for_each_entry(ref, &node->refs, node_entry)
+			seq_printf(m, " %d", ref->proc->pid);
+	}
+	seq_puts(m, "\n");
+	if (node->proc) {
+		list_for_each_entry(w, &node->async_todo, entry)
+			print_binder_work_ilocked(m, node->proc, "    ",
+					  "    pending async transaction",
+					  w, hash_ptrs);
+	}
+}
+
+static void print_binder_ref_olocked(struct seq_file *m,
+				     struct binder_ref *ref)
+{
+	binder_node_lock(ref->node);
+	seq_printf(m, "  ref %d: desc %d %snode %d s %d w %d d %pK\n",
+		   ref->data.debug_id, ref->data.desc,
+		   ref->node->proc ? "" : "dead ",
+		   ref->node->debug_id, ref->data.strong,
+		   ref->data.weak, ref->death);
+	binder_node_unlock(ref->node);
+}
+
+/**
+ * print_next_binder_node_ilocked() - Print binder_node from a locked list
+ * @m:          struct seq_file for output via seq_printf()
+ * @proc:       struct binder_proc we hold the inner_proc_lock to (if any)
+ * @node:       struct binder_node to print fields of
+ * @prev_node:	struct binder_node we hold a temporary reference to (if any)
+ * @hash_ptrs:  whether to hash @node's binder_uintptr_t fields
+ *
+ * Helper function to handle synchronization around printing a struct
+ * binder_node while iterating through @proc->nodes or the dead nodes list.
+ * Caller must hold either @proc->inner_lock (for live nodes) or
+ * binder_dead_nodes_lock. This lock will be released during the body of this
+ * function, but it will be reacquired before returning to the caller.
+ *
+ * Return:	pointer to the struct binder_node we hold a tmpref on
+ */
+static struct binder_node *
+print_next_binder_node_ilocked(struct seq_file *m, struct binder_proc *proc,
+			       struct binder_node *node,
+			       struct binder_node *prev_node, bool hash_ptrs)
+{
+	/*
+	 * Take a temporary reference on the node so that isn't freed while
+	 * we print it.
+	 */
+	binder_inc_node_tmpref_ilocked(node);
+	/*
+	 * Live nodes need to drop the inner proc lock and dead nodes need to
+	 * drop the binder_dead_nodes_lock before trying to take the node lock.
+	 */
+	if (proc)
+		binder_inner_proc_unlock(proc);
+	else
+		spin_unlock(&binder_dead_nodes_lock);
+	if (prev_node)
+		binder_put_node(prev_node);
+	binder_node_inner_lock(node);
+	print_binder_node_nilocked(m, node, hash_ptrs);
+	binder_node_inner_unlock(node);
+	if (proc)
+		binder_inner_proc_lock(proc);
+	else
+		spin_lock(&binder_dead_nodes_lock);
+	return node;
+}
+
+static void print_binder_proc(struct seq_file *m, struct binder_proc *proc,
+			      bool print_all, bool hash_ptrs)
+{
+	struct binder_work *w;
+	struct rb_node *n;
+	size_t start_pos = m->count;
+	size_t header_pos;
+	struct binder_node *last_node = NULL;
+
+	seq_printf(m, "proc %d\n", proc->pid);
+	seq_printf(m, "context %s\n", proc->context->name);
+	header_pos = m->count;
+
+	binder_inner_proc_lock(proc);
+	for (n = rb_first(&proc->threads); n; n = rb_next(n))
+		print_binder_thread_ilocked(m, rb_entry(n, struct binder_thread,
+						rb_node), print_all, hash_ptrs);
+
+	for (n = rb_first(&proc->nodes); n; n = rb_next(n)) {
+		struct binder_node *node = rb_entry(n, struct binder_node,
+						    rb_node);
+		if (!print_all && !node->has_async_transaction)
+			continue;
+
+		last_node = print_next_binder_node_ilocked(m, proc, node,
+							   last_node,
+							   hash_ptrs);
+	}
+	binder_inner_proc_unlock(proc);
+	if (last_node)
+		binder_put_node(last_node);
+
+	if (print_all) {
+		binder_proc_lock(proc);
+		for (n = rb_first(&proc->refs_by_desc); n; n = rb_next(n))
+			print_binder_ref_olocked(m, rb_entry(n,
+							     struct binder_ref,
+							     rb_node_desc));
+		binder_proc_unlock(proc);
+	}
+	binder_alloc_print_allocated(m, &proc->alloc);
+	binder_inner_proc_lock(proc);
+	list_for_each_entry(w, &proc->todo, entry)
+		print_binder_work_ilocked(m, proc, "  ",
+					  "  pending transaction", w,
+					  hash_ptrs);
+	list_for_each_entry(w, &proc->delivered_death, entry) {
+		seq_puts(m, "  has delivered dead binder\n");
+		break;
+	}
+	list_for_each_entry(w, &proc->delivered_freeze, entry) {
+		seq_puts(m, "  has delivered freeze binder\n");
+		break;
+	}
+	binder_inner_proc_unlock(proc);
+	if (!print_all && m->count == header_pos)
+		m->count = start_pos;
+}
+
+static const char * const binder_return_strings[] = {
+	"BR_ERROR",
+	"BR_OK",
+	"BR_TRANSACTION",
+	"BR_REPLY",
+	"BR_ACQUIRE_RESULT",
+	"BR_DEAD_REPLY",
+	"BR_TRANSACTION_COMPLETE",
+	"BR_INCREFS",
+	"BR_ACQUIRE",
+	"BR_RELEASE",
+	"BR_DECREFS",
+	"BR_ATTEMPT_ACQUIRE",
+	"BR_NOOP",
+	"BR_SPAWN_LOOPER",
+	"BR_FINISHED",
+	"BR_DEAD_BINDER",
+	"BR_CLEAR_DEATH_NOTIFICATION_DONE",
+	"BR_FAILED_REPLY",
+	"BR_FROZEN_REPLY",
+	"BR_ONEWAY_SPAM_SUSPECT",
+	"BR_TRANSACTION_PENDING_FROZEN",
+	"BR_FROZEN_BINDER",
+	"BR_CLEAR_FREEZE_NOTIFICATION_DONE",
+};
+
+static const char * const binder_command_strings[] = {
+	"BC_TRANSACTION",
+	"BC_REPLY",
+	"BC_ACQUIRE_RESULT",
+	"BC_FREE_BUFFER",
+	"BC_INCREFS",
+	"BC_ACQUIRE",
+	"BC_RELEASE",
+	"BC_DECREFS",
+	"BC_INCREFS_DONE",
+	"BC_ACQUIRE_DONE",
+	"BC_ATTEMPT_ACQUIRE",
+	"BC_REGISTER_LOOPER",
+	"BC_ENTER_LOOPER",
+	"BC_EXIT_LOOPER",
+	"BC_REQUEST_DEATH_NOTIFICATION",
+	"BC_CLEAR_DEATH_NOTIFICATION",
+	"BC_DEAD_BINDER_DONE",
+	"BC_TRANSACTION_SG",
+	"BC_REPLY_SG",
+	"BC_REQUEST_FREEZE_NOTIFICATION",
+	"BC_CLEAR_FREEZE_NOTIFICATION",
+	"BC_FREEZE_NOTIFICATION_DONE",
+};
+
+static const char * const binder_objstat_strings[] = {
+	"proc",
+	"thread",
+	"node",
+	"ref",
+	"death",
+	"transaction",
+	"transaction_complete",
+	"freeze",
+};
+
+static void print_binder_stats(struct seq_file *m, const char *prefix,
+			       struct binder_stats *stats)
+{
+	int i;
+
+	BUILD_BUG_ON(ARRAY_SIZE(stats->bc) !=
+		     ARRAY_SIZE(binder_command_strings));
+	for (i = 0; i < ARRAY_SIZE(stats->bc); i++) {
+		int temp = atomic_read(&stats->bc[i]);
+
+		if (temp)
+			seq_printf(m, "%s%s: %d\n", prefix,
+				   binder_command_strings[i], temp);
+	}
+
+	BUILD_BUG_ON(ARRAY_SIZE(stats->br) !=
+		     ARRAY_SIZE(binder_return_strings));
+	for (i = 0; i < ARRAY_SIZE(stats->br); i++) {
+		int temp = atomic_read(&stats->br[i]);
+
+		if (temp)
+			seq_printf(m, "%s%s: %d\n", prefix,
+				   binder_return_strings[i], temp);
+	}
+
+	BUILD_BUG_ON(ARRAY_SIZE(stats->obj_created) !=
+		     ARRAY_SIZE(binder_objstat_strings));
+	BUILD_BUG_ON(ARRAY_SIZE(stats->obj_created) !=
+		     ARRAY_SIZE(stats->obj_deleted));
+	for (i = 0; i < ARRAY_SIZE(stats->obj_created); i++) {
+		int created = atomic_read(&stats->obj_created[i]);
+		int deleted = atomic_read(&stats->obj_deleted[i]);
+
+		if (created || deleted)
+			seq_printf(m, "%s%s: active %d total %d\n",
+				prefix,
+				binder_objstat_strings[i],
+				created - deleted,
+				created);
+	}
+}
+
+static void print_binder_proc_stats(struct seq_file *m,
+				    struct binder_proc *proc)
+{
+	struct binder_work *w;
+	struct binder_thread *thread;
+	struct rb_node *n;
+	int count, strong, weak, ready_threads;
+	size_t free_async_space =
+		binder_alloc_get_free_async_space(&proc->alloc);
+
+	seq_printf(m, "proc %d\n", proc->pid);
+	seq_printf(m, "context %s\n", proc->context->name);
+	count = 0;
+	ready_threads = 0;
+	binder_inner_proc_lock(proc);
+	for (n = rb_first(&proc->threads); n; n = rb_next(n))
+		count++;
+
+	list_for_each_entry(thread, &proc->waiting_threads, waiting_thread_node)
+		ready_threads++;
+
+	seq_printf(m, "  threads: %d\n", count);
+	seq_printf(m, "  requested threads: %d+%d/%d\n"
+			"  ready threads %d\n"
+			"  free async space %zd\n", proc->requested_threads,
+			proc->requested_threads_started, proc->max_threads,
+			ready_threads,
+			free_async_space);
+	count = 0;
+	for (n = rb_first(&proc->nodes); n; n = rb_next(n))
+		count++;
+	binder_inner_proc_unlock(proc);
+	seq_printf(m, "  nodes: %d\n", count);
+	count = 0;
+	strong = 0;
+	weak = 0;
+	binder_proc_lock(proc);
+	for (n = rb_first(&proc->refs_by_desc); n; n = rb_next(n)) {
+		struct binder_ref *ref = rb_entry(n, struct binder_ref,
+						  rb_node_desc);
+		count++;
+		strong += ref->data.strong;
+		weak += ref->data.weak;
+	}
+	binder_proc_unlock(proc);
+	seq_printf(m, "  refs: %d s %d w %d\n", count, strong, weak);
+
+	count = binder_alloc_get_allocated_count(&proc->alloc);
+	seq_printf(m, "  buffers: %d\n", count);
+
+	binder_alloc_print_pages(m, &proc->alloc);
+
+	count = 0;
+	binder_inner_proc_lock(proc);
+	list_for_each_entry(w, &proc->todo, entry) {
+		if (w->type == BINDER_WORK_TRANSACTION)
+			count++;
+	}
+	binder_inner_proc_unlock(proc);
+	seq_printf(m, "  pending transactions: %d\n", count);
+
+	print_binder_stats(m, "  ", &proc->stats);
+}
+
+static void print_binder_state(struct seq_file *m, bool hash_ptrs)
+{
+	struct binder_proc *proc;
+	struct binder_node *node;
+	struct binder_node *last_node = NULL;
+
+	seq_puts(m, "binder state:\n");
+
+	spin_lock(&binder_dead_nodes_lock);
+	if (!hlist_empty(&binder_dead_nodes))
+		seq_puts(m, "dead nodes:\n");
+	hlist_for_each_entry(node, &binder_dead_nodes, dead_node)
+		last_node = print_next_binder_node_ilocked(m, NULL, node,
+							   last_node,
+							   hash_ptrs);
+	spin_unlock(&binder_dead_nodes_lock);
+	if (last_node)
+		binder_put_node(last_node);
+
+	mutex_lock(&binder_procs_lock);
+	hlist_for_each_entry(proc, &binder_procs, proc_node)
+		print_binder_proc(m, proc, true, hash_ptrs);
+	mutex_unlock(&binder_procs_lock);
+}
+
+static void print_binder_transactions(struct seq_file *m, bool hash_ptrs)
+{
+	struct binder_proc *proc;
+
+	seq_puts(m, "binder transactions:\n");
+	mutex_lock(&binder_procs_lock);
+	hlist_for_each_entry(proc, &binder_procs, proc_node)
+		print_binder_proc(m, proc, false, hash_ptrs);
+	mutex_unlock(&binder_procs_lock);
+}
+
+static int state_show(struct seq_file *m, void *unused)
+{
+	print_binder_state(m, false);
+	return 0;
+}
+
+static int state_hashed_show(struct seq_file *m, void *unused)
+{
+	print_binder_state(m, true);
+	return 0;
+}
+
+static int stats_show(struct seq_file *m, void *unused)
+{
+	struct binder_proc *proc;
+
+	seq_puts(m, "binder stats:\n");
+
+	print_binder_stats(m, "", &binder_stats);
+
+	mutex_lock(&binder_procs_lock);
+	hlist_for_each_entry(proc, &binder_procs, proc_node)
+		print_binder_proc_stats(m, proc);
+	mutex_unlock(&binder_procs_lock);
+
+	return 0;
+}
+
+static int transactions_show(struct seq_file *m, void *unused)
+{
+	print_binder_transactions(m, false);
+	return 0;
+}
+
+static int transactions_hashed_show(struct seq_file *m, void *unused)
+{
+	print_binder_transactions(m, true);
+	return 0;
+}
+
+static int proc_show(struct seq_file *m, void *unused)
+{
+	struct binder_proc *itr;
+	int pid = (unsigned long)m->private;
+
+	guard(mutex)(&binder_procs_lock);
+	hlist_for_each_entry(itr, &binder_procs, proc_node) {
+		if (itr->pid == pid) {
+			seq_puts(m, "binder proc state:\n");
+			print_binder_proc(m, itr, true, false);
+		}
+	}
+
+	return 0;
+}
+
+static void print_binder_transaction_log_entry(struct seq_file *m,
+					struct binder_transaction_log_entry *e)
+{
+	int debug_id = READ_ONCE(e->debug_id_done);
+	/*
+	 * read barrier to guarantee debug_id_done read before
+	 * we print the log values
+	 */
+	smp_rmb();
+	seq_printf(m,
+		   "%d: %s from %d:%d to %d:%d context %s node %d handle %d size %d:%d ret %d/%d l=%d",
+		   e->debug_id, (e->call_type == 2) ? "reply" :
+		   ((e->call_type == 1) ? "async" : "call "), e->from_proc,
+		   e->from_thread, e->to_proc, e->to_thread, e->context_name,
+		   e->to_node, e->target_handle, e->data_size, e->offsets_size,
+		   e->return_error, e->return_error_param,
+		   e->return_error_line);
+	/*
+	 * read-barrier to guarantee read of debug_id_done after
+	 * done printing the fields of the entry
+	 */
+	smp_rmb();
+	seq_printf(m, debug_id && debug_id == READ_ONCE(e->debug_id_done) ?
+			"\n" : " (incomplete)\n");
+}
+
+static int transaction_log_show(struct seq_file *m, void *unused)
+{
+	struct binder_transaction_log *log = m->private;
+	unsigned int log_cur = atomic_read(&log->cur);
+	unsigned int count;
+	unsigned int cur;
+	int i;
+
+	count = log_cur + 1;
+	cur = count < ARRAY_SIZE(log->entry) && !log->full ?
+		0 : count % ARRAY_SIZE(log->entry);
+	if (count > ARRAY_SIZE(log->entry) || log->full)
+		count = ARRAY_SIZE(log->entry);
+	for (i = 0; i < count; i++) {
+		unsigned int index = cur++ % ARRAY_SIZE(log->entry);
+
+		print_binder_transaction_log_entry(m, &log->entry[index]);
+	}
+	return 0;
+}
+
+const struct file_operations binder_fops = {
+	.owner = THIS_MODULE,
+	.poll = binder_poll,
+	.unlocked_ioctl = binder_ioctl,
+	.compat_ioctl = compat_ptr_ioctl,
+	.mmap = binder_mmap,
+	.open = binder_open,
+	.flush = binder_flush,
+	.release = binder_release,
+};
+
+DEFINE_SHOW_ATTRIBUTE(state);
+DEFINE_SHOW_ATTRIBUTE(state_hashed);
+DEFINE_SHOW_ATTRIBUTE(stats);
+DEFINE_SHOW_ATTRIBUTE(transactions);
+DEFINE_SHOW_ATTRIBUTE(transactions_hashed);
+DEFINE_SHOW_ATTRIBUTE(transaction_log);
+
+const struct binder_debugfs_entry binder_debugfs_entries[] = {
+	{
+		.name = "state",
+		.mode = 0444,
+		.fops = &state_fops,
+		.data = NULL,
+	},
+	{
+		.name = "state_hashed",
+		.mode = 0444,
+		.fops = &state_hashed_fops,
+		.data = NULL,
+	},
+	{
+		.name = "stats",
+		.mode = 0444,
+		.fops = &stats_fops,
+		.data = NULL,
+	},
+	{
+		.name = "transactions",
+		.mode = 0444,
+		.fops = &transactions_fops,
+		.data = NULL,
+	},
+	{
+		.name = "transactions_hashed",
+		.mode = 0444,
+		.fops = &transactions_hashed_fops,
+		.data = NULL,
+	},
+	{
+		.name = "transaction_log",
+		.mode = 0444,
+		.fops = &transaction_log_fops,
+		.data = &binder_transaction_log,
+	},
+	{
+		.name = "failed_transaction_log",
+		.mode = 0444,
+		.fops = &transaction_log_fops,
+		.data = &binder_transaction_log_failed,
+	},
+	{} /* terminator */
+};
+
+void binder_add_device(struct binder_device *device)
+{
+	guard(spinlock)(&binder_devices_lock);
+	hlist_add_head(&device->hlist, &binder_devices);
+}
+
+void binder_remove_device(struct binder_device *device)
+{
+	guard(spinlock)(&binder_devices_lock);
+	hlist_del_init(&device->hlist);
+}
+
+static int __init init_binder_device(const char *name)
+{
+	int ret;
+	struct binder_device *binder_device;
+
+	binder_device = kzalloc_obj(*binder_device);
+	if (!binder_device)
+		return -ENOMEM;
+
+	binder_device->miscdev.fops = &binder_fops;
+	binder_device->miscdev.minor = MISC_DYNAMIC_MINOR;
+	binder_device->miscdev.name = name;
+
+	refcount_set(&binder_device->ref, 1);
+	binder_device->context.binder_context_mgr_uid = INVALID_UID;
+	binder_device->context.name = name;
+	mutex_init(&binder_device->context.context_mgr_node_lock);
+
+	ret = misc_register(&binder_device->miscdev);
+	if (ret < 0) {
+		kfree(binder_device);
+		return ret;
+	}
+
+	binder_add_device(binder_device);
+
+	return ret;
+}
+
+static int __init binder_init(void)
+{
+	int ret;
+	char *device_name, *device_tmp;
+	struct binder_device *device;
+	struct hlist_node *tmp;
+	char *device_names = NULL;
+	const struct binder_debugfs_entry *db_entry;
+
+	ret = binder_alloc_shrinker_init();
+	if (ret)
+		return ret;
+
+	atomic_set(&binder_transaction_log.cur, ~0U);
+	atomic_set(&binder_transaction_log_failed.cur, ~0U);
+
+	binder_debugfs_dir_entry_root = debugfs_create_dir("binder", NULL);
+
+	binder_for_each_debugfs_entry(db_entry)
+		debugfs_create_file(db_entry->name,
+					db_entry->mode,
+					binder_debugfs_dir_entry_root,
+					db_entry->data,
+					db_entry->fops);
+
+	binder_debugfs_dir_entry_proc = debugfs_create_dir("proc",
+						binder_debugfs_dir_entry_root);
+
+	if (!IS_ENABLED(CONFIG_ANDROID_BINDERFS) &&
+	    strcmp(binder_devices_param, "") != 0) {
+		/*
+		* Copy the module_parameter string, because we don't want to
+		* tokenize it in-place.
+		 */
+		device_names = kstrdup(binder_devices_param, GFP_KERNEL);
+		if (!device_names) {
+			ret = -ENOMEM;
+			goto err_alloc_device_names_failed;
+		}
+
+		device_tmp = device_names;
+		while ((device_name = strsep(&device_tmp, ","))) {
+			ret = init_binder_device(device_name);
+			if (ret)
+				goto err_init_binder_device_failed;
+		}
+	}
+
+	ret = genl_register_family(&binder_nl_family);
+	if (ret)
+		goto err_init_binder_device_failed;
+
+	ret = init_binderfs();
+	if (ret)
+		goto err_init_binderfs_failed;
+
+	return ret;
+
+err_init_binderfs_failed:
+	genl_unregister_family(&binder_nl_family);
+
+err_init_binder_device_failed:
+	hlist_for_each_entry_safe(device, tmp, &binder_devices, hlist) {
+		misc_deregister(&device->miscdev);
+		binder_remove_device(device);
+		kfree(device);
+	}
+
+	kfree(device_names);
+
+err_alloc_device_names_failed:
+	debugfs_remove_recursive(binder_debugfs_dir_entry_root);
+	binder_alloc_shrinker_exit();
+
+	return ret;
+}
+
+device_initcall(binder_init);
+
+#define CREATE_TRACE_POINTS
+#include "binder_trace.h"
diff --git a/drivers/android/binder/Makefile b/drivers/android/binder/Makefile
new file mode 100644
index 000000000..7e0cd9782
--- /dev/null
+++ b/drivers/android/binder/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+ccflags-y += -I$(src)	# needed for trace events
+
+obj-$(CONFIG_ANDROID_BINDER_IPC_RUST) += rust_binder.o
+rust_binder-y := \
+	rust_binder_main.o	\
+	rust_binderfs.o		\
+	rust_binder_events.o
diff --git a/drivers/android/binder/allocation.rs b/drivers/android/binder/allocation.rs
new file mode 100644
index 000000000..165cb797e
--- /dev/null
+++ b/drivers/android/binder/allocation.rs
@@ -0,0 +1,612 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use core::mem::{size_of, size_of_val, MaybeUninit};
+use core::ops::Range;
+
+use kernel::{
+    bindings,
+    fs::file::{File, FileDescriptorReservation},
+    prelude::*,
+    sync::{aref::ARef, Arc},
+    transmute::{AsBytes, FromBytes},
+    uaccess::UserSliceReader,
+    uapi,
+};
+
+use crate::{
+    deferred_close::DeferredFdCloser,
+    defs::*,
+    node::{Node, NodeRef},
+    process::Process,
+    DArc,
+};
+
+#[derive(Default)]
+pub(crate) struct AllocationInfo {
+    /// Range within the allocation where we can find the offsets to the object descriptors.
+    pub(crate) offsets: Option<Range<usize>>,
+    /// The target node of the transaction this allocation is associated to.
+    /// Not set for replies.
+    pub(crate) target_node: Option<NodeRef>,
+    /// When this allocation is dropped, call `pending_oneway_finished` on the node.
+    ///
+    /// This is used to serialize oneway transaction on the same node. Binder guarantees that
+    /// oneway transactions to the same node are delivered sequentially in the order they are sent.
+    pub(crate) oneway_node: Option<DArc<Node>>,
+    /// Zero the data in the buffer on free.
+    pub(crate) clear_on_free: bool,
+    /// List of files embedded in this transaction.
+    file_list: FileList,
+}
+
+/// Represents an allocation that the kernel is currently using.
+///
+/// When allocations are idle, the range allocator holds the data related to them.
+///
+/// # Invariants
+///
+/// This allocation corresponds to an allocation in the range allocator, so the relevant pages are
+/// marked in use in the page range.
+pub(crate) struct Allocation {
+    pub(crate) offset: usize,
+    size: usize,
+    pub(crate) ptr: usize,
+    pub(crate) process: Arc<Process>,
+    allocation_info: Option<AllocationInfo>,
+    free_on_drop: bool,
+    #[allow(dead_code)]
+    pub(crate) debug_id: usize,
+}
+
+impl Allocation {
+    pub(crate) fn new(
+        process: Arc<Process>,
+        debug_id: usize,
+        offset: usize,
+        size: usize,
+        ptr: usize,
+    ) -> Self {
+        Self {
+            process,
+            offset,
+            size,
+            ptr,
+            debug_id,
+            allocation_info: None,
+            free_on_drop: true,
+        }
+    }
+
+    fn size_check(&self, offset: usize, size: usize) -> Result {
+        let overflow_fail = offset.checked_add(size).is_none();
+        let cmp_size_fail = offset.wrapping_add(size) > self.size;
+        if overflow_fail || cmp_size_fail {
+            return Err(EFAULT);
+        }
+        Ok(())
+    }
+
+    pub(crate) fn copy_into(
+        &self,
+        reader: &mut UserSliceReader,
+        offset: usize,
+        size: usize,
+    ) -> Result {
+        self.size_check(offset, size)?;
+
+        // SAFETY: While this object exists, the range allocator will keep the range allocated, and
+        // in turn, the pages will be marked as in use.
+        unsafe {
+            self.process
+                .pages
+                .copy_from_user_slice(reader, self.offset + offset, size)
+        }
+    }
+
+    pub(crate) fn read<T: FromBytes>(&self, offset: usize) -> Result<T> {
+        self.size_check(offset, size_of::<T>())?;
+
+        // SAFETY: While this object exists, the range allocator will keep the range allocated, and
+        // in turn, the pages will be marked as in use.
+        unsafe { self.process.pages.read(self.offset + offset) }
+    }
+
+    pub(crate) fn write<T: ?Sized>(&self, offset: usize, obj: &T) -> Result {
+        self.size_check(offset, size_of_val::<T>(obj))?;
+
+        // SAFETY: While this object exists, the range allocator will keep the range allocated, and
+        // in turn, the pages will be marked as in use.
+        unsafe { self.process.pages.write(self.offset + offset, obj) }
+    }
+
+    pub(crate) fn fill_zero(&self) -> Result {
+        // SAFETY: While this object exists, the range allocator will keep the range allocated, and
+        // in turn, the pages will be marked as in use.
+        unsafe { self.process.pages.fill_zero(self.offset, self.size) }
+    }
+
+    pub(crate) fn keep_alive(mut self) {
+        self.process
+            .buffer_make_freeable(self.offset, self.allocation_info.take());
+        self.free_on_drop = false;
+    }
+
+    pub(crate) fn set_info(&mut self, info: AllocationInfo) {
+        self.allocation_info = Some(info);
+    }
+
+    pub(crate) fn get_or_init_info(&mut self) -> &mut AllocationInfo {
+        self.allocation_info.get_or_insert_with(Default::default)
+    }
+
+    pub(crate) fn set_info_offsets(&mut self, offsets: Range<usize>) {
+        self.get_or_init_info().offsets = Some(offsets);
+    }
+
+    pub(crate) fn set_info_oneway_node(&mut self, oneway_node: DArc<Node>) {
+        self.get_or_init_info().oneway_node = Some(oneway_node);
+    }
+
+    pub(crate) fn set_info_clear_on_drop(&mut self) {
+        self.get_or_init_info().clear_on_free = true;
+    }
+
+    pub(crate) fn set_info_target_node(&mut self, target_node: NodeRef) {
+        self.get_or_init_info().target_node = Some(target_node);
+    }
+
+    pub(crate) fn take_oneway_node(&mut self) -> Option<DArc<Node>> {
+        if let Some(info) = self.allocation_info.as_mut() {
+            info.oneway_node.take()
+        } else {
+            None
+        }
+    }
+
+    /// Reserve enough space to push at least `num_fds` fds.
+    pub(crate) fn info_add_fd_reserve(&mut self, num_fds: usize) -> Result {
+        self.get_or_init_info()
+            .file_list
+            .files_to_translate
+            .reserve(num_fds, GFP_KERNEL)?;
+
+        Ok(())
+    }
+
+    pub(crate) fn info_add_fd(
+        &mut self,
+        file: ARef<File>,
+        buffer_offset: usize,
+        close_on_free: bool,
+    ) -> Result {
+        self.get_or_init_info().file_list.files_to_translate.push(
+            FileEntry {
+                file,
+                buffer_offset,
+                close_on_free,
+            },
+            GFP_KERNEL,
+        )?;
+
+        Ok(())
+    }
+
+    pub(crate) fn set_info_close_on_free(&mut self, cof: FdsCloseOnFree) {
+        self.get_or_init_info().file_list.close_on_free = cof.0;
+    }
+
+    pub(crate) fn translate_fds(&mut self) -> Result<TranslatedFds> {
+        let file_list = match self.allocation_info.as_mut() {
+            Some(info) => &mut info.file_list,
+            None => return Ok(TranslatedFds::new()),
+        };
+
+        let files = core::mem::take(&mut file_list.files_to_translate);
+
+        let num_close_on_free = files.iter().filter(|entry| entry.close_on_free).count();
+        let mut close_on_free = KVec::with_capacity(num_close_on_free, GFP_KERNEL)?;
+
+        let mut reservations = KVec::with_capacity(files.len(), GFP_KERNEL)?;
+        for file_info in files {
+            let res = FileDescriptorReservation::get_unused_fd_flags(bindings::O_CLOEXEC)?;
+            let fd = res.reserved_fd();
+            self.write::<u32>(file_info.buffer_offset, &fd)?;
+            crate::trace::trace_transaction_fd_recv(self.debug_id, fd, file_info.buffer_offset);
+
+            reservations.push(
+                Reservation {
+                    res,
+                    file: file_info.file,
+                },
+                GFP_KERNEL,
+            )?;
+            if file_info.close_on_free {
+                close_on_free.push(fd, GFP_KERNEL)?;
+            }
+        }
+
+        Ok(TranslatedFds {
+            reservations,
+            close_on_free: FdsCloseOnFree(close_on_free),
+        })
+    }
+
+    /// Should the looper return to userspace when freeing this allocation?
+    pub(crate) fn looper_need_return_on_free(&self) -> bool {
+        // Closing fds involves pushing task_work for execution when we return to userspace. Hence,
+        // we should return to userspace asap if we are closing fds.
+        match self.allocation_info {
+            Some(ref info) => !info.file_list.close_on_free.is_empty(),
+            None => false,
+        }
+    }
+}
+
+impl Drop for Allocation {
+    fn drop(&mut self) {
+        if !self.free_on_drop {
+            return;
+        }
+
+        if let Some(mut info) = self.allocation_info.take() {
+            if let Some(oneway_node) = info.oneway_node.as_ref() {
+                oneway_node.pending_oneway_finished();
+            }
+
+            info.target_node = None;
+
+            if let Some(offsets) = info.offsets.clone() {
+                let view = AllocationView::new(self, offsets.start);
+                for i in offsets.step_by(size_of::<u64>()) {
+                    if view.cleanup_object(i).is_err() {
+                        pr_warn!("Error cleaning up object at offset {}\n", i)
+                    }
+                }
+            }
+
+            if self.process.task == kernel::current!().group_leader() {
+                for &fd in &info.file_list.close_on_free {
+                    let closer = match DeferredFdCloser::new(GFP_KERNEL) {
+                        Ok(closer) => closer,
+                        Err(kernel::alloc::AllocError) => {
+                            // Ignore allocation failures.
+                            break;
+                        }
+                    };
+
+                    // Here, we ignore errors. The operation can fail if the fd is not valid, or if
+                    // the method is called from a kthread. However, this is always called from a
+                    // syscall, so the latter case cannot happen, and we don't care about the first
+                    // case.
+                    let _ = closer.close_fd(fd);
+                }
+            }
+
+            if info.clear_on_free {
+                if let Err(e) = self.fill_zero() {
+                    pr_warn!("Failed to clear data on free: {:?}", e);
+                }
+            }
+        }
+
+        self.process.buffer_raw_free(self.ptr);
+    }
+}
+
+/// A wrapper around `Allocation` that is being created.
+///
+/// If the allocation is destroyed while wrapped in this wrapper, then the allocation will be
+/// considered to be part of a failed transaction. Successful transactions avoid that by calling
+/// `success`, which skips the destructor.
+#[repr(transparent)]
+pub(crate) struct NewAllocation(pub(crate) Allocation);
+
+impl NewAllocation {
+    pub(crate) fn success(self) -> Allocation {
+        // This skips the destructor.
+        //
+        // SAFETY: This type is `#[repr(transparent)]`, so the layout matches.
+        unsafe { core::mem::transmute(self) }
+    }
+}
+
+impl core::ops::Deref for NewAllocation {
+    type Target = Allocation;
+    fn deref(&self) -> &Allocation {
+        &self.0
+    }
+}
+
+impl core::ops::DerefMut for NewAllocation {
+    fn deref_mut(&mut self) -> &mut Allocation {
+        &mut self.0
+    }
+}
+
+/// A view into the beginning of an allocation.
+///
+/// All attempts to read or write outside of the view will fail. To intentionally access outside of
+/// this view, use the `alloc` field of this struct directly.
+pub(crate) struct AllocationView<'a> {
+    pub(crate) alloc: &'a mut Allocation,
+    limit: usize,
+}
+
+impl<'a> AllocationView<'a> {
+    pub(crate) fn new(alloc: &'a mut Allocation, limit: usize) -> Self {
+        AllocationView { alloc, limit }
+    }
+
+    pub(crate) fn read<T: FromBytes>(&self, offset: usize) -> Result<T> {
+        if offset.checked_add(size_of::<T>()).ok_or(EINVAL)? > self.limit {
+            return Err(EINVAL);
+        }
+        self.alloc.read(offset)
+    }
+
+    pub(crate) fn write<T: AsBytes>(&self, offset: usize, obj: &T) -> Result {
+        if offset.checked_add(size_of::<T>()).ok_or(EINVAL)? > self.limit {
+            return Err(EINVAL);
+        }
+        self.alloc.write(offset, obj)
+    }
+
+    pub(crate) fn copy_into(
+        &self,
+        reader: &mut UserSliceReader,
+        offset: usize,
+        size: usize,
+    ) -> Result {
+        if offset.checked_add(size).ok_or(EINVAL)? > self.limit {
+            return Err(EINVAL);
+        }
+        self.alloc.copy_into(reader, offset, size)
+    }
+
+    pub(crate) fn transfer_binder_object(
+        &self,
+        offset: usize,
+        obj: &uapi::flat_binder_object,
+        strong: bool,
+        node_ref: NodeRef,
+    ) -> Result {
+        let mut newobj = FlatBinderObject::default();
+        let node = node_ref.node.clone();
+        if Arc::ptr_eq(&node_ref.node.owner, &self.alloc.process) {
+            // The receiving process is the owner of the node, so send it a binder object (instead
+            // of a handle).
+            let (ptr, cookie) = node.get_id();
+            newobj.hdr.type_ = if strong {
+                BINDER_TYPE_BINDER
+            } else {
+                BINDER_TYPE_WEAK_BINDER
+            };
+            newobj.flags = obj.flags;
+            newobj.__bindgen_anon_1.binder = ptr as uapi::binder_uintptr_t;
+            newobj.cookie = cookie as uapi::binder_uintptr_t;
+            self.write(offset, &newobj)?;
+            // Increment the user ref count on the node. It will be decremented as part of the
+            // destruction of the buffer, when we see a binder or weak-binder object.
+            node.update_refcount(true, 1, strong);
+        } else {
+            // The receiving process is different from the owner, so we need to insert a handle to
+            // the binder object.
+            let handle = self
+                .alloc
+                .process
+                .as_arc_borrow()
+                .insert_or_update_handle(node_ref, false)?;
+            newobj.hdr.type_ = if strong {
+                BINDER_TYPE_HANDLE
+            } else {
+                BINDER_TYPE_WEAK_HANDLE
+            };
+            newobj.flags = obj.flags;
+            newobj.__bindgen_anon_1.handle = handle;
+            if self.write(offset, &newobj).is_err() {
+                // Decrement ref count on the handle we just created.
+                let _ = self
+                    .alloc
+                    .process
+                    .as_arc_borrow()
+                    .update_ref(handle, false, strong);
+                return Err(EINVAL);
+            }
+        }
+
+        Ok(())
+    }
+
+    fn cleanup_object(&self, index_offset: usize) -> Result {
+        let offset = self.alloc.read::<u64>(index_offset)?;
+        let offset: usize = offset.try_into().map_err(|_| EINVAL)?;
+        let header = self.read::<BinderObjectHeader>(offset)?;
+        match header.type_ {
+            BINDER_TYPE_WEAK_BINDER | BINDER_TYPE_BINDER => {
+                let obj = self.read::<FlatBinderObject>(offset)?;
+                let strong = header.type_ == BINDER_TYPE_BINDER;
+                // SAFETY: The type is `BINDER_TYPE_{WEAK_}BINDER`, so the `binder` field is
+                // populated.
+                let ptr = unsafe { obj.__bindgen_anon_1.binder };
+                let cookie = obj.cookie;
+                self.alloc.process.update_node(ptr, cookie, strong);
+                Ok(())
+            }
+            BINDER_TYPE_WEAK_HANDLE | BINDER_TYPE_HANDLE => {
+                let obj = self.read::<FlatBinderObject>(offset)?;
+                let strong = header.type_ == BINDER_TYPE_HANDLE;
+                // SAFETY: The type is `BINDER_TYPE_{WEAK_}HANDLE`, so the `handle` field is
+                // populated.
+                let handle = unsafe { obj.__bindgen_anon_1.handle };
+                self.alloc
+                    .process
+                    .as_arc_borrow()
+                    .update_ref(handle, false, strong)
+            }
+            _ => Ok(()),
+        }
+    }
+}
+
+/// A binder object as it is serialized.
+///
+/// # Invariants
+///
+/// All bytes must be initialized, and the value of `self.hdr.type_` must be one of the allowed
+/// types.
+#[repr(C)]
+pub(crate) union BinderObject {
+    hdr: uapi::binder_object_header,
+    fbo: uapi::flat_binder_object,
+    fdo: uapi::binder_fd_object,
+    bbo: uapi::binder_buffer_object,
+    fdao: uapi::binder_fd_array_object,
+}
+
+/// A view into a `BinderObject` that can be used in a match statement.
+pub(crate) enum BinderObjectRef<'a> {
+    Binder(&'a mut uapi::flat_binder_object),
+    Handle(&'a mut uapi::flat_binder_object),
+    Fd(&'a mut uapi::binder_fd_object),
+    Ptr(&'a mut uapi::binder_buffer_object),
+    Fda(&'a mut uapi::binder_fd_array_object),
+}
+
+impl BinderObject {
+    pub(crate) fn read_from(reader: &mut UserSliceReader) -> Result<BinderObject> {
+        let object = Self::read_from_inner(|slice| {
+            let read_len = usize::min(slice.len(), reader.len());
+            reader.clone_reader().read_slice(&mut slice[..read_len])?;
+            Ok(())
+        })?;
+
+        // If we used a object type smaller than the largest object size, then we've read more
+        // bytes than we needed to. However, we used `.clone_reader()` to avoid advancing the
+        // original reader. Now, we call `skip` so that the caller's reader is advanced by the
+        // right amount.
+        //
+        // The `skip` call fails if the reader doesn't have `size` bytes available. This could
+        // happen if the type header corresponds to an object type that is larger than the rest of
+        // the reader.
+        //
+        // Any extra bytes beyond the size of the object are inaccessible after this call, so
+        // reading them again from the `reader` later does not result in TOCTOU bugs.
+        reader.skip(object.size())?;
+
+        Ok(object)
+    }
+
+    /// Use the provided reader closure to construct a `BinderObject`.
+    ///
+    /// The closure should write the bytes for the object into the provided slice.
+    pub(crate) fn read_from_inner<R>(reader: R) -> Result<BinderObject>
+    where
+        R: FnOnce(&mut [u8; size_of::<BinderObject>()]) -> Result<()>,
+    {
+        let mut obj = MaybeUninit::<BinderObject>::zeroed();
+
+        // SAFETY: The lengths of `BinderObject` and `[u8; size_of::<BinderObject>()]` are equal,
+        // and the byte array has an alignment requirement of one, so the pointer cast is okay.
+        // Additionally, `obj` was initialized to zeros, so the byte array will not be
+        // uninitialized.
+        (reader)(unsafe { &mut *obj.as_mut_ptr().cast() })?;
+
+        // SAFETY: The entire object is initialized, so accessing this field is safe.
+        let type_ = unsafe { obj.assume_init_ref().hdr.type_ };
+        if Self::type_to_size(type_).is_none() {
+            // The value of `obj.hdr_type_` was invalid.
+            return Err(EINVAL);
+        }
+
+        // SAFETY: All bytes are initialized (since we zeroed them at the start) and we checked
+        // that `self.hdr.type_` is one of the allowed types, so the type invariants are satisfied.
+        unsafe { Ok(obj.assume_init()) }
+    }
+
+    pub(crate) fn as_ref(&mut self) -> BinderObjectRef<'_> {
+        use BinderObjectRef::*;
+        // SAFETY: The constructor ensures that all bytes of `self` are initialized, and all
+        // variants of this union accept all initialized bit patterns.
+        unsafe {
+            match self.hdr.type_ {
+                BINDER_TYPE_WEAK_BINDER | BINDER_TYPE_BINDER => Binder(&mut self.fbo),
+                BINDER_TYPE_WEAK_HANDLE | BINDER_TYPE_HANDLE => Handle(&mut self.fbo),
+                BINDER_TYPE_FD => Fd(&mut self.fdo),
+                BINDER_TYPE_PTR => Ptr(&mut self.bbo),
+                BINDER_TYPE_FDA => Fda(&mut self.fdao),
+                // SAFETY: By the type invariant, the value of `self.hdr.type_` cannot have any
+                // other value than the ones checked above.
+                _ => core::hint::unreachable_unchecked(),
+            }
+        }
+    }
+
+    pub(crate) fn size(&self) -> usize {
+        // SAFETY: The entire object is initialized, so accessing this field is safe.
+        let type_ = unsafe { self.hdr.type_ };
+
+        // SAFETY: The type invariants guarantee that the type field is correct.
+        unsafe { Self::type_to_size(type_).unwrap_unchecked() }
+    }
+
+    fn type_to_size(type_: u32) -> Option<usize> {
+        match type_ {
+            BINDER_TYPE_WEAK_BINDER => Some(size_of::<uapi::flat_binder_object>()),
+            BINDER_TYPE_BINDER => Some(size_of::<uapi::flat_binder_object>()),
+            BINDER_TYPE_WEAK_HANDLE => Some(size_of::<uapi::flat_binder_object>()),
+            BINDER_TYPE_HANDLE => Some(size_of::<uapi::flat_binder_object>()),
+            BINDER_TYPE_FD => Some(size_of::<uapi::binder_fd_object>()),
+            BINDER_TYPE_PTR => Some(size_of::<uapi::binder_buffer_object>()),
+            BINDER_TYPE_FDA => Some(size_of::<uapi::binder_fd_array_object>()),
+            _ => None,
+        }
+    }
+}
+
+#[derive(Default)]
+struct FileList {
+    files_to_translate: KVec<FileEntry>,
+    close_on_free: KVec<u32>,
+}
+
+struct FileEntry {
+    /// The file for which a descriptor will be created in the recipient process.
+    file: ARef<File>,
+    /// The offset in the buffer where the file descriptor is stored.
+    buffer_offset: usize,
+    /// Whether this fd should be closed when the allocation is freed.
+    close_on_free: bool,
+}
+
+pub(crate) struct TranslatedFds {
+    reservations: KVec<Reservation>,
+    /// If commit is called, then these fds should be closed. (If commit is not called, then they
+    /// shouldn't be closed.)
+    close_on_free: FdsCloseOnFree,
+}
+
+struct Reservation {
+    res: FileDescriptorReservation,
+    file: ARef<File>,
+}
+
+impl TranslatedFds {
+    pub(crate) fn new() -> Self {
+        Self {
+            reservations: KVec::new(),
+            close_on_free: FdsCloseOnFree(KVec::new()),
+        }
+    }
+
+    pub(crate) fn commit(self) -> FdsCloseOnFree {
+        for entry in self.reservations {
+            entry.res.fd_install(entry.file);
+        }
+
+        self.close_on_free
+    }
+}
+
+pub(crate) struct FdsCloseOnFree(KVec<u32>);
diff --git a/drivers/android/binder/context.rs b/drivers/android/binder/context.rs
new file mode 100644
index 000000000..ddddb66b3
--- /dev/null
+++ b/drivers/android/binder/context.rs
@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use kernel::{
+    alloc::kvec::KVVec,
+    error::code::*,
+    prelude::*,
+    security,
+    str::{CStr, CString},
+    sync::{Arc, Mutex},
+    task::Kuid,
+};
+
+use crate::{error::BinderError, node::NodeRef, process::Process};
+
+kernel::sync::global_lock! {
+    // SAFETY: We call `init` in the module initializer, so it's initialized before first use.
+    pub(crate) unsafe(uninit) static CONTEXTS: Mutex<ContextList> = ContextList {
+        contexts: KVVec::new(),
+    };
+}
+
+pub(crate) struct ContextList {
+    contexts: KVVec<Arc<Context>>,
+}
+
+pub(crate) fn get_all_contexts() -> Result<KVVec<Arc<Context>>> {
+    let lock = CONTEXTS.lock();
+    let mut ctxs = KVVec::with_capacity(lock.contexts.len(), GFP_KERNEL)?;
+    for ctx in lock.contexts.iter() {
+        ctxs.push(ctx.clone(), GFP_KERNEL)?;
+    }
+    Ok(ctxs)
+}
+
+/// This struct keeps track of the processes using this context, and which process is the context
+/// manager.
+struct Manager {
+    node: Option<NodeRef>,
+    uid: Option<Kuid>,
+    all_procs: KVVec<Arc<Process>>,
+}
+
+/// There is one context per binder file (/dev/binder, /dev/hwbinder, etc)
+#[pin_data]
+pub(crate) struct Context {
+    #[pin]
+    manager: Mutex<Manager>,
+    pub(crate) name: CString,
+}
+
+impl Context {
+    pub(crate) fn new(name: &CStr) -> Result<Arc<Self>> {
+        let name = CString::try_from(name)?;
+        let ctx = Arc::pin_init(
+            try_pin_init!(Context {
+                name,
+                manager <- kernel::new_mutex!(Manager {
+                    all_procs: KVVec::new(),
+                    node: None,
+                    uid: None,
+                }, "Context::manager"),
+            }),
+            GFP_KERNEL,
+        )?;
+
+        CONTEXTS.lock().contexts.push(ctx.clone(), GFP_KERNEL)?;
+
+        Ok(ctx)
+    }
+
+    /// Called when the file for this context is unlinked.
+    ///
+    /// No-op if called twice.
+    pub(crate) fn deregister(self: &Arc<Self>) {
+        // Safe removal using retain
+        CONTEXTS.lock().contexts.retain(|c| !Arc::ptr_eq(c, self));
+    }
+
+    pub(crate) fn register_process(self: &Arc<Self>, proc: Arc<Process>) -> Result {
+        if !Arc::ptr_eq(self, &proc.ctx) {
+            pr_err!("Context::register_process called on the wrong context.");
+            return Err(EINVAL);
+        }
+        self.manager.lock().all_procs.push(proc, GFP_KERNEL)?;
+        Ok(())
+    }
+
+    pub(crate) fn deregister_process(self: &Arc<Self>, proc: &Arc<Process>) {
+        if !Arc::ptr_eq(self, &proc.ctx) {
+            pr_err!("Context::deregister_process called on the wrong context.");
+            return;
+        }
+        let mut manager = self.manager.lock();
+        manager.all_procs.retain(|p| !Arc::ptr_eq(p, proc));
+
+        // Shrink the vector if it has significant unused capacity to avoid memory waste,
+        // but use a conservative strategy to prevent shrink-then-regrow oscillation.
+        // Only shrink when length drops below 1/4 of capacity, and shrink to twice the length.
+        let len = manager.all_procs.len();
+        let cap = manager.all_procs.capacity();
+        if len < cap / 4 {
+            // Shrink to twice the current length. Ignore allocation failures since this
+            // is just an optimization; the vector remains valid even if shrinking fails.
+            let _ = manager.all_procs.shrink_to(len * 2, GFP_KERNEL);
+        }
+    }
+
+    pub(crate) fn set_manager_node(&self, node_ref: NodeRef) -> Result {
+        let mut manager = self.manager.lock();
+        if manager.node.is_some() {
+            pr_warn!("BINDER_SET_CONTEXT_MGR already set");
+            return Err(EBUSY);
+        }
+        security::binder_set_context_mgr(&node_ref.node.owner.cred)?;
+
+        // If the context manager has been set before, ensure that we use the same euid.
+        let caller_uid = Kuid::current_euid();
+        if let Some(ref uid) = manager.uid {
+            if *uid != caller_uid {
+                return Err(EPERM);
+            }
+        }
+
+        manager.node = Some(node_ref);
+        manager.uid = Some(caller_uid);
+        Ok(())
+    }
+
+    pub(crate) fn unset_manager_node(&self) {
+        let node_ref = self.manager.lock().node.take();
+        drop(node_ref);
+    }
+
+    pub(crate) fn get_manager_node(&self, strong: bool) -> Result<NodeRef, BinderError> {
+        self.manager
+            .lock()
+            .node
+            .as_ref()
+            .ok_or_else(BinderError::new_dead)?
+            .clone(strong)
+            .map_err(BinderError::from)
+    }
+
+    pub(crate) fn for_each_proc<F>(&self, mut func: F)
+    where
+        F: FnMut(&Process),
+    {
+        let lock = self.manager.lock();
+        for proc in &lock.all_procs {
+            func(proc);
+        }
+    }
+
+    pub(crate) fn get_all_procs(&self) -> Result<KVVec<Arc<Process>>> {
+        let lock = self.manager.lock();
+        let mut procs = KVVec::with_capacity(lock.all_procs.len(), GFP_KERNEL)?;
+        for proc in lock.all_procs.iter() {
+            procs.push(Arc::clone(proc), GFP_KERNEL)?;
+        }
+        Ok(procs)
+    }
+
+    pub(crate) fn get_procs_with_pid(&self, pid: i32) -> Result<KVVec<Arc<Process>>> {
+        let lock = self.manager.lock();
+        let mut matching_procs = KVVec::new();
+        for proc in lock.all_procs.iter() {
+            if proc.task.pid() == pid {
+                matching_procs.push(Arc::clone(proc), GFP_KERNEL)?;
+            }
+        }
+        Ok(matching_procs)
+    }
+}
diff --git a/drivers/android/binder/debug.rs b/drivers/android/binder/debug.rs
new file mode 100644
index 000000000..824b10c00
--- /dev/null
+++ b/drivers/android/binder/debug.rs
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2026 Google LLC.
+
+//! Binder debugging helpers.
+
+#![allow(dead_code)]
+
+use kernel::bits::bit_u32;
+use kernel::sync::atomic::Atomic;
+
+kernel::impl_flags!(
+    /// Represents multiple debug mask flags.
+    #[derive(Debug, Clone, Default, Copy, PartialEq, Eq)]
+    pub struct DebugMasks(u32);
+
+    /// Represents a single debug mask category.
+    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+    pub enum DebugMask {
+        UserError = bit_u32(0),
+        FailedTransaction = bit_u32(1),
+        DeadTransaction = bit_u32(2),
+        OpenClose = bit_u32(3),
+        DeadBinder = bit_u32(4),
+        DeathNotification = bit_u32(5),
+        ReadWrite = bit_u32(6),
+        UserRefs = bit_u32(7),
+        Threads = bit_u32(8),
+        Transaction = bit_u32(9),
+        TransactionComplete = bit_u32(10),
+        FreeBuffer = bit_u32(11),
+        InternalRefs = bit_u32(12),
+        PriorityCap = bit_u32(13),
+        Spinlocks = bit_u32(14),
+    }
+);
+
+#[no_mangle]
+pub(crate) static rust_binder_debug_mask: Atomic<u32> = Atomic::new(
+    (DebugMask::UserError as u32)
+        | (DebugMask::FailedTransaction as u32)
+        | (DebugMask::DeadTransaction as u32),
+);
+
+/// Checks if the given debug logging category is enabled in the mask.
+pub(crate) fn debug_mask_enabled(mask: DebugMask) -> bool {
+    let current_mask = rust_binder_debug_mask.load(kernel::sync::atomic::Relaxed);
+    DebugMasks(current_mask).contains(mask)
+}
+
+/// Prints a debug log if the specified mask category is enabled.
+#[macro_export]
+macro_rules! binder_debug {
+    // Rule to explicitly specify a PID (used in kworkers).
+    (pid=$pid:expr, $mask:ident, $($arg:tt)*) => {
+        if $crate::debug::debug_mask_enabled($crate::debug::DebugMask::$mask) {
+            kernel::pr_info!(
+                "{}: {}\n",
+                $pid,
+                kernel::prelude::fmt!($($arg)*)
+            );
+        }
+    };
+
+    // Default rule (automatically prepends "PID:TID" of the current calling thread).
+    ($mask:ident, $($arg:tt)*) => {
+        if $crate::debug::debug_mask_enabled($crate::debug::DebugMask::$mask) {
+            let thread = kernel::current!();
+            kernel::pr_info!(
+                "{}:{} {}\n",
+                thread.tgid(),
+                thread.pid(),
+                kernel::prelude::fmt!($($arg)*)
+            );
+        }
+    };
+}
diff --git a/drivers/android/binder/deferred_close.rs b/drivers/android/binder/deferred_close.rs
new file mode 100644
index 000000000..ac895c04d
--- /dev/null
+++ b/drivers/android/binder/deferred_close.rs
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+//! Logic for closing files in a deferred manner.
+//!
+//! This file could make sense to have in `kernel::fs`, but it was rejected for being too
+//! Binder-specific.
+
+use core::mem::MaybeUninit;
+use kernel::{
+    alloc::{AllocError, Flags},
+    bindings,
+    prelude::*,
+};
+
+/// Helper used for closing file descriptors in a way that is safe even if the file is currently
+/// held using `fdget`.
+///
+/// Additional motivation can be found in commit 80cd795630d6 ("binder: fix use-after-free due to
+/// ksys_close() during fdget()") and in the comments on `binder_do_fd_close`.
+pub(crate) struct DeferredFdCloser {
+    inner: KBox<DeferredFdCloserInner>,
+}
+
+/// SAFETY: This just holds an allocation with no real content, so there's no safety issue with
+/// moving it across threads.
+unsafe impl Send for DeferredFdCloser {}
+/// SAFETY: This just holds an allocation with no real content, so there's no safety issue with
+/// moving it across threads.
+unsafe impl Sync for DeferredFdCloser {}
+
+/// # Invariants
+///
+/// If the `file` pointer is non-null, then it points at a `struct file` and owns a refcount to
+/// that file.
+#[repr(C)]
+struct DeferredFdCloserInner {
+    twork: MaybeUninit<bindings::callback_head>,
+    file: *mut bindings::file,
+}
+
+impl DeferredFdCloser {
+    /// Create a new [`DeferredFdCloser`].
+    pub(crate) fn new(flags: Flags) -> Result<Self, AllocError> {
+        Ok(Self {
+            // INVARIANT: The `file` pointer is null, so the type invariant does not apply.
+            inner: KBox::new(
+                DeferredFdCloserInner {
+                    twork: MaybeUninit::uninit(),
+                    file: core::ptr::null_mut(),
+                },
+                flags,
+            )?,
+        })
+    }
+
+    /// Schedule a task work that closes the file descriptor when this task returns to userspace.
+    ///
+    /// Fails if this is called from a context where we cannot run work when returning to
+    /// userspace. (E.g., from a kthread.)
+    pub(crate) fn close_fd(self, fd: u32) -> Result<(), DeferredFdCloseError> {
+        use bindings::task_work_notify_mode_TWA_RESUME as TWA_RESUME;
+
+        // In this method, we schedule the task work before closing the file. This is because
+        // scheduling a task work is fallible, and we need to know whether it will fail before we
+        // attempt to close the file.
+
+        // Task works are not available on kthreads.
+        let current = kernel::current!();
+
+        // Check if this is a kthread.
+        // SAFETY: Reading `flags` from a task is always okay.
+        if unsafe { ((*current.as_ptr()).flags & bindings::PF_KTHREAD) != 0 } {
+            return Err(DeferredFdCloseError::TaskWorkUnavailable);
+        }
+
+        // Transfer ownership of the box's allocation to a raw pointer. This disables the
+        // destructor, so we must manually convert it back to a KBox to drop it.
+        //
+        // Until we convert it back to a `KBox`, there are no aliasing requirements on this
+        // pointer.
+        let inner = KBox::into_raw(self.inner);
+
+        // The `callback_head` field is first in the struct, so this cast correctly gives us a
+        // pointer to the field.
+        let callback_head = inner.cast::<bindings::callback_head>();
+        // SAFETY: This pointer offset operation does not go out-of-bounds.
+        let file_field = unsafe { core::ptr::addr_of_mut!((*inner).file) };
+
+        let current = current.as_ptr();
+
+        // SAFETY: This function currently has exclusive access to the `DeferredFdCloserInner`, so
+        // it is okay for us to perform unsynchronized writes to its `callback_head` field.
+        unsafe { bindings::init_task_work(callback_head, Some(Self::do_close_fd)) };
+
+        // SAFETY: This inserts the `DeferredFdCloserInner` into the task workqueue for the current
+        // task. If this operation is successful, then this transfers exclusive ownership of the
+        // `callback_head` field to the C side until it calls `do_close_fd`, and we don't touch or
+        // invalidate the field during that time.
+        //
+        // When the C side calls `do_close_fd`, the safety requirements of that method are
+        // satisfied because when a task work is executed, the callback is given ownership of the
+        // pointer.
+        //
+        // The file pointer is currently null. If it is changed to be non-null before `do_close_fd`
+        // is called, then that change happens due to the write at the end of this function, and
+        // that write has a safety comment that explains why the refcount can be dropped when
+        // `do_close_fd` runs.
+        let res = unsafe { bindings::task_work_add(current, callback_head, TWA_RESUME) };
+
+        if res != 0 {
+            // SAFETY: Scheduling the task work failed, so we still have ownership of the box, so
+            // we may destroy it.
+            unsafe { drop(KBox::from_raw(inner)) };
+
+            return Err(DeferredFdCloseError::TaskWorkUnavailable);
+        }
+
+        // This removes the fd from the fd table in `current`. The file is not fully closed until
+        // `filp_close` is called. We are given ownership of one refcount to the file.
+        //
+        // SAFETY: This is safe no matter what `fd` is. If the `fd` is valid (that is, if the
+        // pointer is non-null), then we call `filp_close` on the returned pointer as required by
+        // `file_close_fd`.
+        let file = unsafe { bindings::file_close_fd(fd) };
+        if file.is_null() {
+            // We don't clean up the task work since that might be expensive if the task work queue
+            // is long. Just let it execute and let it clean up for itself.
+            return Err(DeferredFdCloseError::BadFd);
+        }
+
+        // Acquire a second refcount to the file.
+        //
+        // SAFETY: The `file` pointer points at a file with a non-zero refcount.
+        unsafe { bindings::get_file(file) };
+
+        // This method closes the fd, consuming one of our two refcounts. There could be active
+        // light refcounts created from that fd, so we must ensure that the file has a positive
+        // refcount for the duration of those active light refcounts. We do that by holding on to
+        // the second refcount until the current task returns to userspace.
+        //
+        // SAFETY: The `file` pointer is valid. Passing `current->files` as the file table to close
+        // it in is correct, since we just got the `fd` from `file_close_fd` which also uses
+        // `current->files`.
+        //
+        // Note: fl_owner_t is currently a void pointer.
+        unsafe { bindings::filp_close(file, (*current).files as bindings::fl_owner_t) };
+
+        // We update the file pointer that the task work is supposed to fput. This transfers
+        // ownership of our last refcount.
+        //
+        // INVARIANT: This changes the `file` field of a `DeferredFdCloserInner` from null to
+        // non-null. This doesn't break the type invariant for `DeferredFdCloserInner` because we
+        // still own a refcount to the file, so we can pass ownership of that refcount to the
+        // `DeferredFdCloserInner`.
+        //
+        // When `do_close_fd` runs, it must be safe for it to `fput` the refcount. However, this is
+        // the case because all light refcounts that are associated with the fd we closed
+        // previously must be dropped when `do_close_fd`, since light refcounts must be dropped
+        // before returning to userspace.
+        //
+        // SAFETY: Task works are executed on the current thread right before we return to
+        // userspace, so this write is guaranteed to happen before `do_close_fd` is called, which
+        // means that a race is not possible here.
+        unsafe { *file_field = file };
+
+        Ok(())
+    }
+
+    /// # Safety
+    ///
+    /// The provided pointer must point at the `twork` field of a `DeferredFdCloserInner` stored in
+    /// a `KBox`, and the caller must pass exclusive ownership of that `KBox`. Furthermore, if the
+    /// file pointer is non-null, then it must be okay to release the refcount by calling `fput`.
+    unsafe extern "C" fn do_close_fd(inner: *mut bindings::callback_head) {
+        // SAFETY: The caller just passed us ownership of this box.
+        let inner = unsafe { KBox::from_raw(inner.cast::<DeferredFdCloserInner>()) };
+        if !inner.file.is_null() {
+            // SAFETY: By the type invariants, we own a refcount to this file, and the caller
+            // guarantees that dropping the refcount now is okay.
+            unsafe { bindings::fput(inner.file) };
+        }
+        // The allocation is freed when `inner` goes out of scope.
+    }
+}
+
+/// Represents a failure to close an fd in a deferred manner.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub(crate) enum DeferredFdCloseError {
+    /// Closing the fd failed because we were unable to schedule a task work.
+    TaskWorkUnavailable,
+    /// Closing the fd failed because the fd does not exist.
+    BadFd,
+}
+
+impl From<DeferredFdCloseError> for Error {
+    fn from(err: DeferredFdCloseError) -> Error {
+        match err {
+            DeferredFdCloseError::TaskWorkUnavailable => ESRCH,
+            DeferredFdCloseError::BadFd => EBADF,
+        }
+    }
+}
diff --git a/drivers/android/binder/defs.rs b/drivers/android/binder/defs.rs
new file mode 100644
index 000000000..8ac9bdd7a
--- /dev/null
+++ b/drivers/android/binder/defs.rs
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use core::mem::MaybeUninit;
+use core::ops::{Deref, DerefMut};
+use core::ptr;
+
+use kernel::{
+    transmute::{AsBytes, FromBytes},
+    uapi::{self, *},
+};
+
+macro_rules! pub_no_prefix {
+    ($prefix:ident, $($newname:ident),+ $(,)?) => {
+        $(pub(crate) const $newname: u32 = kernel::macros::concat_idents!($prefix, $newname);)+
+    };
+}
+
+pub_no_prefix!(
+    binder_driver_return_protocol_,
+    BR_TRANSACTION,
+    BR_TRANSACTION_SEC_CTX,
+    BR_REPLY,
+    BR_DEAD_REPLY,
+    BR_FAILED_REPLY,
+    BR_FROZEN_REPLY,
+    BR_NOOP,
+    BR_SPAWN_LOOPER,
+    BR_TRANSACTION_COMPLETE,
+    BR_TRANSACTION_PENDING_FROZEN,
+    BR_ONEWAY_SPAM_SUSPECT,
+    BR_OK,
+    BR_ERROR,
+    BR_INCREFS,
+    BR_ACQUIRE,
+    BR_RELEASE,
+    BR_DECREFS,
+    BR_DEAD_BINDER,
+    BR_CLEAR_DEATH_NOTIFICATION_DONE,
+    BR_FROZEN_BINDER,
+    BR_CLEAR_FREEZE_NOTIFICATION_DONE,
+);
+
+pub_no_prefix!(
+    binder_driver_command_protocol_,
+    BC_TRANSACTION,
+    BC_TRANSACTION_SG,
+    BC_REPLY,
+    BC_REPLY_SG,
+    BC_FREE_BUFFER,
+    BC_ENTER_LOOPER,
+    BC_EXIT_LOOPER,
+    BC_REGISTER_LOOPER,
+    BC_INCREFS,
+    BC_ACQUIRE,
+    BC_RELEASE,
+    BC_DECREFS,
+    BC_INCREFS_DONE,
+    BC_ACQUIRE_DONE,
+    BC_REQUEST_DEATH_NOTIFICATION,
+    BC_CLEAR_DEATH_NOTIFICATION,
+    BC_DEAD_BINDER_DONE,
+    BC_REQUEST_FREEZE_NOTIFICATION,
+    BC_CLEAR_FREEZE_NOTIFICATION,
+    BC_FREEZE_NOTIFICATION_DONE,
+);
+
+pub_no_prefix!(
+    flat_binder_object_flags_,
+    FLAT_BINDER_FLAG_ACCEPTS_FDS,
+    FLAT_BINDER_FLAG_TXN_SECURITY_CTX
+);
+
+pub_no_prefix!(
+    transaction_flags_,
+    TF_ONE_WAY,
+    TF_ACCEPT_FDS,
+    TF_CLEAR_BUF,
+    TF_UPDATE_TXN
+);
+
+pub(crate) use uapi::{
+    BINDER_TYPE_BINDER, BINDER_TYPE_FD, BINDER_TYPE_FDA, BINDER_TYPE_HANDLE, BINDER_TYPE_PTR,
+    BINDER_TYPE_WEAK_BINDER, BINDER_TYPE_WEAK_HANDLE,
+};
+
+macro_rules! decl_wrapper {
+    ($newname:ident, $wrapped:ty) => {
+        // Define a wrapper around the C type. Use `MaybeUninit` to enforce that the value of
+        // padding bytes must be preserved.
+        #[derive(Copy, Clone)]
+        #[repr(transparent)]
+        pub(crate) struct $newname(MaybeUninit<$wrapped>);
+
+        // SAFETY: This macro is only used with types where this is ok.
+        unsafe impl FromBytes for $newname {}
+        // SAFETY: This macro is only used with types where this is ok.
+        unsafe impl AsBytes for $newname {}
+
+        impl Deref for $newname {
+            type Target = $wrapped;
+            fn deref(&self) -> &Self::Target {
+                // SAFETY: We use `MaybeUninit` only to preserve padding. The value must still
+                // always be valid.
+                unsafe { self.0.assume_init_ref() }
+            }
+        }
+
+        impl DerefMut for $newname {
+            fn deref_mut(&mut self) -> &mut Self::Target {
+                // SAFETY: We use `MaybeUninit` only to preserve padding. The value must still
+                // always be valid.
+                unsafe { self.0.assume_init_mut() }
+            }
+        }
+
+        impl Default for $newname {
+            fn default() -> Self {
+                // Create a new value of this type where all bytes (including padding) are zeroed.
+                Self(MaybeUninit::zeroed())
+            }
+        }
+    };
+}
+
+decl_wrapper!(BinderNodeDebugInfo, uapi::binder_node_debug_info);
+decl_wrapper!(BinderNodeInfoForRef, uapi::binder_node_info_for_ref);
+decl_wrapper!(FlatBinderObject, uapi::flat_binder_object);
+decl_wrapper!(BinderFdObject, uapi::binder_fd_object);
+decl_wrapper!(BinderFdArrayObject, uapi::binder_fd_array_object);
+decl_wrapper!(BinderObjectHeader, uapi::binder_object_header);
+decl_wrapper!(BinderBufferObject, uapi::binder_buffer_object);
+decl_wrapper!(BinderTransactionData, uapi::binder_transaction_data);
+decl_wrapper!(
+    BinderTransactionDataSecctx,
+    uapi::binder_transaction_data_secctx
+);
+decl_wrapper!(BinderTransactionDataSg, uapi::binder_transaction_data_sg);
+decl_wrapper!(BinderWriteRead, uapi::binder_write_read);
+decl_wrapper!(BinderVersion, uapi::binder_version);
+decl_wrapper!(BinderFrozenStatusInfo, uapi::binder_frozen_status_info);
+decl_wrapper!(BinderFreezeInfo, uapi::binder_freeze_info);
+decl_wrapper!(BinderFrozenStateInfo, uapi::binder_frozen_state_info);
+decl_wrapper!(BinderHandleCookie, uapi::binder_handle_cookie);
+decl_wrapper!(ExtendedError, uapi::binder_extended_error);
+
+impl BinderVersion {
+    pub(crate) fn current() -> Self {
+        Self(MaybeUninit::new(uapi::binder_version {
+            protocol_version: BINDER_CURRENT_PROTOCOL_VERSION as i32,
+        }))
+    }
+}
+
+impl BinderTransactionData {
+    pub(crate) fn with_buffers_size(self, buffers_size: u64) -> BinderTransactionDataSg {
+        BinderTransactionDataSg(MaybeUninit::new(uapi::binder_transaction_data_sg {
+            transaction_data: *self,
+            buffers_size,
+        }))
+    }
+}
+
+impl BinderTransactionDataSecctx {
+    /// View the inner data as wrapped in `BinderTransactionData`.
+    pub(crate) fn tr_data(&mut self) -> &mut BinderTransactionData {
+        // SAFETY: Transparent wrapper is safe to transmute.
+        unsafe {
+            &mut *(ptr::from_mut::<uapi::binder_transaction_data>(&mut self.transaction_data)
+                .cast::<BinderTransactionData>())
+        }
+    }
+}
+
+impl ExtendedError {
+    pub(crate) fn new(id: u32, command: u32, param: i32) -> Self {
+        Self(MaybeUninit::new(uapi::binder_extended_error {
+            id,
+            command,
+            param,
+        }))
+    }
+}
diff --git a/drivers/android/binder/error.rs b/drivers/android/binder/error.rs
new file mode 100644
index 000000000..1296072c3
--- /dev/null
+++ b/drivers/android/binder/error.rs
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use kernel::fmt;
+use kernel::prelude::*;
+
+use crate::defs::*;
+
+pub(crate) type BinderResult<T = ()> = core::result::Result<T, BinderError>;
+
+/// An error that will be returned to userspace via the `BINDER_WRITE_READ` ioctl rather than via
+/// errno.
+pub(crate) struct BinderError {
+    pub(crate) reply: u32,
+    pub(crate) source: Option<Error>,
+}
+
+impl BinderError {
+    pub(crate) fn new_dead() -> Self {
+        Self {
+            reply: BR_DEAD_REPLY,
+            source: None,
+        }
+    }
+
+    pub(crate) fn new_frozen() -> Self {
+        Self {
+            reply: BR_FROZEN_REPLY,
+            source: None,
+        }
+    }
+
+    pub(crate) fn new_frozen_oneway() -> Self {
+        Self {
+            reply: BR_TRANSACTION_PENDING_FROZEN,
+            source: None,
+        }
+    }
+
+    pub(crate) fn is_dead(&self) -> bool {
+        self.reply == BR_DEAD_REPLY
+    }
+}
+
+/// Convert an errno into a `BinderError` and store the errno used to construct it. The errno
+/// should be stored as the thread's extended error when given to userspace.
+impl From<Error> for BinderError {
+    fn from(source: Error) -> Self {
+        Self {
+            reply: BR_FAILED_REPLY,
+            source: Some(source),
+        }
+    }
+}
+
+impl From<kernel::fs::file::BadFdError> for BinderError {
+    fn from(source: kernel::fs::file::BadFdError) -> Self {
+        BinderError::from(Error::from(source))
+    }
+}
+
+impl From<kernel::alloc::AllocError> for BinderError {
+    fn from(_: kernel::alloc::AllocError) -> Self {
+        Self {
+            reply: BR_FAILED_REPLY,
+            source: Some(ENOMEM),
+        }
+    }
+}
+
+impl fmt::Debug for BinderError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self.reply {
+            BR_FAILED_REPLY => match self.source.as_ref() {
+                Some(source) => source.fmt(f),
+                None => f.pad("BR_FAILED_REPLY"),
+            },
+            BR_DEAD_REPLY => f.pad("BR_DEAD_REPLY"),
+            BR_FROZEN_REPLY => f.pad("BR_FROZEN_REPLY"),
+            BR_TRANSACTION_PENDING_FROZEN => f.pad("BR_TRANSACTION_PENDING_FROZEN"),
+            BR_TRANSACTION_COMPLETE => f.pad("BR_TRANSACTION_COMPLETE"),
+            _ => match self.source.as_ref() {
+                Some(source) => source.fmt(f),
+                None => self.reply.fmt(f),
+            },
+        }
+    }
+}
diff --git a/drivers/android/binder/freeze.rs b/drivers/android/binder/freeze.rs
new file mode 100644
index 000000000..66912b4cb
--- /dev/null
+++ b/drivers/android/binder/freeze.rs
@@ -0,0 +1,456 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use kernel::{
+    alloc::AllocError,
+    list::ListArc,
+    prelude::*,
+    rbtree::{self, RBTreeNodeReservation},
+    seq_file::SeqFile,
+    seq_print,
+    sync::{Arc, UniqueArc},
+    uaccess::UserSliceReader,
+};
+
+use crate::{
+    defs::*, node::Node, process::Process, thread::Thread, BinderReturnWriter, DArc, DLArc,
+    DTRWrap, DeliverToRead,
+};
+
+#[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd)]
+pub(crate) struct FreezeCookie(u64);
+
+/// Represents a listener for changes to the frozen state of a process.
+pub(crate) struct FreezeListener {
+    /// The node we are listening for.
+    pub(crate) node: DArc<Node>,
+    /// The cookie of this freeze listener.
+    cookie: FreezeCookie,
+    /// What value of `is_frozen` did we most recently tell userspace about?
+    last_is_frozen: Option<bool>,
+    /// We sent a `BR_FROZEN_BINDER` and we are waiting for `BC_FREEZE_NOTIFICATION_DONE` before
+    /// sending any other commands.
+    is_pending: bool,
+    /// Userspace sent `BC_CLEAR_FREEZE_NOTIFICATION` and we need to reply with
+    /// `BR_CLEAR_FREEZE_NOTIFICATION_DONE` as soon as possible. If `is_pending` is set, then we
+    /// must wait for it to be unset before we can reply.
+    is_clearing: bool,
+    /// Number of cleared duplicates that can't be deleted until userspace sends
+    /// `BC_FREEZE_NOTIFICATION_DONE`.
+    num_pending_duplicates: u64,
+    /// Number of cleared duplicates that can be deleted.
+    num_cleared_duplicates: u64,
+}
+
+impl FreezeListener {
+    /// Is it okay to create a new listener with the same cookie as this one for the provided node?
+    ///
+    /// Under some scenarios, userspace may delete a freeze listener and immediately recreate it
+    /// with the same cookie. This results in duplicate listeners. To avoid issues with ambiguity,
+    /// we allow this only if the new listener is for the same node, and we also require that the
+    /// old listener has already been cleared.
+    fn allow_duplicate(&self, node: &DArc<Node>) -> bool {
+        Arc::ptr_eq(&self.node, node) && self.is_clearing
+    }
+}
+
+type UninitFM = UniqueArc<core::mem::MaybeUninit<DTRWrap<FreezeMessage>>>;
+
+/// Represents a notification that the freeze state has changed.
+pub(crate) struct FreezeMessage {
+    cookie: FreezeCookie,
+    pid: i32,
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<0> for FreezeMessage {
+        untracked;
+    }
+}
+
+impl FreezeMessage {
+    fn new(flags: kernel::alloc::Flags) -> Result<UninitFM, AllocError> {
+        UniqueArc::new_uninit(flags)
+    }
+
+    fn init(ua: UninitFM, cookie: FreezeCookie, pid: i32) -> DLArc<FreezeMessage> {
+        match ua.pin_init_with(DTRWrap::new(FreezeMessage { cookie, pid })) {
+            Ok(msg) => ListArc::from(msg),
+            Err(err) => match err {},
+        }
+    }
+}
+
+impl DeliverToRead for FreezeMessage {
+    fn do_work(
+        self: DArc<Self>,
+        thread: &Thread,
+        writer: &mut BinderReturnWriter<'_>,
+    ) -> Result<bool> {
+        let _removed_listener;
+        let mut node_refs = thread.process.node_refs.lock();
+        let Some(mut freeze_entry) = node_refs.freeze_listeners.find_mut(&self.cookie) else {
+            return Ok(true);
+        };
+        let freeze = freeze_entry.get_mut();
+
+        if freeze.num_cleared_duplicates > 0 {
+            freeze.num_cleared_duplicates -= 1;
+            drop(node_refs);
+            writer.write_code(BR_CLEAR_FREEZE_NOTIFICATION_DONE)?;
+            writer.write_payload(&self.cookie.0)?;
+            return Ok(true);
+        }
+
+        if freeze.is_pending {
+            return Ok(true);
+        }
+        if freeze.is_clearing {
+            kernel::warn_on!(freeze.num_cleared_duplicates != 0);
+            if freeze.num_pending_duplicates > 0 {
+                // The primary freeze listener was deleted, so convert a pending duplicate back
+                // into the primary one.
+                freeze.num_pending_duplicates -= 1;
+                freeze.is_pending = true;
+                freeze.is_clearing = true;
+            } else {
+                _removed_listener = freeze_entry.remove_node();
+            }
+            drop(node_refs);
+            writer.write_code(BR_CLEAR_FREEZE_NOTIFICATION_DONE)?;
+            writer.write_payload(&self.cookie.0)?;
+            Ok(true)
+        } else {
+            let is_frozen = freeze.node.owner.inner.lock().is_frozen.is_fully_frozen();
+            if freeze.last_is_frozen == Some(is_frozen) {
+                return Ok(true);
+            }
+
+            let mut state_info = BinderFrozenStateInfo::default();
+            state_info.is_frozen = u32::from(is_frozen);
+            state_info.cookie = freeze.cookie.0;
+            freeze.is_pending = true;
+            freeze.last_is_frozen = Some(is_frozen);
+            drop(node_refs);
+
+            writer.write_code(BR_FROZEN_BINDER)?;
+            writer.write_payload(&state_info)?;
+            // BR_FROZEN_BINDER notifications can cause transactions
+            Ok(false)
+        }
+    }
+
+    fn cancel(self: DArc<Self>) {
+        binder_debug!(
+            pid = self.pid,
+            DeadTransaction,
+            "undelivered freeze notification, {:016x}",
+            self.cookie.0
+        );
+    }
+
+    fn should_sync_wakeup(&self) -> bool {
+        false
+    }
+
+    #[inline(never)]
+    fn debug_print(&self, m: &SeqFile, prefix: &str, _tprefix: &str) -> Result<()> {
+        seq_print!(m, "{}has frozen binder\n", prefix);
+        Ok(())
+    }
+}
+
+impl FreezeListener {
+    /// Called when this freeze listener is cleared abnormally.
+    ///
+    /// This occurs either because the process exited or because the process dropped its last
+    /// refcount on the node ref without explicitly removing the freeze listener first.
+    ///
+    /// The returned `KVVec` is just a value that should be dropped outside of the lock.
+    pub(crate) fn on_process_cleanup(&self, proc: &Process) -> KVVec<Arc<Process>> {
+        if !self.is_clearing {
+            return self.node.remove_freeze_listener(proc);
+        }
+        KVVec::new()
+    }
+}
+
+impl Process {
+    pub(crate) fn request_freeze_notif(
+        self: &Arc<Self>,
+        reader: &mut UserSliceReader,
+    ) -> Result<()> {
+        let hc = reader.read::<BinderHandleCookie>()?;
+        let handle = hc.handle;
+        let cookie = FreezeCookie(hc.cookie);
+
+        let msg = FreezeMessage::new(GFP_KERNEL)?;
+        let alloc = RBTreeNodeReservation::new(GFP_KERNEL)?;
+
+        let mut afl_vec_alloc = KVVec::new();
+        let mut info;
+        let mut freeze_entry;
+        let mut node_refs_guard = self.node_refs.lock();
+        loop {
+            let node_refs = &mut *node_refs_guard;
+            info = match node_refs.by_handle.get_mut(&handle) {
+                Some(info) => info,
+                None => {
+                    binder_debug!(
+                        UserError,
+                        "BC_REQUEST_FREEZE_NOTIFICATION invalid ref {handle}"
+                    );
+                    return Err(EINVAL);
+                }
+            };
+            if info.freeze().is_some() {
+                binder_debug!(UserError, "BC_REQUEST_FREEZE_NOTIFICATION already set");
+                return Err(EINVAL);
+            }
+            let node_ref = info.node_ref();
+            freeze_entry = node_refs.freeze_listeners.entry(cookie);
+
+            if let rbtree::Entry::Occupied(ref dupe) = freeze_entry {
+                if !dupe.get().allow_duplicate(&node_ref.node) {
+                    binder_debug!(UserError, "BC_REQUEST_FREEZE_NOTIFICATION duplicate cookie");
+                    return Err(EINVAL);
+                }
+            }
+
+            // Now we add to the node's freeze listener list, with retry and re-allocate if the
+            // vector is full.
+            //
+            // To ensure that the node is added atomically, this is the first time we modify any
+            // state. When this call succeeds, all other modifications must occur without the
+            // possibility for any failure paths.
+            match node_ref
+                .node
+                .add_freeze_listener(self, &mut afl_vec_alloc)?
+            {
+                Ok(()) => break,
+                Err(resize_target) => {
+                    drop(node_refs_guard);
+                    afl_vec_alloc = KVVec::with_capacity(resize_target, GFP_KERNEL)?;
+                    node_refs_guard = self.node_refs.lock();
+                }
+            }
+        }
+
+        match freeze_entry {
+            rbtree::Entry::Vacant(entry) => {
+                entry.insert(
+                    FreezeListener {
+                        cookie,
+                        node: info.node_ref().node.clone(),
+                        last_is_frozen: None,
+                        is_pending: false,
+                        is_clearing: false,
+                        num_pending_duplicates: 0,
+                        num_cleared_duplicates: 0,
+                    },
+                    alloc,
+                );
+            }
+            rbtree::Entry::Occupied(mut dupe) => {
+                let dupe = dupe.get_mut();
+                if dupe.is_pending {
+                    dupe.num_pending_duplicates += 1;
+                } else {
+                    dupe.num_cleared_duplicates += 1;
+                }
+                dupe.last_is_frozen = None;
+                dupe.is_pending = false;
+                dupe.is_clearing = false;
+            }
+        }
+
+        *info.freeze() = Some(cookie);
+        let msg = FreezeMessage::init(msg, cookie, self.task.pid());
+        drop(node_refs_guard);
+        let _ = self.push_work(msg);
+        Ok(())
+    }
+
+    pub(crate) fn freeze_notif_done(self: &Arc<Self>, reader: &mut UserSliceReader) -> Result<()> {
+        let cookie = FreezeCookie(reader.read()?);
+        let alloc = FreezeMessage::new(GFP_KERNEL)?;
+        let mut node_refs_guard = self.node_refs.lock();
+        let node_refs = &mut *node_refs_guard;
+        let Some(freeze) = node_refs.freeze_listeners.get_mut(&cookie) else {
+            binder_debug!(
+                UserError,
+                "BC_FREEZE_NOTIFICATION_DONE {:016x} not found",
+                cookie.0
+            );
+            return Err(EINVAL);
+        };
+        let mut clear_msg = None;
+        if freeze.num_pending_duplicates > 0 {
+            clear_msg = Some(FreezeMessage::init(alloc, cookie, self.task.pid()));
+            freeze.num_pending_duplicates -= 1;
+            freeze.num_cleared_duplicates += 1;
+        } else {
+            if !freeze.is_pending {
+                binder_debug!(
+                    UserError,
+                    "BC_FREEZE_NOTIFICATION_DONE {:016x} not pending",
+                    cookie.0
+                );
+                return Err(EINVAL);
+            }
+            let is_frozen = freeze.node.owner.inner.lock().is_frozen.is_fully_frozen();
+            if freeze.is_clearing || freeze.last_is_frozen != Some(is_frozen) {
+                // Immediately send another FreezeMessage.
+                clear_msg = Some(FreezeMessage::init(alloc, cookie, self.task.pid()));
+            }
+            freeze.is_pending = false;
+        }
+        drop(node_refs_guard);
+        if let Some(clear_msg) = clear_msg {
+            let _ = self.push_work(clear_msg);
+        }
+        Ok(())
+    }
+
+    pub(crate) fn clear_freeze_notif(self: &Arc<Self>, reader: &mut UserSliceReader) -> Result<()> {
+        let hc = reader.read::<BinderHandleCookie>()?;
+        let handle = hc.handle;
+        let cookie = FreezeCookie(hc.cookie);
+
+        let _to_free_fl;
+        let alloc = FreezeMessage::new(GFP_KERNEL)?;
+        let mut node_refs_guard = self.node_refs.lock();
+        let node_refs = &mut *node_refs_guard;
+        let Some(info) = node_refs.by_handle.get_mut(&handle) else {
+            binder_debug!(
+                UserError,
+                "BC_CLEAR_FREEZE_NOTIFICATION invalid ref {handle}"
+            );
+            return Err(EINVAL);
+        };
+        let Some(info_cookie) = info.freeze() else {
+            binder_debug!(
+                UserError,
+                "BC_CLEAR_FREEZE_NOTIFICATION freeze notification not active"
+            );
+            return Err(EINVAL);
+        };
+        if *info_cookie != cookie {
+            binder_debug!(
+                UserError,
+                "BC_CLEAR_FREEZE_NOTIFICATION freeze notification cookie mismatch"
+            );
+            return Err(EINVAL);
+        }
+        let Some(listener) = node_refs.freeze_listeners.get_mut(&cookie) else {
+            binder_debug!(
+                UserError,
+                "BC_CLEAR_FREEZE_NOTIFICATION invalid cookie {handle}"
+            );
+            return Err(EINVAL);
+        };
+        listener.is_clearing = true;
+        _to_free_fl = listener.node.remove_freeze_listener(self);
+        *info.freeze() = None;
+        let mut msg = None;
+        if !listener.is_pending {
+            msg = Some(FreezeMessage::init(alloc, cookie, self.task.pid()));
+        }
+        drop(node_refs_guard);
+
+        if let Some(msg) = msg {
+            let _ = self.push_work(msg);
+        }
+        Ok(())
+    }
+
+    fn get_freeze_cookie(&self, node: &DArc<Node>) -> Option<FreezeCookie> {
+        let node_refs = &mut *self.node_refs.lock();
+        let handle = node_refs.by_node.get(&node.global_id())?;
+        let node_ref = node_refs.by_handle.get_mut(handle)?;
+        *node_ref.freeze()
+    }
+
+    /// Creates a vector of every freeze listener on this process.
+    ///
+    /// Returns pairs of the remote process listening for notifications and the local node it is
+    /// listening on.
+    #[expect(clippy::type_complexity)]
+    fn find_freeze_recipients(&self) -> Result<KVVec<(DArc<Node>, Arc<Process>)>, AllocError> {
+        // Defined before `inner` to drop after releasing spinlock if `push_within_capacity` fails.
+        let mut node_proc_pair;
+
+        // We pre-allocate space for up to 8 recipients before we take the spinlock. However, if
+        // the allocation fails, use a vector with a capacity of zero instead of failing. After
+        // all, there might not be any freeze listeners, in which case this operation could still
+        // succeed.
+        let mut recipients =
+            KVVec::with_capacity(8, GFP_KERNEL).unwrap_or_else(|_err| KVVec::new());
+
+        let mut inner = self.lock_with_nodes();
+        let mut curr = inner.nodes.cursor_front_mut();
+        while let Some(cursor) = curr {
+            let (key, node) = cursor.current();
+            let key = *key;
+            let list = node.freeze_list(&inner.inner);
+            let len = list.len();
+
+            if recipients.spare_capacity_mut().len() < len {
+                drop(inner);
+                recipients.reserve(len, GFP_KERNEL)?;
+                inner = self.lock_with_nodes();
+                // Find the node we were looking at and try again. If the set of nodes was changed,
+                // then just proceed to the next node. This is ok because we don't guarantee the
+                // inclusion of nodes that are added or removed in parallel with this operation.
+                curr = inner.nodes.cursor_lower_bound_mut(&key);
+                continue;
+            }
+
+            for proc in list {
+                node_proc_pair = (node.clone(), proc.clone());
+                recipients
+                    .push_within_capacity(node_proc_pair)
+                    .map_err(|_| {
+                        pr_err!(
+                            "push_within_capacity failed even though we checked the capacity\n"
+                        );
+                        AllocError
+                    })?;
+            }
+
+            curr = cursor.move_next();
+        }
+        Ok(recipients)
+    }
+
+    /// Prepare allocations for sending freeze messages.
+    pub(crate) fn prepare_freeze_messages(&self) -> Result<FreezeMessages, AllocError> {
+        let recipients = self.find_freeze_recipients()?;
+        let mut batch = KVVec::with_capacity(recipients.len(), GFP_KERNEL)?;
+        for (node, proc) in recipients {
+            let Some(cookie) = proc.get_freeze_cookie(&node) else {
+                // If the freeze listener was removed in the meantime, just discard the
+                // notification.
+                continue;
+            };
+            let msg_alloc = FreezeMessage::new(GFP_KERNEL)?;
+            let msg = FreezeMessage::init(msg_alloc, cookie, proc.task.pid());
+            batch.push((proc, msg), GFP_KERNEL)?;
+        }
+
+        Ok(FreezeMessages { batch })
+    }
+}
+
+pub(crate) struct FreezeMessages {
+    batch: KVVec<(Arc<Process>, DLArc<FreezeMessage>)>,
+}
+
+impl FreezeMessages {
+    pub(crate) fn send_messages(self) {
+        for (proc, msg) in self.batch {
+            let _ = proc.push_work(msg);
+        }
+    }
+}
diff --git a/drivers/android/binder/netlink.rs b/drivers/android/binder/netlink.rs
new file mode 100644
index 000000000..f34e10094
--- /dev/null
+++ b/drivers/android/binder/netlink.rs
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+/* Based on: Documentation/netlink/specs/binder.yaml */
+
+#![allow(unreachable_pub, clippy::wrong_self_convention)]
+use kernel::{
+    net::netlink::{
+        Family,
+        GenlMsg,
+        MulticastGroup,
+        NetlinkSkBuff, //
+    },
+    prelude::*, //
+};
+
+pub static BINDER_NL_FAMILY: Family = Family::const_new(
+    kernel::module::this_module::<crate::LocalModule>(),
+    kernel::uapi::BINDER_FAMILY_NAME,
+    kernel::uapi::BINDER_FAMILY_VERSION,
+    &BINDER_NL_FAMILY_MCGRPS,
+);
+
+static BINDER_NL_FAMILY_MCGRPS: [MulticastGroup; 1] = [MulticastGroup::const_new(c"report")];
+
+/// A multicast event sent to userspace subscribers to notify them about
+/// binder transaction failures. The generated report provides the full
+/// details of the specific transaction that failed. The intention is for
+/// programs to monitor these events and react to the failures as needed.
+pub struct Report {
+    skb: GenlMsg,
+}
+
+impl Report {
+    /// Create a new multicast message.
+    pub fn new(
+        size: usize,
+        portid: u32,
+        seq: u32,
+        flags: kernel::alloc::Flags,
+    ) -> Result<Self, kernel::alloc::AllocError> {
+        const BINDER_CMD_REPORT: u8 = kernel::uapi::BINDER_CMD_REPORT as u8;
+        let skb = NetlinkSkBuff::new(size, flags)?;
+        let skb = skb.genlmsg_put(portid, seq, &BINDER_NL_FAMILY, BINDER_CMD_REPORT)?;
+        Ok(Self { skb })
+    }
+
+    /// Broadcast this message.
+    pub fn multicast(self, portid: u32, flags: kernel::alloc::Flags) -> Result {
+        self.skb.multicast(&BINDER_NL_FAMILY, portid, 0, flags)
+    }
+
+    /// Check if this message type has listeners.
+    pub fn has_listeners() -> bool {
+        BINDER_NL_FAMILY.has_listeners(0)
+    }
+
+    /// The enum binder_driver_return_protocol returned to the sender.
+    pub fn error(&mut self, val: u32) -> Result {
+        const BINDER_A_REPORT_ERROR: c_int = kernel::uapi::BINDER_A_REPORT_ERROR as c_int;
+        self.skb.put_u32(BINDER_A_REPORT_ERROR, val)
+    }
+
+    /// The binder context where the transaction occurred.
+    pub fn context(&mut self, val: &CStr) -> Result {
+        const BINDER_A_REPORT_CONTEXT: c_int = kernel::uapi::BINDER_A_REPORT_CONTEXT as c_int;
+        self.skb.put_string(BINDER_A_REPORT_CONTEXT, val)
+    }
+
+    /// The PID of the sender process.
+    pub fn from_pid(&mut self, val: u32) -> Result {
+        const BINDER_A_REPORT_FROM_PID: c_int = kernel::uapi::BINDER_A_REPORT_FROM_PID as c_int;
+        self.skb.put_u32(BINDER_A_REPORT_FROM_PID, val)
+    }
+
+    /// The TID of the sender thread.
+    pub fn from_tid(&mut self, val: u32) -> Result {
+        const BINDER_A_REPORT_FROM_TID: c_int = kernel::uapi::BINDER_A_REPORT_FROM_TID as c_int;
+        self.skb.put_u32(BINDER_A_REPORT_FROM_TID, val)
+    }
+
+    /// The PID of the recipient process. This attribute may not be present
+    /// if the target could not be determined.
+    pub fn to_pid(&mut self, val: u32) -> Result {
+        const BINDER_A_REPORT_TO_PID: c_int = kernel::uapi::BINDER_A_REPORT_TO_PID as c_int;
+        self.skb.put_u32(BINDER_A_REPORT_TO_PID, val)
+    }
+
+    /// The TID of the recipient thread. This attribute may not be present
+    /// if the target could not be determined.
+    pub fn to_tid(&mut self, val: u32) -> Result {
+        const BINDER_A_REPORT_TO_TID: c_int = kernel::uapi::BINDER_A_REPORT_TO_TID as c_int;
+        self.skb.put_u32(BINDER_A_REPORT_TO_TID, val)
+    }
+
+    /// When present, indicates the failed transaction is a reply.
+    pub fn is_reply(&mut self) -> Result {
+        const BINDER_A_REPORT_IS_REPLY: c_int = kernel::uapi::BINDER_A_REPORT_IS_REPLY as c_int;
+        self.skb.put_flag(BINDER_A_REPORT_IS_REPLY)
+    }
+
+    /// The bitmask of enum transaction_flags from the transaction.
+    pub fn flags(&mut self, val: u32) -> Result {
+        const BINDER_A_REPORT_FLAGS: c_int = kernel::uapi::BINDER_A_REPORT_FLAGS as c_int;
+        self.skb.put_u32(BINDER_A_REPORT_FLAGS, val)
+    }
+
+    /// The application-defined code from the transaction.
+    pub fn code(&mut self, val: u32) -> Result {
+        const BINDER_A_REPORT_CODE: c_int = kernel::uapi::BINDER_A_REPORT_CODE as c_int;
+        self.skb.put_u32(BINDER_A_REPORT_CODE, val)
+    }
+
+    /// The transaction payload size in bytes.
+    pub fn data_size(&mut self, val: u32) -> Result {
+        const BINDER_A_REPORT_DATA_SIZE: c_int = kernel::uapi::BINDER_A_REPORT_DATA_SIZE as c_int;
+        self.skb.put_u32(BINDER_A_REPORT_DATA_SIZE, val)
+    }
+}
diff --git a/drivers/android/binder/node.rs b/drivers/android/binder/node.rs
new file mode 100644
index 000000000..0a82af14c
--- /dev/null
+++ b/drivers/android/binder/node.rs
@@ -0,0 +1,1160 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use kernel::{
+    list::{AtomicTracker, List, ListArc, ListLinks, TryNewListArc},
+    prelude::*,
+    seq_file::SeqFile,
+    seq_print,
+    sync::lock::{spinlock::SpinLockBackend, Guard},
+    sync::{Arc, LockedBy, SpinLock},
+    uapi,
+};
+
+use crate::{
+    defs::*,
+    error::BinderError,
+    process::{NodeRefInfo, Process, ProcessInner},
+    thread::Thread,
+    transaction::Transaction,
+    BinderReturnWriter, DArc, DLArc, DTRWrap, DeliverToRead,
+};
+
+use core::mem;
+use core::ptr;
+
+mod wrapper;
+pub(crate) use self::wrapper::CritIncrWrapper;
+
+#[derive(Debug)]
+pub(crate) struct CouldNotDeliverCriticalIncrement;
+
+/// Keeps track of how this node is scheduled.
+///
+/// There are two ways to schedule a node to a work list. Just schedule the node itself, or
+/// allocate a wrapper that references the node and schedule the wrapper. These wrappers exists to
+/// make it possible to "move" a node from one list to another - when `do_work` is called directly
+/// on the `Node`, then it's a no-op if there's also a pending wrapper.
+///
+/// Wrappers are generally only needed for zero-to-one refcount increments, and there are two cases
+/// of this: weak increments and strong increments. We call such increments "critical" because it
+/// is critical that they are delivered to the thread doing the increment. Some examples:
+///
+/// * One thread makes a zero-to-one strong increment, and another thread makes a zero-to-one weak
+///   increment. Delivering the node to the thread doing the weak increment is wrong, since the
+///   thread doing the strong increment may have ended a long time ago when the command is actually
+///   processed by userspace.
+///
+/// * We have a weak reference and are about to drop it on one thread. But then another thread does
+///   a zero-to-one strong increment. If the strong increment gets sent to the thread that was
+///   about to drop the weak reference, then the strong increment could be processed after the
+///   other thread has already exited, which would be too late.
+///
+/// Note that trying to create a `ListArc` to the node can succeed even if `has_normal_push` is
+/// set. This is because another thread might just have popped the node from a todo list, but not
+/// yet called `do_work`. However, if `has_normal_push` is false, then creating a `ListArc` should
+/// always succeed.
+///
+/// Like the other fields in `NodeInner`, the delivery state is protected by the process lock.
+struct DeliveryState {
+    /// Is the `Node` currently scheduled?
+    has_pushed_node: bool,
+
+    /// Is a wrapper currently scheduled?
+    ///
+    /// The wrapper is used only for strong zero2one increments.
+    has_pushed_wrapper: bool,
+
+    /// Is the currently scheduled `Node` scheduled due to a weak zero2one increment?
+    ///
+    /// Weak zero2one operations are always scheduled using the `Node`.
+    has_weak_zero2one: bool,
+
+    /// Is the currently scheduled wrapper/`Node` scheduled due to a strong zero2one increment?
+    ///
+    /// If `has_pushed_wrapper` is set, then the strong zero2one increment was scheduled using the
+    /// wrapper. Otherwise, `has_pushed_node` must be set and it was scheduled using the `Node`.
+    has_strong_zero2one: bool,
+}
+
+impl DeliveryState {
+    fn should_normal_push(&self) -> bool {
+        !self.has_pushed_node && !self.has_pushed_wrapper
+    }
+
+    fn did_normal_push(&mut self) {
+        assert!(self.should_normal_push());
+        self.has_pushed_node = true;
+    }
+
+    fn should_push_weak_zero2one(&self) -> bool {
+        !self.has_weak_zero2one && !self.has_strong_zero2one
+    }
+
+    fn can_push_weak_zero2one_normally(&self) -> bool {
+        !self.has_pushed_node
+    }
+
+    fn did_push_weak_zero2one(&mut self) {
+        assert!(self.should_push_weak_zero2one());
+        assert!(self.can_push_weak_zero2one_normally());
+        self.has_pushed_node = true;
+        self.has_weak_zero2one = true;
+    }
+
+    fn should_push_strong_zero2one(&self) -> bool {
+        !self.has_strong_zero2one
+    }
+
+    fn can_push_strong_zero2one_normally(&self) -> bool {
+        !self.has_pushed_node
+    }
+
+    fn did_push_strong_zero2one(&mut self) {
+        assert!(self.should_push_strong_zero2one());
+        assert!(self.can_push_strong_zero2one_normally());
+        self.has_pushed_node = true;
+        self.has_strong_zero2one = true;
+    }
+
+    fn did_push_strong_zero2one_wrapper(&mut self) {
+        assert!(self.should_push_strong_zero2one());
+        assert!(!self.can_push_strong_zero2one_normally());
+        self.has_pushed_wrapper = true;
+        self.has_strong_zero2one = true;
+    }
+}
+
+struct CountState {
+    /// The reference count.
+    count: usize,
+    /// Whether the process that owns this node thinks that we hold a refcount on it. (Note that
+    /// even if count is greater than one, we only increment it once in the owning process.)
+    has_count: bool,
+}
+
+impl CountState {
+    fn new() -> Self {
+        Self {
+            count: 0,
+            has_count: false,
+        }
+    }
+}
+
+struct NodeInner {
+    /// Strong refcounts held on this node by `NodeRef` objects.
+    strong: CountState,
+    /// Weak refcounts held on this node by `NodeRef` objects.
+    weak: CountState,
+    delivery_state: DeliveryState,
+    /// The binder driver guarantees that oneway transactions sent to the same node are serialized,
+    /// that is, userspace will not be given the next one until it has finished processing the
+    /// previous oneway transaction. This is done to avoid the case where two oneway transactions
+    /// arrive in opposite order from the order in which they were sent. (E.g., they could be
+    /// delivered to two different threads, which could appear as-if they were sent in opposite
+    /// order.)
+    ///
+    /// To fix that, we store pending oneway transactions in a separate list in the node, and don't
+    /// deliver the next oneway transaction until userspace signals that it has finished processing
+    /// the previous oneway transaction by calling the `BC_FREE_BUFFER` ioctl.
+    oneway_todo: List<DTRWrap<Transaction>>,
+    /// Keeps track of whether this node has a pending oneway transaction.
+    ///
+    /// When this is true, incoming oneway transactions are stored in `oneway_todo`, instead of
+    /// being delivered directly to the process.
+    has_oneway_transaction: bool,
+    /// List of processes to deliver a notification to when this node is destroyed (usually due to
+    /// the process dying).
+    death_list: List<DTRWrap<NodeDeath>, 1>,
+    /// List of processes to deliver freeze notifications to.
+    freeze_list: KVVec<Arc<Process>>,
+    /// The number of active BR_INCREFS or BR_ACQUIRE operations. (should be maximum two)
+    ///
+    /// If this is non-zero, then we postpone any BR_RELEASE or BR_DECREFS notifications until the
+    /// active operations have ended. This avoids the situation an increment and decrement get
+    /// reordered from userspace's perspective.
+    active_inc_refs: u8,
+    /// List of `NodeRefInfo` objects that reference this node.
+    refs: List<NodeRefInfo, { NodeRefInfo::LIST_NODE }>,
+}
+
+use kernel::bindings::rb_node_layout;
+use mem::offset_of;
+pub(crate) const NODE_LAYOUT: rb_node_layout = rb_node_layout {
+    arc_offset: Arc::<Node>::DATA_OFFSET + offset_of!(DTRWrap<Node>, wrapped),
+    debug_id: offset_of!(Node, debug_id),
+    ptr: offset_of!(Node, ptr),
+};
+
+#[pin_data]
+pub(crate) struct Node {
+    pub(crate) debug_id: usize,
+    ptr: u64,
+    pub(crate) cookie: u64,
+    pub(crate) flags: u32,
+    pub(crate) owner: Arc<Process>,
+    inner: LockedBy<NodeInner, ProcessInner>,
+    #[pin]
+    links_track: AtomicTracker,
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<0> for Node {
+        tracked_by links_track: AtomicTracker;
+    }
+}
+
+// Make `oneway_todo` work.
+kernel::list::impl_list_item! {
+    impl ListItem<0> for DTRWrap<Transaction> {
+        using ListLinks { self.links.inner };
+    }
+}
+
+impl Node {
+    pub(crate) fn new(
+        ptr: u64,
+        cookie: u64,
+        flags: u32,
+        owner: Arc<Process>,
+    ) -> impl PinInit<Self> {
+        pin_init!(Self {
+            inner: LockedBy::new(
+                &owner.inner,
+                NodeInner {
+                    strong: CountState::new(),
+                    weak: CountState::new(),
+                    delivery_state: DeliveryState {
+                        has_pushed_node: false,
+                        has_pushed_wrapper: false,
+                        has_weak_zero2one: false,
+                        has_strong_zero2one: false,
+                    },
+                    death_list: List::new(),
+                    oneway_todo: List::new(),
+                    freeze_list: KVVec::new(),
+                    has_oneway_transaction: false,
+                    active_inc_refs: 0,
+                    refs: List::new(),
+                },
+            ),
+            debug_id: super::next_debug_id(),
+            ptr,
+            cookie,
+            flags,
+            owner,
+            links_track <- AtomicTracker::new(),
+        })
+    }
+
+    pub(crate) fn has_oneway_transaction(&self, owner_inner: &mut ProcessInner) -> bool {
+        let inner = self.inner.access_mut(owner_inner);
+        inner.has_oneway_transaction
+    }
+
+    #[inline(never)]
+    pub(crate) fn full_debug_print(
+        &self,
+        m: &SeqFile,
+        owner_inner: &mut ProcessInner,
+    ) -> Result<()> {
+        let inner = self.inner.access_mut(owner_inner);
+        seq_print!(
+            m,
+            "  node {}: u{:016x} c{:016x} hs {} hw {} cs {} cw {}",
+            self.debug_id,
+            self.ptr,
+            self.cookie,
+            inner.strong.has_count,
+            inner.weak.has_count,
+            inner.strong.count,
+            inner.weak.count,
+        );
+        if !inner.refs.is_empty() {
+            seq_print!(m, " proc");
+            for node_ref in &inner.refs {
+                seq_print!(m, " {}", node_ref.process.task.pid());
+            }
+        }
+        seq_print!(m, "\n");
+        for t in &inner.oneway_todo {
+            t.debug_print_inner(m, "    pending async transaction ");
+        }
+        Ok(())
+    }
+
+    /// Insert the `NodeRef` into this `refs` list.
+    ///
+    /// # Safety
+    ///
+    /// It must be the case that `info.node_ref.node` is this node.
+    pub(crate) unsafe fn insert_node_info(
+        &self,
+        info: ListArc<NodeRefInfo, { NodeRefInfo::LIST_NODE }>,
+    ) {
+        self.inner
+            .access_mut(&mut self.owner.inner.lock())
+            .refs
+            .push_front(info);
+    }
+
+    /// Insert the `NodeRef` into this `refs` list.
+    ///
+    /// # Safety
+    ///
+    /// It must be the case that `info.node_ref.node` is this node.
+    pub(crate) unsafe fn remove_node_info(
+        &self,
+        info: &NodeRefInfo,
+    ) -> Option<ListArc<NodeRefInfo, { NodeRefInfo::LIST_NODE }>> {
+        // SAFETY: We always insert `NodeRefInfo` objects into the `refs` list of the node that it
+        // references in `info.node_ref.node`. That is this node, so `info` cannot possibly be in
+        // the `refs` list of another node.
+        unsafe {
+            self.inner
+                .access_mut(&mut self.owner.inner.lock())
+                .refs
+                .remove(info)
+        }
+    }
+
+    /// An id that is unique across all binder nodes on the system. Used as the key in the
+    /// `by_node` map.
+    pub(crate) fn global_id(&self) -> usize {
+        ptr::from_ref(self).addr()
+    }
+
+    pub(crate) fn get_id(&self) -> (u64, u64) {
+        (self.ptr, self.cookie)
+    }
+
+    pub(crate) fn add_death(
+        &self,
+        death: ListArc<DTRWrap<NodeDeath>, 1>,
+        guard: &mut Guard<'_, ProcessInner, SpinLockBackend>,
+    ) {
+        assert!(
+            core::ptr::eq(self, &**death.node),
+            "attempt to add NodeDeath to the wrong death list"
+        );
+        self.inner.access_mut(guard).death_list.push_back(death);
+    }
+
+    pub(crate) fn inc_ref_done_locked(
+        self: &DArc<Node>,
+        _strong: bool,
+        owner_inner: &mut ProcessInner,
+    ) -> Option<DLArc<Node>> {
+        let inner = self.inner.access_mut(owner_inner);
+        if inner.active_inc_refs == 0 {
+            binder_debug!(UserError, "inc_ref_done called when no active inc_refs");
+            return None;
+        }
+
+        inner.active_inc_refs -= 1;
+        if inner.active_inc_refs == 0 {
+            // Having active inc_refs can inhibit dropping of ref-counts. Calculate whether we
+            // would send a refcount decrement, and if so, tell the caller to schedule us.
+            let strong = inner.strong.count > 0;
+            let has_strong = inner.strong.has_count;
+            let weak = strong || inner.weak.count > 0;
+            let has_weak = inner.weak.has_count;
+
+            let should_drop_weak = !weak && has_weak;
+            let should_drop_strong = !strong && has_strong;
+
+            // If we want to drop the ref-count again, tell the caller to schedule a work node for
+            // that.
+            let need_push = should_drop_weak || should_drop_strong;
+
+            if need_push && inner.delivery_state.should_normal_push() {
+                let list_arc = ListArc::try_from_arc(self.clone()).ok().unwrap();
+                inner.delivery_state.did_normal_push();
+                Some(list_arc)
+            } else {
+                None
+            }
+        } else {
+            None
+        }
+    }
+
+    pub(crate) fn update_refcount_locked(
+        self: &DArc<Node>,
+        inc: bool,
+        strong: bool,
+        count: usize,
+        owner_inner: &mut ProcessInner,
+    ) -> Option<DLArc<Node>> {
+        let is_dead = owner_inner.is_dead;
+        let inner = self.inner.access_mut(owner_inner);
+
+        // Get a reference to the state we'll update.
+        let state = if strong {
+            &mut inner.strong
+        } else {
+            &mut inner.weak
+        };
+
+        // Update the count and determine whether we need to push work.
+        let need_push = if inc {
+            state.count += count;
+            // TODO: This method shouldn't be used for zero-to-one increments.
+            !is_dead && !state.has_count
+        } else {
+            if state.count < count {
+                pr_err!("Failure: refcount underflow!");
+                return None;
+            }
+            state.count -= count;
+            !is_dead && state.count == 0 && state.has_count
+        };
+
+        if need_push && inner.delivery_state.should_normal_push() {
+            let list_arc = ListArc::try_from_arc(self.clone()).ok().unwrap();
+            inner.delivery_state.did_normal_push();
+            Some(list_arc)
+        } else {
+            None
+        }
+    }
+
+    pub(crate) fn incr_refcount_allow_zero2one(
+        self: &DArc<Self>,
+        strong: bool,
+        owner_inner: &mut ProcessInner,
+    ) -> Result<Option<DLArc<Node>>, CouldNotDeliverCriticalIncrement> {
+        let is_dead = owner_inner.is_dead;
+        let inner = self.inner.access_mut(owner_inner);
+
+        // Get a reference to the state we'll update.
+        let state = if strong {
+            &mut inner.strong
+        } else {
+            &mut inner.weak
+        };
+
+        // Update the count and determine whether we need to push work.
+        state.count += 1;
+        if is_dead || state.has_count {
+            return Ok(None);
+        }
+
+        // Userspace needs to be notified of this.
+        if !strong && inner.delivery_state.should_push_weak_zero2one() {
+            assert!(inner.delivery_state.can_push_weak_zero2one_normally());
+            let list_arc = ListArc::try_from_arc(self.clone()).ok().unwrap();
+            inner.delivery_state.did_push_weak_zero2one();
+            Ok(Some(list_arc))
+        } else if strong && inner.delivery_state.should_push_strong_zero2one() {
+            if inner.delivery_state.can_push_strong_zero2one_normally() {
+                let list_arc = ListArc::try_from_arc(self.clone()).ok().unwrap();
+                inner.delivery_state.did_push_strong_zero2one();
+                Ok(Some(list_arc))
+            } else {
+                state.count -= 1;
+                Err(CouldNotDeliverCriticalIncrement)
+            }
+        } else {
+            // Work is already pushed, and we don't need to push again.
+            Ok(None)
+        }
+    }
+
+    pub(crate) fn incr_refcount_allow_zero2one_with_wrapper(
+        self: &DArc<Self>,
+        strong: bool,
+        wrapper: CritIncrWrapper,
+        owner_inner: &mut ProcessInner,
+    ) -> Option<DLArc<dyn DeliverToRead>> {
+        match self.incr_refcount_allow_zero2one(strong, owner_inner) {
+            Ok(Some(node)) => Some(node as DLArc<dyn DeliverToRead>),
+            Ok(None) => None,
+            Err(CouldNotDeliverCriticalIncrement) => {
+                assert!(strong);
+                let inner = self.inner.access_mut(owner_inner);
+                inner.strong.count += 1;
+                inner.delivery_state.did_push_strong_zero2one_wrapper();
+                Some(wrapper.init(self.clone()))
+            }
+        }
+    }
+
+    pub(crate) fn update_refcount(self: &DArc<Self>, inc: bool, count: usize, strong: bool) {
+        self.owner
+            .inner
+            .lock()
+            .update_node_refcount(self, inc, strong, count, None);
+    }
+
+    pub(crate) fn populate_counts(
+        &self,
+        out: &mut BinderNodeInfoForRef,
+        guard: &Guard<'_, ProcessInner, SpinLockBackend>,
+    ) {
+        let inner = self.inner.access(guard);
+        out.strong_count = inner.strong.count as u32;
+        out.weak_count = inner.weak.count as u32;
+    }
+
+    pub(crate) fn populate_debug_info(
+        &self,
+        out: &mut BinderNodeDebugInfo,
+        guard: &Guard<'_, ProcessInner, SpinLockBackend>,
+    ) {
+        out.ptr = self.ptr as uapi::binder_uintptr_t;
+        out.cookie = self.cookie as uapi::binder_uintptr_t;
+        let inner = self.inner.access(guard);
+        if inner.strong.has_count {
+            out.has_strong_ref = 1;
+        }
+        if inner.weak.has_count {
+            out.has_weak_ref = 1;
+        }
+    }
+
+    pub(crate) fn force_has_count(&self, guard: &mut Guard<'_, ProcessInner, SpinLockBackend>) {
+        let inner = self.inner.access_mut(guard);
+        inner.strong.has_count = true;
+        inner.weak.has_count = true;
+    }
+
+    fn write(&self, writer: &mut BinderReturnWriter<'_>, code: u32) -> Result {
+        writer.write_code(code)?;
+        writer.write_payload(&self.ptr)?;
+        writer.write_payload(&self.cookie)?;
+        Ok(())
+    }
+
+    pub(crate) fn submit_oneway(
+        &self,
+        transaction: DLArc<Transaction>,
+        guard: &mut Guard<'_, ProcessInner, SpinLockBackend>,
+    ) -> Result<(), (BinderError, DLArc<dyn DeliverToRead>)> {
+        if guard.is_dead {
+            return Err((BinderError::new_dead(), transaction));
+        }
+
+        let inner = self.inner.access_mut(guard);
+        if inner.has_oneway_transaction {
+            inner.oneway_todo.push_back(transaction);
+        } else {
+            inner.has_oneway_transaction = true;
+            guard.push_work(&self.owner, transaction)?;
+        }
+        Ok(())
+    }
+
+    pub(crate) fn release(&self) {
+        let mut guard = self.owner.inner.lock();
+        while let Some(work) = self.inner.access_mut(&mut guard).oneway_todo.pop_front() {
+            drop(guard);
+            work.into_arc().cancel();
+            guard = self.owner.inner.lock();
+        }
+
+        while let Some(death) = self.inner.access_mut(&mut guard).death_list.pop_front() {
+            drop(guard);
+            death.into_arc().set_dead();
+            guard = self.owner.inner.lock();
+        }
+    }
+
+    pub(crate) fn pending_oneway_finished(&self) {
+        let mut guard = self.owner.inner.lock();
+        if guard.is_dead {
+            // Cleanup will happen in `Process::deferred_release`.
+            return;
+        }
+
+        let inner = self.inner.access_mut(&mut guard);
+
+        let transaction = inner.oneway_todo.pop_front();
+        inner.has_oneway_transaction = transaction.is_some();
+        if let Some(transaction) = transaction {
+            match guard.push_work(&self.owner, transaction) {
+                Ok(()) => {}
+                Err((_err, work)) => {
+                    // Process is dead.
+                    // This shouldn't happen due to the `is_dead` check, but if it does, just drop
+                    // the transaction and return.
+                    drop(guard);
+                    drop(work);
+                }
+            }
+        }
+    }
+
+    /// Finds an outdated transaction that the given transaction can replace.
+    ///
+    /// If one is found, it is removed from the list and returned.
+    pub(crate) fn take_outdated_transaction(
+        &self,
+        new: &Transaction,
+        guard: &mut Guard<'_, ProcessInner, SpinLockBackend>,
+    ) -> Option<DLArc<Transaction>> {
+        let inner = self.inner.access_mut(guard);
+        let mut cursor = inner.oneway_todo.cursor_front();
+        while let Some(next) = cursor.peek_next() {
+            if new.can_replace(&next) {
+                return Some(next.remove());
+            }
+            cursor.move_next();
+        }
+        None
+    }
+
+    /// This is split into a separate function since it's called by both `Node::do_work` and
+    /// `NodeWrapper::do_work`.
+    fn do_work_locked(
+        &self,
+        writer: &mut BinderReturnWriter<'_>,
+        mut guard: Guard<'_, ProcessInner, SpinLockBackend>,
+    ) -> Result<bool> {
+        let inner = self.inner.access_mut(&mut guard);
+        let strong = inner.strong.count > 0;
+        let has_strong = inner.strong.has_count;
+        let weak = strong || inner.weak.count > 0;
+        let has_weak = inner.weak.has_count;
+
+        if weak && !has_weak {
+            inner.weak.has_count = true;
+            inner.active_inc_refs += 1;
+        }
+
+        if strong && !has_strong {
+            inner.strong.has_count = true;
+            inner.active_inc_refs += 1;
+        }
+
+        let no_active_inc_refs = inner.active_inc_refs == 0;
+        let should_drop_weak = no_active_inc_refs && (!weak && has_weak);
+        let should_drop_strong = no_active_inc_refs && (!strong && has_strong);
+        if should_drop_weak {
+            inner.weak.has_count = false;
+        }
+        if should_drop_strong {
+            inner.strong.has_count = false;
+        }
+        if no_active_inc_refs && !weak {
+            // Remove the node if there are no references to it.
+            guard.remove_node(self.ptr);
+        }
+        drop(guard);
+
+        if weak && !has_weak {
+            self.write(writer, BR_INCREFS)?;
+        }
+        if strong && !has_strong {
+            self.write(writer, BR_ACQUIRE)?;
+        }
+        if should_drop_strong {
+            self.write(writer, BR_RELEASE)?;
+        }
+        if should_drop_weak {
+            self.write(writer, BR_DECREFS)?;
+        }
+
+        Ok(true)
+    }
+
+    pub(crate) fn add_freeze_listener(
+        &self,
+        process: &Arc<Process>,
+        // If the vector needs to be resized, it's done via this argument.
+        vec_alloc: &mut KVVec<Arc<Process>>,
+    ) -> Result<Result<(), usize>> {
+        let mut guard = self.owner.inner.lock();
+        // Do not check for `guard.dead`. The `dead` flag that matters here is the owner of the
+        // listener, not the target.
+        let inner = self.inner.access_mut(&mut guard);
+        let len = inner.freeze_list.len();
+        if len == inner.freeze_list.capacity() {
+            if len >= vec_alloc.capacity() {
+                // Request the caller to reallocate.
+                return Ok(Err((1 + len).next_power_of_two()));
+            }
+            mem::swap(&mut inner.freeze_list, vec_alloc);
+            for elem in vec_alloc.drain_all() {
+                inner.freeze_list.push_within_capacity(elem)?;
+            }
+        }
+        inner.freeze_list.push_within_capacity(process.clone())?;
+        Ok(Ok(()))
+    }
+
+    pub(crate) fn remove_freeze_listener(&self, p: &Process) -> KVVec<Arc<Process>> {
+        let mut guard = self.owner.inner.lock();
+        let inner = self.inner.access_mut(&mut guard);
+        let len = inner.freeze_list.len();
+        inner
+            .freeze_list
+            .retain(|proc| !core::ptr::eq::<Process>(&**proc, p));
+        if len == inner.freeze_list.len() {
+            pr_warn!(
+                "Could not remove freeze listener for {}\n",
+                p.pid_in_current_ns()
+            );
+        }
+        // If the vector is empty it needs to be freed. However, we can't free it here because that
+        // might sleep, so return it to the caller.
+        if inner.freeze_list.is_empty() {
+            return mem::take(&mut inner.freeze_list);
+        }
+        KVVec::new()
+    }
+
+    pub(crate) fn freeze_list<'a>(&'a self, guard: &'a ProcessInner) -> &'a [Arc<Process>] {
+        &self.inner.access(guard).freeze_list
+    }
+}
+
+impl DeliverToRead for Node {
+    fn do_work(
+        self: DArc<Self>,
+        _thread: &Thread,
+        writer: &mut BinderReturnWriter<'_>,
+    ) -> Result<bool> {
+        let mut owner_inner = self.owner.inner.lock();
+        let inner = self.inner.access_mut(&mut owner_inner);
+
+        assert!(inner.delivery_state.has_pushed_node);
+        if inner.delivery_state.has_pushed_wrapper {
+            // If the wrapper is scheduled, then we are either a normal push or weak zero2one
+            // increment, and the wrapper is a strong zero2one increment, so the wrapper always
+            // takes precedence over us.
+            assert!(inner.delivery_state.has_strong_zero2one);
+            inner.delivery_state.has_pushed_node = false;
+            inner.delivery_state.has_weak_zero2one = false;
+            return Ok(true);
+        }
+
+        inner.delivery_state.has_pushed_node = false;
+        inner.delivery_state.has_weak_zero2one = false;
+        inner.delivery_state.has_strong_zero2one = false;
+
+        self.do_work_locked(writer, owner_inner)
+    }
+
+    fn cancel(self: DArc<Self>) {}
+
+    fn should_sync_wakeup(&self) -> bool {
+        false
+    }
+
+    #[inline(never)]
+    fn debug_print(&self, m: &SeqFile, prefix: &str, _tprefix: &str) -> Result<()> {
+        seq_print!(
+            m,
+            "{}node work {}: u{:016x} c{:016x}\n",
+            prefix,
+            self.debug_id,
+            self.ptr,
+            self.cookie,
+        );
+        Ok(())
+    }
+}
+
+/// Represents something that holds one or more ref-counts to a `Node`.
+///
+/// Whenever process A holds a refcount to a node owned by a different process B, then process A
+/// will store a `NodeRef` that refers to the `Node` in process B. When process A releases the
+/// refcount, we destroy the NodeRef, which decrements the ref-count in process A.
+///
+/// This type is also used for some other cases. For example, a transaction allocation holds a
+/// refcount on the target node, and this is implemented by storing a `NodeRef` in the allocation
+/// so that the destructor of the allocation will drop a refcount of the `Node`.
+pub(crate) struct NodeRef {
+    pub(crate) node: DArc<Node>,
+    /// How many times does this NodeRef hold a refcount on the Node?
+    strong_node_count: usize,
+    weak_node_count: usize,
+    /// How many times does userspace hold a refcount on this NodeRef?
+    strong_count: usize,
+    weak_count: usize,
+}
+
+impl NodeRef {
+    pub(crate) fn new(node: DArc<Node>, strong_count: usize, weak_count: usize) -> Self {
+        Self {
+            node,
+            strong_node_count: strong_count,
+            weak_node_count: weak_count,
+            strong_count,
+            weak_count,
+        }
+    }
+
+    pub(crate) fn absorb(&mut self, mut other: Self) {
+        assert!(
+            Arc::ptr_eq(&self.node, &other.node),
+            "absorb called with differing nodes"
+        );
+        self.strong_node_count += other.strong_node_count;
+        self.weak_node_count += other.weak_node_count;
+        self.strong_count += other.strong_count;
+        self.weak_count += other.weak_count;
+        other.strong_count = 0;
+        other.weak_count = 0;
+        other.strong_node_count = 0;
+        other.weak_node_count = 0;
+
+        if self.strong_node_count >= 2 || self.weak_node_count >= 2 {
+            let mut guard = self.node.owner.inner.lock();
+            let inner = self.node.inner.access_mut(&mut guard);
+
+            if self.strong_node_count >= 2 {
+                inner.strong.count -= self.strong_node_count - 1;
+                self.strong_node_count = 1;
+                assert_ne!(inner.strong.count, 0);
+            }
+            if self.weak_node_count >= 2 {
+                inner.weak.count -= self.weak_node_count - 1;
+                self.weak_node_count = 1;
+                assert_ne!(inner.weak.count, 0);
+            }
+        }
+    }
+
+    pub(crate) fn get_count(&self) -> (usize, usize) {
+        (self.strong_count, self.weak_count)
+    }
+
+    pub(crate) fn clone(&self, strong: bool) -> Result<NodeRef> {
+        if strong && self.strong_count == 0 {
+            binder_debug!(UserError, "tried to use weak ref as strong ref");
+            return Err(EINVAL);
+        }
+        Ok(self
+            .node
+            .owner
+            .inner
+            .lock()
+            .new_node_ref(self.node.clone(), strong, None))
+    }
+
+    /// Updates (increments or decrements) the number of references held against the node. If the
+    /// count being updated transitions from 0 to 1 or from 1 to 0, the node is notified by having
+    /// its `update_refcount` function called.
+    ///
+    /// Returns whether `self` should be removed (when both counts are zero).
+    pub(crate) fn update(&mut self, inc: bool, strong: bool) -> bool {
+        if strong && self.strong_count == 0 {
+            return false;
+        }
+        let (count, node_count, other_count) = if strong {
+            (
+                &mut self.strong_count,
+                &mut self.strong_node_count,
+                self.weak_count,
+            )
+        } else {
+            (
+                &mut self.weak_count,
+                &mut self.weak_node_count,
+                self.strong_count,
+            )
+        };
+        if inc {
+            if *count == 0 {
+                *node_count = 1;
+                self.node.update_refcount(true, 1, strong);
+            }
+            *count += 1;
+        } else {
+            if *count == 0 {
+                binder_debug!(
+                    UserError,
+                    "performed invalid {} decrement on ref",
+                    if strong { "strong" } else { "weak" }
+                );
+                return false;
+            }
+            *count -= 1;
+            if *count == 0 {
+                self.node.update_refcount(false, *node_count, strong);
+                *node_count = 0;
+                return other_count == 0;
+            }
+        }
+        false
+    }
+}
+
+impl Drop for NodeRef {
+    // This destructor is called conditionally from `Allocation::drop`. That branch is often
+    // mispredicted. Inlining this method call reduces the cost of those branch mispredictions.
+    #[inline(always)]
+    fn drop(&mut self) {
+        if self.strong_node_count > 0 {
+            self.node
+                .update_refcount(false, self.strong_node_count, true);
+        }
+        if self.weak_node_count > 0 {
+            self.node
+                .update_refcount(false, self.weak_node_count, false);
+        }
+    }
+}
+
+struct NodeDeathInner {
+    dead: bool,
+    cleared: bool,
+    notification_done: bool,
+    /// Indicates whether the normal flow was interrupted by removing the handle. In this case, we
+    /// need behave as if the death notification didn't exist (i.e., we don't deliver anything to
+    /// the user.
+    aborted: bool,
+}
+
+/// Used to deliver notifications when a process dies.
+///
+/// A process can request to be notified when a process dies using `BC_REQUEST_DEATH_NOTIFICATION`.
+/// This will make the driver send a `BR_DEAD_BINDER` to userspace when the process dies (or
+/// immediately if it is already dead). Userspace is supposed to respond with `BC_DEAD_BINDER_DONE`
+/// once it has processed the notification.
+///
+/// Userspace can unregister from death notifications using the `BC_CLEAR_DEATH_NOTIFICATION`
+/// command. In this case, the kernel will respond with `BR_CLEAR_DEATH_NOTIFICATION_DONE` once the
+/// notification has been removed. Note that if the remote process dies before the kernel has
+/// responded with `BR_CLEAR_DEATH_NOTIFICATION_DONE`, then the kernel will still send a
+/// `BR_DEAD_BINDER`, which userspace must be able to process. In this case, the kernel will wait
+/// for the `BC_DEAD_BINDER_DONE` command before it sends `BR_CLEAR_DEATH_NOTIFICATION_DONE`.
+///
+/// Note that even if the kernel sends a `BR_DEAD_BINDER`, this does not remove the death
+/// notification. Userspace must still remove it manually using `BC_CLEAR_DEATH_NOTIFICATION`.
+///
+/// If a process uses `BC_RELEASE` to destroy its last refcount on a node that has an active death
+/// registration, then the death registration is immediately deleted (we implement this using the
+/// `aborted` field). However, userspace is not supposed to delete a `NodeRef` without first
+/// deregistering death notifications, so this codepath is not executed under normal circumstances.
+#[pin_data]
+pub(crate) struct NodeDeath {
+    node: DArc<Node>,
+    process: Arc<Process>,
+    pub(crate) cookie: u64,
+    #[pin]
+    links_track: AtomicTracker<0>,
+    /// Used by the owner `Node` to store a list of registered death notifications.
+    ///
+    /// # Invariants
+    ///
+    /// Only ever used with the `death_list` list of `self.node`.
+    #[pin]
+    death_links: ListLinks<1>,
+    /// Used by the process to keep track of the death notifications for which we have sent a
+    /// `BR_DEAD_BINDER` but not yet received a `BC_DEAD_BINDER_DONE`.
+    ///
+    /// # Invariants
+    ///
+    /// Only ever used with the `delivered_deaths` list of `self.process`.
+    #[pin]
+    delivered_links: ListLinks<2>,
+    #[pin]
+    delivered_links_track: AtomicTracker<2>,
+    #[pin]
+    inner: SpinLock<NodeDeathInner>,
+}
+
+impl NodeDeath {
+    /// Constructs a new node death notification object.
+    pub(crate) fn new(
+        node: DArc<Node>,
+        process: Arc<Process>,
+        cookie: u64,
+    ) -> impl PinInit<DTRWrap<Self>> {
+        DTRWrap::new(pin_init!(
+            Self {
+                node,
+                process,
+                cookie,
+                links_track <- AtomicTracker::new(),
+                death_links <- ListLinks::new(),
+                delivered_links <- ListLinks::new(),
+                delivered_links_track <- AtomicTracker::new(),
+                inner <- kernel::new_spinlock!(NodeDeathInner {
+                    dead: false,
+                    cleared: false,
+                    notification_done: false,
+                    aborted: false,
+                }, "NodeDeath::inner"),
+            }
+        ))
+    }
+
+    /// Sets the cleared flag to `true`.
+    ///
+    /// It removes `self` from the node's death notification list if needed.
+    ///
+    /// Returns whether it needs to be queued.
+    pub(crate) fn set_cleared(self: &DArc<Self>, abort: bool) -> bool {
+        let (needs_removal, needs_queueing) = {
+            // Update state and determine if we need to queue a work item. We only need to do it
+            // when the node is not dead or if the user already completed the death notification.
+            let mut inner = self.inner.lock();
+            if abort {
+                inner.aborted = true;
+            }
+            if inner.cleared {
+                // Already cleared.
+                return false;
+            }
+            inner.cleared = true;
+            (!inner.dead, !inner.dead || inner.notification_done)
+        };
+
+        // Remove death notification from node.
+        if needs_removal {
+            let mut owner_inner = self.node.owner.inner.lock();
+            let node_inner = self.node.inner.access_mut(&mut owner_inner);
+            // SAFETY: A `NodeDeath` is never inserted into the death list of any node other than
+            // its owner, so it is either in this death list or in no death list.
+            unsafe { node_inner.death_list.remove(self) };
+        }
+        needs_queueing
+    }
+
+    /// Sets the 'notification done' flag to `true`.
+    pub(crate) fn set_notification_done(self: DArc<Self>, thread: &Thread) {
+        let needs_queueing = {
+            let mut inner = self.inner.lock();
+            inner.notification_done = true;
+            inner.cleared
+        };
+        if needs_queueing {
+            if let Some(death) = ListArc::try_from_arc_or_drop(self) {
+                let _ = thread.push_work_if_looper(death);
+            }
+        }
+    }
+
+    /// Sets the 'dead' flag to `true` and queues work item if needed.
+    pub(crate) fn set_dead(self: DArc<Self>) {
+        let needs_queueing = {
+            let mut inner = self.inner.lock();
+            if inner.cleared {
+                false
+            } else {
+                inner.dead = true;
+                true
+            }
+        };
+        if needs_queueing {
+            // Push the death notification to the target process. There is nothing else to do if
+            // it's already dead.
+            if let Some(death) = ListArc::try_from_arc_or_drop(self) {
+                let process = death.process.clone();
+                let _ = process.push_work(death);
+            }
+        }
+    }
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<0> for NodeDeath {
+        tracked_by links_track: AtomicTracker;
+    }
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<1> for DTRWrap<NodeDeath> { untracked; }
+}
+kernel::list::impl_list_item! {
+    impl ListItem<1> for DTRWrap<NodeDeath> {
+        using ListLinks { self.wrapped.death_links };
+    }
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<2> for DTRWrap<NodeDeath> {
+        tracked_by wrapped: NodeDeath;
+    }
+}
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<2> for NodeDeath {
+        tracked_by delivered_links_track: AtomicTracker<2>;
+    }
+}
+kernel::list::impl_list_item! {
+    impl ListItem<2> for DTRWrap<NodeDeath> {
+        using ListLinks { self.wrapped.delivered_links };
+    }
+}
+
+impl DeliverToRead for NodeDeath {
+    fn do_work(
+        self: DArc<Self>,
+        _thread: &Thread,
+        writer: &mut BinderReturnWriter<'_>,
+    ) -> Result<bool> {
+        let done = {
+            let inner = self.inner.lock();
+            if inner.aborted {
+                return Ok(true);
+            }
+            inner.cleared && (!inner.dead || inner.notification_done)
+        };
+
+        let cookie = self.cookie;
+        let cmd = if done {
+            BR_CLEAR_DEATH_NOTIFICATION_DONE
+        } else {
+            let process = self.process.clone();
+            let mut process_inner = process.inner.lock();
+            let inner = self.inner.lock();
+            if inner.aborted {
+                return Ok(true);
+            }
+            // We're still holding the inner lock, so it cannot be aborted while we insert it into
+            // the delivered list.
+            process_inner.death_delivered(self.clone());
+            binder_debug!(
+                DeathNotification,
+                "sending death notification, cookie {:016x}",
+                cookie
+            );
+            BR_DEAD_BINDER
+        };
+
+        writer.write_code(cmd)?;
+        writer.write_payload(&cookie)?;
+        // DEAD_BINDER notifications can cause transactions, so stop processing work items when we
+        // get to a death notification.
+        Ok(cmd != BR_DEAD_BINDER)
+    }
+
+    fn cancel(self: DArc<Self>) {
+        binder_debug!(
+            pid = self.process.task.pid(),
+            DeadTransaction,
+            "undelivered death notification, {:016x}",
+            self.cookie
+        );
+    }
+
+    fn should_sync_wakeup(&self) -> bool {
+        false
+    }
+
+    #[inline(never)]
+    fn debug_print(&self, m: &SeqFile, prefix: &str, _tprefix: &str) -> Result<()> {
+        let inner = self.inner.lock();
+
+        let dead_binder = inner.dead && !inner.notification_done;
+
+        if dead_binder {
+            if inner.cleared {
+                seq_print!(m, "{}has cleared dead binder\n", prefix);
+            } else {
+                seq_print!(m, "{}has dead binder\n", prefix);
+            }
+        } else {
+            seq_print!(m, "{}has cleared death notification\n", prefix);
+        }
+
+        Ok(())
+    }
+}
diff --git a/drivers/android/binder/node/wrapper.rs b/drivers/android/binder/node/wrapper.rs
new file mode 100644
index 000000000..6e4ca01c9
--- /dev/null
+++ b/drivers/android/binder/node/wrapper.rs
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use kernel::{list::ListArc, prelude::*, seq_file::SeqFile, seq_print, sync::UniqueArc};
+
+use crate::{node::Node, thread::Thread, BinderReturnWriter, DArc, DLArc, DTRWrap, DeliverToRead};
+
+use core::mem::MaybeUninit;
+
+pub(crate) struct CritIncrWrapper {
+    inner: UniqueArc<MaybeUninit<DTRWrap<NodeWrapper>>>,
+}
+
+impl CritIncrWrapper {
+    pub(crate) fn new() -> Result<Self> {
+        Ok(CritIncrWrapper {
+            inner: UniqueArc::new_uninit(GFP_KERNEL)?,
+        })
+    }
+
+    pub(super) fn init(self, node: DArc<Node>) -> DLArc<dyn DeliverToRead> {
+        match self.inner.pin_init_with(DTRWrap::new(NodeWrapper { node })) {
+            Ok(initialized) => ListArc::from(initialized) as DLArc<dyn DeliverToRead>,
+            Err(err) => match err {},
+        }
+    }
+}
+
+struct NodeWrapper {
+    node: DArc<Node>,
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<0> for NodeWrapper {
+        untracked;
+    }
+}
+
+impl DeliverToRead for NodeWrapper {
+    fn do_work(
+        self: DArc<Self>,
+        _thread: &Thread,
+        writer: &mut BinderReturnWriter<'_>,
+    ) -> Result<bool> {
+        let node = &self.node;
+        let mut owner_inner = node.owner.inner.lock();
+        let inner = node.inner.access_mut(&mut owner_inner);
+
+        let ds = &mut inner.delivery_state;
+
+        assert!(ds.has_pushed_wrapper);
+        assert!(ds.has_strong_zero2one);
+        ds.has_pushed_wrapper = false;
+        ds.has_strong_zero2one = false;
+
+        node.do_work_locked(writer, owner_inner)
+    }
+
+    fn cancel(self: DArc<Self>) {}
+
+    fn should_sync_wakeup(&self) -> bool {
+        false
+    }
+
+    #[inline(never)]
+    fn debug_print(&self, m: &SeqFile, prefix: &str, _tprefix: &str) -> Result<()> {
+        seq_print!(
+            m,
+            "{}node work {}: u{:016x} c{:016x}\n",
+            prefix,
+            self.node.debug_id,
+            self.node.ptr,
+            self.node.cookie,
+        );
+        Ok(())
+    }
+}
diff --git a/drivers/android/binder/page_range.rs b/drivers/android/binder/page_range.rs
new file mode 100644
index 000000000..52ffbf350
--- /dev/null
+++ b/drivers/android/binder/page_range.rs
@@ -0,0 +1,775 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+//! This module has utilities for managing a page range where unused pages may be reclaimed by a
+//! vma shrinker.
+
+// To avoid deadlocks, locks are taken in the order:
+//
+//  1. mmap lock
+//  2. spinlock
+//  3. lru spinlock
+//
+// The shrinker will use trylock methods because it locks them in a different order.
+
+use crate::AssertSync;
+
+use core::{
+    marker::PhantomPinned,
+    mem::{size_of, size_of_val, MaybeUninit},
+    ptr,
+};
+
+use kernel::{
+    bindings,
+    error::Result,
+    ffi::{c_ulong, c_void},
+    mm::{virt, Mm, MmWithUser},
+    new_mutex, new_spinlock,
+    page::{Page, PAGE_SHIFT, PAGE_SIZE},
+    prelude::*,
+    str::CStr,
+    sync::{aref::ARef, Mutex, SpinLock},
+    task::Pid,
+    transmute::FromBytes,
+    types::Opaque,
+    uaccess::UserSliceReader,
+};
+
+/// Represents a shrinker that can be registered with the kernel.
+///
+/// Each shrinker can be used by many `ShrinkablePageRange` objects.
+#[repr(C)]
+pub(crate) struct Shrinker {
+    inner: Opaque<*mut bindings::shrinker>,
+    list_lru: Opaque<bindings::list_lru>,
+}
+
+// SAFETY: The shrinker and list_lru are thread safe.
+unsafe impl Send for Shrinker {}
+// SAFETY: The shrinker and list_lru are thread safe.
+unsafe impl Sync for Shrinker {}
+
+impl Shrinker {
+    /// Create a new shrinker.
+    ///
+    /// # Safety
+    ///
+    /// Before using this shrinker with a `ShrinkablePageRange`, the `register` method must have
+    /// been called exactly once, and it must not have returned an error.
+    pub(crate) const unsafe fn new() -> Self {
+        Self {
+            inner: Opaque::uninit(),
+            list_lru: Opaque::uninit(),
+        }
+    }
+
+    /// Register this shrinker with the kernel.
+    pub(crate) fn register(&'static self, name: &CStr) -> Result<()> {
+        // SAFETY: These fields are not yet used, so it's okay to zero them.
+        unsafe {
+            self.inner.get().write(ptr::null_mut());
+            self.list_lru.get().write_bytes(0, 1);
+        }
+
+        // SAFETY: The field is not yet used, so we can initialize it.
+        let ret = unsafe { bindings::__list_lru_init(self.list_lru.get(), false, ptr::null_mut()) };
+        if ret != 0 {
+            return Err(Error::from_errno(ret));
+        }
+
+        // SAFETY: The `name` points at a valid c string.
+        let shrinker = unsafe { bindings::shrinker_alloc(0, name.as_char_ptr()) };
+        if shrinker.is_null() {
+            // SAFETY: We initialized it, so its okay to destroy it.
+            unsafe { bindings::list_lru_destroy(self.list_lru.get()) };
+            return Err(Error::from_errno(ret));
+        }
+
+        // SAFETY: We're about to register the shrinker, and these are the fields we need to
+        // initialize. (All other fields are already zeroed.)
+        unsafe {
+            (&raw mut (*shrinker).count_objects).write(Some(rust_shrink_count));
+            (&raw mut (*shrinker).scan_objects).write(Some(rust_shrink_scan));
+            (&raw mut (*shrinker).private_data).write(self.list_lru.get().cast());
+        }
+
+        // SAFETY: The new shrinker has been fully initialized, so we can register it.
+        unsafe { bindings::shrinker_register(shrinker) };
+
+        // SAFETY: This initializes the pointer to the shrinker so that we can use it.
+        unsafe { self.inner.get().write(shrinker) };
+
+        Ok(())
+    }
+}
+
+/// A container that manages a page range in a vma.
+///
+/// The pages can be thought of as an array of booleans of whether the pages are usable. The
+/// methods `use_range` and `stop_using_range` set all booleans in a range to true or false
+/// respectively. Initially, no pages are allocated. When a page is not used, it is not freed
+/// immediately. Instead, it is made available to the memory shrinker to free it if the device is
+/// under memory pressure.
+///
+/// It's okay for `use_range` and `stop_using_range` to race with each other, although there's no
+/// way to know whether an index ends up with true or false if a call to `use_range` races with
+/// another call to `stop_using_range` on a given index.
+///
+/// It's also okay for the two methods to race with themselves, e.g. if two threads call
+/// `use_range` on the same index, then that's fine and neither call will return until the page is
+/// allocated and mapped.
+///
+/// The methods that read or write to a range require that the page is marked as in use. So it is
+/// _not_ okay to call `stop_using_range` on a page that is in use by the methods that read or
+/// write to the page.
+#[pin_data(PinnedDrop)]
+pub(crate) struct ShrinkablePageRange {
+    /// Shrinker object registered with the kernel.
+    shrinker: &'static Shrinker,
+    /// Pid using this page range. Only used as debugging information.
+    pid: Pid,
+    /// The mm for the relevant process.
+    mm: ARef<Mm>,
+    /// Used to synchronize calls to `vm_insert_page` and `zap_vma_range`.
+    #[pin]
+    mm_lock: Mutex<()>,
+    /// Spinlock protecting changes to pages.
+    #[pin]
+    lock: SpinLock<Inner>,
+
+    /// Must not move, since page info has pointers back.
+    #[pin]
+    _pin: PhantomPinned,
+}
+
+// We do not define any ops. For now, used only to check identity of vmas.
+static BINDER_VM_OPS: AssertSync<bindings::vm_operations_struct> = AssertSync(pin_init::zeroed());
+
+// To ensure that we do not accidentally install pages into or zap pages from the wrong vma, we
+// check its vm_ops and private data before using it.
+fn check_vma(vma: &virt::VmaRef, owner: *const ShrinkablePageRange) -> Option<&virt::VmaMixedMap> {
+    // SAFETY: Just reading the vm_ops pointer of any active vma is safe.
+    let vm_ops = unsafe { (*vma.as_ptr()).vm_ops };
+    if !ptr::eq(vm_ops, &BINDER_VM_OPS.0) {
+        return None;
+    }
+
+    // SAFETY: Reading the vm_private_data pointer of a binder-owned vma is safe.
+    let vm_private_data = unsafe { (*vma.as_ptr()).vm_private_data };
+    // The ShrinkablePageRange is only dropped when the Process is dropped, which only happens once
+    // the file's ->release handler is invoked, which means the ShrinkablePageRange outlives any
+    // VMA associated with it, so there can't be any false positives due to pointer reuse here.
+    if !ptr::eq(vm_private_data, owner.cast()) {
+        return None;
+    }
+
+    vma.as_mixedmap_vma()
+}
+
+struct Inner {
+    /// Array of pages.
+    ///
+    /// Since this is also accessed by the shrinker, we can't use a `Box`, which asserts exclusive
+    /// ownership. To deal with that, we manage it using raw pointers.
+    pages: *mut PageInfo,
+    /// Length of the `pages` array.
+    size: usize,
+    /// The address of the vma to insert the pages into.
+    vma_addr: usize,
+}
+
+// SAFETY: proper locking is in place for `Inner`
+unsafe impl Send for Inner {}
+
+type StableMmGuard =
+    kernel::sync::lock::Guard<'static, (), kernel::sync::lock::mutex::MutexBackend>;
+
+/// An array element that describes the current state of a page.
+///
+/// There are three states:
+///
+///  * Free. The page is None. The `lru` element is not queued.
+///  * Available. The page is Some. The `lru` element is queued to the shrinker's lru.
+///  * Used. The page is Some. The `lru` element is not queued.
+///
+/// When an element is available, the shrinker is able to free the page.
+#[repr(C)]
+struct PageInfo {
+    lru: bindings::list_head,
+    page: Option<Page>,
+    range: *const ShrinkablePageRange,
+}
+
+impl PageInfo {
+    /// # Safety
+    ///
+    /// The caller ensures that writing to `me.page` is ok, and that the page is not currently set.
+    unsafe fn set_page(me: *mut PageInfo, page: Page) {
+        // SAFETY: This pointer offset is in bounds.
+        let ptr = unsafe { &raw mut (*me).page };
+
+        // SAFETY: The pointer is valid for writing, so also valid for reading.
+        if unsafe { (*ptr).is_some() } {
+            pr_err!("set_page called when there is already a page");
+            // SAFETY: We will initialize the page again below.
+            unsafe { ptr::drop_in_place(ptr) };
+        }
+
+        // SAFETY: The pointer is valid for writing.
+        unsafe { ptr::write(ptr, Some(page)) };
+    }
+
+    /// # Safety
+    ///
+    /// The caller ensures that reading from `me.page` is ok for the duration of 'a.
+    unsafe fn get_page<'a>(me: *const PageInfo) -> Option<&'a Page> {
+        // SAFETY: This pointer offset is in bounds.
+        let ptr = unsafe { &raw const (*me).page };
+
+        // SAFETY: The pointer is valid for reading.
+        unsafe { (*ptr).as_ref() }
+    }
+
+    /// # Safety
+    ///
+    /// The caller ensures that writing to `me.page` is ok for the duration of 'a.
+    unsafe fn take_page(me: *mut PageInfo) -> Option<Page> {
+        // SAFETY: This pointer offset is in bounds.
+        let ptr = unsafe { &raw mut (*me).page };
+
+        // SAFETY: The pointer is valid for reading.
+        unsafe { (*ptr).take() }
+    }
+
+    /// Add this page to the lru list, if not already in the list.
+    ///
+    /// # Safety
+    ///
+    /// The pointer must be valid, and it must be the right shrinker and nid.
+    unsafe fn list_lru_add(me: *mut PageInfo, nid: i32, shrinker: &'static Shrinker) {
+        // SAFETY: This pointer offset is in bounds.
+        let lru_ptr = unsafe { &raw mut (*me).lru };
+        // SAFETY: The lru pointer is valid, and we're not using it with any other lru list.
+        unsafe { bindings::list_lru_add(shrinker.list_lru.get(), lru_ptr, nid, ptr::null_mut()) };
+    }
+
+    /// Remove this page from the lru list, if it is in the list.
+    ///
+    /// # Safety
+    ///
+    /// The pointer must be valid, and it must be the right shrinker and nid.
+    unsafe fn list_lru_del(me: *mut PageInfo, nid: i32, shrinker: &'static Shrinker) {
+        // SAFETY: This pointer offset is in bounds.
+        let lru_ptr = unsafe { &raw mut (*me).lru };
+        // SAFETY: The lru pointer is valid, and we're not using it with any other lru list.
+        unsafe { bindings::list_lru_del(shrinker.list_lru.get(), lru_ptr, nid, ptr::null_mut()) };
+    }
+}
+
+impl ShrinkablePageRange {
+    /// Create a new `ShrinkablePageRange` using the given shrinker.
+    pub(crate) fn new(shrinker: &'static Shrinker) -> impl PinInit<Self, Error> {
+        try_pin_init!(Self {
+            shrinker,
+            pid: kernel::current!().pid(),
+            mm: ARef::from(&**kernel::current!().mm().ok_or(ESRCH)?),
+            mm_lock <- new_mutex!((), "ShrinkablePageRange::mm"),
+            lock <- new_spinlock!(Inner {
+                pages: ptr::null_mut(),
+                size: 0,
+                vma_addr: 0,
+            }, "ShrinkablePageRange"),
+            _pin: PhantomPinned,
+        })
+    }
+
+    pub(crate) fn stable_trylock_mm(&self) -> Option<StableMmGuard> {
+        // SAFETY: This extends the duration of the reference. Since this call happens before
+        // `mm_lock` is taken in the destructor of `ShrinkablePageRange`, the destructor will block
+        // until the returned guard is dropped. This ensures that the guard is valid until dropped.
+        let mm_lock = unsafe { &*ptr::from_ref(&self.mm_lock) };
+
+        mm_lock.try_lock()
+    }
+
+    /// Register a vma with this page range. Returns the size of the region.
+    pub(crate) fn register_with_vma(&self, vma: &virt::VmaNew) -> Result<usize> {
+        let num_bytes = usize::min(vma.end() - vma.start(), bindings::SZ_4M as usize);
+        let num_pages = num_bytes >> PAGE_SHIFT;
+
+        if !ptr::eq::<Mm>(&*self.mm, &**vma.mm()) {
+            pr_debug!("Failed to register with vma: invalid vma->vm_mm");
+            return Err(EINVAL);
+        }
+        if num_pages == 0 {
+            pr_debug!("Failed to register with vma: size zero");
+            return Err(EINVAL);
+        }
+
+        let mut pages = KVVec::<PageInfo>::with_capacity(num_pages, GFP_KERNEL)?;
+
+        // SAFETY: This just initializes the pages array.
+        unsafe {
+            let self_ptr = ptr::from_ref(self);
+            for i in 0..num_pages {
+                let info = pages.as_mut_ptr().add(i);
+                (&raw mut (*info).range).write(self_ptr);
+                (&raw mut (*info).page).write(None);
+                let lru = &raw mut (*info).lru;
+                (&raw mut (*lru).next).write(lru);
+                (&raw mut (*lru).prev).write(lru);
+            }
+        }
+
+        let mut inner = self.lock.lock();
+        if inner.size > 0 {
+            pr_debug!("Failed to register with vma: already registered");
+            drop(inner);
+            return Err(EBUSY);
+        }
+
+        inner.pages = pages.into_raw_parts().0;
+        inner.size = num_pages;
+        inner.vma_addr = vma.start();
+
+        // This pointer is only used for comparison - it's not dereferenced.
+        //
+        // SAFETY: We own the vma, and we don't use any methods on VmaNew that rely on
+        // `vm_private_data`.
+        unsafe {
+            (*vma.as_ptr()).vm_private_data = ptr::from_ref(self).cast_mut().cast::<c_void>()
+        };
+
+        // SAFETY: We own the vma, and we don't use any methods on VmaNew that rely on
+        // `vm_ops`.
+        unsafe { (*vma.as_ptr()).vm_ops = &BINDER_VM_OPS.0 };
+
+        Ok(num_pages)
+    }
+
+    /// Make sure that the given pages are allocated and mapped.
+    ///
+    /// Must not be called from an atomic context.
+    pub(crate) fn use_range(&self, start: usize, end: usize) -> Result<()> {
+        if start >= end {
+            return Ok(());
+        }
+        let mut inner = self.lock.lock();
+        assert!(end <= inner.size);
+
+        for i in start..end {
+            // SAFETY: This pointer offset is in bounds.
+            let page_info = unsafe { inner.pages.add(i) };
+
+            // SAFETY: The pointer is valid, and we hold the lock so reading from the page is okay.
+            if let Some(page) = unsafe { PageInfo::get_page(page_info) } {
+                // Since we're going to use the page, we should remove it from the lru list so that
+                // the shrinker will not free it.
+                //
+                // SAFETY: The pointer is valid, and this is the right shrinker.
+                //
+                // The shrinker can't free the page between the check and this call to
+                // `list_lru_del` because we hold the lock.
+                unsafe { PageInfo::list_lru_del(page_info, page.nid(), self.shrinker) };
+            } else {
+                // We have to allocate a new page. Use the slow path.
+                drop(inner);
+                // SAFETY: `i < end <= inner.size` so `i` is in bounds.
+                match unsafe { self.use_page_slow(i) } {
+                    Ok(()) => {}
+                    Err(err) => {
+                        pr_warn!("Error in use_page_slow: {:?}", err);
+                        return Err(err);
+                    }
+                }
+                inner = self.lock.lock();
+            }
+        }
+        Ok(())
+    }
+
+    /// Mark the given page as in use, slow path.
+    ///
+    /// Must not be called from an atomic context.
+    ///
+    /// # Safety
+    ///
+    /// Assumes that `i` is in bounds.
+    #[cold]
+    unsafe fn use_page_slow(&self, i: usize) -> Result<()> {
+        let new_page = Page::alloc_page(GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO)?;
+
+        let mm_mutex = self.mm_lock.lock();
+        let inner = self.lock.lock();
+
+        // SAFETY: This pointer offset is in bounds.
+        let page_info = unsafe { inner.pages.add(i) };
+
+        // SAFETY: The pointer is valid, and we hold the lock so reading from the page is okay.
+        if let Some(page) = unsafe { PageInfo::get_page(page_info) } {
+            // The page was already there, or someone else added the page while we didn't hold the
+            // spinlock.
+            //
+            // SAFETY: The pointer is valid, and this is the right shrinker.
+            //
+            // The shrinker can't free the page between the check and this call to
+            // `list_lru_del` because we hold the lock.
+            unsafe { PageInfo::list_lru_del(page_info, page.nid(), self.shrinker) };
+            return Ok(());
+        }
+
+        let vma_addr = inner.vma_addr;
+        // Release the spinlock while we insert the page into the vma.
+        drop(inner);
+
+        // No overflow since we stay in bounds of the vma.
+        let user_page_addr = vma_addr + (i << PAGE_SHIFT);
+
+        // We use `mmput_async` when dropping the `mm` because `use_page_slow` is usually used from
+        // a remote process. If the call to `mmput` races with the process shutting down, then the
+        // caller of `use_page_slow` becomes responsible for cleaning up the `mm`, which doesn't
+        // happen until it returns to userspace. However, the caller might instead go to sleep and
+        // wait for the owner of the `mm` to wake it up, which doesn't happen because it's in the
+        // middle of a shutdown process that won't complete until the `mm` is dropped. This can
+        // amount to a deadlock.
+        //
+        // Using `mmput_async` avoids this, because then the `mm` cleanup is instead queued to a
+        // workqueue.
+        let mm = MmWithUser::into_mmput_async(self.mm.mmget_not_zero().ok_or(ESRCH)?);
+        {
+            let vma_read;
+            let mmap_read;
+            let vma = if let Some(ret) = mm.lock_vma_under_rcu(vma_addr) {
+                vma_read = ret;
+                check_vma(&vma_read, self)
+            } else {
+                mmap_read = mm.mmap_read_lock();
+                mmap_read
+                    .vma_lookup(vma_addr)
+                    .and_then(|vma| check_vma(vma, self))
+            };
+
+            match vma {
+                Some(vma) => vma.vm_insert_page(user_page_addr, &new_page)?,
+                None => return Err(ESRCH),
+            }
+        }
+
+        let inner = self.lock.lock();
+
+        // SAFETY: The `page_info` pointer is valid and currently does not have a page. The page
+        // can be written to since we hold the lock.
+        //
+        // We released and reacquired the spinlock since we checked that the page is null, but we
+        // always hold the mm_lock mutex when setting the page to a non-null value, so it's not
+        // possible for someone else to have changed it since our check.
+        unsafe { PageInfo::set_page(page_info, new_page) };
+
+        drop(inner);
+        drop(mm_mutex);
+
+        Ok(())
+    }
+
+    /// If the given page is in use, then mark it as available so that the shrinker can free it.
+    ///
+    /// May be called from an atomic context.
+    pub(crate) fn stop_using_range(&self, start: usize, end: usize) {
+        if start >= end {
+            return;
+        }
+        let inner = self.lock.lock();
+        assert!(end <= inner.size);
+
+        for i in (start..end).rev() {
+            // SAFETY: The pointer is in bounds.
+            let page_info = unsafe { inner.pages.add(i) };
+
+            // SAFETY: Okay for reading since we have the lock.
+            if let Some(page) = unsafe { PageInfo::get_page(page_info) } {
+                // SAFETY: The pointer is valid, and it's the right shrinker.
+                unsafe { PageInfo::list_lru_add(page_info, page.nid(), self.shrinker) };
+            }
+        }
+    }
+
+    /// Helper for reading or writing to a range of bytes that may overlap with several pages.
+    ///
+    /// # Safety
+    ///
+    /// All pages touched by this operation must be in use for the duration of this call.
+    unsafe fn iterate<T>(&self, mut offset: usize, mut size: usize, mut cb: T) -> Result
+    where
+        T: FnMut(&Page, usize, usize) -> Result,
+    {
+        if size == 0 {
+            return Ok(());
+        }
+
+        let (pages, num_pages) = {
+            let inner = self.lock.lock();
+            (inner.pages, inner.size)
+        };
+        let num_bytes = num_pages << PAGE_SHIFT;
+
+        // Check that the request is within the buffer.
+        if offset.checked_add(size).ok_or(EFAULT)? > num_bytes {
+            return Err(EFAULT);
+        }
+
+        let mut page_index = offset >> PAGE_SHIFT;
+        offset &= PAGE_SIZE - 1;
+        while size > 0 {
+            let available = usize::min(size, PAGE_SIZE - offset);
+            // SAFETY: The pointer is in bounds.
+            let page_info = unsafe { pages.add(page_index) };
+            // SAFETY: The caller guarantees that this page is in the "in use" state for the
+            // duration of this call to `iterate`, so nobody will change the page.
+            let page = unsafe { PageInfo::get_page(page_info) };
+            if page.is_none() {
+                pr_warn!("Page is null!");
+            }
+            let page = page.ok_or(EFAULT)?;
+            cb(page, offset, available)?;
+            size -= available;
+            page_index += 1;
+            offset = 0;
+        }
+        Ok(())
+    }
+
+    /// Copy from userspace into this page range.
+    ///
+    /// # Safety
+    ///
+    /// All pages touched by this operation must be in use for the duration of this call.
+    pub(crate) unsafe fn copy_from_user_slice(
+        &self,
+        reader: &mut UserSliceReader,
+        offset: usize,
+        size: usize,
+    ) -> Result {
+        // SAFETY: `self.iterate` has the same safety requirements as `copy_from_user_slice`.
+        unsafe {
+            self.iterate(offset, size, |page, offset, to_copy| {
+                page.copy_from_user_slice_raw(reader, offset, to_copy)
+            })
+        }
+    }
+
+    /// Copy from this page range into kernel space.
+    ///
+    /// # Safety
+    ///
+    /// All pages touched by this operation must be in use for the duration of this call.
+    pub(crate) unsafe fn read<T: FromBytes>(&self, offset: usize) -> Result<T> {
+        let mut out = MaybeUninit::<T>::uninit();
+        let mut out_offset = 0;
+        // SAFETY: `self.iterate` has the same safety requirements as `read`.
+        unsafe {
+            self.iterate(offset, size_of::<T>(), |page, offset, to_copy| {
+                // SAFETY: The sum of `offset` and `to_copy` is bounded by the size of T.
+                let obj_ptr = out.as_mut_ptr().cast::<u8>().add(out_offset);
+                // SAFETY: The pointer points is in-bounds of the `out` variable, so it is valid.
+                page.read_raw(obj_ptr, offset, to_copy)?;
+                out_offset += to_copy;
+                Ok(())
+            })?;
+        }
+        // SAFETY: We just initialised the data.
+        Ok(unsafe { out.assume_init() })
+    }
+
+    /// Copy from kernel space into this page range.
+    ///
+    /// # Safety
+    ///
+    /// All pages touched by this operation must be in use for the duration of this call.
+    pub(crate) unsafe fn write<T: ?Sized>(&self, offset: usize, obj: &T) -> Result {
+        let mut obj_offset = 0;
+        // SAFETY: `self.iterate` has the same safety requirements as `write`.
+        unsafe {
+            self.iterate(offset, size_of_val(obj), |page, offset, to_copy| {
+                // SAFETY: The sum of `offset` and `to_copy` is bounded by the size of T.
+                let obj_ptr = ptr::from_ref(obj).cast::<u8>().add(obj_offset);
+                // SAFETY: We have a reference to the object, so the pointer is valid.
+                page.write_raw(obj_ptr, offset, to_copy)?;
+                obj_offset += to_copy;
+                Ok(())
+            })
+        }
+    }
+
+    /// Write zeroes to the given range.
+    ///
+    /// # Safety
+    ///
+    /// All pages touched by this operation must be in use for the duration of this call.
+    pub(crate) unsafe fn fill_zero(&self, offset: usize, size: usize) -> Result {
+        // SAFETY: `self.iterate` has the same safety requirements as `copy_into`.
+        unsafe {
+            self.iterate(offset, size, |page, offset, len| {
+                page.fill_zero_raw(offset, len)
+            })
+        }
+    }
+}
+
+#[pinned_drop]
+impl PinnedDrop for ShrinkablePageRange {
+    fn drop(self: Pin<&mut Self>) {
+        let (pages, size) = {
+            let lock = self.lock.lock();
+            (lock.pages, lock.size)
+        };
+
+        if size == 0 {
+            return;
+        }
+
+        // Note: This call is also necessary for the safety of `stable_trylock_mm`.
+        let mm_lock = self.mm_lock.lock();
+
+        // This is the destructor, so unlike the other methods, we only need to worry about races
+        // with the shrinker here. Since we hold the `mm_lock`, we also can't race with the
+        // shrinker, and after this loop, the shrinker will not access any of our pages since we
+        // removed them from the lru list.
+        for i in 0..size {
+            // SAFETY: Loop is in-bounds of the size.
+            let p_ptr = unsafe { pages.add(i) };
+            // SAFETY: No other readers, so we can read.
+            if let Some(p) = unsafe { PageInfo::get_page(p_ptr) } {
+                // SAFETY: The pointer is valid and it's the right shrinker.
+                unsafe { PageInfo::list_lru_del(p_ptr, p.nid(), self.shrinker) };
+            }
+        }
+
+        drop(mm_lock);
+
+        // SAFETY: `pages` was allocated as an `KVVec<PageInfo>` with capacity `size`. Furthermore,
+        // all `size` elements are initialized. Also, the array is no longer shared with the
+        // shrinker due to the above loop.
+        drop(unsafe { KVVec::from_raw_parts(pages, size, size) });
+    }
+}
+
+/// # Safety
+/// Called by the shrinker.
+#[no_mangle]
+unsafe extern "C" fn rust_shrink_count(
+    shrink: *mut bindings::shrinker,
+    _sc: *mut bindings::shrink_control,
+) -> c_ulong {
+    // SAFETY: We can access our own private data.
+    let list_lru = unsafe { (*shrink).private_data.cast::<bindings::list_lru>() };
+    // SAFETY: Accessing the lru list is okay. Just an FFI call.
+    unsafe { bindings::list_lru_count(list_lru) }
+}
+
+/// # Safety
+/// Called by the shrinker.
+#[no_mangle]
+unsafe extern "C" fn rust_shrink_scan(
+    shrink: *mut bindings::shrinker,
+    sc: *mut bindings::shrink_control,
+) -> c_ulong {
+    // SAFETY: We can access our own private data.
+    let list_lru = unsafe { (*shrink).private_data.cast::<bindings::list_lru>() };
+    // SAFETY: Caller guarantees that it is safe to read this field.
+    let nr_to_scan = unsafe { (*sc).nr_to_scan };
+    // SAFETY: Accessing the lru list is okay. Just an FFI call.
+    unsafe {
+        bindings::list_lru_walk(
+            list_lru,
+            Some(rust_shrink_free_page),
+            ptr::null_mut(),
+            nr_to_scan,
+        )
+    }
+}
+
+const LRU_SKIP: bindings::lru_status = bindings::lru_status::LRU_SKIP;
+const LRU_REMOVED_ENTRY: bindings::lru_status = bindings::lru_status::LRU_REMOVED_RETRY;
+
+/// # Safety
+/// Called by the shrinker.
+#[no_mangle]
+unsafe extern "C" fn rust_shrink_free_page(
+    item: *mut bindings::list_head,
+    lru: *mut bindings::list_lru_one,
+    _cb_arg: *mut c_void,
+) -> bindings::lru_status {
+    // Fields that should survive after unlocking the lru lock.
+    let page;
+    let page_index;
+    let mm;
+    let vma_read;
+    let mm_mutex;
+    let vma_addr;
+    let range_ptr;
+
+    {
+        // CAST: The `list_head` field is first in `PageInfo`.
+        let info = item.cast::<PageInfo>();
+        // SAFETY: The `range` field of `PageInfo` is immutable.
+        range_ptr = unsafe { (*info).range };
+        // SAFETY: The `range` outlives its `PageInfo` values.
+        let range = unsafe { &*range_ptr };
+
+        mm = match range.mm.mmget_not_zero() {
+            Some(mm) => MmWithUser::into_mmput_async(mm),
+            None => return LRU_SKIP,
+        };
+
+        mm_mutex = match range.stable_trylock_mm() {
+            Some(guard) => guard,
+            None => return LRU_SKIP,
+        };
+
+        // We can't lock it normally here, since we hold the lru lock.
+        let inner = match range.lock.try_lock() {
+            Some(inner) => inner,
+            None => return LRU_SKIP,
+        };
+
+        vma_addr = inner.vma_addr;
+        vma_read = match mm.lock_vma_under_rcu(vma_addr) {
+            Some(guard) => guard,
+            None => return LRU_SKIP,
+        };
+
+        // SAFETY: The item is in this lru list, so it's okay to remove it.
+        unsafe { bindings::list_lru_isolate(lru, item) };
+
+        // SAFETY: Both pointers are in bounds of the same allocation.
+        page_index = unsafe { info.offset_from(inner.pages) } as usize;
+
+        // SAFETY: We hold the spinlock, so we can take the page.
+        //
+        // This sets the page pointer to zero before we unmap it from the vma. However, we call
+        // `zap_page_range` before we release the mmap lock, so `use_page_slow` will not be able to
+        // insert a new page until after our call to `zap_page_range`.
+        page = unsafe { PageInfo::take_page(info) };
+
+        // From this point on, we don't access this PageInfo or ShrinkablePageRange again, because
+        // they can be freed at any point after we unlock `lru_lock`. This is with the exception of
+        // `mm_mutex` which is kept alive by holding the lock.
+    }
+
+    // SAFETY: The lru lock is locked when this method is called.
+    unsafe { bindings::spin_unlock(&raw mut (*lru).lock) };
+
+    if let Some(vma) = check_vma(&vma_read, range_ptr) {
+        let user_page_addr = vma_addr + (page_index << PAGE_SHIFT);
+        vma.zap_vma_range(user_page_addr, PAGE_SIZE);
+    }
+
+    drop(vma_read);
+    drop(mm_mutex);
+    drop(mm);
+    drop(page);
+
+    LRU_REMOVED_ENTRY
+}
diff --git a/drivers/android/binder/process.rs b/drivers/android/binder/process.rs
new file mode 100644
index 000000000..5372bfbd9
--- /dev/null
+++ b/drivers/android/binder/process.rs
@@ -0,0 +1,1872 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+//! This module defines the `Process` type, which represents a process using a particular binder
+//! context.
+//!
+//! The `Process` object keeps track of all of the resources that this process owns in the binder
+//! context.
+//!
+//! There is one `Process` object for each binder fd that a process has opened, so processes using
+//! several binder contexts have several `Process` objects. This ensures that the contexts are
+//! fully separated.
+
+use core::mem::take;
+
+use kernel::{
+    bindings,
+    bits::bit_u8,
+    cred::Credential,
+    error::Error,
+    fs::file::{self, File},
+    id_pool::IdPool,
+    list::{List, ListArc, ListArcField, ListLinks},
+    mm,
+    prelude::*,
+    rbtree::{self, RBTree, RBTreeNode, RBTreeNodeReservation},
+    seq_file::SeqFile,
+    seq_print,
+    sync::poll::PollTable,
+    sync::{
+        aref::ARef,
+        lock::{spinlock::SpinLockBackend, Guard},
+        poll::PollCondVarBox,
+        Arc, ArcBorrow, CondVar, CondVarTimeoutResult, SetOnce, SpinLock, UniqueArc,
+    },
+    task::{Pid, Task},
+    uaccess::{UserSlice, UserSliceReader},
+    uapi,
+    workqueue::{self, Work},
+};
+
+use crate::{
+    allocation::{Allocation, AllocationInfo, NewAllocation},
+    context::Context,
+    defs::*,
+    error::{BinderError, BinderResult},
+    node::{CouldNotDeliverCriticalIncrement, CritIncrWrapper, Node, NodeDeath, NodeRef},
+    page_range::ShrinkablePageRange,
+    range_alloc::{RangeAllocator, ReserveNew, ReserveNewArgs},
+    stats::BinderStats,
+    thread::{PushWorkRes, Thread},
+    transaction::TransactionInfo,
+    BinderfsProcFile, DArc, DLArc, DTRWrap, DeliverToRead,
+};
+
+#[path = "freeze.rs"]
+mod freeze;
+use self::freeze::{FreezeCookie, FreezeListener};
+
+struct Mapping {
+    address: usize,
+    alloc: RangeAllocator<AllocationInfo>,
+}
+
+impl Mapping {
+    fn new(address: usize, size: usize) -> Self {
+        Self {
+            address,
+            alloc: RangeAllocator::new(size),
+        }
+    }
+}
+
+kernel::impl_flags!(
+    /// Represents multiple deferred work flags.
+    #[derive(Debug, Clone, Default, Copy, PartialEq, Eq)]
+    pub struct DeferWorks(u8);
+
+    /// Represents a single deferred work category.
+    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+    pub enum DeferWork {
+        Flush = bit_u8(0),
+        Release = bit_u8(1),
+    }
+);
+
+#[derive(Copy, Clone)]
+pub(crate) enum IsFrozen {
+    Yes,
+    No,
+    InProgress,
+}
+
+impl IsFrozen {
+    /// Whether incoming transactions should be rejected due to freeze.
+    pub(crate) fn is_frozen(self) -> bool {
+        match self {
+            IsFrozen::Yes => true,
+            IsFrozen::No => false,
+            IsFrozen::InProgress => true,
+        }
+    }
+
+    /// Whether freeze notifications consider this process frozen.
+    pub(crate) fn is_fully_frozen(self) -> bool {
+        match self {
+            IsFrozen::Yes => true,
+            IsFrozen::No => false,
+            IsFrozen::InProgress => false,
+        }
+    }
+}
+
+/// The fields of `Process` protected by the spinlock.
+pub(crate) struct ProcessInner {
+    is_manager: bool,
+    pub(crate) is_dead: bool,
+    threads: RBTree<i32, Arc<Thread>>,
+    /// INVARIANT: Threads pushed to this list must be owned by this process.
+    ready_threads: List<Thread>,
+    nodes: RBTree<u64, DArc<Node>>,
+    mapping: Option<Mapping>,
+    work: List<DTRWrap<dyn DeliverToRead>>,
+    delivered_deaths: List<DTRWrap<NodeDeath>, 2>,
+
+    /// The number of requested threads that haven't registered yet.
+    requested_thread_count: u32,
+    /// The maximum number of threads used by the process thread pool.
+    max_threads: u32,
+    /// The number of threads the started and registered with the thread pool.
+    started_thread_count: u32,
+
+    /// Bitmap of deferred work to do.
+    defer_work: DeferWorks,
+
+    /// Number of transactions to be transmitted before processes in freeze_wait
+    /// are woken up.
+    outstanding_txns: u32,
+    /// Process is frozen and unable to service binder transactions.
+    pub(crate) is_frozen: IsFrozen,
+    /// Process received sync transactions since last frozen.
+    pub(crate) sync_recv: bool,
+    /// Process received async transactions since last frozen.
+    pub(crate) async_recv: bool,
+    pub(crate) binderfs_file: Option<BinderfsProcFile>,
+    /// Check for oneway spam
+    oneway_spam_detection_enabled: bool,
+}
+
+impl ProcessInner {
+    fn new() -> Self {
+        Self {
+            is_manager: false,
+            is_dead: false,
+            threads: RBTree::new(),
+            ready_threads: List::new(),
+            mapping: None,
+            nodes: RBTree::new(),
+            work: List::new(),
+            delivered_deaths: List::new(),
+            requested_thread_count: 0,
+            max_threads: 0,
+            started_thread_count: 0,
+            defer_work: DeferWorks::default(),
+            outstanding_txns: 0,
+            is_frozen: IsFrozen::No,
+            sync_recv: false,
+            async_recv: false,
+            binderfs_file: None,
+            oneway_spam_detection_enabled: false,
+        }
+    }
+
+    /// Schedule the work item for execution on this process.
+    ///
+    /// If any threads are ready for work, then the work item is given directly to that thread and
+    /// it is woken up. Otherwise, it is pushed to the process work list.
+    ///
+    /// This call can fail only if the process is dead. In this case, the work item is returned to
+    /// the caller so that the caller can drop it after releasing the inner process lock. This is
+    /// necessary since the destructor of `Transaction` will take locks that can't necessarily be
+    /// taken while holding the inner process lock.
+    pub(crate) fn push_work(
+        &mut self,
+        proc: &Process,
+        work: DLArc<dyn DeliverToRead>,
+    ) -> Result<(), (BinderError, DLArc<dyn DeliverToRead>)> {
+        let sync = work.should_sync_wakeup();
+
+        // Try to find a ready thread to which to push the work.
+        if let Some(thread) = self.ready_threads.pop_front() {
+            // Push to thread while holding state lock. This prevents the thread from giving up
+            // (for example, because of a signal) when we're about to deliver work.
+            match thread.push_work_inner(work, sync) {
+                PushWorkRes::Ok => Ok(()),
+                PushWorkRes::OkNotifyPoll => {
+                    proc.notify_poll(sync);
+                    Ok(())
+                }
+                PushWorkRes::FailedDead(work) => Err((BinderError::new_dead(), work)),
+            }
+        } else if self.is_dead {
+            Err((BinderError::new_dead(), work))
+        } else {
+            // Didn't find a thread waiting for proc work; this can happen
+            // in two scenarios:
+            // 1. All threads are busy handling transactions
+            //    In that case, one of those threads should call back into
+            //    the kernel driver soon and pick up this work.
+            // 2. Threads are using the (e)poll interface, in which case
+            //    they may be blocked on the waitqueue without having been
+            //    added to waiting_threads. For this case, we wake it up
+            //    directly.
+            self.work.push_back(work);
+
+            // Wake up polling threads, if any.
+            proc.notify_poll(sync);
+
+            Ok(())
+        }
+    }
+
+    pub(crate) fn remove_node(&mut self, ptr: u64) {
+        self.nodes.remove(&ptr);
+    }
+
+    /// Updates the reference count on the given node.
+    pub(crate) fn update_node_refcount(
+        &mut self,
+        node: &DArc<Node>,
+        inc: bool,
+        strong: bool,
+        count: usize,
+        othread: Option<&Thread>,
+    ) {
+        let push = node.update_refcount_locked(inc, strong, count, self);
+
+        // If we decided that we need to push work, push either to the process or to a thread if
+        // one is specified.
+        if let Some(pnode) = push {
+            if let Some(thread) = othread {
+                thread.push_work_deferred(pnode);
+            } else {
+                let _ = self.push_work(&node.owner, pnode);
+                // Nothing to do: `push_work` may fail if the process is dead, but that's ok as in
+                // that case, it doesn't care about the notification.
+            }
+        }
+    }
+
+    pub(crate) fn new_node_ref(
+        &mut self,
+        node: DArc<Node>,
+        strong: bool,
+        thread: Option<&Thread>,
+    ) -> NodeRef {
+        self.update_node_refcount(&node, true, strong, 1, thread);
+        let strong_count = if strong { 1 } else { 0 };
+        NodeRef::new(node, strong_count, 1 - strong_count)
+    }
+
+    pub(crate) fn new_node_ref_with_thread(
+        &mut self,
+        node: DArc<Node>,
+        strong: bool,
+        thread: &Thread,
+        wrapper: Option<CritIncrWrapper>,
+    ) -> Result<NodeRef, CouldNotDeliverCriticalIncrement> {
+        let push = match wrapper {
+            None => node
+                .incr_refcount_allow_zero2one(strong, self)?
+                .map(|node| node as DLArc<dyn DeliverToRead>),
+            Some(wrapper) => node.incr_refcount_allow_zero2one_with_wrapper(strong, wrapper, self),
+        };
+        if let Some(node) = push {
+            thread.push_work_deferred(node);
+        }
+        let strong_count = if strong { 1 } else { 0 };
+        Ok(NodeRef::new(node, strong_count, 1 - strong_count))
+    }
+
+    /// Returns an existing node with the given pointer and cookie, if one exists.
+    ///
+    /// Returns an error if a node with the given pointer but a different cookie exists.
+    fn get_existing_node(&self, ptr: u64, cookie: u64) -> Result<Option<DArc<Node>>> {
+        match self.nodes.get(&ptr) {
+            None => Ok(None),
+            Some(node) => {
+                let (_, node_cookie) = node.get_id();
+                if node_cookie == cookie {
+                    Ok(Some(node.clone()))
+                } else {
+                    Err(EINVAL)
+                }
+            }
+        }
+    }
+
+    fn register_thread(&mut self) -> bool {
+        if self.requested_thread_count == 0 {
+            return false;
+        }
+
+        self.requested_thread_count -= 1;
+        self.started_thread_count += 1;
+        true
+    }
+
+    /// Finds a delivered death notification with the given cookie, removes it from the thread's
+    /// delivered list, and returns it.
+    fn pull_delivered_death(&mut self, cookie: u64) -> Option<DArc<NodeDeath>> {
+        let mut cursor = self.delivered_deaths.cursor_front();
+        while let Some(next) = cursor.peek_next() {
+            if next.cookie == cookie {
+                return Some(next.remove().into_arc());
+            }
+            cursor.move_next();
+        }
+        None
+    }
+
+    pub(crate) fn death_delivered(&mut self, death: DArc<NodeDeath>) {
+        if let Some(death) = ListArc::try_from_arc_or_drop(death) {
+            self.delivered_deaths.push_back(death);
+        } else {
+            pr_warn!("Notification added to `delivered_deaths` twice.");
+        }
+    }
+
+    pub(crate) fn add_outstanding_txn(&mut self) {
+        self.outstanding_txns += 1;
+    }
+
+    fn txns_pending_locked(&self) -> bool {
+        if self.outstanding_txns > 0 {
+            return true;
+        }
+        for thread in self.threads.values() {
+            if thread.has_current_transaction() {
+                return true;
+            }
+        }
+        false
+    }
+}
+
+/// Used to keep track of a node that this process has a handle to.
+#[pin_data]
+pub(crate) struct NodeRefInfo {
+    debug_id: usize,
+    /// The refcount that this process owns to the node.
+    node_ref: ListArcField<NodeRef, { Self::LIST_PROC }>,
+    death: ListArcField<Option<DArc<NodeDeath>>, { Self::LIST_PROC }>,
+    /// Cookie of the active freeze listener for this node.
+    freeze: ListArcField<Option<FreezeCookie>, { Self::LIST_PROC }>,
+    /// Used to store this `NodeRefInfo` in the node's `refs` list.
+    #[pin]
+    links: ListLinks<{ Self::LIST_NODE }>,
+    /// The handle for this `NodeRefInfo`.
+    handle: u32,
+    /// The process that has a handle to the node.
+    pub(crate) process: Arc<Process>,
+}
+
+impl NodeRefInfo {
+    /// The id used for the `Node::refs` list.
+    pub(crate) const LIST_NODE: u64 = 0x2da16350fb724a10;
+    /// The id used for the `ListArc` in `ProcessNodeRefs`.
+    const LIST_PROC: u64 = 0xd703a5263dcc8650;
+
+    fn new(node_ref: NodeRef, handle: u32, process: Arc<Process>) -> impl PinInit<Self> {
+        pin_init!(Self {
+            debug_id: super::next_debug_id(),
+            node_ref: ListArcField::new(node_ref),
+            death: ListArcField::new(None),
+            freeze: ListArcField::new(None),
+            links <- ListLinks::new(),
+            handle,
+            process,
+        })
+    }
+
+    kernel::list::define_list_arc_field_getter! {
+        pub(crate) fn death(&mut self<{Self::LIST_PROC}>) -> &mut Option<DArc<NodeDeath>> { death }
+        pub(crate) fn freeze(&mut self<{Self::LIST_PROC}>) -> &mut Option<FreezeCookie> { freeze }
+        pub(crate) fn node_ref(&mut self<{Self::LIST_PROC}>) -> &mut NodeRef { node_ref }
+        pub(crate) fn node_ref2(&self<{Self::LIST_PROC}>) -> &NodeRef { node_ref }
+    }
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<{Self::LIST_NODE}> for NodeRefInfo { untracked; }
+    impl ListArcSafe<{Self::LIST_PROC}> for NodeRefInfo { untracked; }
+}
+kernel::list::impl_list_item! {
+    impl ListItem<{Self::LIST_NODE}> for NodeRefInfo {
+        using ListLinks { self.links };
+    }
+}
+
+/// Keeps track of references this process has to nodes owned by other processes.
+///
+/// TODO: Currently, the rbtree requires two allocations per node reference, and two tree
+/// traversals to look up a node by `Node::global_id`. Once the rbtree is more powerful, these
+/// extra costs should be eliminated.
+struct ProcessNodeRefs {
+    /// Used to look up nodes using the 32-bit id that this process knows it by.
+    by_handle: RBTree<u32, ListArc<NodeRefInfo, { NodeRefInfo::LIST_PROC }>>,
+    /// Used to quickly find unused ids in `by_handle`.
+    handle_is_present: IdPool,
+    /// Used to look up nodes without knowing their local 32-bit id. The usize is the address of
+    /// the underlying `Node` struct as returned by `Node::global_id`.
+    by_node: RBTree<usize, u32>,
+    /// Used to look up a `FreezeListener` by cookie.
+    ///
+    /// There might be multiple freeze listeners for the same node, but at most one of them is
+    /// active.
+    freeze_listeners: RBTree<FreezeCookie, FreezeListener>,
+}
+
+impl ProcessNodeRefs {
+    fn new() -> Self {
+        Self {
+            by_handle: RBTree::new(),
+            handle_is_present: IdPool::new(),
+            by_node: RBTree::new(),
+            freeze_listeners: RBTree::new(),
+        }
+    }
+}
+
+use core::mem::offset_of;
+use kernel::bindings::rb_process_layout;
+pub(crate) const PROCESS_LAYOUT: rb_process_layout = rb_process_layout {
+    arc_offset: Arc::<Process>::DATA_OFFSET,
+    task: offset_of!(Process, task),
+};
+
+/// A process using binder.
+///
+/// Strictly speaking, there can be multiple of these per process. There is one for each binder fd
+/// that a process has opened, so processes using several binder contexts have several `Process`
+/// objects. This ensures that the contexts are fully separated.
+#[pin_data]
+pub(crate) struct Process {
+    pub(crate) ctx: Arc<Context>,
+
+    // The task leader (process).
+    pub(crate) task: ARef<Task>,
+
+    // Credential associated with file when `Process` is created.
+    pub(crate) cred: ARef<Credential>,
+
+    #[pin]
+    pub(crate) inner: SpinLock<ProcessInner>,
+
+    #[pin]
+    pub(crate) pages: ShrinkablePageRange,
+
+    // Waitqueue of processes waiting for all outstanding transactions to be
+    // processed.
+    #[pin]
+    freeze_wait: CondVar,
+
+    // Node references are in a different lock to avoid recursive acquisition when
+    // incrementing/decrementing a node in another process.
+    #[pin]
+    node_refs: SpinLock<ProcessNodeRefs>,
+
+    // Synchronizes `register_wait` calls to the `PollCondVarBox`.
+    //
+    // The `PollCondVarBox` is not stored here because synchronization is
+    // done for `register_wait` only. Wakeups do not take this lock.
+    poll: SetOnce<PollCondVarBox>,
+
+    // Work node for deferred work item.
+    #[pin]
+    defer_work: Work<Process>,
+
+    // Links for process list in Context.
+    #[pin]
+    links: ListLinks,
+
+    pub(crate) stats: BinderStats,
+}
+
+kernel::impl_has_work! {
+    impl HasWork<Process> for Process { self.defer_work }
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<0> for Process { untracked; }
+}
+kernel::list::impl_list_item! {
+    impl ListItem<0> for Process {
+        using ListLinks { self.links };
+    }
+}
+
+impl workqueue::WorkItem for Process {
+    type Pointer = Arc<Process>;
+
+    fn run(me: Arc<Self>) {
+        let defer;
+        {
+            let mut inner = me.inner.lock();
+            defer = inner.defer_work;
+            inner.defer_work = DeferWorks::default();
+        }
+
+        if defer.contains(DeferWork::Flush) {
+            me.deferred_flush();
+        }
+        if defer.contains(DeferWork::Release) {
+            me.deferred_release();
+        }
+    }
+}
+
+impl Process {
+    fn new(ctx: Arc<Context>, cred: ARef<Credential>) -> Result<Arc<Self>> {
+        let current = kernel::current!();
+        let process = Arc::pin_init::<Error>(
+            try_pin_init!(Process {
+                ctx,
+                cred,
+                inner <- kernel::new_spinlock!(ProcessInner::new(), "Process::inner"),
+                pages <- ShrinkablePageRange::new(&super::BINDER_SHRINKER),
+                node_refs <- kernel::new_spinlock!(ProcessNodeRefs::new(), "Process::node_refs"),
+                freeze_wait <- kernel::new_condvar!("Process::freeze_wait"),
+                task: current.group_leader().into(),
+                defer_work <- kernel::new_work!("Process::defer_work"),
+                links <- ListLinks::new(),
+                stats: BinderStats::new(),
+                poll: SetOnce::new(),
+            }),
+            GFP_KERNEL,
+        )?;
+
+        process.ctx.register_process(process.clone())?;
+
+        Ok(process)
+    }
+
+    pub(crate) fn pid_in_current_ns(&self) -> kernel::task::Pid {
+        self.task.tgid_nr_ns(None)
+    }
+
+    #[inline(never)]
+    pub(crate) fn debug_print_stats(&self, m: &SeqFile, ctx: &Context) -> Result<()> {
+        seq_print!(m, "proc {}\n", self.pid_in_current_ns());
+        seq_print!(m, "context {}\n", &*ctx.name);
+
+        let inner = self.inner.lock();
+        seq_print!(m, "  threads: {}\n", inner.threads.iter().count());
+        seq_print!(
+            m,
+            "  requested threads: {}+{}/{}\n",
+            inner.requested_thread_count,
+            inner.started_thread_count,
+            inner.max_threads,
+        );
+        if let Some(mapping) = &inner.mapping {
+            seq_print!(
+                m,
+                "  free oneway space: {}\n",
+                mapping.alloc.free_oneway_space()
+            );
+            seq_print!(m, "  buffers: {}\n", mapping.alloc.count_buffers());
+        }
+        seq_print!(
+            m,
+            "  outstanding transactions: {}\n",
+            inner.outstanding_txns
+        );
+        seq_print!(m, "  nodes: {}\n", inner.nodes.iter().count());
+        drop(inner);
+
+        {
+            let mut refs = self.node_refs.lock();
+            let (mut count, mut weak, mut strong) = (0, 0, 0);
+            for r in refs.by_handle.values_mut() {
+                let node_ref = r.node_ref();
+                let (nstrong, nweak) = node_ref.get_count();
+                count += 1;
+                weak += nweak;
+                strong += nstrong;
+            }
+            seq_print!(m, "  refs: {count} s {strong} w {weak}\n");
+        }
+
+        self.stats.debug_print("  ", m);
+
+        Ok(())
+    }
+
+    #[inline(never)]
+    pub(crate) fn debug_print(&self, m: &SeqFile, ctx: &Context, print_all: bool) -> Result<()> {
+        seq_print!(m, "proc {}\n", self.pid_in_current_ns());
+        seq_print!(m, "context {}\n", &*ctx.name);
+
+        let mut all_threads = KVec::new();
+        let mut all_nodes = KVec::new();
+        loop {
+            let inner = self.inner.lock();
+            let num_threads = inner.threads.iter().count();
+            let num_nodes = inner.nodes.iter().count();
+
+            if all_threads.capacity() < num_threads || all_nodes.capacity() < num_nodes {
+                drop(inner);
+                all_threads.reserve(num_threads, GFP_KERNEL)?;
+                all_nodes.reserve(num_nodes, GFP_KERNEL)?;
+                continue;
+            }
+
+            for thread in inner.threads.values() {
+                assert!(all_threads.len() < all_threads.capacity());
+                let _ = all_threads.push(thread.clone(), GFP_ATOMIC);
+            }
+
+            for node in inner.nodes.values() {
+                assert!(all_nodes.len() < all_nodes.capacity());
+                let _ = all_nodes.push(node.clone(), GFP_ATOMIC);
+            }
+
+            break;
+        }
+
+        for thread in all_threads {
+            thread.debug_print(m, print_all)?;
+        }
+
+        let mut inner = self.inner.lock();
+        for node in all_nodes {
+            if print_all || node.has_oneway_transaction(&mut inner) {
+                node.full_debug_print(m, &mut inner)?;
+            }
+        }
+        drop(inner);
+
+        if print_all {
+            let mut refs = self.node_refs.lock();
+            for r in refs.by_handle.values_mut() {
+                let node_ref = r.node_ref();
+                let dead = node_ref.node.owner.inner.lock().is_dead;
+                let (strong, weak) = node_ref.get_count();
+                let debug_id = node_ref.node.debug_id;
+
+                seq_print!(
+                    m,
+                    "  ref {}: desc {} {}node {debug_id} s {strong} w {weak}",
+                    r.debug_id,
+                    r.handle,
+                    if dead { "dead " } else { "" }
+                );
+            }
+        }
+
+        let inner = self.inner.lock();
+        for work in &inner.work {
+            work.debug_print(m, "  ", "  pending transaction ")?;
+        }
+        for _death in &inner.delivered_deaths {
+            seq_print!(m, "  has delivered dead binder\n");
+        }
+        if let Some(mapping) = &inner.mapping {
+            mapping.alloc.debug_print(m)?;
+        }
+        drop(inner);
+
+        Ok(())
+    }
+
+    /// Attempts to fetch a work item from the process queue.
+    pub(crate) fn get_work(&self) -> Option<DLArc<dyn DeliverToRead>> {
+        self.inner.lock().work.pop_front()
+    }
+
+    /// Attempts to fetch a work item from the process queue. If none is available, it registers the
+    /// given thread as ready to receive work directly.
+    ///
+    /// This must only be called when the thread is not participating in a transaction chain; when
+    /// it is, work will always be delivered directly to the thread (and not through the process
+    /// queue).
+    pub(crate) fn get_work_or_register<'a>(
+        &'a self,
+        thread: &'a Arc<Thread>,
+    ) -> GetWorkOrRegister<'a> {
+        let mut inner = self.inner.lock();
+        // Try to get work from the process queue.
+        if let Some(work) = inner.work.pop_front() {
+            return GetWorkOrRegister::Work(work);
+        }
+
+        // Register the thread as ready.
+        GetWorkOrRegister::Register(Registration::new(thread, &mut inner))
+    }
+
+    fn get_current_thread(self: ArcBorrow<'_, Self>) -> Result<Arc<Thread>> {
+        let id = {
+            let current = kernel::current!();
+            if self.task != current.group_leader() {
+                pr_err!("get_current_thread was called from the wrong process.");
+                return Err(EINVAL);
+            }
+            current.pid()
+        };
+
+        {
+            let inner = self.inner.lock();
+            if let Some(thread) = inner.threads.get(&id) {
+                return Ok(thread.clone());
+            }
+        }
+
+        // Allocate a new `Thread` without holding any locks.
+        let reservation = RBTreeNodeReservation::new(GFP_KERNEL)?;
+        let ta: Arc<Thread> = Thread::new(id, self.into())?;
+
+        let mut inner = self.inner.lock();
+        match inner.threads.entry(id) {
+            rbtree::Entry::Vacant(entry) => {
+                entry.insert(ta.clone(), reservation);
+                Ok(ta)
+            }
+            rbtree::Entry::Occupied(_entry) => {
+                pr_err!("Cannot create two threads with the same id.");
+                Err(EINVAL)
+            }
+        }
+    }
+
+    pub(crate) fn push_work(&self, work: DLArc<dyn DeliverToRead>) -> BinderResult {
+        // If push_work fails, drop the work item outside the lock.
+        let res = self.inner.lock().push_work(self, work);
+        match res {
+            Ok(()) => Ok(()),
+            Err((err, work)) => {
+                drop(work);
+                Err(err)
+            }
+        }
+    }
+
+    fn set_as_manager(
+        self: ArcBorrow<'_, Self>,
+        info: Option<FlatBinderObject>,
+        thread: &Thread,
+    ) -> Result {
+        let (ptr, cookie, flags) = if let Some(obj) = info {
+            (
+                // SAFETY: The object type for this ioctl is implicitly `BINDER_TYPE_BINDER`, so it
+                // is safe to access the `binder` field.
+                unsafe { obj.__bindgen_anon_1.binder },
+                obj.cookie,
+                obj.flags,
+            )
+        } else {
+            (0, 0, 0)
+        };
+        let node_ref = self.get_node(ptr, cookie, flags, true, thread)?;
+        let node = node_ref.node.clone();
+        self.ctx.set_manager_node(node_ref)?;
+        self.inner.lock().is_manager = true;
+
+        // Force the state of the node to prevent the delivery of acquire/increfs.
+        let mut owner_inner = node.owner.inner.lock();
+        node.force_has_count(&mut owner_inner);
+        Ok(())
+    }
+
+    fn get_node_inner(
+        self: ArcBorrow<'_, Self>,
+        ptr: u64,
+        cookie: u64,
+        flags: u32,
+        strong: bool,
+        thread: &Thread,
+        wrapper: Option<CritIncrWrapper>,
+    ) -> Result<Result<NodeRef, CouldNotDeliverCriticalIncrement>> {
+        // Try to find an existing node.
+        {
+            let mut inner = self.inner.lock();
+            if let Some(node) = inner.get_existing_node(ptr, cookie)? {
+                return Ok(inner.new_node_ref_with_thread(node, strong, thread, wrapper));
+            }
+        }
+
+        // Allocate the node before reacquiring the lock.
+        let node = DTRWrap::arc_pin_init(Node::new(ptr, cookie, flags, self.into()))?.into_arc();
+        let rbnode = RBTreeNode::new(ptr, node.clone(), GFP_KERNEL)?;
+        let mut inner = self.inner.lock();
+        if let Some(node) = inner.get_existing_node(ptr, cookie)? {
+            return Ok(inner.new_node_ref_with_thread(node, strong, thread, wrapper));
+        }
+
+        inner.nodes.insert(rbnode);
+        // This can only fail if someone has already pushed the node to a list, but we just created
+        // it and still hold the lock, so it can't fail right now.
+        let node_ref = inner
+            .new_node_ref_with_thread(node, strong, thread, wrapper)
+            .unwrap();
+
+        Ok(Ok(node_ref))
+    }
+
+    pub(crate) fn get_node(
+        self: ArcBorrow<'_, Self>,
+        ptr: u64,
+        cookie: u64,
+        flags: u32,
+        strong: bool,
+        thread: &Thread,
+    ) -> Result<NodeRef> {
+        let mut wrapper = None;
+        for _ in 0..2 {
+            match self.get_node_inner(ptr, cookie, flags, strong, thread, wrapper) {
+                Err(err) => return Err(err),
+                Ok(Ok(node_ref)) => return Ok(node_ref),
+                Ok(Err(CouldNotDeliverCriticalIncrement)) => {
+                    wrapper = Some(CritIncrWrapper::new()?);
+                }
+            }
+        }
+        // We only get a `CouldNotDeliverCriticalIncrement` error if `wrapper` is `None`, so the
+        // loop should run at most twice.
+        unreachable!()
+    }
+
+    pub(crate) fn insert_or_update_handle(
+        self: ArcBorrow<'_, Process>,
+        node_ref: NodeRef,
+        is_manager: bool,
+    ) -> Result<u32> {
+        {
+            let mut refs = self.node_refs.lock();
+
+            // Do a lookup before inserting.
+            if let Some(handle_ref) = refs.by_node.get(&node_ref.node.global_id()) {
+                let handle = *handle_ref;
+                let info = refs.by_handle.get_mut(&handle).unwrap();
+                info.node_ref().absorb(node_ref);
+                return Ok(handle);
+            }
+        }
+
+        // Reserve memory for tree nodes.
+        let reserve1 = RBTreeNodeReservation::new(GFP_KERNEL)?;
+        let reserve2 = RBTreeNodeReservation::new(GFP_KERNEL)?;
+        let info = UniqueArc::new_uninit(GFP_KERNEL)?;
+
+        let mut refs_lock = self.node_refs.lock();
+        let mut refs = &mut *refs_lock;
+
+        let (unused_id, by_handle_slot) = loop {
+            // ID 0 may only be used by the manager.
+            let start = if is_manager { 0 } else { 1 };
+
+            if let Some(res) = refs.handle_is_present.find_unused_id(start) {
+                match refs.by_handle.entry(res.as_u32()) {
+                    rbtree::Entry::Vacant(entry) => break (res, entry),
+                    rbtree::Entry::Occupied(_) => {
+                        pr_err!("Detected mismatch between handle_is_present and by_handle");
+                        res.acquire();
+                        kernel::warn_on!(true);
+                        return Err(EINVAL);
+                    }
+                }
+            }
+
+            let grow_request = refs.handle_is_present.grow_request().ok_or(ENOMEM)?;
+            drop(refs_lock);
+            let resizer = grow_request.realloc(GFP_KERNEL)?;
+            refs_lock = self.node_refs.lock();
+            refs = &mut *refs_lock;
+            refs.handle_is_present.grow(resizer);
+        };
+        let handle = unused_id.as_u32();
+
+        // Do a lookup again as node may have been inserted before the lock was reacquired.
+        let by_node_slot = match refs.by_node.entry(node_ref.node.global_id()) {
+            rbtree::Entry::Vacant(by_node_slot) => by_node_slot,
+            rbtree::Entry::Occupied(handle_ref) => {
+                // The node was inserted by another thread while we didn't hold the lock.
+                let handle = handle_ref.get();
+                let info = refs.by_handle.get_mut(handle).unwrap();
+                info.node_ref().absorb(node_ref);
+                return Ok(*handle);
+            }
+        };
+
+        let (info_proc, info_node) = {
+            let info_init = NodeRefInfo::new(node_ref, handle, self.into());
+            match info.pin_init_with(info_init) {
+                Ok(info) => ListArc::pair_from_pin_unique(info),
+                // error is infallible
+                Err(err) => match err {},
+            }
+        };
+
+        // Ensure the process is still alive while we insert a new reference.
+        //
+        // This releases the lock before inserting the nodes, but since `is_dead` is set as the
+        // first thing in `deferred_release`, process cleanup will not miss the items inserted into
+        // `refs` below.
+        if self.inner.lock().is_dead {
+            // Explicitly drop the lock so that `info_proc` and `info_node` are dropped outside of
+            // the lock.
+            drop(refs_lock);
+            return Err(ESRCH);
+        }
+
+        // SAFETY: `info_proc` and `info_node` reference the same node, so we are inserting
+        // `info_node` into the right node's `refs` list.
+        unsafe { info_proc.node_ref2().node.insert_node_info(info_node) };
+
+        by_node_slot.insert(handle, reserve1);
+        by_handle_slot.insert(info_proc, reserve2);
+        unused_id.acquire();
+        Ok(handle)
+    }
+
+    pub(crate) fn get_transaction_node(&self, handle: u32) -> BinderResult<NodeRef> {
+        // When handle is zero, try to get the context manager.
+        if handle == 0 {
+            let node_ref = self.ctx.get_manager_node(true)?;
+            if core::ptr::eq(self, &*node_ref.node.owner) {
+                return Err(EINVAL.into());
+            }
+            Ok(node_ref)
+        } else {
+            match self.get_node_from_handle(handle, true) {
+                Ok(node_ref) => Ok(node_ref),
+                Err(err) => {
+                    binder_debug!(UserError, "got transaction to invalid handle {handle}");
+                    Err(err.into())
+                }
+            }
+        }
+    }
+
+    pub(crate) fn get_node_from_handle(&self, handle: u32, strong: bool) -> Result<NodeRef> {
+        self.node_refs
+            .lock()
+            .by_handle
+            .get_mut(&handle)
+            .ok_or(ENOENT)?
+            .node_ref()
+            .clone(strong)
+    }
+
+    pub(crate) fn remove_from_delivered_deaths(&self, death: &DArc<NodeDeath>) {
+        let mut inner = self.inner.lock();
+        // SAFETY: By the invariant on the `delivered_links` field, this is the right linked list.
+        let removed = unsafe { inner.delivered_deaths.remove(death) };
+        drop(inner);
+        drop(removed);
+    }
+
+    pub(crate) fn update_ref(
+        self: ArcBorrow<'_, Process>,
+        handle: u32,
+        inc: bool,
+        strong: bool,
+    ) -> Result {
+        if inc && handle == 0 {
+            if let Ok(node_ref) = self.ctx.get_manager_node(strong) {
+                if core::ptr::eq(&*self, &*node_ref.node.owner) {
+                    return Err(EINVAL);
+                }
+                let _ = self.insert_or_update_handle(node_ref, true);
+                return Ok(());
+            }
+        }
+
+        // To preserve original binder behaviour, we only fail requests where the manager tries to
+        // increment references on itself.
+        let _to_free_by_handle;
+        let _to_free_by_node;
+        let _to_free_freeze_listener;
+        let _to_free_freeze_listener_cleanup;
+        let mut refs = self.node_refs.lock();
+        if let Some(info) = refs.by_handle.get_mut(&handle) {
+            if info.node_ref().update(inc, strong) {
+                // Clean up death if there is one attached to this node reference.
+                //
+                // We remove the entire `info` below, so no need to remove `death` from `info`.
+                if let Some(death) = info.death().as_ref() {
+                    death.set_cleared(true);
+                    self.remove_from_delivered_deaths(death);
+                }
+
+                // Remove reference from process tables, and from the node's `refs` list.
+
+                // SAFETY: We are removing the `NodeRefInfo` from the right node.
+                unsafe { info.node_ref2().node.remove_node_info(info) };
+
+                let id = info.node_ref().node.global_id();
+
+                if let Some(freeze) = *info.freeze() {
+                    if let Some(fl) = refs.freeze_listeners.remove(&freeze) {
+                        _to_free_freeze_listener_cleanup = fl.on_process_cleanup(&self);
+                        _to_free_freeze_listener = fl;
+                    }
+                }
+
+                _to_free_by_handle = refs.by_handle.remove_node(&handle);
+                _to_free_by_node = refs.by_node.remove_node(&id);
+                refs.handle_is_present.release_id(handle as usize);
+
+                if let Some(shrink) = refs.handle_is_present.shrink_request() {
+                    drop(refs);
+                    // This intentionally ignores allocation failures.
+                    if let Ok(new_bitmap) = shrink.realloc(GFP_KERNEL) {
+                        refs = self.node_refs.lock();
+                        refs.handle_is_present.shrink(new_bitmap);
+                    }
+                }
+            }
+        } else {
+            // All refs are cleared in process exit, so this warning is expected in that case.
+            if !self.inner.lock().is_dead {
+                binder_debug!(UserError, "no such ref {handle}");
+            }
+        }
+        Ok(())
+    }
+
+    /// Decrements the refcount of the given node, if one exists.
+    pub(crate) fn update_node(&self, ptr: u64, cookie: u64, strong: bool) {
+        let mut inner = self.inner.lock();
+        if let Ok(Some(node)) = inner.get_existing_node(ptr, cookie) {
+            inner.update_node_refcount(&node, false, strong, 1, None);
+        }
+    }
+
+    pub(crate) fn inc_ref_done(&self, reader: &mut UserSliceReader, strong: bool) -> Result {
+        let ptr = reader.read::<u64>()?;
+        let cookie = reader.read::<u64>()?;
+        let mut inner = self.inner.lock();
+        if let Ok(Some(node)) = inner.get_existing_node(ptr, cookie) {
+            if let Some(node) = node.inc_ref_done_locked(strong, &mut inner) {
+                // This only fails if the process is dead.
+                let _ = inner.push_work(self, node);
+            }
+        }
+        Ok(())
+    }
+
+    pub(crate) fn buffer_alloc(
+        self: &Arc<Self>,
+        debug_id: usize,
+        size: usize,
+        info: &mut TransactionInfo,
+    ) -> BinderResult<NewAllocation> {
+        use kernel::page::PAGE_SIZE;
+
+        let mut reserve_new_args = ReserveNewArgs {
+            debug_id,
+            size,
+            is_oneway: info.is_oneway(),
+            pid: info.from_pid,
+            ..ReserveNewArgs::default()
+        };
+
+        let (new_alloc, addr) = loop {
+            let mut inner = self.inner.lock();
+            let mapping = inner.mapping.as_mut().ok_or_else(BinderError::new_dead)?;
+            let alloc_request = match mapping.alloc.reserve_new(reserve_new_args)? {
+                ReserveNew::Success(new_alloc) => break (new_alloc, mapping.address),
+                ReserveNew::NeedAlloc(request) => request,
+            };
+            drop(inner);
+            // We need to allocate memory and then call `reserve_new` again.
+            reserve_new_args = alloc_request.make_alloc()?;
+        };
+
+        info.oneway_spam_suspect = new_alloc.oneway_spam_detected;
+        let res = Allocation::new(
+            self.clone(),
+            debug_id,
+            new_alloc.offset,
+            size,
+            addr + new_alloc.offset,
+        );
+
+        // This allocation will be marked as in use until the `Allocation` is used to free it.
+        //
+        // This method can't be called while holding a lock, so we release the lock first. It's
+        // okay for several threads to use the method on the same index at the same time. In that
+        // case, one of the calls will allocate the given page (if missing), and the other call
+        // will wait for the other call to finish allocating the page.
+        //
+        // We will not call `stop_using_range` in parallel with this on the same page, because the
+        // allocation can only be removed via the destructor of the `Allocation` object that we
+        // currently own.
+        match self.pages.use_range(
+            new_alloc.offset / PAGE_SIZE,
+            (new_alloc.offset + size).div_ceil(PAGE_SIZE),
+        ) {
+            Ok(()) => {}
+            Err(err) => {
+                pr_warn!("use_range failure {:?}", err);
+                return Err(err.into());
+            }
+        }
+
+        Ok(NewAllocation(res))
+    }
+
+    pub(crate) fn buffer_get(self: &Arc<Self>, ptr: usize) -> Option<Allocation> {
+        let mut inner = self.inner.lock();
+        let mapping = inner.mapping.as_mut()?;
+        let offset = ptr.checked_sub(mapping.address)?;
+        let (size, debug_id, odata) = mapping.alloc.reserve_existing(offset).ok()?;
+        let mut alloc = Allocation::new(self.clone(), debug_id, offset, size, ptr);
+        if let Some(data) = odata {
+            alloc.set_info(data);
+        }
+        Some(alloc)
+    }
+
+    pub(crate) fn buffer_raw_free(&self, ptr: usize) {
+        let mut inner = self.inner.lock();
+        if let Some(ref mut mapping) = &mut inner.mapping {
+            let offset = match ptr.checked_sub(mapping.address) {
+                Some(offset) => offset,
+                None => return,
+            };
+
+            let freed_range = match mapping.alloc.reservation_abort(offset) {
+                Ok(freed_range) => freed_range,
+                Err(_) => {
+                    pr_warn!(
+                        "Pointer {:x} failed to free, base = {:x}\n",
+                        ptr,
+                        mapping.address
+                    );
+                    return;
+                }
+            };
+
+            // No more allocations in this range. Mark them as not in use.
+            //
+            // Must be done before we release the lock so that `use_range` is not used on these
+            // indices until `stop_using_range` returns.
+            self.pages
+                .stop_using_range(freed_range.start_page_idx, freed_range.end_page_idx);
+        }
+    }
+
+    pub(crate) fn buffer_make_freeable(&self, offset: usize, mut data: Option<AllocationInfo>) {
+        let mut inner = self.inner.lock();
+        if let Some(ref mut mapping) = &mut inner.mapping {
+            if mapping.alloc.reservation_commit(offset, &mut data).is_err() {
+                pr_warn!("Offset {} failed to be marked freeable\n", offset);
+            }
+        }
+    }
+
+    fn create_mapping(&self, vma: &mm::virt::VmaNew) -> Result {
+        use kernel::page::PAGE_SIZE;
+        let size = usize::min(vma.end() - vma.start(), bindings::SZ_4M as usize);
+        let mapping = Mapping::new(vma.start(), size);
+        let page_count = self.pages.register_with_vma(vma)?;
+        if page_count * PAGE_SIZE != size {
+            return Err(EINVAL);
+        }
+
+        // Save range allocator for later.
+        self.inner.lock().mapping = Some(mapping);
+
+        Ok(())
+    }
+
+    fn version(&self, data: UserSlice) -> Result {
+        data.writer().write(&BinderVersion::current())
+    }
+
+    pub(crate) fn register_thread(&self) -> bool {
+        self.inner.lock().register_thread()
+    }
+
+    fn remove_thread(&self, thread: Arc<Thread>) {
+        self.inner.lock().threads.remove(&thread.id);
+        thread.release();
+    }
+
+    fn set_max_threads(&self, max: u32) {
+        self.inner.lock().max_threads = max;
+    }
+
+    fn set_oneway_spam_detection_enabled(&self, enabled: u32) {
+        self.inner.lock().oneway_spam_detection_enabled = enabled != 0;
+    }
+
+    pub(crate) fn is_oneway_spam_detection_enabled(&self) -> bool {
+        self.inner.lock().oneway_spam_detection_enabled
+    }
+
+    fn get_node_debug_info(&self, data: UserSlice) -> Result {
+        let (mut reader, mut writer) = data.reader_writer();
+
+        // Read the starting point.
+        let ptr = reader.read::<BinderNodeDebugInfo>()?.ptr;
+        let mut out = BinderNodeDebugInfo::default();
+
+        {
+            let inner = self.inner.lock();
+            for (node_ptr, node) in &inner.nodes {
+                if *node_ptr > ptr {
+                    node.populate_debug_info(&mut out, &inner);
+                    break;
+                }
+            }
+        }
+
+        writer.write(&out)
+    }
+
+    fn get_node_info_from_ref(&self, data: UserSlice) -> Result {
+        let (mut reader, mut writer) = data.reader_writer();
+        let mut out = reader.read::<BinderNodeInfoForRef>()?;
+
+        if out.strong_count != 0
+            || out.weak_count != 0
+            || out.reserved1 != 0
+            || out.reserved2 != 0
+            || out.reserved3 != 0
+        {
+            return Err(EINVAL);
+        }
+
+        // Only the context manager is allowed to use this ioctl.
+        if !self.inner.lock().is_manager {
+            return Err(EPERM);
+        }
+
+        {
+            let mut node_refs = self.node_refs.lock();
+            let node_info = node_refs.by_handle.get_mut(&out.handle).ok_or(ENOENT)?;
+            let node_ref = node_info.node_ref();
+            let owner_inner = node_ref.node.owner.inner.lock();
+            node_ref.node.populate_counts(&mut out, &owner_inner);
+        }
+
+        // Write the result back.
+        writer.write(&out)
+    }
+
+    pub(crate) fn needs_thread(&self) -> bool {
+        let mut inner = self.inner.lock();
+        let ret = inner.requested_thread_count == 0
+            && inner.ready_threads.is_empty()
+            && inner.started_thread_count < inner.max_threads;
+        if ret {
+            inner.requested_thread_count += 1
+        }
+        ret
+    }
+
+    pub(crate) fn request_death(
+        self: &Arc<Self>,
+        reader: &mut UserSliceReader,
+        thread: &Thread,
+    ) -> Result {
+        let handle: u32 = reader.read()?;
+        let cookie: u64 = reader.read()?;
+
+        // Queue BR_ERROR if we can't allocate memory for the death notification.
+        let death = UniqueArc::new_uninit(GFP_KERNEL).inspect_err(|_| {
+            thread.push_return_work(BR_ERROR);
+            binder_debug!(
+                DeathNotification,
+                "BC_REQUEST_DEATH_NOTIFICATION failed due to memory allocation failure"
+            );
+        })?;
+        let mut refs = self.node_refs.lock();
+        let Some(info) = refs.by_handle.get_mut(&handle) else {
+            binder_debug!(
+                UserError,
+                "BC_REQUEST_DEATH_NOTIFICATION invalid ref {handle}"
+            );
+            return Ok(());
+        };
+
+        // Nothing to do if there is already a death notification request for this handle.
+        if info.death().is_some() {
+            binder_debug!(
+                UserError,
+                "BC_REQUEST_DEATH_NOTIFICATION death notification already set"
+            );
+            return Ok(());
+        }
+
+        let death = {
+            let death_init = NodeDeath::new(info.node_ref().node.clone(), self.clone(), cookie);
+            match death.pin_init_with(death_init) {
+                Ok(death) => death,
+                // error is infallible
+                Err(err) => match err {},
+            }
+        };
+
+        // Register the death notification.
+        {
+            let owner = info.node_ref2().node.owner.clone();
+            let mut owner_inner = owner.inner.lock();
+            if owner_inner.is_dead {
+                let death = Arc::from(death);
+                *info.death() = Some(death.clone());
+                drop(owner_inner);
+                death.set_dead();
+            } else {
+                let death = ListArc::from(death);
+                *info.death() = Some(death.clone_arc());
+                info.node_ref().node.add_death(death, &mut owner_inner);
+            }
+        }
+        binder_debug!(
+            DeathNotification,
+            "BC_REQUEST_DEATH_NOTIFICATION handle {handle} cookie {:016x}",
+            cookie
+        );
+        Ok(())
+    }
+
+    pub(crate) fn clear_death(&self, reader: &mut UserSliceReader, thread: &Thread) -> Result {
+        let handle: u32 = reader.read()?;
+        let cookie: u64 = reader.read()?;
+
+        let mut refs = self.node_refs.lock();
+        let Some(info) = refs.by_handle.get_mut(&handle) else {
+            binder_debug!(
+                UserError,
+                "BC_CLEAR_DEATH_NOTIFICATION invalid ref {handle}"
+            );
+            return Ok(());
+        };
+
+        let Some(death) = info.death().take() else {
+            binder_debug!(
+                UserError,
+                "BC_CLEAR_DEATH_NOTIFICATION death notification not active"
+            );
+            return Ok(());
+        };
+        if death.cookie != cookie {
+            *info.death() = Some(death);
+            binder_debug!(
+                UserError,
+                "BC_CLEAR_DEATH_NOTIFICATION death notification cookie mismatch"
+            );
+            return Ok(());
+        }
+
+        // Update state and determine if we need to queue a work item. We only need to do it when
+        // the node is not dead or if the user already completed the death notification.
+        let should_schedule = death.set_cleared(false);
+        drop(refs);
+
+        if should_schedule {
+            if let Some(death) = ListArc::try_from_arc_or_drop(death) {
+                let _ = thread.push_work_if_looper(death);
+            }
+        }
+
+        binder_debug!(
+            DeathNotification,
+            "BC_CLEAR_DEATH_NOTIFICATION handle {handle} cookie {:016x}",
+            cookie
+        );
+        Ok(())
+    }
+
+    pub(crate) fn dead_binder_done(&self, cookie: u64, thread: &Thread) {
+        let death = self.inner.lock().pull_delivered_death(cookie);
+        if let Some(death) = death {
+            death.set_notification_done(thread);
+        }
+    }
+
+    /// Locks the spinlock and move the `nodes` rbtree out.
+    ///
+    /// This allows you to iterate through `nodes` while also allowing you to give other parts of
+    /// the codebase exclusive access to `ProcessInner`.
+    pub(crate) fn lock_with_nodes(&self) -> WithNodes<'_> {
+        let mut inner = self.inner.lock();
+        WithNodes {
+            nodes: take(&mut inner.nodes),
+            inner,
+        }
+    }
+
+    fn deferred_flush(&self) {
+        binder_debug!(pid = self.task.pid(), OpenClose, "flushing process");
+        let inner = self.inner.lock();
+        for thread in inner.threads.values() {
+            thread.exit_looper();
+        }
+    }
+
+    fn deferred_release(self: Arc<Self>) {
+        binder_debug!(pid = self.task.pid(), OpenClose, "releasing process");
+
+        let is_manager = {
+            let mut inner = self.inner.lock();
+            inner.is_dead = true;
+            inner.is_frozen = IsFrozen::No;
+            inner.sync_recv = false;
+            inner.async_recv = false;
+            inner.is_manager
+        };
+
+        if is_manager {
+            self.ctx.unset_manager_node();
+        }
+
+        self.ctx.deregister_process(&self);
+
+        let binderfs_file = self.inner.lock().binderfs_file.take();
+        drop(binderfs_file);
+
+        // Release threads.
+        let threads = {
+            let mut inner = self.inner.lock();
+            let threads = take(&mut inner.threads);
+            let ready = take(&mut inner.ready_threads);
+            drop(inner);
+            drop(ready);
+
+            for thread in threads.values() {
+                thread.release();
+            }
+            threads
+        };
+
+        // Release nodes.
+        {
+            while let Some(node) = {
+                let mut lock = self.inner.lock();
+                lock.nodes.cursor_front_mut().map(|c| c.remove_current().1)
+            } {
+                node.to_key_value().1.release();
+            }
+        }
+
+        // Clean up death listeners and remove nodes from external node info lists.
+        for info in self.node_refs.lock().by_handle.values_mut() {
+            // SAFETY: We are removing the `NodeRefInfo` from the right node.
+            unsafe { info.node_ref2().node.remove_node_info(info) };
+
+            // Clear death notifications from the nodes (that belong to a different process).
+            // No need to remove them from `info` as we clear info below.
+            if let Some(death) = info.death().as_ref() {
+                death.set_cleared(false);
+            }
+        }
+
+        // Clean up freeze listeners.
+        let freeze_listeners = take(&mut self.node_refs.lock().freeze_listeners);
+        for listener in freeze_listeners.values() {
+            listener.on_process_cleanup(&self);
+        }
+        drop(freeze_listeners);
+
+        // Release refs on foreign nodes.
+        {
+            let mut refs = self.node_refs.lock();
+            let by_handle = take(&mut refs.by_handle);
+            let by_node = take(&mut refs.by_node);
+            drop(refs);
+            drop(by_node);
+            drop(by_handle);
+        }
+
+        // Cancel all pending work items.
+        while let Some(work) = self.get_work() {
+            work.into_arc().cancel();
+        }
+
+        // Clear delivered_deaths list.
+        //
+        // Scope ensures that MutexGuard is dropped while executing the body.
+        while let Some(delivered_death) = {
+            // Explicitly bind to avoid tail expression lifetime extension of the lockguard
+            // Can be removed when the kernel moves to edition 2024
+            let maybe_death = self.inner.lock().delivered_deaths.pop_front();
+            maybe_death
+        } {
+            drop(delivered_death);
+        }
+
+        // Free any resources kept alive by allocated buffers.
+        let omapping = self.inner.lock().mapping.take();
+        if let Some(mut mapping) = omapping {
+            let address = mapping.address;
+            mapping
+                .alloc
+                .take_for_each(|offset, size, debug_id, odata| {
+                    let ptr = offset + address;
+                    let mut alloc = Allocation::new(self.clone(), debug_id, offset, size, ptr);
+                    if let Some(data) = odata {
+                        alloc.set_info(data);
+                    }
+                    drop(alloc)
+                });
+        }
+
+        // calls to synchronize_rcu() in thread drop will happen here
+        drop(threads);
+    }
+
+    pub(crate) fn drop_outstanding_txn(&self) {
+        let wake = {
+            let mut inner = self.inner.lock();
+            if inner.outstanding_txns == 0 {
+                pr_err!("outstanding_txns underflow");
+                return;
+            }
+            inner.outstanding_txns -= 1;
+            inner.is_frozen.is_frozen() && inner.outstanding_txns == 0
+        };
+
+        if wake {
+            self.freeze_wait.notify_all();
+        }
+    }
+
+    // #[export_name] is a temporary workaround so that ps output does not become unreadable from
+    // mangled symbol names.
+    #[export_name = "rust_binder_freeze"]
+    pub(crate) fn ioctl_freeze(&self, info: &BinderFreezeInfo) -> Result {
+        if info.enable == 0 {
+            let msgs = self.prepare_freeze_messages()?;
+            let mut inner = self.inner.lock();
+            inner.sync_recv = false;
+            inner.async_recv = false;
+            inner.is_frozen = IsFrozen::No;
+            drop(inner);
+            msgs.send_messages();
+            return Ok(());
+        }
+
+        let mut inner = self.inner.lock();
+        inner.sync_recv = false;
+        inner.async_recv = false;
+        inner.is_frozen = IsFrozen::InProgress;
+
+        if info.timeout_ms > 0 {
+            let mut jiffies = kernel::time::msecs_to_jiffies(info.timeout_ms);
+            while jiffies > 0 {
+                if inner.outstanding_txns == 0 {
+                    break;
+                }
+
+                match self
+                    .freeze_wait
+                    .wait_interruptible_timeout(&mut inner, jiffies)
+                {
+                    CondVarTimeoutResult::Signal { .. } => {
+                        inner.is_frozen = IsFrozen::No;
+                        return Err(ERESTARTSYS);
+                    }
+                    CondVarTimeoutResult::Woken { jiffies: remaining } => {
+                        jiffies = remaining;
+                    }
+                    CondVarTimeoutResult::Timeout => {
+                        jiffies = 0;
+                    }
+                }
+            }
+        }
+
+        if inner.txns_pending_locked() {
+            inner.is_frozen = IsFrozen::No;
+            Err(EAGAIN)
+        } else {
+            drop(inner);
+            match self.prepare_freeze_messages() {
+                Ok(batch) => {
+                    self.inner.lock().is_frozen = IsFrozen::Yes;
+                    batch.send_messages();
+                    Ok(())
+                }
+                Err(kernel::alloc::AllocError) => {
+                    self.inner.lock().is_frozen = IsFrozen::No;
+                    Err(ENOMEM)
+                }
+            }
+        }
+    }
+
+    pub(crate) fn notify_poll(&self, sync: bool) {
+        if let Some(poll) = self.poll.as_ref() {
+            if sync {
+                poll.notify_sync();
+            }
+            poll.notify_all();
+        }
+    }
+}
+
+fn get_frozen_status(data: UserSlice) -> Result {
+    let (mut reader, mut writer) = data.reader_writer();
+
+    let mut info = reader.read::<BinderFrozenStatusInfo>()?;
+    info.sync_recv = 0;
+    info.async_recv = 0;
+    let mut found = false;
+
+    for ctx in crate::context::get_all_contexts()? {
+        ctx.for_each_proc(|proc| {
+            if proc.task.pid() == info.pid as Pid {
+                found = true;
+                let inner = proc.inner.lock();
+                let txns_pending = inner.txns_pending_locked();
+                info.async_recv |= u32::from(inner.async_recv);
+                info.sync_recv |= u32::from(inner.sync_recv);
+                info.sync_recv |= u32::from(txns_pending) << 1;
+            }
+        });
+    }
+
+    if found {
+        writer.write(&info)?;
+        Ok(())
+    } else {
+        Err(EINVAL)
+    }
+}
+
+fn ioctl_freeze(reader: &mut UserSliceReader) -> Result {
+    let info = reader.read::<BinderFreezeInfo>()?;
+
+    // Very unlikely for there to be more than 3, since a process normally uses at most binder and
+    // hwbinder.
+    let mut procs = KVec::with_capacity(3, GFP_KERNEL)?;
+
+    let ctxs = crate::context::get_all_contexts()?;
+    for ctx in ctxs {
+        for proc in ctx.get_procs_with_pid(info.pid as i32)? {
+            procs.push(proc, GFP_KERNEL)?;
+        }
+    }
+
+    for proc in procs {
+        proc.ioctl_freeze(&info)?;
+    }
+    Ok(())
+}
+
+/// The ioctl handler.
+impl Process {
+    /// Ioctls that are write-only from the perspective of userspace.
+    ///
+    /// The kernel will only read from the pointer that userspace provided to us.
+    fn ioctl_write_only(
+        this: ArcBorrow<'_, Process>,
+        _file: &File,
+        cmd: u32,
+        reader: &mut UserSliceReader,
+    ) -> Result {
+        if cmd == uapi::BINDER_FREEZE {
+            return ioctl_freeze(reader);
+        }
+
+        let thread = this.get_current_thread()?;
+        match cmd {
+            uapi::BINDER_SET_MAX_THREADS => this.set_max_threads(reader.read()?),
+            uapi::BINDER_THREAD_EXIT => this.remove_thread(thread),
+            uapi::BINDER_SET_CONTEXT_MGR => this.set_as_manager(None, &thread)?,
+            uapi::BINDER_SET_CONTEXT_MGR_EXT => {
+                this.set_as_manager(Some(reader.read()?), &thread)?
+            }
+            uapi::BINDER_ENABLE_ONEWAY_SPAM_DETECTION => {
+                this.set_oneway_spam_detection_enabled(reader.read()?)
+            }
+            _ => return Err(EINVAL),
+        }
+        Ok(())
+    }
+
+    /// Ioctls that are read/write from the perspective of userspace.
+    ///
+    /// The kernel will both read from and write to the pointer that userspace provided to us.
+    fn ioctl_write_read(
+        this: ArcBorrow<'_, Process>,
+        file: &File,
+        cmd: u32,
+        data: UserSlice,
+    ) -> Result {
+        let blocking = (file.flags() & file::flags::O_NONBLOCK) == 0;
+        match cmd {
+            uapi::BINDER_WRITE_READ => this.get_current_thread()?.write_read(data, blocking)?,
+            uapi::BINDER_GET_NODE_DEBUG_INFO => this.get_node_debug_info(data)?,
+            uapi::BINDER_GET_NODE_INFO_FOR_REF => this.get_node_info_from_ref(data)?,
+            uapi::BINDER_VERSION => this.version(data)?,
+            uapi::BINDER_GET_FROZEN_INFO => get_frozen_status(data)?,
+            uapi::BINDER_GET_EXTENDED_ERROR => {
+                this.get_current_thread()?.get_extended_error(data)?
+            }
+            _ => return Err(EINVAL),
+        }
+        Ok(())
+    }
+}
+
+/// The file operations supported by `Process`.
+impl Process {
+    pub(crate) fn open(ctx: ArcBorrow<'_, Context>, file: &File) -> Result<Arc<Process>> {
+        let proc = Self::new(ctx.into(), ARef::from(file.cred()))?;
+        binder_debug!(OpenClose, "opened process");
+        Ok(proc)
+    }
+
+    pub(crate) fn release(this: Arc<Process>, _file: &File) {
+        let binderfs_file;
+        let should_schedule;
+        {
+            let mut inner = this.inner.lock();
+            should_schedule = inner.defer_work == DeferWorks::empty();
+            inner.defer_work |= DeferWork::Release;
+            binderfs_file = inner.binderfs_file.take();
+        }
+
+        if should_schedule {
+            // Ignore failures to schedule to the workqueue. Those just mean that we're already
+            // scheduled for execution.
+            let _ = workqueue::system().enqueue(this);
+        }
+
+        drop(binderfs_file);
+    }
+
+    pub(crate) fn flush(this: ArcBorrow<'_, Process>) -> Result {
+        let should_schedule;
+        {
+            let mut inner = this.inner.lock();
+            should_schedule = inner.defer_work == DeferWorks::empty();
+            inner.defer_work |= DeferWork::Flush;
+        }
+
+        if should_schedule {
+            // Ignore failures to schedule to the workqueue. Those just mean that we're already
+            // scheduled for execution.
+            let _ = workqueue::system().enqueue(Arc::from(this));
+        }
+        Ok(())
+    }
+
+    pub(crate) fn ioctl(this: ArcBorrow<'_, Process>, file: &File, cmd: u32, arg: usize) -> Result {
+        use kernel::ioctl::{_IOC_DIR, _IOC_SIZE};
+        use kernel::uapi::{_IOC_READ, _IOC_WRITE};
+
+        crate::trace::trace_ioctl(cmd, arg);
+
+        let user_slice = UserSlice::new(UserPtr::from_addr(arg), _IOC_SIZE(cmd));
+
+        const _IOC_READ_WRITE: u32 = _IOC_READ | _IOC_WRITE;
+
+        let res = match _IOC_DIR(cmd) {
+            _IOC_WRITE => Self::ioctl_write_only(this, file, cmd, &mut user_slice.reader()),
+            _IOC_READ_WRITE => Self::ioctl_write_read(this, file, cmd, user_slice),
+            _ => Err(EINVAL),
+        };
+
+        crate::trace::trace_ioctl_done(res);
+        res
+    }
+
+    pub(crate) fn mmap(
+        this: ArcBorrow<'_, Process>,
+        _file: &File,
+        vma: &mm::virt::VmaNew,
+    ) -> Result {
+        // We don't allow mmap to be used in a different process.
+        if this.task != kernel::current!().group_leader() {
+            return Err(EINVAL);
+        }
+        if vma.start() == 0 {
+            return Err(EINVAL);
+        }
+
+        vma.try_clear_maywrite().map_err(|_| EPERM)?;
+        vma.set_dontcopy();
+        vma.set_mixedmap();
+
+        // TODO: Set ops. We need to learn when the user unmaps so that we can stop using it.
+        this.create_mapping(vma)
+    }
+
+    pub(crate) fn poll(
+        this: ArcBorrow<'_, Process>,
+        file: &File,
+        table: PollTable<'_>,
+    ) -> Result<u32> {
+        let thread = this.get_current_thread()?;
+        {
+            let poll = loop {
+                if let Some(poll) = this.poll.as_ref() {
+                    break poll;
+                }
+
+                let poll = PollCondVarBox::new(c"Process::poll", kernel::static_lock_class!())?;
+                // Reuse our existing lock to synchronize callers initializing.
+                let _guard = this.node_refs.lock();
+                this.poll.populate(poll);
+            };
+
+            table.register_wait(file, poll);
+        }
+        let (from_proc, mut mask) = thread.poll()?;
+        if mask == 0 && from_proc && !this.inner.lock().work.is_empty() {
+            mask |= bindings::POLLIN;
+        }
+        Ok(mask)
+    }
+}
+
+/// Represents that a thread has registered with the `ready_threads` list of its process.
+///
+/// The destructor of this type will unregister the thread from the list of ready threads.
+pub(crate) struct Registration<'a> {
+    thread: &'a Arc<Thread>,
+}
+
+impl<'a> Registration<'a> {
+    fn new(thread: &'a Arc<Thread>, guard: &mut Guard<'_, ProcessInner, SpinLockBackend>) -> Self {
+        assert!(core::ptr::eq(&thread.process.inner, guard.lock_ref()));
+        // INVARIANT: We are pushing this thread to the right `ready_threads` list.
+        if let Ok(list_arc) = ListArc::try_from_arc(thread.clone()) {
+            guard.ready_threads.push_front(list_arc);
+        } else {
+            // It is an error to hit this branch, and it should not be reachable. We try to do
+            // something reasonable when the failure path happens. Most likely, the thread in
+            // question will sleep forever.
+            pr_err!("Same thread registered with `ready_threads` twice.");
+        }
+        Self { thread }
+    }
+}
+
+impl Drop for Registration<'_> {
+    fn drop(&mut self) {
+        let mut inner = self.thread.process.inner.lock();
+        // SAFETY: The thread has the invariant that we never push it to any other linked list than
+        // the `ready_threads` list of its parent process. Therefore, the thread is either in that
+        // list, or in no list.
+        unsafe { inner.ready_threads.remove(self.thread) };
+    }
+}
+
+pub(crate) struct WithNodes<'a> {
+    pub(crate) inner: Guard<'a, ProcessInner, SpinLockBackend>,
+    pub(crate) nodes: RBTree<u64, DArc<Node>>,
+}
+
+impl Drop for WithNodes<'_> {
+    fn drop(&mut self) {
+        core::mem::swap(&mut self.nodes, &mut self.inner.nodes);
+        if self.nodes.iter().next().is_some() {
+            pr_err!("nodes array was modified while using lock_with_nodes\n");
+        }
+    }
+}
+
+pub(crate) enum GetWorkOrRegister<'a> {
+    Work(DLArc<dyn DeliverToRead>),
+    Register(Registration<'a>),
+}
diff --git a/drivers/android/binder/range_alloc/array.rs b/drivers/android/binder/range_alloc/array.rs
new file mode 100644
index 000000000..081d19b09
--- /dev/null
+++ b/drivers/android/binder/range_alloc/array.rs
@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use kernel::{
+    page::{PAGE_MASK, PAGE_SIZE},
+    prelude::*,
+    seq_file::SeqFile,
+    seq_print,
+    task::Pid,
+};
+
+use crate::range_alloc::{DescriptorState, FreedRange, Range};
+
+/// Keeps track of allocations in a process' mmap.
+///
+/// Each process has an mmap where the data for incoming transactions will be placed. This struct
+/// keeps track of allocations made in the mmap. For each allocation, we store a descriptor that
+/// has metadata related to the allocation. We also keep track of available free space.
+pub(super) struct ArrayRangeAllocator<T> {
+    /// This stores all ranges that are allocated. Unlike the tree based allocator, we do *not*
+    /// store the free ranges.
+    ///
+    /// Sorted by offset.
+    pub(super) ranges: KVec<Range<T>>,
+    size: usize,
+    free_oneway_space: usize,
+}
+
+struct FindEmptyRes {
+    /// Which index in `ranges` should we insert the new range at?
+    ///
+    /// Inserting the new range at this index keeps `ranges` sorted.
+    insert_at_idx: usize,
+    /// Which offset should we insert the new range at?
+    insert_at_offset: usize,
+}
+
+impl<T> ArrayRangeAllocator<T> {
+    pub(crate) fn new(size: usize, alloc: EmptyArrayAlloc<T>) -> Self {
+        Self {
+            ranges: alloc.ranges,
+            size,
+            free_oneway_space: size / 2,
+        }
+    }
+
+    pub(crate) fn free_oneway_space(&self) -> usize {
+        self.free_oneway_space
+    }
+
+    pub(crate) fn count_buffers(&self) -> usize {
+        self.ranges.len()
+    }
+
+    pub(crate) fn total_size(&self) -> usize {
+        self.size
+    }
+
+    pub(crate) fn is_full(&self) -> bool {
+        self.ranges.len() == self.ranges.capacity()
+    }
+
+    pub(crate) fn debug_print(&self, m: &SeqFile) -> Result<()> {
+        for range in &self.ranges {
+            seq_print!(
+                m,
+                "  buffer {}: {} size {} pid {} oneway {}",
+                0,
+                range.offset,
+                range.size,
+                range.state.pid(),
+                range.state.is_oneway(),
+            );
+            if let DescriptorState::Reserved(_) = range.state {
+                seq_print!(m, " reserved\n");
+            } else {
+                seq_print!(m, " allocated\n");
+            }
+        }
+        Ok(())
+    }
+
+    /// Find somewhere to put a new range.
+    ///
+    /// Unlike the tree implementation, we do not bother to find the smallest gap. The idea is that
+    /// fragmentation isn't a big issue when we don't have many ranges.
+    ///
+    /// Returns the index that the new range should have in `self.ranges` after insertion.
+    fn find_empty_range(&self, size: usize) -> Option<FindEmptyRes> {
+        let after_last_range = self.ranges.last().map(Range::endpoint).unwrap_or(0);
+
+        if size <= self.total_size() - after_last_range {
+            // We can put the range at the end, so just do that.
+            Some(FindEmptyRes {
+                insert_at_idx: self.ranges.len(),
+                insert_at_offset: after_last_range,
+            })
+        } else {
+            let mut end_of_prev = 0;
+            for (i, range) in self.ranges.iter().enumerate() {
+                // Does it fit before the i'th range?
+                if size <= range.offset - end_of_prev {
+                    return Some(FindEmptyRes {
+                        insert_at_idx: i,
+                        insert_at_offset: end_of_prev,
+                    });
+                }
+                end_of_prev = range.endpoint();
+            }
+            None
+        }
+    }
+
+    pub(crate) fn reserve_new(
+        &mut self,
+        debug_id: usize,
+        size: usize,
+        is_oneway: bool,
+        pid: Pid,
+    ) -> Result<(usize, bool)> {
+        // Compute new value of free_oneway_space, which is set only on success.
+        let new_oneway_space = if is_oneway {
+            match self.free_oneway_space.checked_sub(size) {
+                Some(new_oneway_space) => new_oneway_space,
+                None => return Err(ENOSPC),
+            }
+        } else {
+            self.free_oneway_space
+        };
+
+        let FindEmptyRes {
+            insert_at_idx,
+            insert_at_offset,
+        } = self.find_empty_range(size).ok_or(ENOSPC)?;
+        self.free_oneway_space = new_oneway_space;
+
+        let new_range = Range {
+            offset: insert_at_offset,
+            size,
+            state: DescriptorState::new(is_oneway, debug_id, pid),
+        };
+        // Insert the value at the given index to keep the array sorted.
+        self.ranges
+            .insert_within_capacity(insert_at_idx, new_range)
+            .ok()
+            .unwrap();
+
+        // Start detecting spammers once we have less than 20%
+        // of async space left (which is less than 10% of total
+        // buffer size).
+        //
+        // (This will short-circuit, so `low_oneway_space` is
+        // only called when necessary.)
+        let oneway_spam_detected =
+            is_oneway && new_oneway_space < self.size / 10 && self.low_oneway_space(pid);
+
+        Ok((insert_at_offset, oneway_spam_detected))
+    }
+
+    /// Find the amount and size of buffers allocated by the current caller.
+    ///
+    /// The idea is that once we cross the threshold, whoever is responsible
+    /// for the low async space is likely to try to send another async transaction,
+    /// and at some point we'll catch them in the act.  This is more efficient
+    /// than keeping a map per pid.
+    fn low_oneway_space(&self, calling_pid: Pid) -> bool {
+        let mut total_alloc_size = 0;
+        let mut num_buffers = 0;
+
+        // Warn if this pid has more than 50 transactions, or more than 50% of
+        // async space (which is 25% of total buffer size). Oneway spam is only
+        // detected when the threshold is exceeded.
+        for range in &self.ranges {
+            if range.state.is_oneway() && range.state.pid() == calling_pid {
+                total_alloc_size += range.size;
+                num_buffers += 1;
+            }
+        }
+        num_buffers > 50 || total_alloc_size > self.size / 4
+    }
+
+    pub(crate) fn reservation_abort(&mut self, offset: usize) -> Result<FreedRange> {
+        // This could use a binary search, but linear scans are usually faster for small arrays.
+        let i = self
+            .ranges
+            .iter()
+            .position(|range| range.offset == offset)
+            .ok_or(EINVAL)?;
+        let range = &self.ranges[i];
+
+        if let DescriptorState::Allocated(_) = range.state {
+            return Err(EPERM);
+        }
+
+        let size = range.size;
+        let offset = range.offset;
+
+        if range.state.is_oneway() {
+            self.free_oneway_space += size;
+        }
+
+        // This computes the range of pages that are no longer used by *any* allocated range. The
+        // caller will mark them as unused, which means that they can be freed if the system comes
+        // under memory pressure.
+        let mut freed_range = FreedRange::interior_pages(offset, size);
+        if offset % PAGE_SIZE != 0 {
+            if i == 0 || self.ranges[i - 1].endpoint() <= (offset & PAGE_MASK) {
+                freed_range.start_page_idx -= 1;
+            }
+        }
+        if range.endpoint() % PAGE_SIZE != 0 {
+            let page_after = (range.endpoint() & PAGE_MASK) + PAGE_SIZE;
+            if i + 1 == self.ranges.len() || page_after <= self.ranges[i + 1].offset {
+                freed_range.end_page_idx += 1;
+            }
+        }
+
+        self.ranges.remove(i)?;
+        Ok(freed_range)
+    }
+
+    pub(crate) fn reservation_commit(&mut self, offset: usize, data: &mut Option<T>) -> Result {
+        // This could use a binary search, but linear scans are usually faster for small arrays.
+        let range = self
+            .ranges
+            .iter_mut()
+            .find(|range| range.offset == offset)
+            .ok_or(ENOENT)?;
+
+        let DescriptorState::Reserved(reservation) = &range.state else {
+            return Err(ENOENT);
+        };
+
+        range.state = DescriptorState::Allocated(reservation.clone().allocate(data.take()));
+        Ok(())
+    }
+
+    pub(crate) fn reserve_existing(&mut self, offset: usize) -> Result<(usize, usize, Option<T>)> {
+        // This could use a binary search, but linear scans are usually faster for small arrays.
+        let range = self
+            .ranges
+            .iter_mut()
+            .find(|range| range.offset == offset)
+            .ok_or(ENOENT)?;
+
+        let DescriptorState::Allocated(allocation) = &mut range.state else {
+            return Err(ENOENT);
+        };
+
+        let data = allocation.take();
+        let debug_id = allocation.reservation.debug_id;
+        range.state = DescriptorState::Reserved(allocation.reservation.clone());
+        Ok((range.size, debug_id, data))
+    }
+
+    pub(crate) fn take_for_each<F: Fn(usize, usize, usize, Option<T>)>(&mut self, callback: F) {
+        for range in self.ranges.iter_mut() {
+            if let DescriptorState::Allocated(allocation) = &mut range.state {
+                callback(
+                    range.offset,
+                    range.size,
+                    allocation.reservation.debug_id,
+                    allocation.data.take(),
+                );
+            }
+        }
+    }
+}
+
+pub(crate) struct EmptyArrayAlloc<T> {
+    ranges: KVec<Range<T>>,
+}
+
+impl<T> EmptyArrayAlloc<T> {
+    pub(crate) fn try_new(capacity: usize) -> Result<Self> {
+        Ok(Self {
+            ranges: KVec::with_capacity(capacity, GFP_KERNEL)?,
+        })
+    }
+}
diff --git a/drivers/android/binder/range_alloc/mod.rs b/drivers/android/binder/range_alloc/mod.rs
new file mode 100644
index 000000000..1f4734468
--- /dev/null
+++ b/drivers/android/binder/range_alloc/mod.rs
@@ -0,0 +1,329 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use kernel::{page::PAGE_SIZE, prelude::*, seq_file::SeqFile, task::Pid};
+
+mod tree;
+use self::tree::{FromArrayAllocs, ReserveNewTreeAlloc, TreeRangeAllocator};
+
+mod array;
+use self::array::{ArrayRangeAllocator, EmptyArrayAlloc};
+
+enum DescriptorState<T> {
+    Reserved(Reservation),
+    Allocated(Allocation<T>),
+}
+
+impl<T> DescriptorState<T> {
+    fn new(is_oneway: bool, debug_id: usize, pid: Pid) -> Self {
+        DescriptorState::Reserved(Reservation {
+            debug_id,
+            is_oneway,
+            pid,
+        })
+    }
+
+    fn pid(&self) -> Pid {
+        match self {
+            DescriptorState::Reserved(inner) => inner.pid,
+            DescriptorState::Allocated(inner) => inner.reservation.pid,
+        }
+    }
+
+    fn is_oneway(&self) -> bool {
+        match self {
+            DescriptorState::Reserved(inner) => inner.is_oneway,
+            DescriptorState::Allocated(inner) => inner.reservation.is_oneway,
+        }
+    }
+}
+
+#[derive(Clone)]
+struct Reservation {
+    debug_id: usize,
+    is_oneway: bool,
+    pid: Pid,
+}
+
+impl Reservation {
+    fn allocate<T>(self, data: Option<T>) -> Allocation<T> {
+        Allocation {
+            data,
+            reservation: self,
+        }
+    }
+}
+
+struct Allocation<T> {
+    reservation: Reservation,
+    data: Option<T>,
+}
+
+impl<T> Allocation<T> {
+    fn deallocate(self) -> (Reservation, Option<T>) {
+        (self.reservation, self.data)
+    }
+
+    fn debug_id(&self) -> usize {
+        self.reservation.debug_id
+    }
+
+    fn take(&mut self) -> Option<T> {
+        self.data.take()
+    }
+}
+
+/// The array implementation must switch to the tree if it wants to go beyond this number of
+/// ranges.
+const TREE_THRESHOLD: usize = 8;
+
+/// Represents a range of pages that have just become completely free.
+#[derive(Copy, Clone)]
+pub(crate) struct FreedRange {
+    pub(crate) start_page_idx: usize,
+    pub(crate) end_page_idx: usize,
+}
+
+impl FreedRange {
+    fn interior_pages(offset: usize, size: usize) -> FreedRange {
+        FreedRange {
+            // Divide round up
+            start_page_idx: offset.div_ceil(PAGE_SIZE),
+            // Divide round down
+            end_page_idx: (offset + size) / PAGE_SIZE,
+        }
+    }
+}
+
+struct Range<T> {
+    offset: usize,
+    size: usize,
+    state: DescriptorState<T>,
+}
+
+impl<T> Range<T> {
+    fn endpoint(&self) -> usize {
+        self.offset + self.size
+    }
+}
+
+pub(crate) struct RangeAllocator<T> {
+    inner: Impl<T>,
+}
+
+enum Impl<T> {
+    Empty(usize),
+    Array(ArrayRangeAllocator<T>),
+    Tree(TreeRangeAllocator<T>),
+}
+
+impl<T> RangeAllocator<T> {
+    pub(crate) fn new(size: usize) -> Self {
+        Self {
+            inner: Impl::Empty(size),
+        }
+    }
+
+    pub(crate) fn free_oneway_space(&self) -> usize {
+        match &self.inner {
+            Impl::Empty(size) => size / 2,
+            Impl::Array(array) => array.free_oneway_space(),
+            Impl::Tree(tree) => tree.free_oneway_space(),
+        }
+    }
+
+    pub(crate) fn count_buffers(&self) -> usize {
+        match &self.inner {
+            Impl::Empty(_size) => 0,
+            Impl::Array(array) => array.count_buffers(),
+            Impl::Tree(tree) => tree.count_buffers(),
+        }
+    }
+
+    pub(crate) fn debug_print(&self, m: &SeqFile) -> Result<()> {
+        match &self.inner {
+            Impl::Empty(_size) => Ok(()),
+            Impl::Array(array) => array.debug_print(m),
+            Impl::Tree(tree) => tree.debug_print(m),
+        }
+    }
+
+    /// Try to reserve a new buffer, using the provided allocation if necessary.
+    pub(crate) fn reserve_new(&mut self, mut args: ReserveNewArgs<T>) -> Result<ReserveNew<T>> {
+        match &mut self.inner {
+            Impl::Empty(size) => {
+                let empty_array = match args.empty_array_alloc.take() {
+                    Some(empty_array) => ArrayRangeAllocator::new(*size, empty_array),
+                    None => {
+                        return Ok(ReserveNew::NeedAlloc(ReserveNewNeedAlloc {
+                            args,
+                            need_empty_array_alloc: true,
+                            need_new_tree_alloc: false,
+                            need_tree_alloc: false,
+                        }))
+                    }
+                };
+
+                self.inner = Impl::Array(empty_array);
+                self.reserve_new(args)
+            }
+            Impl::Array(array) if array.is_full() => {
+                let allocs = match args.new_tree_alloc {
+                    Some(ref mut allocs) => allocs,
+                    None => {
+                        return Ok(ReserveNew::NeedAlloc(ReserveNewNeedAlloc {
+                            args,
+                            need_empty_array_alloc: false,
+                            need_new_tree_alloc: true,
+                            need_tree_alloc: true,
+                        }))
+                    }
+                };
+
+                let new_tree =
+                    TreeRangeAllocator::from_array(array.total_size(), &mut array.ranges, allocs);
+
+                self.inner = Impl::Tree(new_tree);
+                self.reserve_new(args)
+            }
+            Impl::Array(array) => {
+                let (offset, oneway_spam_detected) =
+                    array.reserve_new(args.debug_id, args.size, args.is_oneway, args.pid)?;
+                Ok(ReserveNew::Success(ReserveNewSuccess {
+                    offset,
+                    oneway_spam_detected,
+                    _empty_array_alloc: args.empty_array_alloc,
+                    _new_tree_alloc: args.new_tree_alloc,
+                    _tree_alloc: args.tree_alloc,
+                }))
+            }
+            Impl::Tree(tree) => {
+                let alloc = match args.tree_alloc {
+                    Some(alloc) => alloc,
+                    None => {
+                        return Ok(ReserveNew::NeedAlloc(ReserveNewNeedAlloc {
+                            args,
+                            need_empty_array_alloc: false,
+                            need_new_tree_alloc: false,
+                            need_tree_alloc: true,
+                        }));
+                    }
+                };
+                let (offset, oneway_spam_detected) =
+                    tree.reserve_new(args.debug_id, args.size, args.is_oneway, args.pid, alloc)?;
+                Ok(ReserveNew::Success(ReserveNewSuccess {
+                    offset,
+                    oneway_spam_detected,
+                    _empty_array_alloc: args.empty_array_alloc,
+                    _new_tree_alloc: args.new_tree_alloc,
+                    _tree_alloc: None,
+                }))
+            }
+        }
+    }
+
+    /// Deletes the allocations at `offset`.
+    pub(crate) fn reservation_abort(&mut self, offset: usize) -> Result<FreedRange> {
+        match &mut self.inner {
+            Impl::Empty(_size) => Err(EINVAL),
+            Impl::Array(array) => array.reservation_abort(offset),
+            Impl::Tree(tree) => {
+                let freed_range = tree.reservation_abort(offset)?;
+                if tree.is_empty() {
+                    self.inner = Impl::Empty(tree.total_size());
+                }
+                Ok(freed_range)
+            }
+        }
+    }
+
+    /// Called when an allocation is no longer in use by the kernel.
+    ///
+    /// The value in `data` will be stored, if any. A mutable reference is used to avoid dropping
+    /// the `T` when an error is returned.
+    pub(crate) fn reservation_commit(&mut self, offset: usize, data: &mut Option<T>) -> Result {
+        match &mut self.inner {
+            Impl::Empty(_size) => Err(EINVAL),
+            Impl::Array(array) => array.reservation_commit(offset, data),
+            Impl::Tree(tree) => tree.reservation_commit(offset, data),
+        }
+    }
+
+    /// Called when the kernel starts using an allocation.
+    ///
+    /// Returns the size of the existing entry and the data associated with it.
+    pub(crate) fn reserve_existing(&mut self, offset: usize) -> Result<(usize, usize, Option<T>)> {
+        match &mut self.inner {
+            Impl::Empty(_size) => Err(EINVAL),
+            Impl::Array(array) => array.reserve_existing(offset),
+            Impl::Tree(tree) => tree.reserve_existing(offset),
+        }
+    }
+
+    /// Call the provided callback at every allocated region.
+    ///
+    /// This destroys the range allocator. Used only during shutdown.
+    pub(crate) fn take_for_each<F: Fn(usize, usize, usize, Option<T>)>(&mut self, callback: F) {
+        match &mut self.inner {
+            Impl::Empty(_size) => {}
+            Impl::Array(array) => array.take_for_each(callback),
+            Impl::Tree(tree) => tree.take_for_each(callback),
+        }
+    }
+}
+
+/// The arguments for `reserve_new`.
+#[derive(Default)]
+pub(crate) struct ReserveNewArgs<T> {
+    pub(crate) size: usize,
+    pub(crate) is_oneway: bool,
+    pub(crate) debug_id: usize,
+    pub(crate) pid: Pid,
+    pub(crate) empty_array_alloc: Option<EmptyArrayAlloc<T>>,
+    pub(crate) new_tree_alloc: Option<FromArrayAllocs<T>>,
+    pub(crate) tree_alloc: Option<ReserveNewTreeAlloc<T>>,
+}
+
+/// The return type of `ReserveNew`.
+pub(crate) enum ReserveNew<T> {
+    Success(ReserveNewSuccess<T>),
+    NeedAlloc(ReserveNewNeedAlloc<T>),
+}
+
+/// Returned by `reserve_new` when the reservation was successul.
+pub(crate) struct ReserveNewSuccess<T> {
+    pub(crate) offset: usize,
+    pub(crate) oneway_spam_detected: bool,
+
+    // If the user supplied an allocation that we did not end up using, then we return it here.
+    // The caller will kfree it outside of the lock.
+    _empty_array_alloc: Option<EmptyArrayAlloc<T>>,
+    _new_tree_alloc: Option<FromArrayAllocs<T>>,
+    _tree_alloc: Option<ReserveNewTreeAlloc<T>>,
+}
+
+/// Returned by `reserve_new` to request the caller to make an allocation before calling the method
+/// again.
+pub(crate) struct ReserveNewNeedAlloc<T> {
+    args: ReserveNewArgs<T>,
+    need_empty_array_alloc: bool,
+    need_new_tree_alloc: bool,
+    need_tree_alloc: bool,
+}
+
+impl<T> ReserveNewNeedAlloc<T> {
+    /// Make the necessary allocations for another call to `reserve_new`.
+    pub(crate) fn make_alloc(mut self) -> Result<ReserveNewArgs<T>> {
+        if self.need_empty_array_alloc && self.args.empty_array_alloc.is_none() {
+            self.args.empty_array_alloc = Some(EmptyArrayAlloc::try_new(TREE_THRESHOLD)?);
+        }
+        if self.need_new_tree_alloc && self.args.new_tree_alloc.is_none() {
+            self.args.new_tree_alloc = Some(FromArrayAllocs::try_new(TREE_THRESHOLD)?);
+        }
+        if self.need_tree_alloc && self.args.tree_alloc.is_none() {
+            self.args.tree_alloc = Some(ReserveNewTreeAlloc::try_new()?);
+        }
+        Ok(self.args)
+    }
+}
diff --git a/drivers/android/binder/range_alloc/tree.rs b/drivers/android/binder/range_alloc/tree.rs
new file mode 100644
index 000000000..48796fcdb
--- /dev/null
+++ b/drivers/android/binder/range_alloc/tree.rs
@@ -0,0 +1,488 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use kernel::{
+    page::PAGE_SIZE,
+    prelude::*,
+    rbtree::{RBTree, RBTreeNode, RBTreeNodeReservation},
+    seq_file::SeqFile,
+    seq_print,
+    task::Pid,
+};
+
+use crate::range_alloc::{DescriptorState, FreedRange, Range};
+
+/// Keeps track of allocations in a process' mmap.
+///
+/// Each process has an mmap where the data for incoming transactions will be placed. This struct
+/// keeps track of allocations made in the mmap. For each allocation, we store a descriptor that
+/// has metadata related to the allocation. We also keep track of available free space.
+pub(super) struct TreeRangeAllocator<T> {
+    /// This collection contains descriptors for *both* ranges containing an allocation, *and* free
+    /// ranges between allocations. The free ranges get merged, so there are never two free ranges
+    /// next to each other.
+    tree: RBTree<usize, Descriptor<T>>,
+    /// Contains an entry for every free range in `self.tree`. This tree sorts the ranges by size,
+    /// letting us look up the smallest range whose size is at least some lower bound.
+    free_tree: RBTree<FreeKey, ()>,
+    size: usize,
+    free_oneway_space: usize,
+}
+
+impl<T> TreeRangeAllocator<T> {
+    pub(crate) fn from_array(
+        size: usize,
+        ranges: &mut KVec<Range<T>>,
+        alloc: &mut FromArrayAllocs<T>,
+    ) -> Self {
+        let mut tree = TreeRangeAllocator {
+            tree: RBTree::new(),
+            free_tree: RBTree::new(),
+            size,
+            free_oneway_space: size / 2,
+        };
+
+        let mut free_offset = 0;
+        for range in ranges.drain_all() {
+            let free_size = range.offset - free_offset;
+            if free_size > 0 {
+                let free_node = alloc.free_tree.pop().unwrap();
+                tree.free_tree
+                    .insert(free_node.into_node((free_size, free_offset), ()));
+                let tree_node = alloc.tree.pop().unwrap();
+                tree.tree.insert(
+                    tree_node.into_node(free_offset, Descriptor::new(free_offset, free_size)),
+                );
+            }
+            free_offset = range.endpoint();
+
+            if range.state.is_oneway() {
+                tree.free_oneway_space = tree.free_oneway_space.saturating_sub(range.size);
+            }
+
+            let free_res = alloc.free_tree.pop().unwrap();
+            let tree_node = alloc.tree.pop().unwrap();
+            let mut desc = Descriptor::new(range.offset, range.size);
+            desc.state = Some((range.state, free_res));
+            tree.tree.insert(tree_node.into_node(range.offset, desc));
+        }
+
+        // After the last range, we may need a free range.
+        if free_offset < size {
+            let free_size = size - free_offset;
+            let free_node = alloc.free_tree.pop().unwrap();
+            tree.free_tree
+                .insert(free_node.into_node((free_size, free_offset), ()));
+            let tree_node = alloc.tree.pop().unwrap();
+            tree.tree
+                .insert(tree_node.into_node(free_offset, Descriptor::new(free_offset, free_size)));
+        }
+
+        tree
+    }
+
+    pub(crate) fn is_empty(&self) -> bool {
+        let mut tree_iter = self.tree.values();
+        // There's always at least one range, because index zero is either the start of a free or
+        // allocated range.
+        let first_value = tree_iter.next().unwrap();
+        if tree_iter.next().is_some() {
+            // There are never two free ranges next to each other, so if there is more than one
+            // descriptor, then at least one of them must hold an allocated range.
+            return false;
+        }
+        // There is only one descriptor. Return true if it is for a free range.
+        first_value.state.is_none()
+    }
+
+    pub(crate) fn total_size(&self) -> usize {
+        self.size
+    }
+
+    pub(crate) fn free_oneway_space(&self) -> usize {
+        self.free_oneway_space
+    }
+
+    pub(crate) fn count_buffers(&self) -> usize {
+        self.tree
+            .values()
+            .filter(|desc| desc.state.is_some())
+            .count()
+    }
+
+    pub(crate) fn debug_print(&self, m: &SeqFile) -> Result<()> {
+        for desc in self.tree.values() {
+            let state = match &desc.state {
+                Some(state) => &state.0,
+                None => continue,
+            };
+            seq_print!(
+                m,
+                "  buffer: {} size {} pid {}",
+                desc.offset,
+                desc.size,
+                state.pid(),
+            );
+            if state.is_oneway() {
+                seq_print!(m, " oneway");
+            }
+            match state {
+                DescriptorState::Reserved(_res) => {
+                    seq_print!(m, " reserved\n");
+                }
+                DescriptorState::Allocated(_alloc) => {
+                    seq_print!(m, " allocated\n");
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn find_best_match(&mut self, size: usize) -> Option<&mut Descriptor<T>> {
+        let free_cursor = self.free_tree.cursor_lower_bound(&(size, 0))?;
+        let ((_, offset), ()) = free_cursor.current();
+        self.tree.get_mut(offset)
+    }
+
+    /// Try to reserve a new buffer, using the provided allocation if necessary.
+    pub(crate) fn reserve_new(
+        &mut self,
+        debug_id: usize,
+        size: usize,
+        is_oneway: bool,
+        pid: Pid,
+        alloc: ReserveNewTreeAlloc<T>,
+    ) -> Result<(usize, bool)> {
+        // Compute new value of free_oneway_space, which is set only on success.
+        let new_oneway_space = if is_oneway {
+            match self.free_oneway_space.checked_sub(size) {
+                Some(new_oneway_space) => new_oneway_space,
+                None => return Err(ENOSPC),
+            }
+        } else {
+            self.free_oneway_space
+        };
+
+        let (found_size, found_off, tree_node, free_tree_node) = match self.find_best_match(size) {
+            None => {
+                pr_warn!("ENOSPC from range_alloc.reserve_new - size: {}", size);
+                return Err(ENOSPC);
+            }
+            Some(desc) => {
+                let found_size = desc.size;
+                let found_offset = desc.offset;
+
+                // In case we need to break up the descriptor
+                let new_desc = Descriptor::new(found_offset + size, found_size - size);
+                let (tree_node, free_tree_node, desc_node_res) = alloc.initialize(new_desc);
+
+                desc.state = Some((
+                    DescriptorState::new(is_oneway, debug_id, pid),
+                    desc_node_res,
+                ));
+                desc.size = size;
+
+                (found_size, found_offset, tree_node, free_tree_node)
+            }
+        };
+        self.free_oneway_space = new_oneway_space;
+        self.free_tree.remove(&(found_size, found_off));
+
+        if found_size != size {
+            self.tree.insert(tree_node);
+            self.free_tree.insert(free_tree_node);
+        }
+
+        // Start detecting spammers once we have less than 20%
+        // of async space left (which is less than 10% of total
+        // buffer size).
+        //
+        // (This will short-circuit, so `low_oneway_space` is
+        // only called when necessary.)
+        let oneway_spam_detected =
+            is_oneway && new_oneway_space < self.size / 10 && self.low_oneway_space(pid);
+
+        Ok((found_off, oneway_spam_detected))
+    }
+
+    pub(crate) fn reservation_abort(&mut self, offset: usize) -> Result<FreedRange> {
+        let mut cursor = self.tree.cursor_lower_bound_mut(&offset).ok_or_else(|| {
+            pr_warn!(
+                "EINVAL from range_alloc.reservation_abort - offset: {}",
+                offset
+            );
+            EINVAL
+        })?;
+
+        let (_, desc) = cursor.current_mut();
+
+        if desc.offset != offset {
+            pr_warn!(
+                "EINVAL from range_alloc.reservation_abort - offset: {}",
+                offset
+            );
+            return Err(EINVAL);
+        }
+
+        let (reservation, free_node_res) = desc.try_change_state(|state| match state {
+            Some((DescriptorState::Reserved(reservation), free_node_res)) => {
+                (None, Ok((reservation, free_node_res)))
+            }
+            None => {
+                pr_warn!(
+                    "EINVAL from range_alloc.reservation_abort - offset: {}",
+                    offset
+                );
+                (None, Err(EINVAL))
+            }
+            allocated => {
+                pr_warn!(
+                    "EPERM from range_alloc.reservation_abort - offset: {}",
+                    offset
+                );
+                (allocated, Err(EPERM))
+            }
+        })?;
+
+        let mut size = desc.size;
+        let mut offset = desc.offset;
+        let free_oneway_space_add = if reservation.is_oneway { size } else { 0 };
+
+        self.free_oneway_space += free_oneway_space_add;
+
+        let mut freed_range = FreedRange::interior_pages(offset, size);
+        // Compute how large the next free region needs to be to include one more page in
+        // the newly freed range.
+        let add_next_page_needed = match (offset + size) % PAGE_SIZE {
+            0 => usize::MAX,
+            unalign => PAGE_SIZE - unalign,
+        };
+        // Compute how large the previous free region needs to be to include one more page
+        // in the newly freed range.
+        let add_prev_page_needed = match offset % PAGE_SIZE {
+            0 => usize::MAX,
+            unalign => unalign,
+        };
+
+        // Merge next into current if next is free
+        let remove_next = match cursor.peek_next() {
+            Some((_, next)) if next.state.is_none() => {
+                if next.size >= add_next_page_needed {
+                    freed_range.end_page_idx += 1;
+                }
+                self.free_tree.remove(&(next.size, next.offset));
+                size += next.size;
+                true
+            }
+            _ => false,
+        };
+
+        if remove_next {
+            let (_, desc) = cursor.current_mut();
+            desc.size = size;
+            cursor.remove_next();
+        }
+
+        // Merge current into prev if prev is free
+        match cursor.peek_prev_mut() {
+            Some((_, prev)) if prev.state.is_none() => {
+                if prev.size >= add_prev_page_needed {
+                    freed_range.start_page_idx -= 1;
+                }
+                // merge previous with current, remove current
+                self.free_tree.remove(&(prev.size, prev.offset));
+                offset = prev.offset;
+                size += prev.size;
+                prev.size = size;
+                cursor.remove_current();
+            }
+            _ => {}
+        };
+
+        self.free_tree
+            .insert(free_node_res.into_node((size, offset), ()));
+
+        Ok(freed_range)
+    }
+
+    pub(crate) fn reservation_commit(&mut self, offset: usize, data: &mut Option<T>) -> Result {
+        let desc = self.tree.get_mut(&offset).ok_or(ENOENT)?;
+
+        desc.try_change_state(|state| match state {
+            Some((DescriptorState::Reserved(reservation), free_node_res)) => (
+                Some((
+                    DescriptorState::Allocated(reservation.allocate(data.take())),
+                    free_node_res,
+                )),
+                Ok(()),
+            ),
+            other => (other, Err(ENOENT)),
+        })
+    }
+
+    /// Takes an entry at the given offset from [`DescriptorState::Allocated`] to
+    /// [`DescriptorState::Reserved`].
+    ///
+    /// Returns the size of the existing entry and the data associated with it.
+    pub(crate) fn reserve_existing(&mut self, offset: usize) -> Result<(usize, usize, Option<T>)> {
+        let desc = self.tree.get_mut(&offset).ok_or_else(|| {
+            pr_warn!(
+                "ENOENT from range_alloc.reserve_existing - offset: {}",
+                offset
+            );
+            ENOENT
+        })?;
+
+        let (debug_id, data) = desc.try_change_state(|state| match state {
+            Some((DescriptorState::Allocated(allocation), free_node_res)) => {
+                let (reservation, data) = allocation.deallocate();
+                let debug_id = reservation.debug_id;
+                (
+                    Some((DescriptorState::Reserved(reservation), free_node_res)),
+                    Ok((debug_id, data)),
+                )
+            }
+            other => {
+                pr_warn!(
+                    "ENOENT from range_alloc.reserve_existing - offset: {}",
+                    offset
+                );
+                (other, Err(ENOENT))
+            }
+        })?;
+
+        Ok((desc.size, debug_id, data))
+    }
+
+    /// Call the provided callback at every allocated region.
+    ///
+    /// This destroys the range allocator. Used only during shutdown.
+    pub(crate) fn take_for_each<F: Fn(usize, usize, usize, Option<T>)>(&mut self, callback: F) {
+        for (_, desc) in self.tree.iter_mut() {
+            if let Some((DescriptorState::Allocated(allocation), _)) = &mut desc.state {
+                callback(
+                    desc.offset,
+                    desc.size,
+                    allocation.debug_id(),
+                    allocation.take(),
+                );
+            }
+        }
+    }
+
+    /// Find the amount and size of buffers allocated by the current caller.
+    ///
+    /// The idea is that once we cross the threshold, whoever is responsible
+    /// for the low async space is likely to try to send another async transaction,
+    /// and at some point we'll catch them in the act.  This is more efficient
+    /// than keeping a map per pid.
+    fn low_oneway_space(&self, calling_pid: Pid) -> bool {
+        let mut total_alloc_size = 0;
+        let mut num_buffers = 0;
+        for (_, desc) in self.tree.iter() {
+            if let Some((state, _)) = &desc.state {
+                if state.is_oneway() && state.pid() == calling_pid {
+                    total_alloc_size += desc.size;
+                    num_buffers += 1;
+                }
+            }
+        }
+
+        // Warn if this pid has more than 50 transactions, or more than 50% of
+        // async space (which is 25% of total buffer size). Oneway spam is only
+        // detected when the threshold is exceeded.
+        num_buffers > 50 || total_alloc_size > self.size / 4
+    }
+}
+
+type TreeDescriptorState<T> = (DescriptorState<T>, FreeNodeRes);
+struct Descriptor<T> {
+    size: usize,
+    offset: usize,
+    state: Option<TreeDescriptorState<T>>,
+}
+
+impl<T> Descriptor<T> {
+    fn new(offset: usize, size: usize) -> Self {
+        Self {
+            size,
+            offset,
+            state: None,
+        }
+    }
+
+    fn try_change_state<F, Data>(&mut self, f: F) -> Result<Data>
+    where
+        F: FnOnce(Option<TreeDescriptorState<T>>) -> (Option<TreeDescriptorState<T>>, Result<Data>),
+    {
+        let (new_state, result) = f(self.state.take());
+        self.state = new_state;
+        result
+    }
+}
+
+// (Descriptor.size, Descriptor.offset)
+type FreeKey = (usize, usize);
+type FreeNodeRes = RBTreeNodeReservation<FreeKey, ()>;
+
+/// An allocation for use by `reserve_new`.
+pub(crate) struct ReserveNewTreeAlloc<T> {
+    tree_node_res: RBTreeNodeReservation<usize, Descriptor<T>>,
+    free_tree_node_res: FreeNodeRes,
+    desc_node_res: FreeNodeRes,
+}
+
+impl<T> ReserveNewTreeAlloc<T> {
+    pub(crate) fn try_new() -> Result<Self> {
+        let tree_node_res = RBTreeNodeReservation::new(GFP_KERNEL)?;
+        let free_tree_node_res = RBTreeNodeReservation::new(GFP_KERNEL)?;
+        let desc_node_res = RBTreeNodeReservation::new(GFP_KERNEL)?;
+        Ok(Self {
+            tree_node_res,
+            free_tree_node_res,
+            desc_node_res,
+        })
+    }
+
+    fn initialize(
+        self,
+        desc: Descriptor<T>,
+    ) -> (
+        RBTreeNode<usize, Descriptor<T>>,
+        RBTreeNode<FreeKey, ()>,
+        FreeNodeRes,
+    ) {
+        let size = desc.size;
+        let offset = desc.offset;
+        (
+            self.tree_node_res.into_node(offset, desc),
+            self.free_tree_node_res.into_node((size, offset), ()),
+            self.desc_node_res,
+        )
+    }
+}
+
+/// An allocation for creating a tree from an `ArrayRangeAllocator`.
+pub(crate) struct FromArrayAllocs<T> {
+    tree: KVec<RBTreeNodeReservation<usize, Descriptor<T>>>,
+    free_tree: KVec<RBTreeNodeReservation<FreeKey, ()>>,
+}
+
+impl<T> FromArrayAllocs<T> {
+    pub(crate) fn try_new(len: usize) -> Result<Self> {
+        let num_descriptors = 2 * len + 1;
+
+        let mut tree = KVec::with_capacity(num_descriptors, GFP_KERNEL)?;
+        for _ in 0..num_descriptors {
+            tree.push(RBTreeNodeReservation::new(GFP_KERNEL)?, GFP_KERNEL)?;
+        }
+
+        let mut free_tree = KVec::with_capacity(num_descriptors, GFP_KERNEL)?;
+        for _ in 0..num_descriptors {
+            free_tree.push(RBTreeNodeReservation::new(GFP_KERNEL)?, GFP_KERNEL)?;
+        }
+
+        Ok(Self { tree, free_tree })
+    }
+}
diff --git a/drivers/android/binder/rust_binder.h b/drivers/android/binder/rust_binder.h
new file mode 100644
index 000000000..3936b9d0b
--- /dev/null
+++ b/drivers/android/binder/rust_binder.h
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2025 Google, Inc.
+ */
+
+#ifndef _LINUX_RUST_BINDER_H
+#define _LINUX_RUST_BINDER_H
+
+#include <uapi/linux/android/binder.h>
+#include <uapi/linux/android/binderfs.h>
+
+/*
+ * These symbols are exposed by `rust_binderfs.c` and exist here so that Rust
+ * Binder can call them.
+ */
+int init_rust_binderfs(void);
+
+struct dentry;
+struct inode;
+struct dentry *rust_binderfs_create_proc_file(struct inode *nodp, int pid);
+void rust_binderfs_remove_file(struct dentry *dentry);
+
+/*
+ * The internal data types in the Rust Binder driver are opaque to C, so we use
+ * void pointer typedefs for these types.
+ */
+
+typedef void *rust_binder_transaction;
+typedef void *rust_binder_process;
+typedef void *rust_binder_node;
+
+struct rb_process_layout {
+	size_t arc_offset;
+	size_t task;
+};
+
+struct rb_transaction_layout {
+	size_t debug_id;
+	size_t code;
+	size_t flags;
+	size_t from_thread;
+	size_t to_proc;
+	size_t target_node;
+};
+
+struct rb_node_layout {
+	size_t arc_offset;
+	size_t debug_id;
+	size_t ptr;
+};
+
+struct rust_binder_layout {
+	struct rb_transaction_layout t;
+	struct rb_process_layout p;
+	struct rb_node_layout n;
+};
+
+extern const struct rust_binder_layout RUST_BINDER_LAYOUT;
+
+static inline size_t rust_binder_transaction_debug_id(rust_binder_transaction t)
+{
+	return *(size_t *) (t + RUST_BINDER_LAYOUT.t.debug_id);
+}
+
+static inline u32 rust_binder_transaction_code(rust_binder_transaction t)
+{
+	return *(u32 *) (t + RUST_BINDER_LAYOUT.t.code);
+}
+
+static inline u32 rust_binder_transaction_flags(rust_binder_transaction t)
+{
+	return *(u32 *) (t + RUST_BINDER_LAYOUT.t.flags);
+}
+
+// Nullable!
+static inline rust_binder_node rust_binder_transaction_target_node(rust_binder_transaction t)
+{
+	void *p = *(void **) (t + RUST_BINDER_LAYOUT.t.target_node);
+
+	if (p)
+		p = p + RUST_BINDER_LAYOUT.n.arc_offset;
+	return p;
+}
+
+static inline rust_binder_process rust_binder_transaction_to_proc(rust_binder_transaction t)
+{
+	void *p = *(void **) (t + RUST_BINDER_LAYOUT.t.to_proc);
+
+	return p + RUST_BINDER_LAYOUT.p.arc_offset;
+}
+
+static inline struct task_struct *rust_binder_process_task(rust_binder_process t)
+{
+	return *(struct task_struct **) (t + RUST_BINDER_LAYOUT.p.task);
+}
+
+static inline size_t rust_binder_node_debug_id(rust_binder_node t)
+{
+	return *(size_t *) (t + RUST_BINDER_LAYOUT.n.debug_id);
+}
+
+static inline binder_uintptr_t rust_binder_node_ptr(rust_binder_node t)
+{
+	return *(binder_uintptr_t *) (t + RUST_BINDER_LAYOUT.n.ptr);
+}
+
+#endif
diff --git a/drivers/android/binder/rust_binder_events.c b/drivers/android/binder/rust_binder_events.c
new file mode 100644
index 000000000..5792aa59c
--- /dev/null
+++ b/drivers/android/binder/rust_binder_events.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* rust_binder_events.c
+ *
+ * Rust Binder tracepoints.
+ *
+ * Copyright 2025 Google LLC
+ */
+
+#include "rust_binder.h"
+
+const char * const binder_command_strings[] = {
+	"BC_TRANSACTION",
+	"BC_REPLY",
+	"BC_ACQUIRE_RESULT",
+	"BC_FREE_BUFFER",
+	"BC_INCREFS",
+	"BC_ACQUIRE",
+	"BC_RELEASE",
+	"BC_DECREFS",
+	"BC_INCREFS_DONE",
+	"BC_ACQUIRE_DONE",
+	"BC_ATTEMPT_ACQUIRE",
+	"BC_REGISTER_LOOPER",
+	"BC_ENTER_LOOPER",
+	"BC_EXIT_LOOPER",
+	"BC_REQUEST_DEATH_NOTIFICATION",
+	"BC_CLEAR_DEATH_NOTIFICATION",
+	"BC_DEAD_BINDER_DONE",
+	"BC_TRANSACTION_SG",
+	"BC_REPLY_SG",
+	"BC_REQUEST_FREEZE_NOTIFICATION",
+	"BC_CLEAR_FREEZE_NOTIFICATION",
+	"BC_FREEZE_NOTIFICATION_DONE",
+};
+
+const char * const binder_return_strings[] = {
+	"BR_ERROR",
+	"BR_OK",
+	"BR_TRANSACTION",
+	"BR_REPLY",
+	"BR_ACQUIRE_RESULT",
+	"BR_DEAD_REPLY",
+	"BR_TRANSACTION_COMPLETE",
+	"BR_INCREFS",
+	"BR_ACQUIRE",
+	"BR_RELEASE",
+	"BR_DECREFS",
+	"BR_ATTEMPT_ACQUIRE",
+	"BR_NOOP",
+	"BR_SPAWN_LOOPER",
+	"BR_FINISHED",
+	"BR_DEAD_BINDER",
+	"BR_CLEAR_DEATH_NOTIFICATION_DONE",
+	"BR_FAILED_REPLY",
+	"BR_FROZEN_REPLY",
+	"BR_ONEWAY_SPAM_SUSPECT",
+	"BR_TRANSACTION_PENDING_FROZEN",
+	"BR_FROZEN_BINDER",
+	"BR_CLEAR_FREEZE_NOTIFICATION_DONE",
+};
+
+#define CREATE_TRACE_POINTS
+#define CREATE_RUST_TRACE_POINTS
+#include "rust_binder_events.h"
diff --git a/drivers/android/binder/rust_binder_events.h b/drivers/android/binder/rust_binder_events.h
new file mode 100644
index 000000000..1a446787c
--- /dev/null
+++ b/drivers/android/binder/rust_binder_events.h
@@ -0,0 +1,183 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2025 Google, Inc.
+ */
+
+#undef TRACE_SYSTEM
+#undef TRACE_INCLUDE_FILE
+#undef TRACE_INCLUDE_PATH
+#define TRACE_SYSTEM rust_binder
+#define TRACE_INCLUDE_FILE rust_binder_events
+#define TRACE_INCLUDE_PATH ../drivers/android/binder
+
+#if !defined(_RUST_BINDER_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _RUST_BINDER_TRACE_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(binder_ioctl,
+	TP_PROTO(unsigned int cmd, unsigned long arg),
+	TP_ARGS(cmd, arg),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, cmd)
+		__field(unsigned long, arg)
+	),
+	TP_fast_assign(
+		__entry->cmd = cmd;
+		__entry->arg = arg;
+	),
+	TP_printk("cmd=0x%x arg=0x%lx", __entry->cmd, __entry->arg)
+);
+
+DECLARE_EVENT_CLASS(binder_function_return_class,
+	TP_PROTO(int ret),
+	TP_ARGS(ret),
+	TP_STRUCT__entry(
+		__field(int, ret)
+	),
+	TP_fast_assign(
+		__entry->ret = ret;
+	),
+	TP_printk("ret=%d", __entry->ret)
+);
+
+#define DEFINE_RBINDER_FUNCTION_RETURN_EVENT(name)	\
+DEFINE_EVENT(binder_function_return_class, name,	\
+	TP_PROTO(int ret), \
+	TP_ARGS(ret))
+
+DEFINE_RBINDER_FUNCTION_RETURN_EVENT(binder_ioctl_done);
+DEFINE_RBINDER_FUNCTION_RETURN_EVENT(binder_read_done);
+DEFINE_RBINDER_FUNCTION_RETURN_EVENT(binder_write_done);
+
+TRACE_EVENT(binder_wait_for_work,
+	TP_PROTO(bool proc_work, bool transaction_stack, bool thread_todo),
+	TP_ARGS(proc_work, transaction_stack, thread_todo),
+	TP_STRUCT__entry(
+		__field(bool, proc_work)
+		__field(bool, transaction_stack)
+		__field(bool, thread_todo)
+	),
+	TP_fast_assign(
+		__entry->proc_work = proc_work;
+		__entry->transaction_stack = transaction_stack;
+		__entry->thread_todo = thread_todo;
+	),
+	TP_printk("proc_work=%d transaction_stack=%d thread_todo=%d",
+		  __entry->proc_work, __entry->transaction_stack,
+		  __entry->thread_todo)
+);
+
+TRACE_EVENT(binder_transaction,
+	TP_PROTO(bool reply, rust_binder_transaction t, struct task_struct *thread),
+	TP_ARGS(reply, t, thread),
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, target_node)
+		__field(int, to_proc)
+		__field(int, to_thread)
+		__field(int, reply)
+		__field(unsigned int, code)
+		__field(unsigned int, flags)
+	),
+	TP_fast_assign(
+		rust_binder_process to = rust_binder_transaction_to_proc(t);
+		rust_binder_node target_node = rust_binder_transaction_target_node(t);
+
+		__entry->debug_id = rust_binder_transaction_debug_id(t);
+		__entry->target_node = target_node ? rust_binder_node_debug_id(target_node) : 0;
+		__entry->to_proc = rust_binder_process_task(to)->pid;
+		__entry->to_thread = thread ? thread->pid : 0;
+		__entry->reply = reply;
+		__entry->code = rust_binder_transaction_code(t);
+		__entry->flags = rust_binder_transaction_flags(t);
+	),
+	TP_printk("transaction=%d dest_node=%d dest_proc=%d dest_thread=%d reply=%d flags=0x%x code=0x%x",
+		  __entry->debug_id, __entry->target_node,
+		  __entry->to_proc, __entry->to_thread,
+		  __entry->reply, __entry->flags, __entry->code)
+);
+
+TRACE_EVENT(binder_transaction_received,
+	TP_PROTO(rust_binder_transaction t),
+	TP_ARGS(t),
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+	),
+	TP_fast_assign(
+		__entry->debug_id = rust_binder_transaction_debug_id(t);
+	),
+	TP_printk("transaction=%d", __entry->debug_id)
+);
+
+TRACE_EVENT(binder_transaction_fd_send,
+	TP_PROTO(int t_debug_id, int fd, size_t offset),
+	TP_ARGS(t_debug_id, fd, offset),
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, fd)
+		__field(size_t, offset)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t_debug_id;
+		__entry->fd = fd;
+		__entry->offset = offset;
+	),
+	TP_printk("transaction=%d src_fd=%d offset=%zu",
+		  __entry->debug_id, __entry->fd, __entry->offset)
+);
+
+TRACE_EVENT(binder_transaction_fd_recv,
+	TP_PROTO(int t_debug_id, int fd, size_t offset),
+	TP_ARGS(t_debug_id, fd, offset),
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, fd)
+		__field(size_t, offset)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t_debug_id;
+		__entry->fd = fd;
+		__entry->offset = offset;
+	),
+	TP_printk("transaction=%d dest_fd=%d offset=%zu",
+		  __entry->debug_id, __entry->fd, __entry->offset)
+);
+
+TRACE_EVENT(binder_command,
+	TP_PROTO(uint32_t cmd),
+	TP_ARGS(cmd),
+	TP_STRUCT__entry(
+		__field(uint32_t, cmd)
+	),
+	TP_fast_assign(
+		__entry->cmd = cmd;
+	),
+	TP_printk("cmd=0x%x %s",
+		  __entry->cmd,
+		  _IOC_NR(__entry->cmd) < ARRAY_SIZE(binder_command_strings) ?
+			  binder_command_strings[_IOC_NR(__entry->cmd)] :
+			  "unknown")
+);
+
+TRACE_EVENT(binder_return,
+	TP_PROTO(uint32_t cmd),
+	TP_ARGS(cmd),
+	TP_STRUCT__entry(
+		__field(uint32_t, cmd)
+	),
+	TP_fast_assign(
+		__entry->cmd = cmd;
+	),
+	TP_printk("cmd=0x%x %s",
+		  __entry->cmd,
+		  _IOC_NR(__entry->cmd) < ARRAY_SIZE(binder_return_strings) ?
+			  binder_return_strings[_IOC_NR(__entry->cmd)] :
+			  "unknown")
+);
+
+#endif /* _RUST_BINDER_TRACE_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/drivers/android/binder/rust_binder_internal.h b/drivers/android/binder/rust_binder_internal.h
new file mode 100644
index 000000000..78288fe79
--- /dev/null
+++ b/drivers/android/binder/rust_binder_internal.h
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* rust_binder_internal.h
+ *
+ * This file contains internal data structures used by Rust Binder. Mostly,
+ * these are type definitions used only by binderfs or things that Rust Binder
+ * define and export to binderfs.
+ *
+ * It does not include things exported by binderfs to Rust Binder since this
+ * file is not included as input to bindgen.
+ *
+ * Copyright (C) 2025 Google LLC.
+ */
+
+#ifndef _LINUX_RUST_BINDER_INTERNAL_H
+#define _LINUX_RUST_BINDER_INTERNAL_H
+
+#define RUST_BINDERFS_SUPER_MAGIC	0x6c6f6f71
+
+#include <linux/seq_file.h>
+#include <uapi/linux/android/binder.h>
+#include <uapi/linux/android/binderfs.h>
+
+/*
+ * The internal data types in the Rust Binder driver are opaque to C, so we use
+ * void pointer typedefs for these types.
+ */
+typedef void *rust_binder_context;
+
+/**
+ * struct binder_device - information about a binder device node
+ * @minor:     the minor number used by this device
+ * @ctx:       the Rust Context used by this device, or null for binder-control
+ *
+ * This is used as the private data for files directly in binderfs, but not
+ * files in the binder_logs subdirectory. This struct owns a refcount on `ctx`
+ * and the entry for `minor` in `binderfs_minors`. For binder-control `ctx` is
+ * null.
+ */
+struct binder_device {
+	int minor;
+	rust_binder_context ctx;
+};
+
+int rust_binder_stats_show(struct seq_file *m, void *unused);
+int rust_binder_state_show(struct seq_file *m, void *unused);
+int rust_binder_transactions_show(struct seq_file *m, void *unused);
+int rust_binder_proc_show(struct seq_file *m, void *pid);
+
+extern const struct file_operations rust_binder_fops;
+rust_binder_context rust_binder_new_context(char *name);
+void rust_binder_remove_context(rust_binder_context device);
+
+/**
+ * binderfs_mount_opts - mount options for binderfs
+ * @max: maximum number of allocatable binderfs binder devices
+ * @stats_mode: enable binder stats in binderfs.
+ */
+struct binderfs_mount_opts {
+	int max;
+	int stats_mode;
+};
+
+/**
+ * binderfs_info - information about a binderfs mount
+ * @ipc_ns:         The ipc namespace the binderfs mount belongs to.
+ * @control_dentry: This records the dentry of this binderfs mount
+ *                  binder-control device.
+ * @root_uid:       uid that needs to be used when a new binder device is
+ *                  created.
+ * @root_gid:       gid that needs to be used when a new binder device is
+ *                  created.
+ * @mount_opts:     The mount options in use.
+ * @device_count:   The current number of allocated binder devices.
+ * @proc_log_dir:   Pointer to the directory dentry containing process-specific
+ *                  logs.
+ */
+struct binderfs_info {
+	struct ipc_namespace *ipc_ns;
+	struct dentry *control_dentry;
+	kuid_t root_uid;
+	kgid_t root_gid;
+	struct binderfs_mount_opts mount_opts;
+	int device_count;
+	struct dentry *proc_log_dir;
+};
+
+#endif /* _LINUX_RUST_BINDER_INTERNAL_H */
diff --git a/drivers/android/binder/rust_binder_main.rs b/drivers/android/binder/rust_binder_main.rs
new file mode 100644
index 000000000..955c4c348
--- /dev/null
+++ b/drivers/android/binder/rust_binder_main.rs
@@ -0,0 +1,626 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+//! Binder -- the Android IPC mechanism.
+
+#![crate_name = "rust_binder"]
+#![recursion_limit = "256"]
+
+use kernel::{
+    bindings::{self, seq_file},
+    fs::File,
+    list::{ListArc, ListArcSafe, ListLinksSelfPtr, TryNewListArc},
+    module::this_module,
+    prelude::*,
+    seq_file::SeqFile,
+    seq_print,
+    sync::atomic::{ordering::Relaxed, Atomic},
+    sync::poll::PollTable,
+    sync::Arc,
+    task::Pid,
+    transmute::AsBytes,
+    types::ForeignOwnable,
+    uaccess::UserSliceWriter,
+};
+
+use crate::{context::Context, page_range::Shrinker, process::Process, thread::Thread};
+
+use core::ptr::NonNull;
+
+mod allocation;
+mod context;
+mod deferred_close;
+mod defs;
+#[macro_use]
+mod debug;
+mod error;
+mod netlink;
+mod node;
+mod page_range;
+mod process;
+mod range_alloc;
+mod stats;
+mod thread;
+mod trace;
+mod transaction;
+
+#[allow(warnings)] // generated bindgen code
+mod binderfs {
+    use kernel::bindings::{dentry, inode};
+
+    extern "C" {
+        pub fn init_rust_binderfs() -> kernel::ffi::c_int;
+    }
+    extern "C" {
+        pub fn rust_binderfs_create_proc_file(
+            nodp: *mut inode,
+            pid: kernel::ffi::c_int,
+        ) -> *mut dentry;
+    }
+    extern "C" {
+        pub fn rust_binderfs_remove_file(dentry: *mut dentry);
+    }
+    pub type rust_binder_context = *mut kernel::ffi::c_void;
+    #[repr(C)]
+    #[derive(Copy, Clone)]
+    pub struct binder_device {
+        pub minor: kernel::ffi::c_int,
+        pub ctx: rust_binder_context,
+    }
+    impl Default for binder_device {
+        fn default() -> Self {
+            let mut s = ::core::mem::MaybeUninit::<Self>::uninit();
+            unsafe {
+                ::core::ptr::write_bytes(s.as_mut_ptr(), 0, 1);
+                s.assume_init()
+            }
+        }
+    }
+}
+
+module! {
+    type: BinderModule,
+    name: "rust_binder",
+    authors: ["Wedson Almeida Filho", "Alice Ryhl"],
+    description: "Android Binder",
+    license: "GPL",
+}
+
+use kernel::bindings::rust_binder_layout;
+#[no_mangle]
+static RUST_BINDER_LAYOUT: rust_binder_layout = rust_binder_layout {
+    t: transaction::TRANSACTION_LAYOUT,
+    p: process::PROCESS_LAYOUT,
+    n: node::NODE_LAYOUT,
+};
+
+fn next_debug_id() -> usize {
+    static NEXT_DEBUG_ID: Atomic<usize> = Atomic::new(0);
+
+    NEXT_DEBUG_ID.fetch_add(1, Relaxed)
+}
+
+/// Provides a single place to write Binder return values via the
+/// supplied `UserSliceWriter`.
+pub(crate) struct BinderReturnWriter<'a> {
+    writer: UserSliceWriter,
+    thread: &'a Thread,
+}
+
+impl<'a> BinderReturnWriter<'a> {
+    fn new(writer: UserSliceWriter, thread: &'a Thread) -> Self {
+        BinderReturnWriter { writer, thread }
+    }
+
+    /// Write a return code back to user space.
+    /// Should be a `BR_` constant from [`defs`] e.g. [`defs::BR_TRANSACTION_COMPLETE`].
+    fn write_code(&mut self, code: u32) -> Result {
+        crate::trace::trace_return(code);
+        stats::GLOBAL_STATS.inc_br(code);
+        self.thread.process.stats.inc_br(code);
+        self.writer.write(&code)
+    }
+
+    /// Write something *other than* a return code to user space.
+    fn write_payload<T: AsBytes>(&mut self, payload: &T) -> Result {
+        self.writer.write(payload)
+    }
+
+    fn len(&self) -> usize {
+        self.writer.len()
+    }
+}
+
+/// Specifies how a type should be delivered to the read part of a BINDER_WRITE_READ ioctl.
+///
+/// When a value is pushed to the todo list for a process or thread, it is stored as a trait object
+/// with the type `Arc<dyn DeliverToRead>`. Trait objects are a Rust feature that lets you
+/// implement dynamic dispatch over many different types. This lets us store many different types
+/// in the todo list.
+trait DeliverToRead: ListArcSafe + Send + Sync {
+    /// Performs work. Returns true if remaining work items in the queue should be processed
+    /// immediately, or false if it should return to caller before processing additional work
+    /// items.
+    fn do_work(
+        self: DArc<Self>,
+        thread: &Thread,
+        writer: &mut BinderReturnWriter<'_>,
+    ) -> Result<bool>;
+
+    /// Cancels the given work item. This is called instead of [`DeliverToRead::do_work`] when work
+    /// won't be delivered.
+    fn cancel(self: DArc<Self>);
+
+    /// Should we use `wake_up_interruptible_sync` or `wake_up_interruptible` when scheduling this
+    /// work item?
+    ///
+    /// Generally only set to true for non-oneway transactions.
+    fn should_sync_wakeup(&self) -> bool;
+
+    fn debug_print(&self, m: &SeqFile, prefix: &str, transaction_prefix: &str) -> Result<()>;
+}
+
+// Wrapper around a `DeliverToRead` with linked list links.
+#[pin_data]
+struct DTRWrap<T: ?Sized> {
+    #[pin]
+    links: ListLinksSelfPtr<DTRWrap<dyn DeliverToRead>>,
+    #[pin]
+    wrapped: T,
+}
+kernel::list::impl_list_arc_safe! {
+    impl{T: ListArcSafe + ?Sized} ListArcSafe<0> for DTRWrap<T> {
+        tracked_by wrapped: T;
+    }
+}
+kernel::list::impl_list_item! {
+    impl ListItem<0> for DTRWrap<dyn DeliverToRead> {
+        using ListLinksSelfPtr { self.links };
+    }
+}
+
+impl<T: ?Sized> core::ops::Deref for DTRWrap<T> {
+    type Target = T;
+    fn deref(&self) -> &T {
+        &self.wrapped
+    }
+}
+
+type DArc<T> = kernel::sync::Arc<DTRWrap<T>>;
+type DLArc<T> = kernel::list::ListArc<DTRWrap<T>>;
+
+impl<T: ListArcSafe> DTRWrap<T> {
+    fn new(val: impl PinInit<T>) -> impl PinInit<Self> {
+        pin_init!(Self {
+            links <- ListLinksSelfPtr::new(),
+            wrapped <- val,
+        })
+    }
+
+    fn arc_try_new(val: T) -> Result<DLArc<T>, kernel::alloc::AllocError> {
+        ListArc::pin_init(
+            try_pin_init!(Self {
+                links <- ListLinksSelfPtr::new(),
+                wrapped: val,
+            }),
+            GFP_KERNEL,
+        )
+        .map_err(|_| kernel::alloc::AllocError)
+    }
+
+    fn arc_pin_init(init: impl PinInit<T>) -> Result<DLArc<T>, kernel::error::Error> {
+        ListArc::pin_init(
+            try_pin_init!(Self {
+                links <- ListLinksSelfPtr::new(),
+                wrapped <- init,
+            }),
+            GFP_KERNEL,
+        )
+    }
+}
+
+struct DeliverCode {
+    code: u32,
+    skip: Atomic<bool>,
+    pid: i32,
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<0> for DeliverCode { untracked; }
+}
+
+impl DeliverCode {
+    fn new(code: u32, pid: i32) -> Self {
+        Self {
+            code,
+            skip: Atomic::new(false),
+            pid,
+        }
+    }
+
+    /// Disable this DeliverCode and make it do nothing.
+    ///
+    /// This is used instead of removing it from the work list, since `LinkedList::remove` is
+    /// unsafe, whereas this method is not.
+    fn skip(&self) {
+        self.skip.store(true, Relaxed);
+    }
+}
+
+impl DeliverToRead for DeliverCode {
+    fn do_work(
+        self: DArc<Self>,
+        _thread: &Thread,
+        writer: &mut BinderReturnWriter<'_>,
+    ) -> Result<bool> {
+        if !self.skip.load(Relaxed) {
+            writer.write_code(self.code)?;
+        }
+        Ok(true)
+    }
+
+    fn cancel(self: DArc<Self>) {
+        if !self.skip.load(Relaxed) {
+            binder_debug!(
+                pid = self.pid,
+                DeadTransaction,
+                "undelivered TRANSACTION_COMPLETE"
+            );
+        }
+    }
+
+    fn should_sync_wakeup(&self) -> bool {
+        false
+    }
+
+    fn debug_print(&self, m: &SeqFile, prefix: &str, _tprefix: &str) -> Result<()> {
+        seq_print!(m, "{}", prefix);
+        if self.skip.load(Relaxed) {
+            seq_print!(m, "(skipped) ");
+        }
+        if self.code == defs::BR_TRANSACTION_COMPLETE {
+            seq_print!(m, "transaction complete\n");
+        } else {
+            seq_print!(m, "transaction error: {}\n", self.code);
+        }
+        Ok(())
+    }
+}
+
+fn ptr_align(value: usize) -> Option<usize> {
+    let size = core::mem::size_of::<usize>() - 1;
+    Some(value.checked_add(size)? & !size)
+}
+
+// SAFETY: We call register in `init`.
+static BINDER_SHRINKER: Shrinker = unsafe { Shrinker::new() };
+
+struct BinderModule {
+    _netlink: kernel::net::netlink::Registration,
+}
+
+impl kernel::Module for BinderModule {
+    fn init(_module: &'static kernel::ThisModule) -> Result<Self> {
+        // SAFETY: The module initializer never runs twice, so we only call this once.
+        unsafe { crate::context::CONTEXTS.init() };
+
+        let netlink = crate::netlink::BINDER_NL_FAMILY.register()?;
+        BINDER_SHRINKER.register(c"android-binder")?;
+
+        // SAFETY: The module is being loaded, so we can initialize binderfs.
+        unsafe { kernel::error::to_result(binderfs::init_rust_binderfs())? };
+
+        Ok(Self { _netlink: netlink })
+    }
+}
+
+/// Makes the inner type Sync.
+#[repr(transparent)]
+pub struct AssertSync<T>(T);
+// SAFETY: Used only to insert C bindings types into globals, which is safe.
+unsafe impl<T> Sync for AssertSync<T> {}
+
+/// File operations that rust_binderfs.c can use.
+#[no_mangle]
+#[used]
+pub static rust_binder_fops: AssertSync<kernel::bindings::file_operations> = {
+    let ops = kernel::bindings::file_operations {
+        owner: this_module::<LocalModule>().as_ptr(),
+        poll: Some(rust_binder_poll),
+        unlocked_ioctl: Some(rust_binder_ioctl),
+        compat_ioctl: bindings::compat_ptr_ioctl,
+        mmap: Some(rust_binder_mmap),
+        open: Some(rust_binder_open),
+        release: Some(rust_binder_release),
+        flush: Some(rust_binder_flush),
+        ..pin_init::zeroed()
+    };
+    AssertSync(ops)
+};
+
+/// # Safety
+/// Only called by binderfs.
+#[no_mangle]
+unsafe extern "C" fn rust_binder_new_context(
+    name: *const kernel::ffi::c_char,
+) -> *mut kernel::ffi::c_void {
+    // SAFETY: The caller will always provide a valid c string here.
+    let name = unsafe { kernel::str::CStr::from_char_ptr(name) };
+    match Context::new(name) {
+        Ok(ctx) => Arc::into_foreign(ctx),
+        Err(_err) => core::ptr::null_mut(),
+    }
+}
+
+/// # Safety
+/// Only called by binderfs.
+#[no_mangle]
+unsafe extern "C" fn rust_binder_remove_context(device: *mut kernel::ffi::c_void) {
+    if !device.is_null() {
+        // SAFETY: The caller ensures that the `device` pointer came from a previous call to
+        // `rust_binder_new_device`.
+        let ctx = unsafe { Arc::<Context>::from_foreign(device) };
+        ctx.deregister();
+        drop(ctx);
+    }
+}
+
+/// # Safety
+/// Only called by binderfs.
+unsafe extern "C" fn rust_binder_open(
+    inode: *mut bindings::inode,
+    file_ptr: *mut bindings::file,
+) -> kernel::ffi::c_int {
+    // SAFETY: The `rust_binderfs.c` file ensures that `i_private` is set to a
+    // `struct binder_device`.
+    let device = unsafe { (*inode).i_private } as *const binderfs::binder_device;
+
+    assert!(!device.is_null());
+
+    // SAFETY: The `rust_binderfs.c` file ensures that `device->ctx` holds a binder context when
+    // using the rust binder fops.
+    let ctx = unsafe { Arc::<Context>::borrow((*device).ctx) };
+
+    // SAFETY: The caller provides a valid file pointer to a new `struct file`.
+    let file = unsafe { File::from_raw_file(file_ptr) };
+    let process = match Process::open(ctx, file) {
+        Ok(process) => process,
+        Err(err) => return err.to_errno(),
+    };
+
+    // SAFETY: This is an `inode` for a newly created binder file.
+    match unsafe { BinderfsProcFile::new(inode, process.task.pid()) } {
+        Ok(Some(file)) => process.inner.lock().binderfs_file = Some(file),
+        Ok(None) => { /* pid already exists */ }
+        Err(err) => return err.to_errno(),
+    }
+
+    // SAFETY: This file is associated with Rust binder, so we own the `private_data` field.
+    unsafe { (*file_ptr).private_data = process.into_foreign() };
+    0
+}
+
+/// # Safety
+/// Only called by binderfs.
+unsafe extern "C" fn rust_binder_release(
+    _inode: *mut bindings::inode,
+    file: *mut bindings::file,
+) -> kernel::ffi::c_int {
+    // SAFETY: We previously set `private_data` in `rust_binder_open`.
+    let process = unsafe { Arc::<Process>::from_foreign((*file).private_data) };
+    // SAFETY: The caller ensures that the file is valid.
+    let file = unsafe { File::from_raw_file(file) };
+    Process::release(process, file);
+    0
+}
+
+/// # Safety
+/// Only called by binderfs.
+unsafe extern "C" fn rust_binder_ioctl(
+    file: *mut bindings::file,
+    cmd: kernel::ffi::c_uint,
+    arg: kernel::ffi::c_ulong,
+) -> kernel::ffi::c_long {
+    // SAFETY: We previously set `private_data` in `rust_binder_open`.
+    let f = unsafe { Arc::<Process>::borrow((*file).private_data) };
+    // SAFETY: The caller ensures that the file is valid.
+    match Process::ioctl(f, unsafe { File::from_raw_file(file) }, cmd, arg) {
+        Ok(()) => 0,
+        Err(err) => err.to_errno() as isize,
+    }
+}
+
+/// # Safety
+/// Only called by binderfs.
+unsafe extern "C" fn rust_binder_mmap(
+    file: *mut bindings::file,
+    vma: *mut bindings::vm_area_struct,
+) -> kernel::ffi::c_int {
+    // SAFETY: We previously set `private_data` in `rust_binder_open`.
+    let f = unsafe { Arc::<Process>::borrow((*file).private_data) };
+    // SAFETY: The caller ensures that the vma is valid.
+    let area = unsafe { kernel::mm::virt::VmaNew::from_raw(vma) };
+    // SAFETY: The caller ensures that the file is valid.
+    match Process::mmap(f, unsafe { File::from_raw_file(file) }, area) {
+        Ok(()) => 0,
+        Err(err) => err.to_errno(),
+    }
+}
+
+/// # Safety
+/// Only called by binderfs.
+unsafe extern "C" fn rust_binder_poll(
+    file: *mut bindings::file,
+    wait: *mut bindings::poll_table_struct,
+) -> bindings::__poll_t {
+    // SAFETY: We previously set `private_data` in `rust_binder_open`.
+    let f = unsafe { Arc::<Process>::borrow((*file).private_data) };
+    // SAFETY: The caller ensures that the file is valid.
+    let fileref = unsafe { File::from_raw_file(file) };
+    // SAFETY: The caller ensures that the `PollTable` is valid.
+    match Process::poll(f, fileref, unsafe { PollTable::from_raw(wait) }) {
+        Ok(v) => v,
+        Err(_) => bindings::POLLERR,
+    }
+}
+
+/// # Safety
+/// Only called by binderfs.
+unsafe extern "C" fn rust_binder_flush(
+    file: *mut bindings::file,
+    _id: bindings::fl_owner_t,
+) -> kernel::ffi::c_int {
+    // SAFETY: We previously set `private_data` in `rust_binder_open`.
+    let f = unsafe { Arc::<Process>::borrow((*file).private_data) };
+    match Process::flush(f) {
+        Ok(()) => 0,
+        Err(err) => err.to_errno(),
+    }
+}
+
+/// # Safety
+/// Only called by binderfs.
+#[no_mangle]
+unsafe extern "C" fn rust_binder_stats_show(
+    ptr: *mut seq_file,
+    _: *mut kernel::ffi::c_void,
+) -> kernel::ffi::c_int {
+    // SAFETY: The caller ensures that the pointer is valid and exclusive for the duration in which
+    // this method is called.
+    let m = unsafe { SeqFile::from_raw(ptr) };
+    if let Err(err) = rust_binder_stats_show_impl(m) {
+        seq_print!(m, "failed to generate state: {:?}\n", err);
+    }
+    0
+}
+
+/// # Safety
+/// Only called by binderfs.
+#[no_mangle]
+unsafe extern "C" fn rust_binder_state_show(
+    ptr: *mut seq_file,
+    _: *mut kernel::ffi::c_void,
+) -> kernel::ffi::c_int {
+    // SAFETY: The caller ensures that the pointer is valid and exclusive for the duration in which
+    // this method is called.
+    let m = unsafe { SeqFile::from_raw(ptr) };
+    if let Err(err) = rust_binder_state_show_impl(m) {
+        seq_print!(m, "failed to generate state: {:?}\n", err);
+    }
+    0
+}
+
+/// # Safety
+/// Only called by binderfs.
+#[no_mangle]
+unsafe extern "C" fn rust_binder_proc_show(
+    ptr: *mut seq_file,
+    _: *mut kernel::ffi::c_void,
+) -> kernel::ffi::c_int {
+    // SAFETY: Accessing the private field of `seq_file` is okay.
+    let pid = unsafe { (*ptr).private }.addr() as Pid;
+    // SAFETY: The caller ensures that the pointer is valid and exclusive for the duration in which
+    // this method is called.
+    let m = unsafe { SeqFile::from_raw(ptr) };
+    if let Err(err) = rust_binder_proc_show_impl(m, pid) {
+        seq_print!(m, "failed to generate state: {:?}\n", err);
+    }
+    0
+}
+
+/// # Safety
+/// Only called by binderfs.
+#[no_mangle]
+unsafe extern "C" fn rust_binder_transactions_show(
+    ptr: *mut seq_file,
+    _: *mut kernel::ffi::c_void,
+) -> kernel::ffi::c_int {
+    // SAFETY: The caller ensures that the pointer is valid and exclusive for the duration in which
+    // this method is called.
+    let m = unsafe { SeqFile::from_raw(ptr) };
+    if let Err(err) = rust_binder_transactions_show_impl(m) {
+        seq_print!(m, "failed to generate state: {:?}\n", err);
+    }
+    0
+}
+
+fn rust_binder_transactions_show_impl(m: &SeqFile) -> Result<()> {
+    seq_print!(m, "binder transactions:\n");
+    let contexts = context::get_all_contexts()?;
+    for ctx in contexts {
+        let procs = ctx.get_all_procs()?;
+        for proc in procs {
+            proc.debug_print(m, &ctx, false)?;
+            seq_print!(m, "\n");
+        }
+    }
+    Ok(())
+}
+
+fn rust_binder_stats_show_impl(m: &SeqFile) -> Result<()> {
+    seq_print!(m, "binder stats:\n");
+    stats::GLOBAL_STATS.debug_print("", m);
+    let contexts = context::get_all_contexts()?;
+    for ctx in contexts {
+        let procs = ctx.get_all_procs()?;
+        for proc in procs {
+            proc.debug_print_stats(m, &ctx)?;
+            seq_print!(m, "\n");
+        }
+    }
+    Ok(())
+}
+
+fn rust_binder_state_show_impl(m: &SeqFile) -> Result<()> {
+    seq_print!(m, "binder state:\n");
+    let contexts = context::get_all_contexts()?;
+    for ctx in contexts {
+        let procs = ctx.get_all_procs()?;
+        for proc in procs {
+            proc.debug_print(m, &ctx, true)?;
+            seq_print!(m, "\n");
+        }
+    }
+    Ok(())
+}
+
+fn rust_binder_proc_show_impl(m: &SeqFile, pid: Pid) -> Result<()> {
+    seq_print!(m, "binder proc state:\n");
+    let contexts = context::get_all_contexts()?;
+    for ctx in contexts {
+        let procs = ctx.get_procs_with_pid(pid)?;
+        for proc in procs {
+            proc.debug_print(m, &ctx, true)?;
+            seq_print!(m, "\n");
+        }
+    }
+    Ok(())
+}
+
+struct BinderfsProcFile(NonNull<bindings::dentry>);
+
+// SAFETY: Safe to drop any thread.
+unsafe impl Send for BinderfsProcFile {}
+
+impl BinderfsProcFile {
+    /// # Safety
+    ///
+    /// Takes an inode from a newly created binder file.
+    unsafe fn new(nodp: *mut bindings::inode, pid: i32) -> Result<Option<Self>> {
+        // SAFETY: The caller passes an `inode` for a newly created binder file.
+        let dentry = unsafe { binderfs::rust_binderfs_create_proc_file(nodp, pid) };
+        match kernel::error::from_err_ptr(dentry) {
+            Ok(dentry) => Ok(NonNull::new(dentry).map(Self)),
+            Err(err) if err == EEXIST => Ok(None),
+            Err(err) => Err(err),
+        }
+    }
+}
+
+impl Drop for BinderfsProcFile {
+    fn drop(&mut self) {
+        // SAFETY: This is a dentry from `rust_binderfs_remove_file` that has not been deleted yet.
+        unsafe { binderfs::rust_binderfs_remove_file(self.0.as_ptr()) };
+    }
+}
diff --git a/drivers/android/binder/rust_binderfs.c b/drivers/android/binder/rust_binderfs.c
new file mode 100644
index 000000000..300cc6556
--- /dev/null
+++ b/drivers/android/binder/rust_binderfs.c
@@ -0,0 +1,793 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/compiler_types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/fsnotify.h>
+#include <linux/gfp.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/ipc_namespace.h>
+#include <linux/kdev_t.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/namei.h>
+#include <linux/magic.h>
+#include <linux/major.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/mount.h>
+#include <linux/fs_parser.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/spinlock_types.h>
+#include <linux/stddef.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/user_namespace.h>
+#include <linux/xarray.h>
+#include <uapi/asm-generic/errno-base.h>
+#include <uapi/linux/android/binder.h>
+#include <uapi/linux/android/binderfs.h>
+
+#include "rust_binder.h"
+#include "rust_binder_internal.h"
+
+#define FIRST_INODE 1
+#define SECOND_INODE 2
+#define INODE_OFFSET 3
+#define BINDERFS_MAX_MINOR (1U << MINORBITS)
+/* Ensure that the initial ipc namespace always has devices available. */
+#define BINDERFS_MAX_MINOR_CAPPED (BINDERFS_MAX_MINOR - 4)
+
+DEFINE_SHOW_ATTRIBUTE(rust_binder_stats);
+DEFINE_SHOW_ATTRIBUTE(rust_binder_state);
+DEFINE_SHOW_ATTRIBUTE(rust_binder_transactions);
+DEFINE_SHOW_ATTRIBUTE(rust_binder_proc);
+
+char *rust_binder_devices_param = CONFIG_ANDROID_BINDER_DEVICES;
+module_param_named(rust_devices, rust_binder_devices_param, charp, 0444);
+
+extern u32 rust_binder_debug_mask;
+module_param_named(debug_mask, rust_binder_debug_mask, uint, 0644);
+
+static dev_t binderfs_dev;
+static DEFINE_MUTEX(binderfs_minors_mutex);
+static DEFINE_IDA(binderfs_minors);
+
+enum binderfs_param {
+	Opt_max,
+	Opt_stats_mode,
+};
+
+enum binderfs_stats_mode {
+	binderfs_stats_mode_unset,
+	binderfs_stats_mode_global,
+};
+
+struct binder_features {
+	bool oneway_spam_detection;
+	bool extended_error;
+	bool freeze_notification;
+};
+
+static const struct constant_table binderfs_param_stats[] = {
+	{ "global", binderfs_stats_mode_global },
+	{}
+};
+
+static const struct fs_parameter_spec binderfs_fs_parameters[] = {
+	fsparam_u32("max",	Opt_max),
+	fsparam_enum("stats",	Opt_stats_mode, binderfs_param_stats),
+	{}
+};
+
+static struct binder_features binder_features = {
+	.oneway_spam_detection = true,
+	.extended_error = true,
+	.freeze_notification = true,
+};
+
+static inline struct binderfs_info *BINDERFS_SB(const struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+/**
+ * binderfs_binder_device_create - allocate inode from super block of a
+ *                                 binderfs mount
+ * @ref_inode: inode from wich the super block will be taken
+ * @userp:     buffer to copy information about new device for userspace to
+ * @req:       struct binderfs_device as copied from userspace
+ *
+ * This function allocates a new binder_device and reserves a new minor
+ * number for it.
+ * Minor numbers are limited and tracked globally in binderfs_minors. The
+ * function will stash a struct binder_device for the specific binder
+ * device in i_private of the inode.
+ * It will go on to allocate a new inode from the super block of the
+ * filesystem mount, stash a struct binder_device in its i_private field
+ * and attach a dentry to that inode.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+static int binderfs_binder_device_create(struct inode *ref_inode,
+					 struct binderfs_device __user *userp,
+					 struct binderfs_device *req)
+{
+	int minor, ret;
+	struct dentry *dentry, *root;
+	struct binder_device *device = NULL;
+	rust_binder_context ctx = NULL;
+	struct inode *inode = NULL;
+	struct super_block *sb = ref_inode->i_sb;
+	struct binderfs_info *info = sb->s_fs_info;
+#if defined(CONFIG_IPC_NS)
+	bool use_reserve = (info->ipc_ns == &init_ipc_ns);
+#else
+	bool use_reserve = true;
+#endif
+
+	/* Reserve new minor number for the new device. */
+	mutex_lock(&binderfs_minors_mutex);
+	if (++info->device_count <= info->mount_opts.max)
+		minor = ida_alloc_max(&binderfs_minors,
+				      use_reserve ? BINDERFS_MAX_MINOR - 1 :
+						    BINDERFS_MAX_MINOR_CAPPED - 1,
+				      GFP_KERNEL);
+	else
+		minor = -ENOSPC;
+	if (minor < 0) {
+		--info->device_count;
+		mutex_unlock(&binderfs_minors_mutex);
+		return minor;
+	}
+	mutex_unlock(&binderfs_minors_mutex);
+
+	ret = -ENOMEM;
+	device = kzalloc_obj(*device);
+	if (!device)
+		goto err;
+
+	req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */
+
+	ctx = rust_binder_new_context(req->name);
+	if (!ctx)
+		goto err;
+
+	inode = new_inode(sb);
+	if (!inode)
+		goto err;
+
+	inode->i_ino = minor + INODE_OFFSET;
+	simple_inode_init_ts(inode);
+	init_special_inode(inode, S_IFCHR | 0600,
+			   MKDEV(MAJOR(binderfs_dev), minor));
+	inode->i_fop = &rust_binder_fops;
+	inode->i_uid = info->root_uid;
+	inode->i_gid = info->root_gid;
+
+	req->major = MAJOR(binderfs_dev);
+	req->minor = minor;
+	device->ctx = ctx;
+	device->minor = minor;
+
+	if (userp && copy_to_user(userp, req, sizeof(*req))) {
+		ret = -EFAULT;
+		goto err;
+	}
+
+	root = sb->s_root;
+	dentry = simple_start_creating(root, req->name);
+	if (IS_ERR(dentry)) {
+		ret = PTR_ERR(dentry);
+		goto err;
+	}
+
+	inode->i_private = device;
+	d_make_persistent(dentry, inode);
+
+	fsnotify_create(root->d_inode, dentry);
+	simple_done_creating(dentry);
+
+	return 0;
+
+err:
+	kfree(device);
+	rust_binder_remove_context(ctx);
+	mutex_lock(&binderfs_minors_mutex);
+	--info->device_count;
+	ida_free(&binderfs_minors, minor);
+	mutex_unlock(&binderfs_minors_mutex);
+	iput(inode);
+
+	return ret;
+}
+
+/**
+ * binder_ctl_ioctl - handle binder device node allocation requests
+ *
+ * The request handler for the binder-control device. All requests operate on
+ * the binderfs mount the binder-control device resides in:
+ * - BINDER_CTL_ADD
+ *   Allocate a new binder device.
+ *
+ * Return: %0 on success, negative errno on failure.
+ */
+static long binder_ctl_ioctl(struct file *file, unsigned int cmd,
+			     unsigned long arg)
+{
+	int ret = -EINVAL;
+	struct inode *inode = file_inode(file);
+	struct binderfs_device __user *device = (struct binderfs_device __user *)arg;
+	struct binderfs_device device_req;
+
+	switch (cmd) {
+	case BINDER_CTL_ADD:
+		ret = copy_from_user(&device_req, device, sizeof(device_req));
+		if (ret) {
+			ret = -EFAULT;
+			break;
+		}
+
+		ret = binderfs_binder_device_create(inode, device, &device_req);
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+static void binderfs_evict_inode(struct inode *inode)
+{
+	struct binder_device *device = inode->i_private;
+	struct binderfs_info *info = BINDERFS_SB(inode->i_sb);
+
+	clear_inode(inode);
+
+	if (!S_ISCHR(inode->i_mode) || !device)
+		return;
+
+	mutex_lock(&binderfs_minors_mutex);
+	--info->device_count;
+	ida_free(&binderfs_minors, device->minor);
+	mutex_unlock(&binderfs_minors_mutex);
+
+	/* ctx is null for binder-control, but this function ignores null pointers */
+	rust_binder_remove_context(device->ctx);
+
+	kfree(device);
+}
+
+static int binderfs_fs_context_parse_param(struct fs_context *fc,
+					   struct fs_parameter *param)
+{
+	int opt;
+	struct binderfs_mount_opts *ctx = fc->fs_private;
+	struct fs_parse_result result;
+
+	opt = fs_parse(fc, binderfs_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_max:
+		if (result.uint_32 > BINDERFS_MAX_MINOR)
+			return invalfc(fc, "Bad value for '%s'", param->key);
+
+		ctx->max = result.uint_32;
+		break;
+	case Opt_stats_mode:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		ctx->stats_mode = result.uint_32;
+		break;
+	default:
+		return invalfc(fc, "Unsupported parameter '%s'", param->key);
+	}
+
+	return 0;
+}
+
+static int binderfs_fs_context_reconfigure(struct fs_context *fc)
+{
+	struct binderfs_mount_opts *ctx = fc->fs_private;
+	struct binderfs_info *info = BINDERFS_SB(fc->root->d_sb);
+
+	if (info->mount_opts.stats_mode != ctx->stats_mode)
+		return invalfc(fc, "Binderfs stats mode cannot be changed during a remount");
+
+	info->mount_opts.stats_mode = ctx->stats_mode;
+	info->mount_opts.max = ctx->max;
+	return 0;
+}
+
+static int binderfs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct binderfs_info *info = BINDERFS_SB(root->d_sb);
+
+	if (info->mount_opts.max <= BINDERFS_MAX_MINOR)
+		seq_printf(seq, ",max=%d", info->mount_opts.max);
+
+	switch (info->mount_opts.stats_mode) {
+	case binderfs_stats_mode_unset:
+		break;
+	case binderfs_stats_mode_global:
+		seq_puts(seq, ",stats=global");
+		break;
+	}
+
+	return 0;
+}
+
+static const struct super_operations binderfs_super_ops = {
+	.evict_inode    = binderfs_evict_inode,
+	.show_options	= binderfs_show_options,
+	.statfs         = simple_statfs,
+};
+
+static inline bool is_binderfs_control_device(const struct dentry *dentry)
+{
+	struct binderfs_info *info = dentry->d_sb->s_fs_info;
+
+	return info->control_dentry == dentry;
+}
+
+static int binderfs_rename(struct mnt_idmap *idmap,
+			   struct inode *old_dir, struct dentry *old_dentry,
+			   struct inode *new_dir, struct dentry *new_dentry,
+			   unsigned int flags)
+{
+	if (is_binderfs_control_device(old_dentry) ||
+	    is_binderfs_control_device(new_dentry))
+		return -EPERM;
+
+	return simple_rename(idmap, old_dir, old_dentry, new_dir,
+			     new_dentry, flags);
+}
+
+static int binderfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	if (is_binderfs_control_device(dentry))
+		return -EPERM;
+
+	return simple_unlink(dir, dentry);
+}
+
+static const struct file_operations binder_ctl_fops = {
+	.owner		= THIS_MODULE,
+	.open		= nonseekable_open,
+	.unlocked_ioctl	= binder_ctl_ioctl,
+	.compat_ioctl	= binder_ctl_ioctl,
+	.llseek		= noop_llseek,
+};
+
+/**
+ * binderfs_binder_ctl_create - create a new binder-control device
+ * @sb: super block of the binderfs mount
+ *
+ * This function creates a new binder-control device node in the binderfs mount
+ * referred to by @sb.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+static int binderfs_binder_ctl_create(struct super_block *sb)
+{
+	int minor, ret;
+	struct dentry *dentry;
+	struct binder_device *device;
+	struct inode *inode = NULL;
+	struct dentry *root = sb->s_root;
+	struct binderfs_info *info = sb->s_fs_info;
+#if defined(CONFIG_IPC_NS)
+	bool use_reserve = (info->ipc_ns == &init_ipc_ns);
+#else
+	bool use_reserve = true;
+#endif
+
+	device = kzalloc_obj(*device);
+	if (!device)
+		return -ENOMEM;
+
+	ret = -ENOMEM;
+	inode = new_inode(sb);
+	if (!inode)
+		goto out;
+
+	/* Reserve a new minor number for the new device. */
+	mutex_lock(&binderfs_minors_mutex);
+	minor = ida_alloc_max(&binderfs_minors,
+			      use_reserve ? BINDERFS_MAX_MINOR - 1 :
+					    BINDERFS_MAX_MINOR_CAPPED - 1,
+			      GFP_KERNEL);
+	mutex_unlock(&binderfs_minors_mutex);
+	if (minor < 0) {
+		ret = minor;
+		goto out;
+	}
+
+	inode->i_ino = SECOND_INODE;
+	simple_inode_init_ts(inode);
+	init_special_inode(inode, S_IFCHR | 0600,
+			   MKDEV(MAJOR(binderfs_dev), minor));
+	inode->i_fop = &binder_ctl_fops;
+	inode->i_uid = info->root_uid;
+	inode->i_gid = info->root_gid;
+
+	device->minor = minor;
+	device->ctx = NULL;
+
+	dentry = d_alloc_name(root, "binder-control");
+	if (!dentry)
+		goto out;
+
+	inode->i_private = device;
+	info->control_dentry = dentry;
+	d_make_persistent(dentry, inode);
+	dput(dentry);
+
+	return 0;
+
+out:
+	kfree(device);
+	iput(inode);
+
+	return ret;
+}
+
+static const struct inode_operations binderfs_dir_inode_operations = {
+	.lookup = simple_lookup,
+	.rename = binderfs_rename,
+	.unlink = binderfs_unlink,
+};
+
+static struct inode *binderfs_make_inode(struct super_block *sb, int mode)
+{
+	struct inode *ret;
+
+	ret = new_inode(sb);
+	if (ret) {
+		ret->i_ino = iunique(sb, BINDERFS_MAX_MINOR + INODE_OFFSET);
+		ret->i_mode = mode;
+		simple_inode_init_ts(ret);
+	}
+	return ret;
+}
+
+void rust_binderfs_remove_file(struct dentry *dentry)
+{
+	simple_recursive_removal(dentry, NULL);
+}
+
+static struct dentry *rust_binderfs_create_file(struct dentry *parent, const char *name,
+						const struct file_operations *fops,
+						void *data)
+{
+	struct dentry *dentry;
+	struct inode *new_inode;
+
+	new_inode = binderfs_make_inode(parent->d_sb, S_IFREG | 0444);
+	if (!new_inode)
+		return ERR_PTR(-ENOMEM);
+	new_inode->i_fop = fops;
+	new_inode->i_private = data;
+
+	dentry = simple_start_creating(parent, name);
+	if (IS_ERR(dentry)) {
+		iput(new_inode);
+		return dentry;
+	}
+
+	d_make_persistent(dentry, new_inode);
+	fsnotify_create(parent->d_inode, dentry);
+	simple_done_creating(dentry);
+	return dentry;
+}
+
+struct dentry *rust_binderfs_create_proc_file(struct inode *nodp, int pid)
+{
+	struct binderfs_info *info = nodp->i_sb->s_fs_info;
+	struct dentry *dir = info->proc_log_dir;
+	char strbuf[20 + 1];
+	void *data = (void *)(unsigned long) pid;
+
+	if (!dir)
+		return NULL;
+
+	snprintf(strbuf, sizeof(strbuf), "%u", pid);
+	return rust_binderfs_create_file(dir, strbuf, &rust_binder_proc_fops, data);
+}
+
+static struct dentry *binderfs_create_dir(struct dentry *parent,
+					  const char *name)
+{
+	struct dentry *dentry;
+	struct inode *new_inode;
+
+	new_inode = binderfs_make_inode(parent->d_sb, S_IFDIR | 0755);
+	if (!new_inode)
+		return ERR_PTR(-ENOMEM);
+
+	new_inode->i_fop = &simple_dir_operations;
+	new_inode->i_op = &simple_dir_inode_operations;
+
+	dentry = simple_start_creating(parent, name);
+	if (IS_ERR(dentry)) {
+		iput(new_inode);
+		return dentry;
+	}
+
+	inc_nlink(parent->d_inode);
+	set_nlink(new_inode, 2);
+	d_make_persistent(dentry, new_inode);
+	fsnotify_mkdir(parent->d_inode, dentry);
+	simple_done_creating(dentry);
+	return dentry;
+}
+
+static int binder_features_show(struct seq_file *m, void *unused)
+{
+	bool *feature = m->private;
+
+	seq_printf(m, "%d\n", *feature);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(binder_features);
+
+static int init_binder_features(struct super_block *sb)
+{
+	struct dentry *dentry, *dir;
+
+	dir = binderfs_create_dir(sb->s_root, "features");
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+
+	dentry = rust_binderfs_create_file(dir, "oneway_spam_detection",
+				      &binder_features_fops,
+				      &binder_features.oneway_spam_detection);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	dentry = rust_binderfs_create_file(dir, "extended_error",
+				      &binder_features_fops,
+				      &binder_features.extended_error);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	dentry = rust_binderfs_create_file(dir, "freeze_notification",
+				      &binder_features_fops,
+				      &binder_features.freeze_notification);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	return 0;
+}
+
+static int init_binder_logs(struct super_block *sb)
+{
+	struct dentry *binder_logs_root_dir, *dentry, *proc_log_dir;
+	struct binderfs_info *info;
+	int ret = 0;
+
+	binder_logs_root_dir = binderfs_create_dir(sb->s_root,
+						   "binder_logs");
+	if (IS_ERR(binder_logs_root_dir)) {
+		ret = PTR_ERR(binder_logs_root_dir);
+		goto out;
+	}
+
+	dentry = rust_binderfs_create_file(binder_logs_root_dir, "stats",
+				      &rust_binder_stats_fops, NULL);
+	if (IS_ERR(dentry)) {
+		ret = PTR_ERR(dentry);
+		goto out;
+	}
+
+	dentry = rust_binderfs_create_file(binder_logs_root_dir, "state",
+				      &rust_binder_state_fops, NULL);
+	if (IS_ERR(dentry)) {
+		ret = PTR_ERR(dentry);
+		goto out;
+	}
+
+	dentry = rust_binderfs_create_file(binder_logs_root_dir, "transactions",
+				      &rust_binder_transactions_fops, NULL);
+	if (IS_ERR(dentry)) {
+		ret = PTR_ERR(dentry);
+		goto out;
+	}
+
+	proc_log_dir = binderfs_create_dir(binder_logs_root_dir, "proc");
+	if (IS_ERR(proc_log_dir)) {
+		ret = PTR_ERR(proc_log_dir);
+		goto out;
+	}
+	info = sb->s_fs_info;
+	info->proc_log_dir = proc_log_dir;
+
+out:
+	return ret;
+}
+
+static int binderfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	int ret;
+	struct binderfs_info *info;
+	struct binderfs_mount_opts *ctx = fc->fs_private;
+	struct inode *inode = NULL;
+	struct binderfs_device device_info = {};
+	const char *name;
+	size_t len;
+
+	sb->s_blocksize = PAGE_SIZE;
+	sb->s_blocksize_bits = PAGE_SHIFT;
+
+	/*
+	 * The binderfs filesystem can be mounted by userns root in a
+	 * non-initial userns. By default such mounts have the SB_I_NODEV flag
+	 * set in s_iflags to prevent security issues where userns root can
+	 * just create random device nodes via mknod() since it owns the
+	 * filesystem mount. But binderfs does not allow to create any files
+	 * including devices nodes. The only way to create binder devices nodes
+	 * is through the binder-control device which userns root is explicitly
+	 * allowed to do. So removing the SB_I_NODEV flag from s_iflags is both
+	 * necessary and safe.
+	 */
+	sb->s_iflags &= ~SB_I_NODEV;
+	sb->s_iflags |= SB_I_NOEXEC;
+	sb->s_magic = RUST_BINDERFS_SUPER_MAGIC;
+	sb->s_op = &binderfs_super_ops;
+	sb->s_time_gran = 1;
+
+	sb->s_fs_info = kzalloc_obj(struct binderfs_info);
+	if (!sb->s_fs_info)
+		return -ENOMEM;
+	info = sb->s_fs_info;
+
+	info->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns);
+
+	info->root_gid = make_kgid(sb->s_user_ns, 0);
+	if (!gid_valid(info->root_gid))
+		info->root_gid = GLOBAL_ROOT_GID;
+	info->root_uid = make_kuid(sb->s_user_ns, 0);
+	if (!uid_valid(info->root_uid))
+		info->root_uid = GLOBAL_ROOT_UID;
+	info->mount_opts.max = ctx->max;
+	info->mount_opts.stats_mode = ctx->stats_mode;
+
+	inode = new_inode(sb);
+	if (!inode)
+		return -ENOMEM;
+
+	inode->i_ino = FIRST_INODE;
+	inode->i_fop = &simple_dir_operations;
+	inode->i_mode = S_IFDIR | 0755;
+	simple_inode_init_ts(inode);
+	inode->i_op = &binderfs_dir_inode_operations;
+	set_nlink(inode, 2);
+
+	sb->s_root = d_make_root(inode);
+	if (!sb->s_root)
+		return -ENOMEM;
+
+	ret = binderfs_binder_ctl_create(sb);
+	if (ret)
+		return ret;
+
+	name = rust_binder_devices_param;
+	for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) {
+		strscpy(device_info.name, name, len + 1);
+		ret = binderfs_binder_device_create(inode, NULL, &device_info);
+		if (ret)
+			return ret;
+		name += len;
+		if (*name == ',')
+			name++;
+	}
+
+	ret = init_binder_features(sb);
+	if (ret)
+		return ret;
+
+	if (info->mount_opts.stats_mode == binderfs_stats_mode_global)
+		return init_binder_logs(sb);
+
+	return 0;
+}
+
+static int binderfs_fs_context_get_tree(struct fs_context *fc)
+{
+	return get_tree_nodev(fc, binderfs_fill_super);
+}
+
+static void binderfs_fs_context_free(struct fs_context *fc)
+{
+	struct binderfs_mount_opts *ctx = fc->fs_private;
+
+	kfree(ctx);
+}
+
+static const struct fs_context_operations binderfs_fs_context_ops = {
+	.free		= binderfs_fs_context_free,
+	.get_tree	= binderfs_fs_context_get_tree,
+	.parse_param	= binderfs_fs_context_parse_param,
+	.reconfigure	= binderfs_fs_context_reconfigure,
+};
+
+static int binderfs_init_fs_context(struct fs_context *fc)
+{
+	struct binderfs_mount_opts *ctx;
+
+	ctx = kzalloc_obj(struct binderfs_mount_opts);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->max = BINDERFS_MAX_MINOR;
+	ctx->stats_mode = binderfs_stats_mode_unset;
+
+	fc->fs_private = ctx;
+	fc->ops = &binderfs_fs_context_ops;
+
+	return 0;
+}
+
+static void binderfs_kill_super(struct super_block *sb)
+{
+	struct binderfs_info *info = sb->s_fs_info;
+
+	/*
+	 * During inode eviction struct binderfs_info is needed.
+	 * So first wipe the super_block then free struct binderfs_info.
+	 */
+	kill_anon_super(sb);
+
+	if (info && info->ipc_ns)
+		put_ipc_ns(info->ipc_ns);
+
+	kfree(info);
+}
+
+static struct file_system_type binder_fs_type = {
+	.name			= "binder",
+	.init_fs_context	= binderfs_init_fs_context,
+	.parameters		= binderfs_fs_parameters,
+	.kill_sb		= binderfs_kill_super,
+	.fs_flags		= FS_USERNS_MOUNT,
+};
+
+int init_rust_binderfs(void)
+{
+	int ret;
+	const char *name;
+	size_t len;
+
+	/* Verify that the default binderfs device names are valid. */
+	name = rust_binder_devices_param;
+	for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) {
+		if (len > BINDERFS_MAX_NAME)
+			return -E2BIG;
+		name += len;
+		if (*name == ',')
+			name++;
+	}
+
+	/* Allocate new major number for binderfs. */
+	ret = alloc_chrdev_region(&binderfs_dev, 0, BINDERFS_MAX_MINOR,
+				  "rust_binder");
+	if (ret)
+		return ret;
+
+	ret = register_filesystem(&binder_fs_type);
+	if (ret) {
+		unregister_chrdev_region(binderfs_dev, BINDERFS_MAX_MINOR);
+		return ret;
+	}
+
+	return ret;
+}
diff --git a/drivers/android/binder/stats.rs b/drivers/android/binder/stats.rs
new file mode 100644
index 000000000..ec81dc774
--- /dev/null
+++ b/drivers/android/binder/stats.rs
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+//! Keep track of statistics for binder_logs.
+
+use crate::defs::*;
+use kernel::sync::atomic::{ordering::Relaxed, Atomic};
+use kernel::{ioctl::_IOC_NR, seq_file::SeqFile, seq_print};
+
+const BC_COUNT: usize = _IOC_NR(BC_FREEZE_NOTIFICATION_DONE) as usize + 1;
+const BR_COUNT: usize = _IOC_NR(BR_CLEAR_FREEZE_NOTIFICATION_DONE) as usize + 1;
+
+pub(crate) static GLOBAL_STATS: BinderStats = BinderStats::new();
+
+pub(crate) struct BinderStats {
+    bc: [Atomic<u32>; BC_COUNT],
+    br: [Atomic<u32>; BR_COUNT],
+}
+
+impl BinderStats {
+    pub(crate) const fn new() -> Self {
+        #[expect(clippy::declare_interior_mutable_const)]
+        const ZERO: Atomic<u32> = Atomic::new(0);
+
+        Self {
+            bc: [ZERO; BC_COUNT],
+            br: [ZERO; BR_COUNT],
+        }
+    }
+
+    pub(crate) fn inc_bc(&self, bc: u32) {
+        let idx = _IOC_NR(bc) as usize;
+        if let Some(bc_ref) = self.bc.get(idx) {
+            bc_ref.fetch_add(1, Relaxed);
+        }
+    }
+
+    pub(crate) fn inc_br(&self, br: u32) {
+        let idx = _IOC_NR(br) as usize;
+        if let Some(br_ref) = self.br.get(idx) {
+            br_ref.fetch_add(1, Relaxed);
+        }
+    }
+
+    pub(crate) fn debug_print(&self, prefix: &str, m: &SeqFile) {
+        for (i, cnt) in self.bc.iter().enumerate() {
+            let cnt = cnt.load(Relaxed);
+            if cnt > 0 {
+                seq_print!(m, "{}{}: {}\n", prefix, command_string(i), cnt);
+            }
+        }
+        for (i, cnt) in self.br.iter().enumerate() {
+            let cnt = cnt.load(Relaxed);
+            if cnt > 0 {
+                seq_print!(m, "{}{}: {}\n", prefix, return_string(i), cnt);
+            }
+        }
+    }
+}
+
+mod strings {
+    use core::str::from_utf8_unchecked;
+    use kernel::str::{CStr, CStrExt as _};
+
+    extern "C" {
+        static binder_command_strings: [*const u8; super::BC_COUNT];
+        static binder_return_strings: [*const u8; super::BR_COUNT];
+    }
+
+    pub(super) fn command_string(i: usize) -> &'static str {
+        // SAFETY: Accessing `binder_command_strings` is always safe.
+        let c_str_ptr = unsafe { binder_command_strings[i] };
+        // SAFETY: The `binder_command_strings` array only contains nul-terminated strings.
+        let bytes = unsafe { CStr::from_char_ptr(c_str_ptr) }.to_bytes();
+        // SAFETY: The `binder_command_strings` array only contains strings with ascii-chars.
+        unsafe { from_utf8_unchecked(bytes) }
+    }
+
+    pub(super) fn return_string(i: usize) -> &'static str {
+        // SAFETY: Accessing `binder_return_strings` is always safe.
+        let c_str_ptr = unsafe { binder_return_strings[i] };
+        // SAFETY: The `binder_command_strings` array only contains nul-terminated strings.
+        let bytes = unsafe { CStr::from_char_ptr(c_str_ptr) }.to_bytes();
+        // SAFETY: The `binder_command_strings` array only contains strings with ascii-chars.
+        unsafe { from_utf8_unchecked(bytes) }
+    }
+}
+use strings::{command_string, return_string};
diff --git a/drivers/android/binder/thread.rs b/drivers/android/binder/thread.rs
new file mode 100644
index 000000000..18a14aa8a
--- /dev/null
+++ b/drivers/android/binder/thread.rs
@@ -0,0 +1,1756 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+//! This module defines the `Thread` type, which represents a userspace thread that is using
+//! binder.
+//!
+//! The `Process` object stores all of the threads in an rb tree.
+
+use kernel::{
+    bindings,
+    bits::bit_u32,
+    fs::LocalFile,
+    list::{AtomicTracker, List, ListArc, ListLinks, TryNewListArc},
+    prelude::*,
+    security,
+    seq_file::SeqFile,
+    seq_print,
+    sync::atomic::{ordering::Relaxed, Atomic},
+    sync::{aref::ARef, Arc, CondVar, SpinLock},
+    task::Task,
+    uaccess::{UserPtr, UserSlice, UserSliceReader},
+    uapi,
+};
+
+use crate::{
+    allocation::{Allocation, AllocationView, BinderObject, BinderObjectRef, NewAllocation},
+    defs::*,
+    error::BinderResult,
+    process::{GetWorkOrRegister, Process},
+    ptr_align,
+    stats::GLOBAL_STATS,
+    transaction::{Transaction, TransactionFlag, TransactionFlags, TransactionInfo},
+    BinderReturnWriter, DArc, DLArc, DTRWrap, DeliverCode, DeliverToRead,
+};
+
+use core::mem::size_of;
+
+fn is_aligned(value: usize, to: usize) -> bool {
+    value % to == 0
+}
+
+/// Stores the layout of the scatter-gather entries. This is used during the `translate_objects`
+/// call and is discarded when it returns.
+struct ScatterGatherState {
+    /// A struct that tracks the amount of unused buffer space.
+    unused_buffer_space: UnusedBufferSpace,
+    /// Scatter-gather entries to copy.
+    sg_entries: KVec<ScatterGatherEntry>,
+    /// Indexes into `sg_entries` corresponding to the last binder_buffer_object that
+    /// was processed and all of its ancestors. The array is in sorted order.
+    ancestors: KVec<usize>,
+}
+
+/// This entry specifies an additional buffer that should be copied using the scatter-gather
+/// mechanism.
+struct ScatterGatherEntry {
+    /// The index in the offset array of the BINDER_TYPE_PTR that this entry originates from.
+    obj_index: usize,
+    /// Offset in target buffer.
+    offset: usize,
+    /// User address in source buffer.
+    sender_uaddr: usize,
+    /// Number of bytes to copy.
+    length: usize,
+    /// The minimum offset of the next fixup in this buffer.
+    fixup_min_offset: usize,
+    /// The offsets within this buffer that contain pointers which should be translated.
+    pointer_fixups: KVec<PointerFixupEntry>,
+}
+
+/// This entry specifies that a fixup should happen at `target_offset` of the
+/// buffer.
+enum PointerFixupEntry {
+    /// A fixup for a `binder_buffer_object`.
+    Fixup {
+        /// The translated pointer to write.
+        pointer_value: u64,
+        /// The offset at which the value should be written. The offset is relative
+        /// to the original buffer.
+        target_offset: usize,
+    },
+    /// A skip for a `binder_fd_array_object`.
+    Skip {
+        /// The number of bytes to skip.
+        skip: usize,
+        /// The offset at which the skip should happen. The offset is relative
+        /// to the original buffer.
+        target_offset: usize,
+    },
+}
+
+/// Return type of `apply_and_validate_fixup_in_parent`.
+struct ParentFixupInfo {
+    /// The index of the parent buffer in `sg_entries`.
+    parent_sg_index: usize,
+    /// The number of ancestors of the buffer.
+    ///
+    /// The buffer is considered an ancestor of itself, so this is always at
+    /// least one.
+    num_ancestors: usize,
+    /// New value of `fixup_min_offset` if this fixup is applied.
+    new_min_offset: usize,
+    /// The offset of the fixup in the target buffer.
+    target_offset: usize,
+}
+
+impl ScatterGatherState {
+    /// Called when a `binder_buffer_object` or `binder_fd_array_object` tries
+    /// to access a region in its parent buffer. These accesses have various
+    /// restrictions, which this method verifies.
+    ///
+    /// The `parent_offset` and `length` arguments describe the offset and
+    /// length of the access in the parent buffer.
+    ///
+    /// # Detailed restrictions
+    ///
+    /// Obviously the fixup must be in-bounds for the parent buffer.
+    ///
+    /// For safety reasons, we only allow fixups inside a buffer to happen
+    /// at increasing offsets; additionally, we only allow fixup on the last
+    /// buffer object that was verified, or one of its parents.
+    ///
+    /// Example of what is allowed:
+    ///
+    /// A
+    ///   B (parent = A, offset = 0)
+    ///   C (parent = A, offset = 16)
+    ///     D (parent = C, offset = 0)
+    ///   E (parent = A, offset = 32) // min_offset is 16 (C.parent_offset)
+    ///
+    /// Examples of what is not allowed:
+    ///
+    /// Decreasing offsets within the same parent:
+    /// A
+    ///   C (parent = A, offset = 16)
+    ///   B (parent = A, offset = 0) // decreasing offset within A
+    ///
+    /// Arcerring to a parent that wasn't the last object or any of its parents:
+    /// A
+    ///   B (parent = A, offset = 0)
+    ///   C (parent = A, offset = 0)
+    ///   C (parent = A, offset = 16)
+    ///     D (parent = B, offset = 0) // B is not A or any of A's parents
+    fn validate_parent_fixup(
+        &self,
+        parent: usize,
+        parent_offset: usize,
+        length: usize,
+    ) -> Result<ParentFixupInfo> {
+        // Using `position` would also be correct, but `rposition` avoids
+        // quadratic running times.
+        let ancestors_i = self
+            .ancestors
+            .iter()
+            .copied()
+            .rposition(|sg_idx| self.sg_entries[sg_idx].obj_index == parent)
+            .ok_or(EINVAL)?;
+        let sg_idx = self.ancestors[ancestors_i];
+        let sg_entry = match self.sg_entries.get(sg_idx) {
+            Some(sg_entry) => sg_entry,
+            None => {
+                pr_err!(
+                    "self.ancestors[{}] is {}, but self.sg_entries.len() is {}",
+                    ancestors_i,
+                    sg_idx,
+                    self.sg_entries.len()
+                );
+                return Err(EINVAL);
+            }
+        };
+        if sg_entry.fixup_min_offset > parent_offset {
+            pr_warn!(
+                "validate_parent_fixup: fixup_min_offset={}, parent_offset={}",
+                sg_entry.fixup_min_offset,
+                parent_offset
+            );
+            return Err(EINVAL);
+        }
+        let new_min_offset = parent_offset.checked_add(length).ok_or(EINVAL)?;
+        if new_min_offset > sg_entry.length {
+            pr_warn!(
+                "validate_parent_fixup: new_min_offset={}, sg_entry.length={}",
+                new_min_offset,
+                sg_entry.length
+            );
+            return Err(EINVAL);
+        }
+        let target_offset = sg_entry.offset.checked_add(parent_offset).ok_or(EINVAL)?;
+        // The `ancestors_i + 1` operation can't overflow since the output of the addition is at
+        // most `self.ancestors.len()`, which also fits in a usize.
+        Ok(ParentFixupInfo {
+            parent_sg_index: sg_idx,
+            num_ancestors: ancestors_i + 1,
+            new_min_offset,
+            target_offset,
+        })
+    }
+}
+
+/// Keeps track of how much unused buffer space is left. The initial amount is the number of bytes
+/// requested by the user using the `buffers_size` field of `binder_transaction_data_sg`. Each time
+/// we translate an object of type `BINDER_TYPE_PTR`, some of the unused buffer space is consumed.
+struct UnusedBufferSpace {
+    /// The start of the remaining space.
+    offset: usize,
+    /// The end of the remaining space.
+    limit: usize,
+}
+impl UnusedBufferSpace {
+    /// Claim the next `size` bytes from the unused buffer space. The offset for the claimed chunk
+    /// into the buffer is returned.
+    fn claim_next(&mut self, size: usize) -> Result<usize> {
+        // We require every chunk to be aligned.
+        let size = ptr_align(size).ok_or(EINVAL)?;
+        let new_offset = self.offset.checked_add(size).ok_or(EINVAL)?;
+
+        if new_offset <= self.limit {
+            let offset = self.offset;
+            self.offset = new_offset;
+            Ok(offset)
+        } else {
+            Err(EINVAL)
+        }
+    }
+}
+
+#[must_use]
+pub(crate) enum PushWorkRes {
+    Ok,
+    OkNotifyPoll,
+    FailedDead(DLArc<dyn DeliverToRead>),
+}
+
+impl PushWorkRes {
+    fn is_ok(&self) -> bool {
+        match self {
+            PushWorkRes::Ok => true,
+            PushWorkRes::OkNotifyPoll => true,
+            PushWorkRes::FailedDead(_) => false,
+        }
+    }
+}
+
+/// The fields of `Thread` protected by the spinlock.
+struct InnerThread {
+    /// Determines the looper state of the thread. It is a bit-wise combination of the constants
+    /// prefixed with `LOOPER_`.
+    looper_flags: LooperFlags,
+
+    /// Determines whether the looper should return.
+    looper_need_return: bool,
+
+    /// Determines if thread is dead.
+    is_dead: bool,
+
+    /// Work item used to deliver error codes to the thread that started a transaction. Stored here
+    /// so that it can be reused.
+    reply_work: DArc<ThreadError>,
+
+    /// Work item used to deliver error codes to the current thread. Stored here so that it can be
+    /// reused.
+    return_work: DArc<ThreadError>,
+
+    /// Determines whether the work list below should be processed. When set to false, `work_list`
+    /// is treated as if it were empty.
+    process_work_list: bool,
+    /// List of work items to deliver to userspace.
+    work_list: List<DTRWrap<dyn DeliverToRead>>,
+    current_transaction: Option<DArc<Transaction>>,
+
+    /// Extended error information for this thread.
+    extended_error: ExtendedError,
+}
+
+kernel::impl_flags!(
+    /// Represents multiple looper flags.
+    #[derive(Debug, Clone, Default, Copy, PartialEq, Eq)]
+    pub struct LooperFlags(u32);
+
+    /// Represents a single looper flag.
+    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+    pub enum LooperFlag {
+        Registered = bit_u32(0),
+        Entered = bit_u32(1),
+        Exited = bit_u32(2),
+        Invalid = bit_u32(3),
+        Waiting = bit_u32(4),
+        WaitingProc = bit_u32(5),
+        Poll = bit_u32(6),
+    }
+);
+
+impl InnerThread {
+    fn new(pid: i32) -> Result<Self> {
+        fn next_err_id() -> u32 {
+            static EE_ID: Atomic<u32> = Atomic::new(0);
+            EE_ID.fetch_add(1, Relaxed)
+        }
+
+        Ok(Self {
+            looper_flags: LooperFlags::default(),
+            looper_need_return: false,
+            is_dead: false,
+            process_work_list: false,
+            reply_work: ThreadError::try_new(pid)?,
+            return_work: ThreadError::try_new(pid)?,
+            work_list: List::new(),
+            current_transaction: None,
+            extended_error: ExtendedError::new(next_err_id(), BR_OK, 0),
+        })
+    }
+
+    fn pop_work(&mut self) -> Option<DLArc<dyn DeliverToRead>> {
+        if !self.process_work_list {
+            return None;
+        }
+
+        let ret = self.work_list.pop_front();
+        self.process_work_list = !self.work_list.is_empty();
+        ret
+    }
+
+    fn push_work(&mut self, work: DLArc<dyn DeliverToRead>) -> PushWorkRes {
+        if self.is_dead {
+            return PushWorkRes::FailedDead(work);
+        }
+        self.work_list.push_back(work);
+        self.process_work_list = true;
+        if self.looper_flags.contains(LooperFlag::Poll) {
+            PushWorkRes::OkNotifyPoll
+        } else {
+            PushWorkRes::Ok
+        }
+    }
+
+    fn push_reply_work(&mut self, code: u32) -> PushWorkRes {
+        if let Ok(work) = ListArc::try_from_arc(self.reply_work.clone()) {
+            work.set_error_code(code);
+            self.push_work(work)
+        } else {
+            pr_warn!("Thread reply work is already in use.");
+            PushWorkRes::Ok
+        }
+    }
+
+    fn push_return_work(&mut self, reply: u32) {
+        if let Ok(work) = ListArc::try_from_arc(self.return_work.clone()) {
+            work.set_error_code(reply);
+            // Not notifying: Reply to current thread.
+            let _ = self.push_work(work);
+        } else {
+            pr_warn!("Thread return work is already in use.");
+        }
+    }
+
+    /// Used to push work items that do not need to be processed immediately and can wait until the
+    /// thread gets another work item.
+    fn push_work_deferred(&mut self, work: DLArc<dyn DeliverToRead>) {
+        self.work_list.push_back(work);
+    }
+
+    /// Fetches the transaction this thread can reply to. If the thread has a pending transaction
+    /// (that it could respond to) but it has also issued a transaction, it must first wait for the
+    /// previously-issued transaction to complete.
+    ///
+    /// The `thread` parameter should be the thread containing this `ThreadInner`.
+    fn pop_transaction_to_reply(&mut self, thread: &Thread) -> Result<DArc<Transaction>> {
+        let transaction = self.current_transaction.take().ok_or(EINVAL)?;
+        if core::ptr::eq(thread, transaction.from.as_ref()) {
+            self.current_transaction = Some(transaction);
+            return Err(EINVAL);
+        }
+        // Find a new current transaction for this thread.
+        self.current_transaction = transaction.find_from(thread).cloned();
+        Ok(transaction)
+    }
+
+    fn pop_transaction_replied(&mut self, transaction: &DArc<Transaction>) -> bool {
+        match self.current_transaction.take() {
+            None => false,
+            Some(old) => {
+                if !Arc::ptr_eq(transaction, &old) {
+                    self.current_transaction = Some(old);
+                    return false;
+                }
+                self.current_transaction = old.clone_next();
+                true
+            }
+        }
+    }
+
+    fn looper_enter(&mut self) {
+        self.looper_flags |= LooperFlag::Entered;
+        if self.looper_flags.contains(LooperFlag::Registered) {
+            self.looper_flags |= LooperFlag::Invalid;
+        }
+    }
+
+    fn looper_register(&mut self, valid: bool) {
+        self.looper_flags |= LooperFlag::Registered;
+        if !valid || self.looper_flags.contains(LooperFlag::Entered) {
+            self.looper_flags |= LooperFlag::Invalid;
+        }
+    }
+
+    fn looper_exit(&mut self) {
+        self.looper_flags |= LooperFlag::Exited;
+    }
+
+    /// Determines whether the thread is part of a pool, i.e., if it is a looper.
+    fn is_looper(&self) -> bool {
+        self.looper_flags
+            .contains_any(LooperFlag::Entered | LooperFlag::Registered)
+    }
+
+    /// Determines whether the thread should attempt to fetch work items from the process queue.
+    /// This is generally case when the thread is registered as a looper and not part of a
+    /// transaction stack. But if there is local work, we want to return to userspace before we
+    /// deliver any remote work.
+    fn should_use_process_work_queue(&self) -> bool {
+        self.current_transaction.is_none() && !self.process_work_list && self.is_looper()
+    }
+
+    fn poll(&mut self) -> u32 {
+        self.looper_flags |= LooperFlag::Poll;
+        if self.process_work_list || self.looper_need_return {
+            bindings::POLLIN
+        } else {
+            0
+        }
+    }
+}
+
+/// This represents a thread that's used with binder.
+#[pin_data]
+pub(crate) struct Thread {
+    pub(crate) id: i32,
+    pub(crate) process: Arc<Process>,
+    pub(crate) task: ARef<Task>,
+    #[pin]
+    inner: SpinLock<InnerThread>,
+    #[pin]
+    work_condvar: CondVar,
+    /// Used to insert this thread into the process' `ready_threads` list.
+    ///
+    /// INVARIANT: May never be used for any other list than the `self.process.ready_threads`.
+    #[pin]
+    links: ListLinks,
+    #[pin]
+    links_track: AtomicTracker,
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<0> for Thread {
+        tracked_by links_track: AtomicTracker;
+    }
+}
+kernel::list::impl_list_item! {
+    impl ListItem<0> for Thread {
+        using ListLinks { self.links };
+    }
+}
+
+impl Thread {
+    pub(crate) fn new(id: i32, process: Arc<Process>) -> Result<Arc<Self>> {
+        let inner = InnerThread::new(process.task.pid())?;
+
+        Arc::pin_init(
+            try_pin_init!(Thread {
+                id,
+                process,
+                task: ARef::from(&**kernel::current!()),
+                inner <- kernel::new_spinlock!(inner, "Thread::inner"),
+                work_condvar <- kernel::new_condvar!("Thread::work_condvar"),
+                links <- ListLinks::new(),
+                links_track <- AtomicTracker::new(),
+            }),
+            GFP_KERNEL,
+        )
+    }
+
+    #[inline(never)]
+    pub(crate) fn debug_print(self: &Arc<Self>, m: &SeqFile, print_all: bool) -> Result<()> {
+        let inner = self.inner.lock();
+
+        if print_all || inner.current_transaction.is_some() || !inner.work_list.is_empty() {
+            seq_print!(
+                m,
+                "  thread {}: l {:02x} need_return {}\n",
+                self.id,
+                u32::from(inner.looper_flags),
+                inner.looper_need_return,
+            );
+        }
+
+        let mut t_opt = inner.current_transaction.as_ref();
+        while let Some(t) = t_opt {
+            if Arc::ptr_eq(&t.from, self) {
+                t.debug_print_inner(m, "    outgoing transaction ");
+                t_opt = t.from_parent.as_ref();
+            } else if Arc::ptr_eq(&t.to, &self.process) {
+                t.debug_print_inner(m, "    incoming transaction ");
+                t_opt = t.find_from(self);
+            } else {
+                t.debug_print_inner(m, "    bad transaction ");
+                t_opt = None;
+            }
+        }
+
+        for work in &inner.work_list {
+            work.debug_print(m, "    ", "    pending transaction ")?;
+        }
+        Ok(())
+    }
+
+    pub(crate) fn clear_extended_error(&self, debug_id: usize) {
+        self.inner.lock().extended_error = ExtendedError::new(debug_id as u32, BR_OK, 0);
+    }
+
+    pub(crate) fn get_extended_error(&self, data: UserSlice) -> Result {
+        let mut writer = data.writer();
+        let mut inner = self.inner.lock();
+        let ee = inner.extended_error;
+        inner.extended_error = ExtendedError::new(0, BR_OK, 0);
+        drop(inner);
+        writer.write(&ee)?;
+        Ok(())
+    }
+
+    pub(crate) fn set_current_transaction(&self, transaction: DArc<Transaction>) {
+        self.inner.lock().current_transaction = Some(transaction);
+    }
+
+    pub(crate) fn has_current_transaction(&self) -> bool {
+        self.inner.lock().current_transaction.is_some()
+    }
+
+    /// Attempts to fetch a work item from the thread-local queue. The behaviour if the queue is
+    /// empty depends on `wait`: if it is true, the function waits for some work to be queued (or a
+    /// signal); otherwise it returns indicating that none is available.
+    // #[export_name] is a temporary workaround so that ps output does not become unreadable from
+    // mangled symbol names.
+    #[export_name = "rust_binder_waitlcl"]
+    fn get_work_local(self: &Arc<Self>, wait: bool) -> Result<Option<DLArc<dyn DeliverToRead>>> {
+        {
+            let mut inner = self.inner.lock();
+            if inner.looper_need_return {
+                return Ok(inner.pop_work());
+            }
+        }
+
+        // Try once if the caller does not want to wait.
+        if !wait {
+            return self.inner.lock().pop_work().ok_or(EAGAIN).map(Some);
+        }
+
+        // Loop waiting only on the local queue (i.e., not registering with the process queue).
+        let mut inner = self.inner.lock();
+        loop {
+            if let Some(work) = inner.pop_work() {
+                return Ok(Some(work));
+            }
+
+            inner.looper_flags |= LooperFlag::Waiting;
+            let signal_pending = self.work_condvar.wait_interruptible_freezable(&mut inner);
+            inner.looper_flags &= !LooperFlag::Waiting;
+
+            if signal_pending {
+                return Err(EINTR);
+            }
+            if inner.looper_need_return {
+                return Ok(None);
+            }
+        }
+    }
+
+    /// Attempts to fetch a work item from the thread-local queue, falling back to the process-wide
+    /// queue if none is available locally.
+    ///
+    /// This must only be called when the thread is not participating in a transaction chain. If it
+    /// is, the local version (`get_work_local`) should be used instead.
+    // #[export_name] is a temporary workaround so that ps output does not become unreadable from
+    // mangled symbol names.
+    #[export_name = "rust_binder_wait"]
+    fn get_work(self: &Arc<Self>, wait: bool) -> Result<Option<DLArc<dyn DeliverToRead>>> {
+        // Try to get work from the thread's work queue, using only a local lock.
+        {
+            let mut inner = self.inner.lock();
+            if let Some(work) = inner.pop_work() {
+                return Ok(Some(work));
+            }
+            if inner.looper_need_return {
+                drop(inner);
+                return Ok(self.process.get_work());
+            }
+        }
+
+        // If the caller doesn't want to wait, try to grab work from the process queue.
+        //
+        // We know nothing will have been queued directly to the thread queue because it is not in
+        // a transaction and it is not in the process' ready list.
+        if !wait {
+            return self.process.get_work().ok_or(EAGAIN).map(Some);
+        }
+
+        // Get work from the process queue. If none is available, atomically register as ready.
+        let reg = match self.process.get_work_or_register(self) {
+            GetWorkOrRegister::Work(work) => return Ok(Some(work)),
+            GetWorkOrRegister::Register(reg) => reg,
+        };
+
+        let mut inner = self.inner.lock();
+        loop {
+            if let Some(work) = inner.pop_work() {
+                return Ok(Some(work));
+            }
+
+            inner.looper_flags |= LooperFlag::Waiting | LooperFlag::WaitingProc;
+            let signal_pending = self.work_condvar.wait_interruptible_freezable(&mut inner);
+            inner.looper_flags &= !(LooperFlag::Waiting | LooperFlag::WaitingProc);
+
+            if signal_pending || inner.looper_need_return {
+                // We need to return now. We need to pull the thread off the list of ready threads
+                // (by dropping `reg`), then check the state again after it's off the list to
+                // ensure that something was not queued in the meantime. If something has been
+                // queued, we just return it (instead of the error).
+                drop(inner);
+                drop(reg);
+
+                let res = match self.inner.lock().pop_work() {
+                    Some(work) => Ok(Some(work)),
+                    None if signal_pending => Err(EINTR),
+                    None => Ok(None),
+                };
+                return res;
+            }
+        }
+    }
+
+    /// Push the provided work item to be delivered to user space via this thread.
+    ///
+    /// Returns whether the item was successfully pushed. This can only fail if the thread is dead.
+    pub(crate) fn push_work(&self, work: DLArc<dyn DeliverToRead>) -> PushWorkRes {
+        let sync = work.should_sync_wakeup();
+        self.push_work_inner(work, sync)
+    }
+
+    pub(crate) fn push_work_inner(
+        &self,
+        work: DLArc<dyn DeliverToRead>,
+        sync: bool,
+    ) -> PushWorkRes {
+        let res = self.inner.lock().push_work(work);
+
+        if res.is_ok() {
+            if sync {
+                self.work_condvar.notify_sync();
+            } else {
+                self.work_condvar.notify_one();
+            }
+        }
+
+        res
+    }
+
+    /// Attempts to push to given work item to the thread if it's a looper thread (i.e., if it's
+    /// part of a thread pool) and is alive. Otherwise, push the work item to the process instead.
+    pub(crate) fn push_work_if_looper(&self, work: DLArc<dyn DeliverToRead>) -> BinderResult {
+        let mut inner = self.inner.lock();
+        if inner.is_looper() && !inner.is_dead {
+            // Not notifying: Reply to current thread.
+            let _ = inner.push_work(work);
+            Ok(())
+        } else {
+            drop(inner);
+            self.process.push_work(work)
+        }
+    }
+
+    pub(crate) fn push_work_deferred(&self, work: DLArc<dyn DeliverToRead>) {
+        self.inner.lock().push_work_deferred(work);
+    }
+
+    pub(crate) fn push_return_work(&self, reply: u32) {
+        self.inner.lock().push_return_work(reply);
+    }
+
+    fn translate_object(
+        &self,
+        obj_index: usize,
+        offset: usize,
+        object: BinderObjectRef<'_>,
+        view: &mut AllocationView<'_>,
+        allow_fds: bool,
+        sg_state: &mut ScatterGatherState,
+    ) -> BinderResult {
+        match object {
+            BinderObjectRef::Binder(obj) => {
+                let strong = obj.hdr.type_ == BINDER_TYPE_BINDER;
+                // SAFETY: `binder` is a `binder_uintptr_t`; any bit pattern is a valid
+                // representation.
+                let ptr = unsafe { obj.__bindgen_anon_1.binder };
+                let cookie = obj.cookie;
+                let flags = obj.flags;
+                let node = self
+                    .process
+                    .as_arc_borrow()
+                    .get_node(ptr, cookie, flags, strong, self)?;
+                security::binder_transfer_binder(&self.process.cred, &view.alloc.process.cred)?;
+                view.transfer_binder_object(offset, obj, strong, node)?;
+            }
+            BinderObjectRef::Handle(obj) => {
+                let strong = obj.hdr.type_ == BINDER_TYPE_HANDLE;
+                // SAFETY: `handle` is a `u32`; any bit pattern is a valid representation.
+                let handle = unsafe { obj.__bindgen_anon_1.handle };
+                let node = self.process.get_node_from_handle(handle, strong)?;
+                security::binder_transfer_binder(&self.process.cred, &view.alloc.process.cred)?;
+                view.transfer_binder_object(offset, obj, strong, node)?;
+            }
+            BinderObjectRef::Fd(obj) => {
+                if !allow_fds {
+                    return Err(EPERM.into());
+                }
+
+                // SAFETY: `fd` is a `u32`; any bit pattern is a valid representation.
+                let fd = unsafe { obj.__bindgen_anon_1.fd };
+                let file = LocalFile::fget(fd)?;
+                // SAFETY: The binder driver never calls `fdget_pos` and this code runs from an
+                // ioctl, so there are no active calls to `fdget_pos` on this thread.
+                let file = unsafe { LocalFile::assume_no_fdget_pos(file) };
+                security::binder_transfer_file(
+                    &self.process.cred,
+                    &view.alloc.process.cred,
+                    &file,
+                )?;
+
+                let mut obj_write = BinderFdObject::default();
+                obj_write.hdr.type_ = BINDER_TYPE_FD;
+                // This will be overwritten with the actual fd when the transaction is received.
+                obj_write.__bindgen_anon_1.fd = u32::MAX;
+                obj_write.cookie = obj.cookie;
+                view.write::<BinderFdObject>(offset, &obj_write)?;
+
+                const FD_FIELD_OFFSET: usize =
+                    core::mem::offset_of!(uapi::binder_fd_object, __bindgen_anon_1.fd);
+
+                let field_offset = offset + FD_FIELD_OFFSET;
+                crate::trace::trace_transaction_fd_send(view.alloc.debug_id, fd, field_offset);
+
+                view.alloc.info_add_fd(file, field_offset, false)?;
+            }
+            BinderObjectRef::Ptr(obj) => {
+                let obj_length = obj.length.try_into().map_err(|_| EINVAL)?;
+                let alloc_offset = match sg_state.unused_buffer_space.claim_next(obj_length) {
+                    Ok(alloc_offset) => alloc_offset,
+                    Err(err) => {
+                        binder_debug!(
+                            UserError,
+                            "failed to claim space for a BINDER_TYPE_PTR (offset: {}, limit: {}, size: {})",
+                            sg_state.unused_buffer_space.offset,
+                            sg_state.unused_buffer_space.limit,
+                            obj_length
+                        );
+                        return Err(err.into());
+                    }
+                };
+
+                let sg_state_idx = sg_state.sg_entries.len();
+                sg_state.sg_entries.push(
+                    ScatterGatherEntry {
+                        obj_index,
+                        offset: alloc_offset,
+                        sender_uaddr: obj.buffer as usize,
+                        length: obj_length,
+                        pointer_fixups: KVec::new(),
+                        fixup_min_offset: 0,
+                    },
+                    GFP_KERNEL,
+                )?;
+
+                let buffer_ptr_in_user_space = (view.alloc.ptr + alloc_offset) as u64;
+
+                if obj.flags & uapi::BINDER_BUFFER_FLAG_HAS_PARENT == 0 {
+                    sg_state.ancestors.clear();
+                    sg_state.ancestors.push(sg_state_idx, GFP_KERNEL)?;
+                } else {
+                    // Another buffer also has a pointer to this buffer, and we need to fixup that
+                    // pointer too.
+
+                    let parent_index = usize::try_from(obj.parent).map_err(|_| EINVAL)?;
+                    let parent_offset = usize::try_from(obj.parent_offset).map_err(|_| EINVAL)?;
+
+                    let info = sg_state.validate_parent_fixup(
+                        parent_index,
+                        parent_offset,
+                        size_of::<u64>(),
+                    )?;
+
+                    sg_state.ancestors.truncate(info.num_ancestors);
+                    sg_state.ancestors.push(sg_state_idx, GFP_KERNEL)?;
+
+                    let parent_entry = match sg_state.sg_entries.get_mut(info.parent_sg_index) {
+                        Some(parent_entry) => parent_entry,
+                        None => {
+                            pr_err!(
+                                "validate_parent_fixup returned index out of bounds for sg.entries"
+                            );
+                            return Err(EINVAL.into());
+                        }
+                    };
+
+                    parent_entry.fixup_min_offset = info.new_min_offset;
+                    parent_entry.pointer_fixups.push(
+                        PointerFixupEntry::Fixup {
+                            pointer_value: buffer_ptr_in_user_space,
+                            target_offset: info.target_offset,
+                        },
+                        GFP_KERNEL,
+                    )?;
+                }
+
+                let mut obj_write = BinderBufferObject::default();
+                obj_write.hdr.type_ = BINDER_TYPE_PTR;
+                obj_write.flags = obj.flags;
+                obj_write.buffer = buffer_ptr_in_user_space;
+                obj_write.length = obj.length;
+                obj_write.parent = obj.parent;
+                obj_write.parent_offset = obj.parent_offset;
+                view.write::<BinderBufferObject>(offset, &obj_write)?;
+            }
+            BinderObjectRef::Fda(obj) => {
+                if !allow_fds {
+                    return Err(EPERM.into());
+                }
+                let parent_index = usize::try_from(obj.parent).map_err(|_| EINVAL)?;
+                let parent_offset = usize::try_from(obj.parent_offset).map_err(|_| EINVAL)?;
+                let num_fds = usize::try_from(obj.num_fds).map_err(|_| EINVAL)?;
+                let fds_len = num_fds.checked_mul(size_of::<u32>()).ok_or(EINVAL)?;
+
+                if !is_aligned(parent_offset, size_of::<u32>()) {
+                    binder_debug!(UserError, "FDA parent offset not aligned correctly");
+                    return Err(EINVAL.into());
+                }
+
+                let info = sg_state.validate_parent_fixup(parent_index, parent_offset, fds_len)?;
+                view.alloc.info_add_fd_reserve(num_fds)?;
+
+                sg_state.ancestors.truncate(info.num_ancestors);
+                let parent_entry = match sg_state.sg_entries.get_mut(info.parent_sg_index) {
+                    Some(parent_entry) => parent_entry,
+                    None => {
+                        pr_err!(
+                            "validate_parent_fixup returned index out of bounds for sg.entries"
+                        );
+                        return Err(EINVAL.into());
+                    }
+                };
+
+                if !is_aligned(parent_entry.sender_uaddr, size_of::<u32>()) {
+                    binder_debug!(UserError, "FDA parent buffer not aligned correctly");
+                    return Err(EINVAL.into());
+                }
+
+                parent_entry.fixup_min_offset = info.new_min_offset;
+                parent_entry
+                    .pointer_fixups
+                    .push(
+                        PointerFixupEntry::Skip {
+                            skip: fds_len,
+                            target_offset: info.target_offset,
+                        },
+                        GFP_KERNEL,
+                    )
+                    .map_err(|_| ENOMEM)?;
+
+                let fda_uaddr = parent_entry
+                    .sender_uaddr
+                    .checked_add(parent_offset)
+                    .ok_or(EINVAL)?;
+
+                let mut fda_bytes = KVec::new();
+                UserSlice::new(UserPtr::from_addr(fda_uaddr as usize), fds_len)
+                    .read_all(&mut fda_bytes, GFP_KERNEL)?;
+
+                if fds_len != fda_bytes.len() {
+                    pr_err!("UserSlice::read_all returned wrong length in BINDER_TYPE_FDA");
+                    return Err(EINVAL.into());
+                }
+
+                for i in (0..fds_len).step_by(size_of::<u32>()) {
+                    let fd = {
+                        let mut fd_bytes = [0u8; size_of::<u32>()];
+                        fd_bytes.copy_from_slice(&fda_bytes[i..i + size_of::<u32>()]);
+                        u32::from_ne_bytes(fd_bytes)
+                    };
+
+                    let file = LocalFile::fget(fd)?;
+                    // SAFETY: The binder driver never calls `fdget_pos` and this code runs from an
+                    // ioctl, so there are no active calls to `fdget_pos` on this thread.
+                    let file = unsafe { LocalFile::assume_no_fdget_pos(file) };
+                    security::binder_transfer_file(
+                        &self.process.cred,
+                        &view.alloc.process.cred,
+                        &file,
+                    )?;
+
+                    // The `validate_parent_fixup` call ensuers that this addition will not
+                    // overflow.
+                    view.alloc.info_add_fd(file, info.target_offset + i, true)?;
+                }
+                drop(fda_bytes);
+
+                let mut obj_write = BinderFdArrayObject::default();
+                obj_write.hdr.type_ = BINDER_TYPE_FDA;
+                obj_write.num_fds = obj.num_fds;
+                obj_write.parent = obj.parent;
+                obj_write.parent_offset = obj.parent_offset;
+                view.write::<BinderFdArrayObject>(offset, &obj_write)?;
+            }
+        }
+        Ok(())
+    }
+
+    fn apply_sg(&self, alloc: &mut Allocation, sg_state: &mut ScatterGatherState) -> BinderResult {
+        for sg_entry in &mut sg_state.sg_entries {
+            let mut end_of_previous_fixup = sg_entry.offset;
+            let offset_end = sg_entry.offset.checked_add(sg_entry.length).ok_or(EINVAL)?;
+
+            let mut reader =
+                UserSlice::new(UserPtr::from_addr(sg_entry.sender_uaddr), sg_entry.length).reader();
+            for fixup in &mut sg_entry.pointer_fixups {
+                let (fixup_len, fixup_offset) = match fixup {
+                    PointerFixupEntry::Fixup { target_offset, .. } => {
+                        (size_of::<u64>(), *target_offset)
+                    }
+                    PointerFixupEntry::Skip {
+                        skip,
+                        target_offset,
+                    } => (*skip, *target_offset),
+                };
+
+                let target_offset_end = fixup_offset.checked_add(fixup_len).ok_or(EINVAL)?;
+                if fixup_offset < end_of_previous_fixup || offset_end < target_offset_end {
+                    binder_debug!(
+                        UserError,
+                        "fixups oob {fixup_offset} {end_of_previous_fixup} {offset_end} {target_offset_end}"
+                    );
+                    return Err(EINVAL.into());
+                }
+
+                let copy_off = end_of_previous_fixup;
+                let copy_len = fixup_offset - end_of_previous_fixup;
+                if let Err(err) = alloc.copy_into(&mut reader, copy_off, copy_len) {
+                    binder_debug!(UserError, "failed copying into alloc: {err:?}");
+                    return Err(err.into());
+                }
+                if let PointerFixupEntry::Fixup { pointer_value, .. } = fixup {
+                    let res = alloc.write::<u64>(fixup_offset, pointer_value);
+                    if let Err(err) = res {
+                        binder_debug!(UserError, "failed copying ptr into alloc: {err:?}");
+                        return Err(err.into());
+                    }
+                }
+                if let Err(err) = reader.skip(fixup_len) {
+                    binder_debug!(
+                        UserError,
+                        "failed skipping {fixup_len} from reader: {err:?}"
+                    );
+                    return Err(err.into());
+                }
+                end_of_previous_fixup = target_offset_end;
+            }
+            let copy_off = end_of_previous_fixup;
+            let copy_len = offset_end - end_of_previous_fixup;
+            if let Err(err) = alloc.copy_into(&mut reader, copy_off, copy_len) {
+                binder_debug!(UserError, "failed copying remainder into alloc: {err:?}");
+                return Err(err.into());
+            }
+        }
+        Ok(())
+    }
+
+    /// This method copies the payload of a transaction into the target process.
+    ///
+    /// The resulting payload will have several different components, which will be stored next to
+    /// each other in the allocation. Furthermore, various objects can be embedded in the payload,
+    /// and those objects have to be translated so that they make sense to the target transaction.
+    pub(crate) fn copy_transaction_data(
+        &self,
+        to_process: Arc<Process>,
+        info: &mut TransactionInfo,
+        debug_id: usize,
+        allow_fds: bool,
+        txn_security_ctx_offset: Option<&mut usize>,
+    ) -> BinderResult<NewAllocation> {
+        let mut secctx = if let Some(offset) = txn_security_ctx_offset {
+            let secid = self.process.cred.get_secid();
+            let ctx = match security::SecurityCtx::from_secid(secid) {
+                Ok(ctx) => ctx,
+                Err(err) => {
+                    pr_warn!("Failed to get security ctx for id {}: {:?}", secid, err);
+                    return Err(err.into());
+                }
+            };
+            Some((offset, ctx))
+        } else {
+            None
+        };
+
+        let data_size = info.data_size;
+        let aligned_data_size = ptr_align(data_size).ok_or(EINVAL)?;
+        let offsets_size = info.offsets_size;
+        let buffers_size = info.buffers_size;
+        let aligned_secctx_size = match secctx.as_ref() {
+            Some((_offset, ctx)) => ptr_align(ctx.len()).ok_or(EINVAL)?,
+            None => 0,
+        };
+
+        if !is_aligned(offsets_size, size_of::<u64>()) {
+            return Err(EINVAL.into());
+        }
+        if !is_aligned(buffers_size, size_of::<u64>()) {
+            return Err(EINVAL.into());
+        }
+
+        // This guarantees that at least `sizeof(usize)` bytes will be allocated.
+        let len = usize::max(
+            aligned_data_size
+                .checked_add(offsets_size)
+                .and_then(|sum| sum.checked_add(buffers_size))
+                .and_then(|sum| sum.checked_add(aligned_secctx_size))
+                .ok_or(ENOMEM)?,
+            size_of::<u64>(),
+        );
+        let secctx_off = aligned_data_size + offsets_size + buffers_size;
+        let mut alloc = match to_process.buffer_alloc(debug_id, len, info) {
+            Ok(alloc) => alloc,
+            Err(err) => {
+                pr_warn!(
+                    "Failed to allocate buffer. len:{}, is_oneway:{}",
+                    len,
+                    info.is_oneway(),
+                );
+                return Err(err);
+            }
+        };
+
+        let mut buffer_reader = UserSlice::new(info.data_ptr, data_size).reader();
+        let mut end_of_previous_object = 0;
+        let mut sg_state = None;
+
+        // Copy offsets if there are any.
+        if offsets_size > 0 {
+            let mut offsets_reader = UserSlice::new(info.offsets_ptr, offsets_size).reader();
+
+            let offsets_start = aligned_data_size;
+            let offsets_end = aligned_data_size + offsets_size;
+
+            // This state is used for BINDER_TYPE_PTR objects.
+            let sg_state = sg_state.insert(ScatterGatherState {
+                unused_buffer_space: UnusedBufferSpace {
+                    offset: offsets_end,
+                    limit: offsets_end + buffers_size,
+                },
+                sg_entries: KVec::new(),
+                ancestors: KVec::new(),
+            });
+
+            // Traverse the objects specified.
+            let mut view = AllocationView::new(&mut alloc, data_size);
+            for (index, index_offset) in (offsets_start..offsets_end)
+                .step_by(size_of::<u64>())
+                .enumerate()
+            {
+                let offset = offsets_reader.read::<u64>()?;
+                view.alloc.write(index_offset, &offset)?;
+                let offset: usize = offset.try_into().map_err(|_| EINVAL)?;
+
+                if offset < end_of_previous_object || !is_aligned(offset, size_of::<u32>()) {
+                    binder_debug!(UserError, "got transaction with invalid offset");
+                    return Err(EINVAL.into());
+                }
+
+                // Copy data between two objects.
+                if end_of_previous_object < offset {
+                    view.copy_into(
+                        &mut buffer_reader,
+                        end_of_previous_object,
+                        offset - end_of_previous_object,
+                    )?;
+                }
+
+                let mut object = BinderObject::read_from(&mut buffer_reader)?;
+
+                match self.translate_object(
+                    index,
+                    offset,
+                    object.as_ref(),
+                    &mut view,
+                    allow_fds,
+                    sg_state,
+                ) {
+                    Ok(()) => end_of_previous_object = offset + object.size(),
+                    Err(err) => {
+                        binder_debug!(UserError, "error while translating object: {err:?}");
+                        return Err(err);
+                    }
+                }
+
+                // Update the indexes containing objects to clean up.
+                let offset_after_object = index_offset + size_of::<u64>();
+                view.alloc
+                    .set_info_offsets(offsets_start..offset_after_object);
+            }
+        }
+
+        // Copy remaining raw data.
+        alloc.copy_into(
+            &mut buffer_reader,
+            end_of_previous_object,
+            data_size - end_of_previous_object,
+        )?;
+
+        if let Some(sg_state) = sg_state.as_mut() {
+            self.apply_sg(&mut alloc, sg_state)?;
+        }
+
+        if let Some((off_out, secctx)) = secctx.as_mut() {
+            if let Err(err) = alloc.write(secctx_off, secctx.as_bytes()) {
+                binder_debug!(UserError, "failed to write security context: {err:?}");
+                return Err(err.into());
+            }
+            **off_out = secctx_off;
+        }
+        Ok(alloc)
+    }
+
+    fn unwind_transaction_stack(self: &Arc<Self>) {
+        let mut thread = self.clone();
+        while let Ok(transaction) = {
+            let mut inner = thread.inner.lock();
+            inner.pop_transaction_to_reply(thread.as_ref())
+        } {
+            binder_debug!(
+                DeadTransaction,
+                "release transaction {} in, still active",
+                transaction.debug_id
+            );
+
+            let reply = Err(BR_DEAD_REPLY);
+            if !transaction
+                .from
+                .deliver_single_reply(reply, &transaction, None)
+            {
+                break;
+            }
+
+            thread = transaction.from.clone();
+        }
+    }
+
+    pub(crate) fn deliver_reply(
+        &self,
+        reply: Result<DLArc<Transaction>, u32>,
+        transaction: &DArc<Transaction>,
+        extended_error: Option<ExtendedError>,
+    ) {
+        if self.deliver_single_reply(reply, transaction, extended_error) {
+            transaction.from.unwind_transaction_stack();
+        }
+    }
+
+    /// Delivers a reply to the thread that started a transaction. The reply can either be a
+    /// reply-transaction or an error code to be delivered instead.
+    ///
+    /// Returns whether the thread is dead. If it is, the caller is expected to unwind the
+    /// transaction stack by completing transactions for threads that are dead.
+    fn deliver_single_reply(
+        &self,
+        reply: Result<DLArc<Transaction>, u32>,
+        transaction: &DArc<Transaction>,
+        extended_error: Option<ExtendedError>,
+    ) -> bool {
+        if let Ok(transaction) = &reply {
+            crate::trace::trace_transaction(true, transaction, Some(&self.task));
+            transaction.set_outstanding(&mut self.process.inner.lock());
+        }
+
+        let ret = {
+            let mut inner = self.inner.lock();
+            if !inner.pop_transaction_replied(transaction) {
+                return false;
+            }
+
+            if inner.is_dead {
+                return true;
+            }
+
+            if let Some(ee) = extended_error {
+                if inner.extended_error.command == BR_OK {
+                    inner.extended_error = ee;
+                }
+            }
+
+            match reply {
+                Ok(work) => inner.push_work(work),
+                Err(code) => inner.push_reply_work(code),
+            }
+        };
+
+        // Notify the thread now that we've released the inner lock.
+        self.work_condvar.notify_sync();
+        if matches!(ret, PushWorkRes::OkNotifyPoll) {
+            self.process.notify_poll(true);
+        }
+        false
+    }
+
+    /// Determines if the given transaction is the current transaction for this thread.
+    fn is_current_transaction(&self, transaction: &DArc<Transaction>) -> bool {
+        let inner = self.inner.lock();
+        match &inner.current_transaction {
+            None => false,
+            Some(current) => Arc::ptr_eq(current, transaction),
+        }
+    }
+
+    /// Determines the current top of the transaction stack. It fails if the top is in another
+    /// thread (i.e., this thread belongs to a stack but it has called another thread). The top is
+    /// [`None`] if the thread is not currently participating in a transaction stack.
+    fn top_of_transaction_stack(&self) -> Result<Option<DArc<Transaction>>> {
+        let inner = self.inner.lock();
+        if let Some(cur) = &inner.current_transaction {
+            if core::ptr::eq(self, cur.from.as_ref()) {
+                pr_warn!("got new transaction with bad transaction stack");
+                return Err(EINVAL);
+            }
+            Ok(Some(cur.clone()))
+        } else {
+            Ok(None)
+        }
+    }
+
+    // No inlining avoids allocating stack space for `BinderTransactionData` for the entire
+    // duration of `transaction()`.
+    #[inline(never)]
+    fn read_transaction_info(
+        &self,
+        cmd: u32,
+        reader: &mut UserSliceReader,
+        info: &mut TransactionInfo,
+    ) -> Result<()> {
+        let td = match cmd {
+            BC_TRANSACTION | BC_REPLY => {
+                reader.read::<BinderTransactionData>()?.with_buffers_size(0)
+            }
+            BC_TRANSACTION_SG | BC_REPLY_SG => reader.read::<BinderTransactionDataSg>()?,
+            _ => return Err(EINVAL),
+        };
+
+        // SAFETY: Above `read` call initializes all bytes, so this union read is ok.
+        let trd_data_ptr = unsafe { &td.transaction_data.data.ptr };
+
+        info.is_reply = matches!(cmd, BC_REPLY | BC_REPLY_SG);
+        info.from_pid = self.process.task.pid();
+        info.from_tid = self.id;
+        info.code = td.transaction_data.code;
+        info.flags = TransactionFlags::from_bits(td.transaction_data.flags);
+        info.data_ptr = UserPtr::from_addr(trd_data_ptr.buffer as usize);
+        info.data_size = td.transaction_data.data_size as usize;
+        info.offsets_ptr = UserPtr::from_addr(trd_data_ptr.offsets as usize);
+        info.offsets_size = td.transaction_data.offsets_size as usize;
+        info.buffers_size = td.buffers_size as usize;
+        // SAFETY: Above `read` call initializes all bytes, so this union read is ok.
+        info.target_handle = unsafe { td.transaction_data.target.handle };
+
+        info.debug_id = super::next_debug_id();
+
+        Ok(())
+    }
+
+    #[inline(never)]
+    fn transaction(self: &Arc<Self>, cmd: u32, reader: &mut UserSliceReader) -> Result<()> {
+        let mut info = TransactionInfo::zeroed();
+        self.read_transaction_info(cmd, reader, &mut info)?;
+
+        self.clear_extended_error(info.debug_id);
+
+        let ret = if info.is_reply {
+            self.reply_inner(&mut info)
+        } else if info.is_oneway() {
+            self.oneway_transaction_inner(&mut info)
+        } else {
+            self.transaction_inner(&mut info)
+        };
+
+        if let Err(err) = ret {
+            self.push_return_work(err.reply);
+            if err.reply != BR_TRANSACTION_COMPLETE {
+                info.reply = err.reply;
+                if let Some(source) = &err.source {
+                    info.errno = source.to_errno();
+
+                    {
+                        let mut inner = self.inner.lock();
+                        inner.extended_error =
+                            ExtendedError::new(info.debug_id as u32, err.reply, source.to_errno());
+                    }
+
+                    binder_debug!(
+                        FailedTransaction,
+                        "transaction {} to {}:{} failed {:?}, code {} size {}-{}",
+                        if info.is_reply {
+                            "reply"
+                        } else if info.is_oneway() {
+                            "async"
+                        } else {
+                            "call"
+                        },
+                        info.to_pid,
+                        info.to_tid,
+                        err,
+                        info.code,
+                        info.data_size,
+                        info.offsets_size
+                    );
+                }
+            }
+        }
+
+        if info.oneway_spam_suspect {
+            // If this is both a oneway spam suspect and a failure, we report it twice. This is
+            // useful in case the transaction failed with BR_TRANSACTION_PENDING_FROZEN.
+            info.report_netlink(BR_ONEWAY_SPAM_SUSPECT, &self.process.ctx);
+        }
+        if info.reply != 0 {
+            info.report_netlink(info.reply, &self.process.ctx);
+        }
+
+        Ok(())
+    }
+
+    fn transaction_inner(self: &Arc<Self>, info: &mut TransactionInfo) -> BinderResult {
+        let node_ref = self.process.get_transaction_node(info.target_handle)?;
+        info.to_pid = node_ref.node.owner.task.pid();
+        security::binder_transaction(&self.process.cred, &node_ref.node.owner.cred)?;
+        // TODO: We need to ensure that there isn't a pending transaction in the work queue. How
+        // could this happen?
+        let top = self.top_of_transaction_stack()?;
+        let list_completion = DTRWrap::arc_try_new(DeliverCode::new(
+            BR_TRANSACTION_COMPLETE,
+            self.process.task.pid(),
+        ))?;
+        let completion = list_completion.clone_arc();
+        let transaction = Transaction::new(node_ref, top, self, info)?;
+
+        // Check that the transaction stack hasn't changed while the lock was released, then update
+        // it with the new transaction.
+        {
+            let mut inner = self.inner.lock();
+            if !transaction.is_stacked_on(&inner.current_transaction) {
+                binder_debug!(UserError, "got new transaction with bad transaction stack");
+                return Err(EINVAL.into());
+            }
+            inner.current_transaction = Some(transaction.clone_arc());
+            // We push the completion as a deferred work so that we wait for the reply before
+            // returning to userland.
+            inner.push_work_deferred(list_completion);
+        }
+
+        if let Err(e) = transaction.submit(info) {
+            completion.skip();
+            // Define `transaction` first to drop it after `inner`.
+            let transaction;
+            let mut inner = self.inner.lock();
+            transaction = inner.current_transaction.take().unwrap();
+            inner.current_transaction = transaction.clone_next();
+            Err(e)
+        } else {
+            Ok(())
+        }
+    }
+
+    fn reply_inner(self: &Arc<Self>, info: &mut TransactionInfo) -> BinderResult {
+        let orig = match self.inner.lock().pop_transaction_to_reply(self) {
+            Ok(orig) => orig,
+            Err(err) => {
+                binder_debug!(UserError, "got reply transaction with no transaction stack");
+                return Err(err.into());
+            }
+        };
+        if !orig.from.is_current_transaction(&orig) {
+            binder_debug!(
+                UserError,
+                "got reply transaction with bad transaction stack"
+            );
+            return Err(EINVAL.into());
+        }
+
+        info.to_tid = orig.from.id;
+        info.to_pid = orig.from.process.task.pid();
+
+        // We need to complete the transaction even if we cannot complete building the reply.
+        let out = (|| -> BinderResult<_> {
+            let completion = DTRWrap::arc_try_new(DeliverCode::new(
+                BR_TRANSACTION_COMPLETE,
+                self.process.task.pid(),
+            ))?;
+            let process = orig.from.process.clone();
+            let allow_fds = orig.flags.contains(TransactionFlag::AcceptFds);
+            let reply = Transaction::new_reply(self, process, info, allow_fds)?;
+            // Not notifying: Reply to current thread.
+            let _ = self.inner.lock().push_work(completion);
+            orig.from.deliver_reply(Ok(reply), &orig, None);
+            Ok(())
+        })()
+        .map_err(|mut err| {
+            // At this point we only return `BR_TRANSACTION_COMPLETE` to the caller, and we must let
+            // the sender know that the transaction has completed (with an error in this case).
+
+            pr_warn!(
+                "{}:{} reply to {} failed: {err:?}",
+                info.from_pid,
+                info.from_tid,
+                info.to_pid
+            );
+            let param = err.source.as_ref().map_or(0, |e| e.to_errno());
+            let ee = ExtendedError::new(info.debug_id as u32, err.reply, param);
+            orig.from
+                .deliver_reply(Err(BR_FAILED_REPLY), &orig, Some(ee));
+            info.reply = BR_FAILED_REPLY;
+            err.reply = BR_TRANSACTION_COMPLETE;
+            err
+        });
+
+        out
+    }
+
+    fn oneway_transaction_inner(self: &Arc<Self>, info: &mut TransactionInfo) -> BinderResult {
+        let node_ref = self.process.get_transaction_node(info.target_handle)?;
+        info.to_pid = node_ref.node.owner.task.pid();
+        security::binder_transaction(&self.process.cred, &node_ref.node.owner.cred)?;
+        let transaction = Transaction::new(node_ref, None, self, info)?;
+        let code = if self.process.is_oneway_spam_detection_enabled() && info.oneway_spam_suspect {
+            BR_ONEWAY_SPAM_SUSPECT
+        } else {
+            BR_TRANSACTION_COMPLETE
+        };
+        let list_completion =
+            DTRWrap::arc_try_new(DeliverCode::new(code, self.process.task.pid()))?;
+        let completion = list_completion.clone_arc();
+        // Not notifying: Reply to current thread.
+        let _ = self.inner.lock().push_work(list_completion);
+        match transaction.submit(info) {
+            Ok(()) => Ok(()),
+            Err(err) => {
+                completion.skip();
+                Err(err)
+            }
+        }
+    }
+
+    fn write(self: &Arc<Self>, req: &mut BinderWriteRead) -> Result {
+        let write_start = req.write_buffer.wrapping_add(req.write_consumed);
+        let write_len = req.write_size.saturating_sub(req.write_consumed);
+        let mut reader =
+            UserSlice::new(UserPtr::from_addr(write_start as usize), write_len as usize).reader();
+
+        while reader.len() >= size_of::<u32>() && self.inner.lock().return_work.is_unused() {
+            let before = reader.len();
+            let cmd = reader.read::<u32>()?;
+            crate::trace::trace_command(cmd);
+            GLOBAL_STATS.inc_bc(cmd);
+            self.process.stats.inc_bc(cmd);
+            match cmd {
+                BC_TRANSACTION | BC_TRANSACTION_SG | BC_REPLY | BC_REPLY_SG => {
+                    self.transaction(cmd, &mut reader)?;
+                }
+                BC_FREE_BUFFER => {
+                    let buffer = self.process.buffer_get(reader.read()?);
+                    if let Some(buffer) = buffer {
+                        if buffer.looper_need_return_on_free() {
+                            self.inner.lock().looper_need_return = true;
+                        }
+                        drop(buffer);
+                    }
+                }
+                BC_INCREFS => {
+                    self.process
+                        .as_arc_borrow()
+                        .update_ref(reader.read()?, true, false)?
+                }
+                BC_ACQUIRE => {
+                    self.process
+                        .as_arc_borrow()
+                        .update_ref(reader.read()?, true, true)?
+                }
+                BC_RELEASE => {
+                    self.process
+                        .as_arc_borrow()
+                        .update_ref(reader.read()?, false, true)?
+                }
+                BC_DECREFS => {
+                    self.process
+                        .as_arc_borrow()
+                        .update_ref(reader.read()?, false, false)?
+                }
+                BC_INCREFS_DONE => self.process.inc_ref_done(&mut reader, false)?,
+                BC_ACQUIRE_DONE => self.process.inc_ref_done(&mut reader, true)?,
+                BC_REQUEST_DEATH_NOTIFICATION => self.process.request_death(&mut reader, self)?,
+                BC_CLEAR_DEATH_NOTIFICATION => self.process.clear_death(&mut reader, self)?,
+                BC_DEAD_BINDER_DONE => self.process.dead_binder_done(reader.read()?, self),
+                BC_REGISTER_LOOPER => {
+                    let valid = self.process.register_thread();
+                    self.inner.lock().looper_register(valid);
+                }
+                BC_ENTER_LOOPER => self.inner.lock().looper_enter(),
+                BC_EXIT_LOOPER => self.inner.lock().looper_exit(),
+                BC_REQUEST_FREEZE_NOTIFICATION => self.process.request_freeze_notif(&mut reader)?,
+                BC_CLEAR_FREEZE_NOTIFICATION => self.process.clear_freeze_notif(&mut reader)?,
+                BC_FREEZE_NOTIFICATION_DONE => self.process.freeze_notif_done(&mut reader)?,
+
+                // Fail if given an unknown error code.
+                // BC_ATTEMPT_ACQUIRE and BC_ACQUIRE_RESULT are no longer supported.
+                _ => return Err(EINVAL),
+            }
+            // Update the number of write bytes consumed.
+            req.write_consumed += (before - reader.len()) as u64;
+        }
+
+        Ok(())
+    }
+
+    fn read(self: &Arc<Self>, req: &mut BinderWriteRead, wait: bool) -> Result {
+        let read_start = req.read_buffer.wrapping_add(req.read_consumed);
+        let read_len = req.read_size.saturating_sub(req.read_consumed);
+        let mut writer = BinderReturnWriter::new(
+            UserSlice::new(UserPtr::from_addr(read_start as usize), read_len as usize).writer(),
+            self,
+        );
+        let (in_pool, has_transaction, thread_todo, use_proc_queue) = {
+            let inner = self.inner.lock();
+            (
+                inner.is_looper(),
+                inner.current_transaction.is_some(),
+                !inner.work_list.is_empty(),
+                inner.should_use_process_work_queue(),
+            )
+        };
+
+        crate::trace::trace_wait_for_work(use_proc_queue, has_transaction, thread_todo);
+
+        let getter = if use_proc_queue {
+            Self::get_work
+        } else {
+            Self::get_work_local
+        };
+
+        // Reserve some room at the beginning of the read buffer so that we can send a
+        // BR_SPAWN_LOOPER if we need to.
+        let mut has_noop_placeholder = false;
+        if req.read_consumed == 0 {
+            if let Err(err) = writer.write_code(BR_NOOP) {
+                pr_warn!("Failure when writing BR_NOOP at beginning of buffer.");
+                return Err(err);
+            }
+            has_noop_placeholder = true;
+        }
+
+        // Loop doing work while there is room in the buffer.
+        let initial_len = writer.len();
+        while writer.len() >= size_of::<uapi::binder_transaction_data_secctx>() + 4 {
+            match getter(self, wait && initial_len == writer.len()) {
+                Ok(Some(work)) => match work.into_arc().do_work(self, &mut writer) {
+                    Ok(true) => {}
+                    Ok(false) => break,
+                    Err(err) => {
+                        return Err(err);
+                    }
+                },
+                Ok(None) => {
+                    break;
+                }
+                Err(err) => {
+                    // Propagate the error if we haven't written anything else.
+                    if err != EINTR && err != EAGAIN {
+                        pr_warn!("Failure in work getter: {:?}", err);
+                    }
+                    if initial_len == writer.len() {
+                        return Err(err);
+                    } else {
+                        break;
+                    }
+                }
+            }
+        }
+
+        req.read_consumed += read_len - writer.len() as u64;
+
+        // Write BR_SPAWN_LOOPER if the process needs more threads for its pool.
+        if has_noop_placeholder && in_pool && self.process.needs_thread() {
+            let mut writer = UserSlice::new(
+                UserPtr::from_addr(req.read_buffer as usize),
+                req.read_size as usize,
+            )
+            .writer();
+            writer.write(&BR_SPAWN_LOOPER)?;
+        }
+        Ok(())
+    }
+
+    pub(crate) fn write_read(self: &Arc<Self>, data: UserSlice, wait: bool) -> Result {
+        let (mut reader, mut writer) = data.reader_writer();
+        let mut req = reader.read::<BinderWriteRead>()?;
+
+        // Go through the write buffer.
+        let mut ret = Ok(());
+        if req.write_size > 0 {
+            ret = self.write(&mut req);
+            crate::trace::trace_write_done(ret);
+            if let Err(err) = ret {
+                pr_warn!(
+                    "Write failure {:?} in pid:{}",
+                    err,
+                    self.process.pid_in_current_ns()
+                );
+                req.read_consumed = 0;
+                writer.write(&req)?;
+                self.inner.lock().looper_need_return = false;
+                return ret;
+            }
+        }
+
+        // Go through the work queue.
+        if req.read_size > 0 {
+            ret = self.read(&mut req, wait);
+            crate::trace::trace_read_done(ret);
+            if ret.is_err() && ret != Err(EINTR) {
+                pr_warn!(
+                    "Read failure {:?} in pid:{}",
+                    ret,
+                    self.process.pid_in_current_ns()
+                );
+            }
+        }
+
+        // Write the request back so that the consumed fields are visible to the caller.
+        writer.write(&req)?;
+
+        self.inner.lock().looper_need_return = false;
+
+        ret
+    }
+
+    pub(crate) fn poll(&self) -> Result<(bool, u32)> {
+        let mut inner = self.inner.lock();
+        Ok((inner.should_use_process_work_queue(), inner.poll()))
+    }
+
+    /// Make the call to `get_work` or `get_work_local` return immediately, if any.
+    pub(crate) fn exit_looper(&self) {
+        let mut inner = self.inner.lock();
+        let should_notify = inner.looper_flags.contains(LooperFlag::Waiting);
+        if should_notify {
+            inner.looper_need_return = true;
+        }
+        drop(inner);
+
+        if should_notify {
+            self.work_condvar.notify_one();
+        }
+    }
+
+    pub(crate) fn release(self: &Arc<Self>) {
+        self.inner.lock().is_dead = true;
+
+        self.unwind_transaction_stack();
+
+        // Cancel all pending work items.
+        while let Ok(Some(work)) = self.get_work_local(false) {
+            work.into_arc().cancel();
+        }
+    }
+}
+
+#[pin_data]
+struct ThreadError {
+    error_code: Atomic<u32>,
+    pid: i32,
+    #[pin]
+    links_track: AtomicTracker,
+}
+
+impl ThreadError {
+    fn try_new(pid: i32) -> Result<DArc<Self>> {
+        DTRWrap::arc_pin_init(pin_init!(Self {
+            error_code: Atomic::new(BR_OK),
+            pid,
+            links_track <- AtomicTracker::new(),
+        }))
+        .map(ListArc::into_arc)
+    }
+
+    fn set_error_code(&self, code: u32) {
+        self.error_code.store(code, Relaxed);
+    }
+
+    fn is_unused(&self) -> bool {
+        self.error_code.load(Relaxed) == BR_OK
+    }
+}
+
+impl DeliverToRead for ThreadError {
+    fn do_work(
+        self: DArc<Self>,
+        _thread: &Thread,
+        writer: &mut BinderReturnWriter<'_>,
+    ) -> Result<bool> {
+        let code = self.error_code.load(Relaxed);
+        self.error_code.store(BR_OK, Relaxed);
+        writer.write_code(code)?;
+        Ok(true)
+    }
+
+    fn cancel(self: DArc<Self>) {
+        let code = self.error_code.load(Relaxed);
+        if code != BR_OK {
+            binder_debug!(
+                pid = self.pid,
+                DeadTransaction,
+                "undelivered TRANSACTION_ERROR: {code}"
+            );
+        }
+    }
+
+    fn should_sync_wakeup(&self) -> bool {
+        false
+    }
+
+    fn debug_print(&self, m: &SeqFile, prefix: &str, _tprefix: &str) -> Result<()> {
+        seq_print!(
+            m,
+            "{}transaction error: {}\n",
+            prefix,
+            self.error_code.load(Relaxed)
+        );
+        Ok(())
+    }
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<0> for ThreadError {
+        tracked_by links_track: AtomicTracker;
+    }
+}
diff --git a/drivers/android/binder/trace.rs b/drivers/android/binder/trace.rs
new file mode 100644
index 000000000..06aabb3cc
--- /dev/null
+++ b/drivers/android/binder/trace.rs
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use crate::transaction::Transaction;
+
+use core::ptr;
+
+use kernel::bindings::{rust_binder_transaction, task_struct};
+use kernel::error::Result;
+use kernel::ffi::{c_int, c_uint, c_ulong};
+use kernel::task::Task;
+use kernel::tracepoint::declare_trace;
+
+declare_trace! {
+    unsafe fn binder_ioctl(cmd: c_uint, arg: c_ulong);
+    unsafe fn binder_ioctl_done(ret: c_int);
+    unsafe fn binder_read_done(ret: c_int);
+    unsafe fn binder_write_done(ret: c_int);
+    unsafe fn binder_wait_for_work(proc_work: bool, transaction_stack: bool, thread_todo: bool);
+    unsafe fn binder_transaction(reply: bool, t: rust_binder_transaction, thread: *mut task_struct);
+    unsafe fn binder_transaction_received(t: rust_binder_transaction);
+    unsafe fn binder_transaction_fd_send(t_debug_id: c_int, fd: c_int, offset: usize);
+    unsafe fn binder_transaction_fd_recv(t_debug_id: c_int, fd: c_int, offset: usize);
+    unsafe fn binder_command(cmd: u32);
+    unsafe fn binder_return(ret: u32);
+}
+
+#[inline]
+fn raw_transaction(t: &Transaction) -> rust_binder_transaction {
+    ptr::from_ref(t).cast_mut().cast()
+}
+
+#[inline]
+fn to_errno(ret: Result) -> i32 {
+    match ret {
+        Ok(()) => 0,
+        Err(err) => err.to_errno(),
+    }
+}
+
+#[inline]
+pub(crate) fn trace_ioctl(cmd: u32, arg: usize) {
+    // SAFETY: Always safe to call.
+    unsafe { binder_ioctl(cmd, arg as c_ulong) }
+}
+
+#[inline]
+pub(crate) fn trace_ioctl_done(ret: Result) {
+    // SAFETY: Always safe to call.
+    unsafe { binder_ioctl_done(to_errno(ret)) }
+}
+#[inline]
+pub(crate) fn trace_read_done(ret: Result) {
+    // SAFETY: Always safe to call.
+    unsafe { binder_read_done(to_errno(ret)) }
+}
+#[inline]
+pub(crate) fn trace_write_done(ret: Result) {
+    // SAFETY: Always safe to call.
+    unsafe { binder_write_done(to_errno(ret)) }
+}
+
+#[inline]
+pub(crate) fn trace_wait_for_work(proc_work: bool, transaction_stack: bool, thread_todo: bool) {
+    // SAFETY: Always safe to call.
+    unsafe { binder_wait_for_work(proc_work, transaction_stack, thread_todo) }
+}
+
+#[inline]
+pub(crate) fn trace_transaction(reply: bool, t: &Transaction, thread: Option<&Task>) {
+    let thread = match thread {
+        Some(thread) => thread.as_ptr(),
+        None => core::ptr::null_mut(),
+    };
+    // SAFETY: The raw transaction is valid for the duration of this call. The thread pointer is
+    // valid or null.
+    unsafe { binder_transaction(reply, raw_transaction(t), thread) }
+}
+
+#[inline]
+pub(crate) fn trace_transaction_received(t: &Transaction) {
+    // SAFETY: The raw transaction is valid for the duration of this call.
+    unsafe { binder_transaction_received(raw_transaction(t)) }
+}
+
+#[inline]
+pub(crate) fn trace_transaction_fd_send(t_debug_id: usize, fd: u32, offset: usize) {
+    // SAFETY: This function is always safe to call.
+    unsafe { binder_transaction_fd_send(t_debug_id as c_int, fd as c_int, offset) }
+}
+#[inline]
+pub(crate) fn trace_transaction_fd_recv(t_debug_id: usize, fd: u32, offset: usize) {
+    // SAFETY: This function is always safe to call.
+    unsafe { binder_transaction_fd_recv(t_debug_id as c_int, fd as c_int, offset) }
+}
+
+#[inline]
+pub(crate) fn trace_command(cmd: u32) {
+    // SAFETY: This function is always safe to call.
+    unsafe { binder_command(cmd) }
+}
+#[inline]
+pub(crate) fn trace_return(ret: u32) {
+    // SAFETY: This function is always safe to call.
+    unsafe { binder_return(ret) }
+}
diff --git a/drivers/android/binder/transaction.rs b/drivers/android/binder/transaction.rs
new file mode 100644
index 000000000..245f1556b
--- /dev/null
+++ b/drivers/android/binder/transaction.rs
@@ -0,0 +1,590 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2025 Google LLC.
+
+use kernel::{
+    net::netlink::GENLMSG_DEFAULT_SIZE,
+    prelude::*,
+    seq_file::SeqFile,
+    seq_print,
+    sync::atomic::{ordering::Relaxed, Atomic},
+    sync::{Arc, SpinLock},
+    task::{Kuid, Pid},
+    time::{Instant, Monotonic},
+    types::ScopeGuard,
+    uapi,
+};
+
+use crate::{
+    allocation::{Allocation, TranslatedFds},
+    defs::*,
+    error::{BinderError, BinderResult},
+    netlink::Report,
+    node::{Node, NodeRef},
+    process::{Process, ProcessInner},
+    ptr_align,
+    thread::{PushWorkRes, Thread},
+    BinderReturnWriter, DArc, DLArc, DTRWrap, DeliverToRead,
+};
+
+kernel::impl_flags!(
+    /// Represents multiple transaction flags.
+    #[derive(Debug, Clone, Default, Copy, PartialEq, Eq, Zeroable)]
+    pub struct TransactionFlags(u32);
+
+    /// Represents a single transaction flag.
+    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+    pub enum TransactionFlag {
+        OneWay = TF_ONE_WAY,
+        AcceptFds = TF_ACCEPT_FDS,
+        ClearBuf = TF_CLEAR_BUF,
+        UpdateTxn = TF_UPDATE_TXN,
+    }
+);
+
+impl TransactionFlags {
+    /// Creates a `TransactionFlags` from a raw `u32` value.
+    pub(crate) fn from_bits(bits: u32) -> Self {
+        Self(bits)
+    }
+
+    /// Checks if the Oneway flag is set.
+    pub(crate) fn is_oneway(self) -> bool {
+        self.contains(TransactionFlag::OneWay)
+    }
+}
+
+#[derive(Zeroable)]
+pub(crate) struct TransactionInfo {
+    pub(crate) from_pid: Pid,
+    pub(crate) from_tid: Pid,
+    pub(crate) to_pid: Pid,
+    pub(crate) to_tid: Pid,
+    pub(crate) code: u32,
+    pub(crate) flags: TransactionFlags,
+    pub(crate) data_ptr: UserPtr,
+    pub(crate) data_size: usize,
+    pub(crate) offsets_ptr: UserPtr,
+    pub(crate) offsets_size: usize,
+    pub(crate) buffers_size: usize,
+    pub(crate) target_handle: u32,
+    pub(crate) errno: i32,
+    pub(crate) reply: u32,
+    pub(crate) oneway_spam_suspect: bool,
+    pub(crate) is_reply: bool,
+    pub(crate) debug_id: usize,
+}
+
+impl TransactionInfo {
+    #[inline]
+    pub(crate) fn is_oneway(&self) -> bool {
+        self.flags.is_oneway()
+    }
+
+    pub(crate) fn report_netlink(&self, reply: u32, ctx: &crate::Context) {
+        if let Err(err) = self.report_netlink_inner(reply, ctx) {
+            pr_warn!(
+                "{}:{} netlink report failed: {err:?}\n",
+                self.from_pid,
+                self.from_tid
+            );
+        }
+    }
+
+    fn report_netlink_inner(&self, reply: u32, ctx: &crate::Context) -> kernel::error::Result {
+        if !Report::has_listeners() {
+            return Ok(());
+        }
+        let mut report = Report::new(GENLMSG_DEFAULT_SIZE, 0, 0, GFP_KERNEL)?;
+
+        report.error(reply)?;
+        report.context(&ctx.name)?;
+        report.from_pid(self.from_pid as u32)?;
+        report.from_tid(self.from_tid as u32)?;
+        if self.to_pid != 0 {
+            report.to_pid(self.to_pid as u32)?;
+        }
+        if self.to_tid != 0 {
+            report.to_tid(self.to_tid as u32)?;
+        }
+
+        if self.is_reply {
+            report.is_reply()?;
+        }
+        report.flags(u32::from(self.flags))?;
+        report.code(self.code)?;
+        report.data_size(self.data_size as u32)?;
+
+        report.multicast(0, GFP_KERNEL)?;
+        Ok(())
+    }
+}
+
+use core::mem::offset_of;
+use kernel::bindings::rb_transaction_layout;
+pub(crate) const TRANSACTION_LAYOUT: rb_transaction_layout = rb_transaction_layout {
+    debug_id: offset_of!(Transaction, debug_id),
+    code: offset_of!(Transaction, code),
+    flags: offset_of!(Transaction, flags),
+    from_thread: offset_of!(Transaction, from),
+    to_proc: offset_of!(Transaction, to),
+    target_node: offset_of!(Transaction, target_node),
+};
+
+#[pin_data(PinnedDrop)]
+pub(crate) struct Transaction {
+    pub(crate) debug_id: usize,
+    target_node: Option<DArc<Node>>,
+    pub(crate) from_parent: Option<DArc<Transaction>>,
+    pub(crate) from: Arc<Thread>,
+    pub(crate) to: Arc<Process>,
+    #[pin]
+    allocation: SpinLock<Option<Allocation>>,
+    is_outstanding: Atomic<bool>,
+    code: u32,
+    pub(crate) flags: TransactionFlags,
+    data_size: usize,
+    offsets_size: usize,
+    data_address: usize,
+    sender_euid: Kuid,
+    txn_security_ctx_off: Option<usize>,
+    start_time: Instant<Monotonic>,
+}
+
+kernel::list::impl_list_arc_safe! {
+    impl ListArcSafe<0> for Transaction { untracked; }
+}
+
+impl Transaction {
+    pub(crate) fn new(
+        node_ref: NodeRef,
+        from_parent: Option<DArc<Transaction>>,
+        from: &Arc<Thread>,
+        info: &mut TransactionInfo,
+    ) -> BinderResult<DLArc<Self>> {
+        let allow_fds = node_ref.node.flags & FLAT_BINDER_FLAG_ACCEPTS_FDS != 0;
+        let txn_security_ctx = node_ref.node.flags & FLAT_BINDER_FLAG_TXN_SECURITY_CTX != 0;
+        let mut txn_security_ctx_off = if txn_security_ctx { Some(0) } else { None };
+        let to = node_ref.node.owner.clone();
+        let mut alloc = match from.copy_transaction_data(
+            to.clone(),
+            info,
+            info.debug_id,
+            allow_fds,
+            txn_security_ctx_off.as_mut(),
+        ) {
+            Ok(alloc) => alloc,
+            Err(err) => {
+                if !err.is_dead() {
+                    pr_warn!("Failure in copy_transaction_data: {:?}", err);
+                }
+                return Err(err);
+            }
+        };
+        if info.is_oneway() {
+            if from_parent.is_some() {
+                pr_warn!("Oneway transaction should not be in a transaction stack.");
+                return Err(EINVAL.into());
+            }
+            alloc.set_info_oneway_node(node_ref.node.clone());
+        }
+        if info.flags.contains(TransactionFlag::ClearBuf) {
+            alloc.set_info_clear_on_drop();
+        }
+        let target_node = node_ref.node.clone();
+        alloc.set_info_target_node(node_ref);
+        let data_address = alloc.ptr;
+
+        Ok(DTRWrap::arc_pin_init(pin_init!(Transaction {
+            debug_id: info.debug_id,
+            target_node: Some(target_node),
+            from_parent,
+            sender_euid: Kuid::current_euid(),
+            from: from.clone(),
+            to,
+            code: info.code,
+            flags: info.flags,
+            data_size: info.data_size,
+            offsets_size: info.offsets_size,
+            data_address,
+            allocation <- kernel::new_spinlock!(Some(alloc.success()), "Transaction::new"),
+            is_outstanding: Atomic::new(false),
+            txn_security_ctx_off,
+            start_time: Instant::now(),
+        }))?)
+    }
+
+    pub(crate) fn new_reply(
+        from: &Arc<Thread>,
+        to: Arc<Process>,
+        info: &mut TransactionInfo,
+        allow_fds: bool,
+    ) -> BinderResult<DLArc<Self>> {
+        let mut alloc =
+            match from.copy_transaction_data(to.clone(), info, info.debug_id, allow_fds, None) {
+                Ok(alloc) => alloc,
+                Err(err) => {
+                    pr_warn!("Failure in copy_transaction_data: {:?}", err);
+                    return Err(err);
+                }
+            };
+        if info.flags.contains(TransactionFlag::ClearBuf) {
+            alloc.set_info_clear_on_drop();
+        }
+        Ok(DTRWrap::arc_pin_init(pin_init!(Transaction {
+            debug_id: info.debug_id,
+            target_node: None,
+            from_parent: None,
+            sender_euid: Kuid::current_euid(),
+            from: from.clone(),
+            to,
+            code: info.code,
+            flags: info.flags,
+            data_size: info.data_size,
+            offsets_size: info.offsets_size,
+            data_address: alloc.ptr,
+            allocation <- kernel::new_spinlock!(Some(alloc.success()), "Transaction::new"),
+            is_outstanding: Atomic::new(false),
+            txn_security_ctx_off: None,
+            start_time: Instant::now(),
+        }))?)
+    }
+
+    #[inline(never)]
+    pub(crate) fn debug_print_inner(&self, m: &SeqFile, prefix: &str) {
+        seq_print!(
+            m,
+            "{}{}: from {}:{} to {} code {:x} flags {:x} elapsed {}ms",
+            prefix,
+            self.debug_id,
+            self.from.process.task.pid(),
+            self.from.id,
+            self.to.task.pid(),
+            self.code,
+            u32::from(self.flags),
+            self.start_time.elapsed().as_millis(),
+        );
+        if let Some(target_node) = &self.target_node {
+            seq_print!(m, " node {}", target_node.debug_id);
+        }
+        seq_print!(m, " size {}:{}\n", self.data_size, self.offsets_size);
+    }
+
+    /// Determines if the transaction is stacked on top of the given transaction.
+    pub(crate) fn is_stacked_on(&self, onext: &Option<DArc<Self>>) -> bool {
+        match (&self.from_parent, onext) {
+            (None, None) => true,
+            (Some(from_parent), Some(next)) => Arc::ptr_eq(from_parent, next),
+            _ => false,
+        }
+    }
+
+    /// Returns a pointer to the next transaction on the transaction stack, if there is one.
+    pub(crate) fn clone_next(&self) -> Option<DArc<Self>> {
+        Some(self.from_parent.as_ref()?.clone())
+    }
+
+    /// Searches in the transaction stack for a thread that belongs to the target process. This is
+    /// useful when finding a target for a new transaction: if the node belongs to a process that
+    /// is already part of the transaction stack, we reuse the thread.
+    fn find_target_thread(&self) -> Option<Arc<Thread>> {
+        let mut it = &self.from_parent;
+        while let Some(transaction) = it {
+            if Arc::ptr_eq(&transaction.from.process, &self.to) {
+                return Some(transaction.from.clone());
+            }
+            it = &transaction.from_parent;
+        }
+        None
+    }
+
+    /// Searches in the transaction stack for a transaction originating at the given thread.
+    pub(crate) fn find_from(&self, thread: &Thread) -> Option<&DArc<Transaction>> {
+        let mut it = &self.from_parent;
+        while let Some(transaction) = it {
+            if core::ptr::eq(thread, transaction.from.as_ref()) {
+                return Some(transaction);
+            }
+
+            it = &transaction.from_parent;
+        }
+        None
+    }
+
+    pub(crate) fn set_outstanding(&self, to_process: &mut ProcessInner) {
+        // No race because this method is only called once.
+        if !self.is_outstanding.load(Relaxed) {
+            self.is_outstanding.store(true, Relaxed);
+            to_process.add_outstanding_txn();
+        }
+    }
+
+    /// Decrement `outstanding_txns` in `to` if it hasn't already been decremented.
+    fn drop_outstanding_txn(&self) {
+        // No race because this is called at most twice, and one of the calls are in the
+        // destructor, which is guaranteed to not race with any other operations on the
+        // transaction. It also cannot race with `set_outstanding`, since submission happens
+        // before delivery.
+        if self.is_outstanding.load(Relaxed) {
+            self.is_outstanding.store(false, Relaxed);
+            self.to.drop_outstanding_txn();
+        }
+    }
+
+    /// Submits the transaction to a work queue. Uses a thread if there is one in the transaction
+    /// stack, otherwise uses the destination process.
+    ///
+    /// Not used for replies.
+    pub(crate) fn submit(self: DLArc<Self>, info: &mut TransactionInfo) -> BinderResult {
+        // Defined before `process_inner` so that the destructor runs after releasing the lock.
+        let _t_outdated;
+        let _oneway_node;
+
+        let oneway = self.flags.is_oneway();
+        let process = self.to.clone();
+        let mut process_inner = process.inner.lock();
+
+        self.set_outstanding(&mut process_inner);
+
+        if oneway {
+            if let Some(target_node) = self.target_node.clone() {
+                crate::trace::trace_transaction(false, &self, None);
+                if process_inner.is_frozen.is_frozen() {
+                    process_inner.async_recv = true;
+                    if self.flags.contains(TransactionFlag::UpdateTxn) {
+                        if let Some(t_outdated) =
+                            target_node.take_outdated_transaction(&self, &mut process_inner)
+                        {
+                            let mut alloc_guard = t_outdated.allocation.lock();
+                            if let Some(alloc) = (*alloc_guard).as_mut() {
+                                // Take the oneway node to prevent `Allocation::drop` from calling
+                                // `pending_oneway_finished()`, which would be incorrect as this
+                                // transaction is not being submitted.
+                                _oneway_node = alloc.take_oneway_node();
+                            }
+                            drop(alloc_guard);
+                            // Save the transaction to be dropped after locks are released.
+                            _t_outdated = t_outdated;
+                        }
+                    }
+                }
+                match target_node.submit_oneway(self, &mut process_inner) {
+                    Ok(()) => {}
+                    Err((err, work)) => {
+                        drop(process_inner);
+                        // Drop work after releasing process lock.
+                        drop(work);
+                        return Err(err);
+                    }
+                }
+
+                if process_inner.is_frozen.is_frozen() {
+                    return Err(BinderError::new_frozen_oneway());
+                } else {
+                    return Ok(());
+                }
+            } else {
+                pr_err!("Failed to submit oneway transaction to node.");
+            }
+        }
+
+        if process_inner.is_frozen.is_frozen() {
+            process_inner.sync_recv = true;
+            return Err(BinderError::new_frozen());
+        }
+
+        let res = if let Some(thread) = self.find_target_thread() {
+            info.to_tid = thread.id;
+            crate::trace::trace_transaction(false, &self, Some(&thread.task));
+            match thread.push_work(self) {
+                PushWorkRes::Ok => Ok(()),
+                PushWorkRes::OkNotifyPoll => {
+                    process.notify_poll(true);
+                    Ok(())
+                }
+                PushWorkRes::FailedDead(me) => Err((BinderError::new_dead(), me)),
+            }
+        } else {
+            crate::trace::trace_transaction(false, &self, None);
+            process_inner.push_work(&process, self)
+        };
+        drop(process_inner);
+
+        match res {
+            Ok(()) => Ok(()),
+            Err((err, work)) => {
+                // Drop work after releasing process lock.
+                drop(work);
+                Err(err)
+            }
+        }
+    }
+
+    /// Check whether one oneway transaction can supersede another.
+    pub(crate) fn can_replace(&self, old: &Transaction) -> bool {
+        if self.from.process.task.pid() != old.from.process.task.pid() {
+            return false;
+        }
+
+        let required = TransactionFlag::OneWay | TransactionFlag::UpdateTxn;
+        if !(self.flags.contains_all(required) && old.flags.contains_all(required)) {
+            return false;
+        }
+
+        let target_node_match = match (self.target_node.as_ref(), old.target_node.as_ref()) {
+            (None, None) => true,
+            (Some(tn1), Some(tn2)) => Arc::ptr_eq(tn1, tn2),
+            _ => false,
+        };
+
+        self.code == old.code && self.flags == old.flags && target_node_match
+    }
+
+    fn prepare_file_list(&self) -> Result<TranslatedFds> {
+        let mut alloc = self.allocation.lock().take().ok_or(ESRCH)?;
+
+        match alloc.translate_fds() {
+            Ok(translated) => {
+                *self.allocation.lock() = Some(alloc);
+                Ok(translated)
+            }
+            Err(err) => {
+                // Free the allocation eagerly.
+                drop(alloc);
+                Err(err)
+            }
+        }
+    }
+}
+
+impl DeliverToRead for Transaction {
+    fn do_work(
+        self: DArc<Self>,
+        thread: &Thread,
+        writer: &mut BinderReturnWriter<'_>,
+    ) -> Result<bool> {
+        let send_failed_reply = ScopeGuard::new(|| {
+            if self.target_node.is_some() && !self.flags.is_oneway() {
+                let reply = Err(BR_FAILED_REPLY);
+                self.from.deliver_reply(reply, &self, None);
+            }
+            self.drop_outstanding_txn();
+        });
+
+        let files = if let Ok(list) = self.prepare_file_list() {
+            list
+        } else {
+            // On failure to process the list, we send a reply back to the sender and ignore the
+            // transaction on the recipient.
+            binder_debug!(
+                FailedTransaction,
+                "transaction {} to {} failed, fd fixups failed, size {}-{}",
+                self.debug_id,
+                self.to.task.pid(),
+                self.data_size,
+                self.offsets_size
+            );
+            return Ok(true);
+        };
+
+        let mut tr_sec = BinderTransactionDataSecctx::default();
+        let tr = tr_sec.tr_data();
+        if let Some(target_node) = &self.target_node {
+            let (ptr, cookie) = target_node.get_id();
+            tr.target.ptr = ptr as uapi::binder_uintptr_t;
+            tr.cookie = cookie as uapi::binder_uintptr_t;
+        };
+        tr.code = self.code;
+        tr.flags = u32::from(self.flags);
+        tr.data_size = self.data_size as uapi::binder_size_t;
+        tr.data.ptr.buffer = self.data_address as uapi::binder_uintptr_t;
+        tr.offsets_size = self.offsets_size as uapi::binder_size_t;
+        if tr.offsets_size > 0 {
+            tr.data.ptr.offsets =
+                (self.data_address + ptr_align(self.data_size).unwrap()) as uapi::binder_uintptr_t;
+        }
+        tr.sender_euid = self.sender_euid.into_uid_in_current_ns();
+        tr.sender_pid = 0;
+        if self.target_node.is_some() && !self.flags.is_oneway() {
+            // Not a reply and not one-way.
+            tr.sender_pid = self.from.process.pid_in_current_ns();
+        }
+        let code = if self.target_node.is_none() {
+            BR_REPLY
+        } else if self.txn_security_ctx_off.is_some() {
+            BR_TRANSACTION_SEC_CTX
+        } else {
+            BR_TRANSACTION
+        };
+
+        // Write the transaction code and data to the user buffer.
+        writer.write_code(code)?;
+        if let Some(off) = self.txn_security_ctx_off {
+            tr_sec.secctx = (self.data_address + off) as u64;
+            writer.write_payload(&tr_sec)?;
+        } else {
+            writer.write_payload(&*tr)?;
+        }
+
+        let mut alloc = self.allocation.lock().take().ok_or(ESRCH)?;
+
+        // Dismiss the completion of transaction with a failure. No failure paths are allowed from
+        // here on out.
+        send_failed_reply.dismiss();
+
+        // Commit files, and set FDs in FDA to be closed on buffer free.
+        let close_on_free = files.commit();
+        alloc.set_info_close_on_free(close_on_free);
+
+        // It is now the user's responsibility to clear the allocation.
+        alloc.keep_alive();
+
+        self.drop_outstanding_txn();
+
+        crate::trace::trace_transaction_received(&self);
+
+        // When this is not a reply and not a oneway transaction, update `current_transaction`. If
+        // it's a reply, `current_transaction` has already been updated appropriately.
+        if self.target_node.is_some() && tr_sec.transaction_data.flags & TF_ONE_WAY == 0 {
+            thread.set_current_transaction(self);
+        }
+
+        Ok(false)
+    }
+
+    fn cancel(self: DArc<Self>) {
+        let allocation = self.allocation.lock().take();
+        drop(allocation);
+
+        // If this is not a reply or oneway transaction, then send a dead reply.
+        if self.target_node.is_some() && !self.flags.is_oneway() {
+            let reply = Err(BR_DEAD_REPLY);
+            self.from.deliver_reply(reply, &self, None);
+        } else {
+            binder_debug!(
+                pid = self.to.task.pid(),
+                DeadTransaction,
+                "undelivered transaction {}, process died",
+                self.debug_id
+            );
+        }
+
+        self.drop_outstanding_txn();
+    }
+
+    fn should_sync_wakeup(&self) -> bool {
+        !self.flags.is_oneway()
+    }
+
+    fn debug_print(&self, m: &SeqFile, _prefix: &str, tprefix: &str) -> Result<()> {
+        self.debug_print_inner(m, tprefix);
+        Ok(())
+    }
+}
+
+#[pinned_drop]
+impl PinnedDrop for Transaction {
+    fn drop(self: Pin<&mut Self>) {
+        self.drop_outstanding_txn();
+    }
+}
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
new file mode 100644
index 000000000..e4488ad86
--- /dev/null
+++ b/drivers/android/binder_alloc.c
@@ -0,0 +1,1409 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* binder_alloc.c
+ *
+ * Android IPC Subsystem
+ *
+ * Copyright (C) 2007-2017 Google, Inc.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/list.h>
+#include <linux/sched/mm.h>
+#include <linux/module.h>
+#include <linux/rtmutex.h>
+#include <linux/rbtree.h>
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/list_lru.h>
+#include <linux/ratelimit.h>
+#include <asm/cacheflush.h>
+#include <linux/uaccess.h>
+#include <linux/highmem.h>
+#include <linux/sizes.h>
+#include <kunit/visibility.h>
+#include "binder_alloc.h"
+#include "binder_trace.h"
+
+static struct list_lru binder_freelist;
+
+static DEFINE_MUTEX(binder_alloc_mmap_lock);
+
+enum {
+	BINDER_DEBUG_USER_ERROR             = 1U << 0,
+	BINDER_DEBUG_OPEN_CLOSE             = 1U << 1,
+	BINDER_DEBUG_BUFFER_ALLOC           = 1U << 2,
+	BINDER_DEBUG_BUFFER_ALLOC_ASYNC     = 1U << 3,
+};
+static uint32_t binder_alloc_debug_mask = BINDER_DEBUG_USER_ERROR;
+
+module_param_named(debug_mask, binder_alloc_debug_mask,
+		   uint, 0644);
+
+#define binder_alloc_debug(mask, x...) \
+	do { \
+		if (binder_alloc_debug_mask & mask) \
+			pr_info_ratelimited(x); \
+	} while (0)
+
+static struct binder_buffer *binder_buffer_next(struct binder_buffer *buffer)
+{
+	return list_entry(buffer->entry.next, struct binder_buffer, entry);
+}
+
+static struct binder_buffer *binder_buffer_prev(struct binder_buffer *buffer)
+{
+	return list_entry(buffer->entry.prev, struct binder_buffer, entry);
+}
+
+VISIBLE_IF_KUNIT size_t binder_alloc_buffer_size(struct binder_alloc *alloc,
+						 struct binder_buffer *buffer)
+{
+	if (list_is_last(&buffer->entry, &alloc->buffers))
+		return alloc->vm_start + alloc->buffer_size - buffer->user_data;
+	return binder_buffer_next(buffer)->user_data - buffer->user_data;
+}
+EXPORT_SYMBOL_IF_KUNIT(binder_alloc_buffer_size);
+
+static void binder_insert_free_buffer(struct binder_alloc *alloc,
+				      struct binder_buffer *new_buffer)
+{
+	struct rb_node **p = &alloc->free_buffers.rb_node;
+	struct rb_node *parent = NULL;
+	struct binder_buffer *buffer;
+	size_t buffer_size;
+	size_t new_buffer_size;
+
+	BUG_ON(!new_buffer->free);
+
+	new_buffer_size = binder_alloc_buffer_size(alloc, new_buffer);
+
+	binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+		     "%d: add free buffer, size %zd, at %p\n",
+		      alloc->pid, new_buffer_size, new_buffer);
+
+	while (*p) {
+		parent = *p;
+		buffer = rb_entry(parent, struct binder_buffer, rb_node);
+		BUG_ON(!buffer->free);
+
+		buffer_size = binder_alloc_buffer_size(alloc, buffer);
+
+		if (new_buffer_size < buffer_size)
+			p = &parent->rb_left;
+		else
+			p = &parent->rb_right;
+	}
+	rb_link_node(&new_buffer->rb_node, parent, p);
+	rb_insert_color(&new_buffer->rb_node, &alloc->free_buffers);
+}
+
+static void binder_insert_allocated_buffer_locked(
+		struct binder_alloc *alloc, struct binder_buffer *new_buffer)
+{
+	struct rb_node **p = &alloc->allocated_buffers.rb_node;
+	struct rb_node *parent = NULL;
+	struct binder_buffer *buffer;
+
+	BUG_ON(new_buffer->free);
+
+	while (*p) {
+		parent = *p;
+		buffer = rb_entry(parent, struct binder_buffer, rb_node);
+		BUG_ON(buffer->free);
+
+		if (new_buffer->user_data < buffer->user_data)
+			p = &parent->rb_left;
+		else if (new_buffer->user_data > buffer->user_data)
+			p = &parent->rb_right;
+		else
+			BUG();
+	}
+	rb_link_node(&new_buffer->rb_node, parent, p);
+	rb_insert_color(&new_buffer->rb_node, &alloc->allocated_buffers);
+}
+
+static struct binder_buffer *binder_alloc_prepare_to_free_locked(
+		struct binder_alloc *alloc,
+		unsigned long user_ptr)
+{
+	struct rb_node *n = alloc->allocated_buffers.rb_node;
+	struct binder_buffer *buffer;
+
+	while (n) {
+		buffer = rb_entry(n, struct binder_buffer, rb_node);
+		BUG_ON(buffer->free);
+
+		if (user_ptr < buffer->user_data) {
+			n = n->rb_left;
+		} else if (user_ptr > buffer->user_data) {
+			n = n->rb_right;
+		} else {
+			/*
+			 * Guard against user threads attempting to
+			 * free the buffer when in use by kernel or
+			 * after it's already been freed.
+			 */
+			if (!buffer->allow_user_free)
+				return ERR_PTR(-EPERM);
+			buffer->allow_user_free = 0;
+			return buffer;
+		}
+	}
+	return NULL;
+}
+
+/**
+ * binder_alloc_prepare_to_free() - get buffer given user ptr
+ * @alloc:	binder_alloc for this proc
+ * @user_ptr:	User pointer to buffer data
+ *
+ * Validate userspace pointer to buffer data and return buffer corresponding to
+ * that user pointer. Search the rb tree for buffer that matches user data
+ * pointer.
+ *
+ * Return:	Pointer to buffer or NULL
+ */
+struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc,
+						   unsigned long user_ptr)
+{
+	guard(mutex)(&alloc->mutex);
+	return binder_alloc_prepare_to_free_locked(alloc, user_ptr);
+}
+
+static inline void
+binder_set_installed_page(struct binder_alloc *alloc,
+			  unsigned long index,
+			  struct page *page)
+{
+	/* Pairs with acquire in binder_get_installed_page() */
+	smp_store_release(&alloc->pages[index], page);
+}
+
+static inline struct page *
+binder_get_installed_page(struct binder_alloc *alloc, unsigned long index)
+{
+	/* Pairs with release in binder_set_installed_page() */
+	return smp_load_acquire(&alloc->pages[index]);
+}
+
+static void binder_lru_freelist_add(struct binder_alloc *alloc,
+				    unsigned long start, unsigned long end)
+{
+	unsigned long page_addr;
+	struct page *page;
+
+	trace_binder_update_page_range(alloc, false, start, end);
+
+	for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
+		size_t index;
+		int ret;
+
+		index = (page_addr - alloc->vm_start) / PAGE_SIZE;
+		page = binder_get_installed_page(alloc, index);
+		if (!page)
+			continue;
+
+		trace_binder_free_lru_start(alloc, index);
+
+		ret = list_lru_add(alloc->freelist,
+				   page_to_lru(page),
+				   page_to_nid(page),
+				   NULL);
+		WARN_ON(!ret);
+
+		trace_binder_free_lru_end(alloc, index);
+	}
+}
+
+static inline
+void binder_alloc_set_mapped(struct binder_alloc *alloc, bool state)
+{
+	/* pairs with smp_load_acquire in binder_alloc_is_mapped() */
+	smp_store_release(&alloc->mapped, state);
+}
+
+static inline bool binder_alloc_is_mapped(struct binder_alloc *alloc)
+{
+	/* pairs with smp_store_release in binder_alloc_set_mapped() */
+	return smp_load_acquire(&alloc->mapped);
+}
+
+static struct page *binder_page_lookup(struct binder_alloc *alloc,
+				       unsigned long addr)
+{
+	struct mm_struct *mm = alloc->mm;
+	struct page *page;
+	long npages = 0;
+
+	/*
+	 * Find an existing page in the remote mm. If missing,
+	 * don't attempt to fault-in just propagate an error.
+	 */
+	mmap_read_lock(mm);
+	if (binder_alloc_is_mapped(alloc))
+		npages = get_user_pages_remote(mm, addr, 1, FOLL_NOFAULT,
+					       &page, NULL);
+	mmap_read_unlock(mm);
+
+	return npages > 0 ? page : NULL;
+}
+
+static int binder_page_insert(struct binder_alloc *alloc,
+			      unsigned long addr,
+			      struct page *page)
+{
+	struct mm_struct *mm = alloc->mm;
+	struct vm_area_struct *vma;
+	int ret = -ESRCH;
+
+	/* attempt per-vma lock first */
+	vma = lock_vma_under_rcu(mm, addr);
+	if (vma) {
+		if (binder_alloc_is_mapped(alloc))
+			ret = vm_insert_page(vma, addr, page);
+		vma_end_read(vma);
+		return ret;
+	}
+
+	/* fall back to mmap_lock */
+	mmap_read_lock(mm);
+	vma = vma_lookup(mm, addr);
+	if (vma && binder_alloc_is_mapped(alloc))
+		ret = vm_insert_page(vma, addr, page);
+	mmap_read_unlock(mm);
+
+	return ret;
+}
+
+static struct page *binder_page_alloc(struct binder_alloc *alloc,
+				      unsigned long index)
+{
+	struct binder_shrinker_mdata *mdata;
+	struct page *page;
+
+	page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+	if (!page)
+		return NULL;
+
+	/* allocate and install shrinker metadata under page->private */
+	mdata = kzalloc_obj(*mdata);
+	if (!mdata) {
+		__free_page(page);
+		return NULL;
+	}
+
+	mdata->alloc = alloc;
+	mdata->page_index = index;
+	INIT_LIST_HEAD(&mdata->lru);
+	set_page_private(page, (unsigned long)mdata);
+
+	return page;
+}
+
+static void binder_free_page(struct page *page)
+{
+	kfree((struct binder_shrinker_mdata *)page_private(page));
+	__free_page(page);
+}
+
+static int binder_install_single_page(struct binder_alloc *alloc,
+				      unsigned long index,
+				      unsigned long addr)
+{
+	struct page *page;
+	int ret;
+
+	if (!mmget_not_zero(alloc->mm))
+		return -ESRCH;
+
+	page = binder_page_alloc(alloc, index);
+	if (!page) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = binder_page_insert(alloc, addr, page);
+	switch (ret) {
+	case -EBUSY:
+		/*
+		 * EBUSY is ok. Someone installed the pte first but the
+		 * alloc->pages[index] has not been updated yet. Discard
+		 * our page and look up the one already installed.
+		 */
+		ret = 0;
+		binder_free_page(page);
+		page = binder_page_lookup(alloc, addr);
+		if (!page) {
+			pr_err("%d: failed to find page at offset %lx\n",
+			       alloc->pid, addr - alloc->vm_start);
+			ret = -ESRCH;
+			break;
+		}
+		fallthrough;
+	case 0:
+		/* Mark page installation complete and safe to use */
+		binder_set_installed_page(alloc, index, page);
+		break;
+	default:
+		binder_free_page(page);
+		pr_err("%d: %s failed to insert page at offset %lx with %d\n",
+		       alloc->pid, __func__, addr - alloc->vm_start, ret);
+		break;
+	}
+out:
+	mmput_async(alloc->mm);
+	return ret;
+}
+
+static int binder_install_buffer_pages(struct binder_alloc *alloc,
+				       struct binder_buffer *buffer,
+				       size_t size)
+{
+	unsigned long start, final;
+	unsigned long page_addr;
+
+	start = buffer->user_data & PAGE_MASK;
+	final = PAGE_ALIGN(buffer->user_data + size);
+
+	for (page_addr = start; page_addr < final; page_addr += PAGE_SIZE) {
+		unsigned long index;
+		int ret;
+
+		index = (page_addr - alloc->vm_start) / PAGE_SIZE;
+		if (binder_get_installed_page(alloc, index))
+			continue;
+
+		trace_binder_alloc_page_start(alloc, index);
+
+		ret = binder_install_single_page(alloc, index, page_addr);
+		if (ret)
+			return ret;
+
+		trace_binder_alloc_page_end(alloc, index);
+	}
+
+	return 0;
+}
+
+/* The range of pages should exclude those shared with other buffers */
+static void binder_lru_freelist_del(struct binder_alloc *alloc,
+				    unsigned long start, unsigned long end)
+{
+	unsigned long page_addr;
+	struct page *page;
+
+	trace_binder_update_page_range(alloc, true, start, end);
+
+	for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
+		unsigned long index;
+		bool on_lru;
+
+		index = (page_addr - alloc->vm_start) / PAGE_SIZE;
+		page = binder_get_installed_page(alloc, index);
+
+		if (page) {
+			trace_binder_alloc_lru_start(alloc, index);
+
+			on_lru = list_lru_del(alloc->freelist,
+					      page_to_lru(page),
+					      page_to_nid(page),
+					      NULL);
+			WARN_ON(!on_lru);
+
+			trace_binder_alloc_lru_end(alloc, index);
+			continue;
+		}
+
+		if (index + 1 > alloc->pages_high)
+			alloc->pages_high = index + 1;
+	}
+}
+
+static void debug_no_space_locked(struct binder_alloc *alloc)
+{
+	size_t largest_alloc_size = 0;
+	struct binder_buffer *buffer;
+	size_t allocated_buffers = 0;
+	size_t largest_free_size = 0;
+	size_t total_alloc_size = 0;
+	size_t total_free_size = 0;
+	size_t free_buffers = 0;
+	size_t buffer_size;
+	struct rb_node *n;
+
+	for (n = rb_first(&alloc->allocated_buffers); n; n = rb_next(n)) {
+		buffer = rb_entry(n, struct binder_buffer, rb_node);
+		buffer_size = binder_alloc_buffer_size(alloc, buffer);
+		allocated_buffers++;
+		total_alloc_size += buffer_size;
+		if (buffer_size > largest_alloc_size)
+			largest_alloc_size = buffer_size;
+	}
+
+	for (n = rb_first(&alloc->free_buffers); n; n = rb_next(n)) {
+		buffer = rb_entry(n, struct binder_buffer, rb_node);
+		buffer_size = binder_alloc_buffer_size(alloc, buffer);
+		free_buffers++;
+		total_free_size += buffer_size;
+		if (buffer_size > largest_free_size)
+			largest_free_size = buffer_size;
+	}
+
+	binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+			   "allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n",
+			   total_alloc_size, allocated_buffers,
+			   largest_alloc_size, total_free_size,
+			   free_buffers, largest_free_size);
+}
+
+static bool debug_low_async_space_locked(struct binder_alloc *alloc)
+{
+	/*
+	 * Find the amount and size of buffers allocated by the current caller;
+	 * The idea is that once we cross the threshold, whoever is responsible
+	 * for the low async space is likely to try to send another async txn,
+	 * and at some point we'll catch them in the act. This is more efficient
+	 * than keeping a map per pid.
+	 */
+	struct binder_buffer *buffer;
+	size_t total_alloc_size = 0;
+	int pid = current->tgid;
+	size_t num_buffers = 0;
+	struct rb_node *n;
+
+	/*
+	 * Only start detecting spammers once we have less than 20% of async
+	 * space left (which is less than 10% of total buffer size).
+	 */
+	if (alloc->free_async_space >= alloc->buffer_size / 10) {
+		alloc->oneway_spam_detected = false;
+		return false;
+	}
+
+	for (n = rb_first(&alloc->allocated_buffers); n != NULL;
+		 n = rb_next(n)) {
+		buffer = rb_entry(n, struct binder_buffer, rb_node);
+		if (buffer->pid != pid)
+			continue;
+		if (!buffer->async_transaction)
+			continue;
+		total_alloc_size += binder_alloc_buffer_size(alloc, buffer);
+		num_buffers++;
+	}
+
+	/*
+	 * Warn if this pid has more than 50 transactions, or more than 50% of
+	 * async space (which is 25% of total buffer size). Oneway spam is only
+	 * detected when the threshold is exceeded.
+	 */
+	if (num_buffers > 50 || total_alloc_size > alloc->buffer_size / 4) {
+		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+			     "%d: pid %d spamming oneway? %zd buffers allocated for a total size of %zd\n",
+			      alloc->pid, pid, num_buffers, total_alloc_size);
+		if (!alloc->oneway_spam_detected) {
+			alloc->oneway_spam_detected = true;
+			return true;
+		}
+	}
+	return false;
+}
+
+/* Callers preallocate @new_buffer, it is freed by this function if unused */
+static struct binder_buffer *binder_alloc_new_buf_locked(
+				struct binder_alloc *alloc,
+				struct binder_buffer *new_buffer,
+				size_t size,
+				int is_async)
+{
+	struct rb_node *n = alloc->free_buffers.rb_node;
+	struct rb_node *best_fit = NULL;
+	struct binder_buffer *buffer;
+	unsigned long next_used_page;
+	unsigned long curr_last_page;
+	size_t buffer_size;
+
+	if (is_async && alloc->free_async_space < size) {
+		binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+			     "%d: binder_alloc_buf size %zd failed, no async space left\n",
+			      alloc->pid, size);
+		buffer = ERR_PTR(-ENOSPC);
+		goto out;
+	}
+
+	while (n) {
+		buffer = rb_entry(n, struct binder_buffer, rb_node);
+		BUG_ON(!buffer->free);
+		buffer_size = binder_alloc_buffer_size(alloc, buffer);
+
+		if (size < buffer_size) {
+			best_fit = n;
+			n = n->rb_left;
+		} else if (size > buffer_size) {
+			n = n->rb_right;
+		} else {
+			best_fit = n;
+			break;
+		}
+	}
+
+	if (unlikely(!best_fit)) {
+		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+				   "%d: binder_alloc_buf size %zd failed, no address space\n",
+				   alloc->pid, size);
+		debug_no_space_locked(alloc);
+		buffer = ERR_PTR(-ENOSPC);
+		goto out;
+	}
+
+	if (buffer_size != size) {
+		/* Found an oversized buffer and needs to be split */
+		buffer = rb_entry(best_fit, struct binder_buffer, rb_node);
+		buffer_size = binder_alloc_buffer_size(alloc, buffer);
+
+		WARN_ON(n || buffer_size == size);
+		new_buffer->user_data = buffer->user_data + size;
+		list_add(&new_buffer->entry, &buffer->entry);
+		new_buffer->free = 1;
+		binder_insert_free_buffer(alloc, new_buffer);
+		new_buffer = NULL;
+	}
+
+	binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+		     "%d: binder_alloc_buf size %zd got buffer %p size %zd\n",
+		      alloc->pid, size, buffer, buffer_size);
+
+	/*
+	 * Now we remove the pages from the freelist. A clever calculation
+	 * with buffer_size determines if the last page is shared with an
+	 * adjacent in-use buffer. In such case, the page has been already
+	 * removed from the freelist so we trim our range short.
+	 */
+	next_used_page = (buffer->user_data + buffer_size) & PAGE_MASK;
+	curr_last_page = PAGE_ALIGN(buffer->user_data + size);
+	binder_lru_freelist_del(alloc, PAGE_ALIGN(buffer->user_data),
+				min(next_used_page, curr_last_page));
+
+	rb_erase(&buffer->rb_node, &alloc->free_buffers);
+	buffer->free = 0;
+	buffer->allow_user_free = 0;
+	binder_insert_allocated_buffer_locked(alloc, buffer);
+	buffer->async_transaction = is_async;
+	buffer->oneway_spam_suspect = false;
+	if (is_async) {
+		alloc->free_async_space -= size;
+		binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
+			     "%d: binder_alloc_buf size %zd async free %zd\n",
+			      alloc->pid, size, alloc->free_async_space);
+		if (debug_low_async_space_locked(alloc))
+			buffer->oneway_spam_suspect = true;
+	}
+
+out:
+	/* Discard possibly unused new_buffer */
+	kfree(new_buffer);
+	return buffer;
+}
+
+/* Calculate the sanitized total size, returns 0 for invalid request */
+static inline size_t sanitized_size(size_t data_size,
+				    size_t offsets_size,
+				    size_t extra_buffers_size)
+{
+	size_t total, tmp;
+
+	/* Align to pointer size and check for overflows */
+	tmp = ALIGN(data_size, sizeof(void *)) +
+		ALIGN(offsets_size, sizeof(void *));
+	if (tmp < data_size || tmp < offsets_size)
+		return 0;
+	total = tmp + ALIGN(extra_buffers_size, sizeof(void *));
+	if (total < tmp || total < extra_buffers_size)
+		return 0;
+
+	/* Pad 0-sized buffers so they get a unique address */
+	total = max(total, sizeof(void *));
+
+	return total;
+}
+
+/**
+ * binder_alloc_new_buf() - Allocate a new binder buffer
+ * @alloc:              binder_alloc for this proc
+ * @data_size:          size of user data buffer
+ * @offsets_size:       user specified buffer offset
+ * @extra_buffers_size: size of extra space for meta-data (eg, security context)
+ * @is_async:           buffer for async transaction
+ *
+ * Allocate a new buffer given the requested sizes. Returns
+ * the kernel version of the buffer pointer. The size allocated
+ * is the sum of the three given sizes (each rounded up to
+ * pointer-sized boundary)
+ *
+ * Return:	The allocated buffer or %ERR_PTR(-errno) if error
+ */
+struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
+					   size_t data_size,
+					   size_t offsets_size,
+					   size_t extra_buffers_size,
+					   int is_async)
+{
+	struct binder_buffer *buffer, *next;
+	size_t size;
+	int ret;
+
+	/* Check binder_alloc is fully initialized */
+	if (!binder_alloc_is_mapped(alloc)) {
+		binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+				   "%d: binder_alloc_buf, no vma\n",
+				   alloc->pid);
+		return ERR_PTR(-ESRCH);
+	}
+
+	size = sanitized_size(data_size, offsets_size, extra_buffers_size);
+	if (unlikely(!size)) {
+		binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+				   "%d: got transaction with invalid size %zd-%zd-%zd\n",
+				   alloc->pid, data_size, offsets_size,
+				   extra_buffers_size);
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* Preallocate the next buffer */
+	next = kzalloc_obj(*next);
+	if (!next)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&alloc->mutex);
+	buffer = binder_alloc_new_buf_locked(alloc, next, size, is_async);
+	if (IS_ERR(buffer)) {
+		mutex_unlock(&alloc->mutex);
+		goto out;
+	}
+
+	buffer->data_size = data_size;
+	buffer->offsets_size = offsets_size;
+	buffer->extra_buffers_size = extra_buffers_size;
+	buffer->pid = current->tgid;
+	mutex_unlock(&alloc->mutex);
+
+	ret = binder_install_buffer_pages(alloc, buffer, size);
+	if (ret) {
+		binder_alloc_free_buf(alloc, buffer);
+		buffer = ERR_PTR(ret);
+	}
+out:
+	return buffer;
+}
+EXPORT_SYMBOL_IF_KUNIT(binder_alloc_new_buf);
+
+static unsigned long buffer_start_page(struct binder_buffer *buffer)
+{
+	return buffer->user_data & PAGE_MASK;
+}
+
+static unsigned long prev_buffer_end_page(struct binder_buffer *buffer)
+{
+	return (buffer->user_data - 1) & PAGE_MASK;
+}
+
+static void binder_delete_free_buffer(struct binder_alloc *alloc,
+				      struct binder_buffer *buffer)
+{
+	struct binder_buffer *prev, *next;
+
+	if (PAGE_ALIGNED(buffer->user_data))
+		goto skip_freelist;
+
+	BUG_ON(alloc->buffers.next == &buffer->entry);
+	prev = binder_buffer_prev(buffer);
+	BUG_ON(!prev->free);
+	if (prev_buffer_end_page(prev) == buffer_start_page(buffer))
+		goto skip_freelist;
+
+	if (!list_is_last(&buffer->entry, &alloc->buffers)) {
+		next = binder_buffer_next(buffer);
+		if (buffer_start_page(next) == buffer_start_page(buffer))
+			goto skip_freelist;
+	}
+
+	binder_lru_freelist_add(alloc, buffer_start_page(buffer),
+				buffer_start_page(buffer) + PAGE_SIZE);
+skip_freelist:
+	list_del(&buffer->entry);
+	kfree(buffer);
+}
+
+static void binder_free_buf_locked(struct binder_alloc *alloc,
+				   struct binder_buffer *buffer)
+{
+	size_t size, buffer_size;
+
+	buffer_size = binder_alloc_buffer_size(alloc, buffer);
+
+	size = ALIGN(buffer->data_size, sizeof(void *)) +
+		ALIGN(buffer->offsets_size, sizeof(void *)) +
+		ALIGN(buffer->extra_buffers_size, sizeof(void *));
+
+	binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+		     "%d: binder_free_buf %p size %zd buffer_size %zd\n",
+		      alloc->pid, buffer, size, buffer_size);
+
+	BUG_ON(buffer->free);
+	BUG_ON(size > buffer_size);
+	BUG_ON(buffer->transaction != NULL);
+	BUG_ON(buffer->user_data < alloc->vm_start);
+	BUG_ON(buffer->user_data > alloc->vm_start + alloc->buffer_size);
+
+	if (buffer->async_transaction) {
+		alloc->free_async_space += buffer_size;
+		binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
+			     "%d: binder_free_buf size %zd async free %zd\n",
+			      alloc->pid, size, alloc->free_async_space);
+	}
+
+	binder_lru_freelist_add(alloc, PAGE_ALIGN(buffer->user_data),
+				(buffer->user_data + buffer_size) & PAGE_MASK);
+
+	rb_erase(&buffer->rb_node, &alloc->allocated_buffers);
+	buffer->free = 1;
+	if (!list_is_last(&buffer->entry, &alloc->buffers)) {
+		struct binder_buffer *next = binder_buffer_next(buffer);
+
+		if (next->free) {
+			rb_erase(&next->rb_node, &alloc->free_buffers);
+			binder_delete_free_buffer(alloc, next);
+		}
+	}
+	if (alloc->buffers.next != &buffer->entry) {
+		struct binder_buffer *prev = binder_buffer_prev(buffer);
+
+		if (prev->free) {
+			binder_delete_free_buffer(alloc, buffer);
+			rb_erase(&prev->rb_node, &alloc->free_buffers);
+			buffer = prev;
+		}
+	}
+	binder_insert_free_buffer(alloc, buffer);
+}
+
+/**
+ * binder_alloc_get_page() - get kernel pointer for given buffer offset
+ * @alloc: binder_alloc for this proc
+ * @buffer: binder buffer to be accessed
+ * @buffer_offset: offset into @buffer data
+ * @pgoffp: address to copy final page offset to
+ *
+ * Lookup the struct page corresponding to the address
+ * at @buffer_offset into @buffer->user_data. If @pgoffp is not
+ * NULL, the byte-offset into the page is written there.
+ *
+ * The caller is responsible to ensure that the offset points
+ * to a valid address within the @buffer and that @buffer is
+ * not freeable by the user. Since it can't be freed, we are
+ * guaranteed that the corresponding elements of @alloc->pages[]
+ * cannot change.
+ *
+ * Return: struct page
+ */
+static struct page *binder_alloc_get_page(struct binder_alloc *alloc,
+					  struct binder_buffer *buffer,
+					  binder_size_t buffer_offset,
+					  pgoff_t *pgoffp)
+{
+	binder_size_t buffer_space_offset = buffer_offset +
+		(buffer->user_data - alloc->vm_start);
+	pgoff_t pgoff = buffer_space_offset & ~PAGE_MASK;
+	size_t index = buffer_space_offset >> PAGE_SHIFT;
+
+	*pgoffp = pgoff;
+
+	return alloc->pages[index];
+}
+
+/**
+ * binder_alloc_clear_buf() - zero out buffer
+ * @alloc: binder_alloc for this proc
+ * @buffer: binder buffer to be cleared
+ *
+ * memset the given buffer to 0
+ */
+static void binder_alloc_clear_buf(struct binder_alloc *alloc,
+				   struct binder_buffer *buffer)
+{
+	size_t bytes = binder_alloc_buffer_size(alloc, buffer);
+	binder_size_t buffer_offset = 0;
+
+	while (bytes) {
+		unsigned long size;
+		struct page *page;
+		pgoff_t pgoff;
+
+		page = binder_alloc_get_page(alloc, buffer,
+					     buffer_offset, &pgoff);
+		size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
+		memset_page(page, pgoff, 0, size);
+		bytes -= size;
+		buffer_offset += size;
+	}
+}
+
+/**
+ * binder_alloc_free_buf() - free a binder buffer
+ * @alloc:	binder_alloc for this proc
+ * @buffer:	kernel pointer to buffer
+ *
+ * Free the buffer allocated via binder_alloc_new_buf()
+ */
+void binder_alloc_free_buf(struct binder_alloc *alloc,
+			    struct binder_buffer *buffer)
+{
+	/*
+	 * We could eliminate the call to binder_alloc_clear_buf()
+	 * from binder_alloc_deferred_release() by moving this to
+	 * binder_free_buf_locked(). However, that could
+	 * increase contention for the alloc mutex if clear_on_free
+	 * is used frequently for large buffers. The mutex is not
+	 * needed for correctness here.
+	 */
+	if (buffer->clear_on_free) {
+		binder_alloc_clear_buf(alloc, buffer);
+		buffer->clear_on_free = false;
+	}
+	mutex_lock(&alloc->mutex);
+	binder_free_buf_locked(alloc, buffer);
+	mutex_unlock(&alloc->mutex);
+}
+EXPORT_SYMBOL_IF_KUNIT(binder_alloc_free_buf);
+
+/**
+ * binder_alloc_mmap_handler() - map virtual address space for proc
+ * @alloc:	alloc structure for this proc
+ * @vma:	vma passed to mmap()
+ *
+ * Called by binder_mmap() to initialize the space specified in
+ * vma for allocating binder buffers
+ *
+ * Return:
+ *      0 = success
+ *      -EBUSY = address space already mapped
+ *      -ENOMEM = failed to map memory to given address space
+ */
+int binder_alloc_mmap_handler(struct binder_alloc *alloc,
+			      struct vm_area_struct *vma)
+{
+	struct binder_buffer *buffer;
+	const char *failure_string;
+	int ret;
+
+	if (unlikely(vma->vm_mm != alloc->mm)) {
+		ret = -EINVAL;
+		failure_string = "invalid vma->vm_mm";
+		goto err_invalid_mm;
+	}
+
+	mutex_lock(&binder_alloc_mmap_lock);
+	if (alloc->buffer_size) {
+		ret = -EBUSY;
+		failure_string = "already mapped";
+		goto err_already_mapped;
+	}
+	alloc->buffer_size = min_t(unsigned long, vma->vm_end - vma->vm_start,
+				   SZ_4M);
+	mutex_unlock(&binder_alloc_mmap_lock);
+
+	alloc->vm_start = vma->vm_start;
+
+	alloc->pages = kvzalloc_objs(alloc->pages[0],
+				     alloc->buffer_size / PAGE_SIZE);
+	if (!alloc->pages) {
+		ret = -ENOMEM;
+		failure_string = "alloc page array";
+		goto err_alloc_pages_failed;
+	}
+
+	buffer = kzalloc_obj(*buffer);
+	if (!buffer) {
+		ret = -ENOMEM;
+		failure_string = "alloc buffer struct";
+		goto err_alloc_buf_struct_failed;
+	}
+
+	buffer->user_data = alloc->vm_start;
+	list_add(&buffer->entry, &alloc->buffers);
+	buffer->free = 1;
+	binder_insert_free_buffer(alloc, buffer);
+	alloc->free_async_space = alloc->buffer_size / 2;
+
+	/* Signal binder_alloc is fully initialized */
+	binder_alloc_set_mapped(alloc, true);
+
+	return 0;
+
+err_alloc_buf_struct_failed:
+	kvfree(alloc->pages);
+	alloc->pages = NULL;
+err_alloc_pages_failed:
+	alloc->vm_start = 0;
+	mutex_lock(&binder_alloc_mmap_lock);
+	alloc->buffer_size = 0;
+err_already_mapped:
+	mutex_unlock(&binder_alloc_mmap_lock);
+err_invalid_mm:
+	binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
+			   "%s: %d %lx-%lx %s failed %d\n", __func__,
+			   alloc->pid, vma->vm_start, vma->vm_end,
+			   failure_string, ret);
+	return ret;
+}
+EXPORT_SYMBOL_IF_KUNIT(binder_alloc_mmap_handler);
+
+void binder_alloc_deferred_release(struct binder_alloc *alloc)
+{
+	struct rb_node *n;
+	int buffers, page_count;
+	struct binder_buffer *buffer;
+
+	buffers = 0;
+	mutex_lock(&alloc->mutex);
+	BUG_ON(alloc->mapped);
+
+	while ((n = rb_first(&alloc->allocated_buffers))) {
+		buffer = rb_entry(n, struct binder_buffer, rb_node);
+
+		/* Transaction should already have been freed */
+		BUG_ON(buffer->transaction);
+
+		if (buffer->clear_on_free) {
+			binder_alloc_clear_buf(alloc, buffer);
+			buffer->clear_on_free = false;
+		}
+		binder_free_buf_locked(alloc, buffer);
+		buffers++;
+	}
+
+	while (!list_empty(&alloc->buffers)) {
+		buffer = list_first_entry(&alloc->buffers,
+					  struct binder_buffer, entry);
+		WARN_ON(!buffer->free);
+
+		list_del(&buffer->entry);
+		WARN_ON_ONCE(!list_empty(&alloc->buffers));
+		kfree(buffer);
+	}
+
+	page_count = 0;
+	if (alloc->pages) {
+		int i;
+
+		for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
+			struct page *page;
+			bool on_lru;
+
+			page = binder_get_installed_page(alloc, i);
+			if (!page)
+				continue;
+
+			on_lru = list_lru_del(alloc->freelist,
+					      page_to_lru(page),
+					      page_to_nid(page),
+					      NULL);
+			binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
+				     "%s: %d: page %d %s\n",
+				     __func__, alloc->pid, i,
+				     on_lru ? "on lru" : "active");
+			binder_free_page(page);
+			page_count++;
+		}
+	}
+	mutex_unlock(&alloc->mutex);
+	kvfree(alloc->pages);
+	if (alloc->mm)
+		mmdrop(alloc->mm);
+
+	binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE,
+		     "%s: %d buffers %d, pages %d\n",
+		     __func__, alloc->pid, buffers, page_count);
+}
+EXPORT_SYMBOL_IF_KUNIT(binder_alloc_deferred_release);
+
+/**
+ * binder_alloc_print_allocated() - print buffer info
+ * @m:     seq_file for output via seq_printf()
+ * @alloc: binder_alloc for this proc
+ *
+ * Prints information about every buffer associated with
+ * the binder_alloc state to the given seq_file
+ */
+void binder_alloc_print_allocated(struct seq_file *m,
+				  struct binder_alloc *alloc)
+{
+	struct binder_buffer *buffer;
+	struct rb_node *n;
+
+	guard(mutex)(&alloc->mutex);
+	for (n = rb_first(&alloc->allocated_buffers); n; n = rb_next(n)) {
+		buffer = rb_entry(n, struct binder_buffer, rb_node);
+		seq_printf(m, "  buffer %d: %lx size %zd:%zd:%zd %s\n",
+			   buffer->debug_id,
+			   buffer->user_data - alloc->vm_start,
+			   buffer->data_size, buffer->offsets_size,
+			   buffer->extra_buffers_size,
+			   buffer->transaction ? "active" : "delivered");
+	}
+}
+
+/**
+ * binder_alloc_print_pages() - print page usage
+ * @m:     seq_file for output via seq_printf()
+ * @alloc: binder_alloc for this proc
+ */
+void binder_alloc_print_pages(struct seq_file *m,
+			      struct binder_alloc *alloc)
+{
+	struct page *page;
+	int i;
+	int active = 0;
+	int lru = 0;
+	int free = 0;
+
+	mutex_lock(&alloc->mutex);
+	/*
+	 * Make sure the binder_alloc is fully initialized, otherwise we might
+	 * read inconsistent state.
+	 */
+	if (binder_alloc_is_mapped(alloc)) {
+		for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
+			page = binder_get_installed_page(alloc, i);
+			if (!page)
+				free++;
+			else if (list_empty(page_to_lru(page)))
+				active++;
+			else
+				lru++;
+		}
+	}
+	mutex_unlock(&alloc->mutex);
+	seq_printf(m, "  pages: %d:%d:%d\n", active, lru, free);
+	seq_printf(m, "  pages high watermark: %zu\n", alloc->pages_high);
+}
+
+/**
+ * binder_alloc_get_allocated_count() - return count of buffers
+ * @alloc: binder_alloc for this proc
+ *
+ * Return: count of allocated buffers
+ */
+int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
+{
+	struct rb_node *n;
+	int count = 0;
+
+	guard(mutex)(&alloc->mutex);
+	for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
+		count++;
+	return count;
+}
+
+
+/**
+ * binder_alloc_vma_close() - invalidate address space
+ * @alloc: binder_alloc for this proc
+ *
+ * Called from binder_vma_close() when releasing address space.
+ * Clears alloc->mapped to prevent new incoming transactions from
+ * allocating more buffers.
+ */
+void binder_alloc_vma_close(struct binder_alloc *alloc)
+{
+	binder_alloc_set_mapped(alloc, false);
+}
+EXPORT_SYMBOL_IF_KUNIT(binder_alloc_vma_close);
+
+/**
+ * binder_alloc_free_page() - shrinker callback to free pages
+ * @item:   item to free
+ * @lru:    list_lru instance of the item
+ * @cb_arg: callback argument
+ *
+ * Called from list_lru_walk() in binder_shrink_scan() to free
+ * up pages when the system is under memory pressure.
+ */
+enum lru_status binder_alloc_free_page(struct list_head *item,
+				       struct list_lru_one *lru,
+				       void *cb_arg)
+	__must_hold(&lru->lock)
+{
+	struct binder_shrinker_mdata *mdata = container_of(item, typeof(*mdata), lru);
+	struct binder_alloc *alloc = mdata->alloc;
+	struct mm_struct *mm = alloc->mm;
+	struct vm_area_struct *vma;
+	struct page *page_to_free;
+	unsigned long page_addr;
+	int mm_locked = 0;
+	size_t index;
+
+	if (!mmget_not_zero(mm))
+		goto err_mmget;
+
+	index = mdata->page_index;
+	page_addr = alloc->vm_start + index * PAGE_SIZE;
+
+	/* attempt per-vma lock first */
+	vma = lock_vma_under_rcu(mm, page_addr);
+	if (!vma) {
+		/* fall back to mmap_lock */
+		if (!mmap_read_trylock(mm))
+			goto err_mmap_read_lock_failed;
+		mm_locked = 1;
+		vma = vma_lookup(mm, page_addr);
+	}
+
+	if (!mutex_trylock(&alloc->mutex))
+		goto err_get_alloc_mutex_failed;
+
+	/*
+	 * Since a binder_alloc can only be mapped once, we ensure
+	 * the vma corresponds to this mapping by checking whether
+	 * the binder_alloc is still mapped.
+	 */
+	if (vma && !binder_alloc_is_mapped(alloc))
+		goto err_invalid_vma;
+
+	trace_binder_unmap_kernel_start(alloc, index);
+
+	page_to_free = alloc->pages[index];
+	binder_set_installed_page(alloc, index, NULL);
+
+	trace_binder_unmap_kernel_end(alloc, index);
+
+	list_lru_isolate(lru, item);
+	spin_unlock(&lru->lock);
+
+	if (vma) {
+		trace_binder_unmap_user_start(alloc, index);
+
+		zap_vma_range(vma, page_addr, PAGE_SIZE);
+
+		trace_binder_unmap_user_end(alloc, index);
+	}
+
+	mutex_unlock(&alloc->mutex);
+	if (mm_locked)
+		mmap_read_unlock(mm);
+	else
+		vma_end_read(vma);
+	mmput_async(mm);
+	binder_free_page(page_to_free);
+
+	return LRU_REMOVED_RETRY;
+
+err_invalid_vma:
+	mutex_unlock(&alloc->mutex);
+err_get_alloc_mutex_failed:
+	if (mm_locked)
+		mmap_read_unlock(mm);
+	else
+		vma_end_read(vma);
+err_mmap_read_lock_failed:
+	mmput_async(mm);
+err_mmget:
+	return LRU_SKIP;
+}
+EXPORT_SYMBOL_IF_KUNIT(binder_alloc_free_page);
+
+static unsigned long
+binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+	return list_lru_count(&binder_freelist);
+}
+
+static unsigned long
+binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+	return list_lru_walk(&binder_freelist, binder_alloc_free_page,
+			    NULL, sc->nr_to_scan);
+}
+
+static struct shrinker *binder_shrinker;
+
+VISIBLE_IF_KUNIT void __binder_alloc_init(struct binder_alloc *alloc,
+					  struct list_lru *freelist)
+{
+	alloc->pid = current->tgid;
+	alloc->mm = current->mm;
+	mmgrab(alloc->mm);
+	mutex_init(&alloc->mutex);
+	INIT_LIST_HEAD(&alloc->buffers);
+	alloc->freelist = freelist;
+}
+EXPORT_SYMBOL_IF_KUNIT(__binder_alloc_init);
+
+/**
+ * binder_alloc_init() - called by binder_open() for per-proc initialization
+ * @alloc: binder_alloc for this proc
+ *
+ * Called from binder_open() to initialize binder_alloc fields for
+ * new binder proc
+ */
+void binder_alloc_init(struct binder_alloc *alloc)
+{
+	__binder_alloc_init(alloc, &binder_freelist);
+}
+
+int binder_alloc_shrinker_init(void)
+{
+	int ret;
+
+	ret = list_lru_init(&binder_freelist);
+	if (ret)
+		return ret;
+
+	binder_shrinker = shrinker_alloc(0, "android-binder");
+	if (!binder_shrinker) {
+		list_lru_destroy(&binder_freelist);
+		return -ENOMEM;
+	}
+
+	binder_shrinker->count_objects = binder_shrink_count;
+	binder_shrinker->scan_objects = binder_shrink_scan;
+
+	shrinker_register(binder_shrinker);
+
+	return 0;
+}
+
+void binder_alloc_shrinker_exit(void)
+{
+	shrinker_free(binder_shrinker);
+	list_lru_destroy(&binder_freelist);
+}
+
+/**
+ * check_buffer() - verify that buffer/offset is safe to access
+ * @alloc: binder_alloc for this proc
+ * @buffer: binder buffer to be accessed
+ * @offset: offset into @buffer data
+ * @bytes: bytes to access from offset
+ *
+ * Check that the @offset/@bytes are within the size of the given
+ * @buffer and that the buffer is currently active and not freeable.
+ * Offsets must also be multiples of sizeof(u32). The kernel is
+ * allowed to touch the buffer in two cases:
+ *
+ * 1) when the buffer is being created:
+ *     (buffer->free == 0 && buffer->allow_user_free == 0)
+ * 2) when the buffer is being torn down:
+ *     (buffer->free == 0 && buffer->transaction == NULL).
+ *
+ * Return: true if the buffer is safe to access
+ */
+static inline bool check_buffer(struct binder_alloc *alloc,
+				struct binder_buffer *buffer,
+				binder_size_t offset, size_t bytes)
+{
+	size_t buffer_size = binder_alloc_buffer_size(alloc, buffer);
+
+	return buffer_size >= bytes &&
+		offset <= buffer_size - bytes &&
+		IS_ALIGNED(offset, sizeof(u32)) &&
+		!buffer->free &&
+		(!buffer->allow_user_free || !buffer->transaction);
+}
+
+/**
+ * binder_alloc_copy_user_to_buffer() - copy src user to tgt user
+ * @alloc: binder_alloc for this proc
+ * @buffer: binder buffer to be accessed
+ * @buffer_offset: offset into @buffer data
+ * @from: userspace pointer to source buffer
+ * @bytes: bytes to copy
+ *
+ * Copy bytes from source userspace to target buffer.
+ *
+ * Return: bytes remaining to be copied
+ */
+unsigned long
+binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
+				 struct binder_buffer *buffer,
+				 binder_size_t buffer_offset,
+				 const void __user *from,
+				 size_t bytes)
+{
+	if (!check_buffer(alloc, buffer, buffer_offset, bytes))
+		return bytes;
+
+	while (bytes) {
+		unsigned long size;
+		unsigned long ret;
+		struct page *page;
+		pgoff_t pgoff;
+		void *kptr;
+
+		page = binder_alloc_get_page(alloc, buffer,
+					     buffer_offset, &pgoff);
+		size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
+		kptr = kmap_local_page(page) + pgoff;
+		ret = copy_from_user(kptr, from, size);
+		kunmap_local(kptr);
+		if (ret)
+			return bytes - size + ret;
+		bytes -= size;
+		from += size;
+		buffer_offset += size;
+	}
+	return 0;
+}
+
+static int binder_alloc_do_buffer_copy(struct binder_alloc *alloc,
+				       bool to_buffer,
+				       struct binder_buffer *buffer,
+				       binder_size_t buffer_offset,
+				       void *ptr,
+				       size_t bytes)
+{
+	/* All copies must be 32-bit aligned and 32-bit size */
+	if (!check_buffer(alloc, buffer, buffer_offset, bytes))
+		return -EINVAL;
+
+	while (bytes) {
+		unsigned long size;
+		struct page *page;
+		pgoff_t pgoff;
+
+		page = binder_alloc_get_page(alloc, buffer,
+					     buffer_offset, &pgoff);
+		size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
+		if (to_buffer)
+			memcpy_to_page(page, pgoff, ptr, size);
+		else
+			memcpy_from_page(ptr, page, pgoff, size);
+		bytes -= size;
+		pgoff = 0;
+		ptr = ptr + size;
+		buffer_offset += size;
+	}
+	return 0;
+}
+
+int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
+				struct binder_buffer *buffer,
+				binder_size_t buffer_offset,
+				void *src,
+				size_t bytes)
+{
+	return binder_alloc_do_buffer_copy(alloc, true, buffer, buffer_offset,
+					   src, bytes);
+}
+
+int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
+				  void *dest,
+				  struct binder_buffer *buffer,
+				  binder_size_t buffer_offset,
+				  size_t bytes)
+{
+	return binder_alloc_do_buffer_copy(alloc, false, buffer, buffer_offset,
+					   dest, bytes);
+}
diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h
new file mode 100644
index 000000000..d6f1f6f2d
--- /dev/null
+++ b/drivers/android/binder_alloc.h
@@ -0,0 +1,189 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017 Google, Inc.
+ */
+
+#ifndef _LINUX_BINDER_ALLOC_H
+#define _LINUX_BINDER_ALLOC_H
+
+#include <linux/rbtree.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/rtmutex.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/list_lru.h>
+#include <uapi/linux/android/binder.h>
+
+struct binder_transaction;
+
+/**
+ * struct binder_buffer - buffer used for binder transactions
+ * @entry:              entry alloc->buffers
+ * @rb_node:            node for allocated_buffers/free_buffers rb trees
+ * @free:               %true if buffer is free
+ * @clear_on_free:      %true if buffer must be zeroed after use
+ * @allow_user_free:    %true if user is allowed to free buffer
+ * @async_transaction:  %true if buffer is in use for an async txn
+ * @oneway_spam_suspect: %true if total async allocate size just exceed
+ * spamming detect threshold
+ * @debug_id:           unique ID for debugging
+ * @transaction:        pointer to associated struct binder_transaction
+ * @target_node:        struct binder_node associated with this buffer
+ * @data_size:          size of @transaction data
+ * @offsets_size:       size of array of offsets
+ * @extra_buffers_size: size of space for other objects (like sg lists)
+ * @user_data:          user pointer to base of buffer space
+ * @pid:                pid to attribute the buffer to (caller)
+ *
+ * Bookkeeping structure for binder transaction buffers
+ */
+struct binder_buffer {
+	struct list_head entry; /* free and allocated entries by address */
+	struct rb_node rb_node; /* free entry by size or allocated entry */
+				/* by address */
+	unsigned free:1;
+	unsigned clear_on_free:1;
+	unsigned allow_user_free:1;
+	unsigned async_transaction:1;
+	unsigned oneway_spam_suspect:1;
+	unsigned debug_id:27;
+	struct binder_transaction *transaction;
+	struct binder_node *target_node;
+	size_t data_size;
+	size_t offsets_size;
+	size_t extra_buffers_size;
+	unsigned long user_data;
+	int pid;
+};
+
+/**
+ * struct binder_shrinker_mdata - binder metadata used to reclaim pages
+ * @lru:         LRU entry in binder_freelist
+ * @alloc:       binder_alloc owning the page to reclaim
+ * @page_index:  offset in @alloc->pages[] into the page to reclaim
+ */
+struct binder_shrinker_mdata {
+	struct list_head lru;
+	struct binder_alloc *alloc;
+	unsigned long page_index;
+};
+
+static inline struct list_head *page_to_lru(struct page *p)
+{
+	struct binder_shrinker_mdata *mdata;
+
+	mdata = (struct binder_shrinker_mdata *)page_private(p);
+
+	return &mdata->lru;
+}
+
+/**
+ * struct binder_alloc - per-binder proc state for binder allocator
+ * @mutex:              protects binder_alloc fields
+ * @mm:                 copy of task->mm (invariant after open)
+ * @vm_start:           base of per-proc address space mapped via mmap
+ * @buffers:            list of all buffers for this proc
+ * @free_buffers:       rb tree of buffers available for allocation
+ *                      sorted by size
+ * @allocated_buffers:  rb tree of allocated buffers sorted by address
+ * @free_async_space:   VA space available for async buffers. This is
+ *                      initialized at mmap time to 1/2 the full VA space
+ * @pages:              array of struct page *
+ * @freelist:           lru list to use for free pages (invariant after init)
+ * @buffer_size:        size of address space specified via mmap
+ * @pid:                pid for associated binder_proc (invariant after init)
+ * @pages_high:         high watermark of offset in @pages
+ * @mapped:             whether the vm area is mapped, each binder instance is
+ *                      allowed a single mapping throughout its lifetime
+ * @oneway_spam_detected: %true if oneway spam detection fired, clear that
+ * flag once the async buffer has returned to a healthy state
+ *
+ * Bookkeeping structure for per-proc address space management for binder
+ * buffers. It is normally initialized during binder_init() and binder_mmap()
+ * calls. The address space is used for both user-visible buffers and for
+ * struct binder_buffer objects used to track the user buffers
+ */
+struct binder_alloc {
+	struct mutex mutex;
+	struct mm_struct *mm;
+	unsigned long vm_start;
+	struct list_head buffers;
+	struct rb_root free_buffers;
+	struct rb_root allocated_buffers;
+	size_t free_async_space;
+	struct page **pages;
+	struct list_lru *freelist;
+	size_t buffer_size;
+	int pid;
+	size_t pages_high;
+	bool mapped;
+	bool oneway_spam_detected;
+};
+
+enum lru_status binder_alloc_free_page(struct list_head *item,
+				       struct list_lru_one *lru,
+				       void *cb_arg);
+struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
+					   size_t data_size,
+					   size_t offsets_size,
+					   size_t extra_buffers_size,
+					   int is_async);
+void binder_alloc_init(struct binder_alloc *alloc);
+int binder_alloc_shrinker_init(void);
+void binder_alloc_shrinker_exit(void);
+void binder_alloc_vma_close(struct binder_alloc *alloc);
+struct binder_buffer *
+binder_alloc_prepare_to_free(struct binder_alloc *alloc,
+			     unsigned long user_ptr);
+void binder_alloc_free_buf(struct binder_alloc *alloc,
+			   struct binder_buffer *buffer);
+int binder_alloc_mmap_handler(struct binder_alloc *alloc,
+			      struct vm_area_struct *vma);
+void binder_alloc_deferred_release(struct binder_alloc *alloc);
+int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
+void binder_alloc_print_allocated(struct seq_file *m,
+				  struct binder_alloc *alloc);
+void binder_alloc_print_pages(struct seq_file *m,
+			      struct binder_alloc *alloc);
+
+/**
+ * binder_alloc_get_free_async_space() - get free space available for async
+ * @alloc:	binder_alloc for this proc
+ *
+ * Return:	the bytes remaining in the address-space for async transactions
+ */
+static inline size_t
+binder_alloc_get_free_async_space(struct binder_alloc *alloc)
+{
+	guard(mutex)(&alloc->mutex);
+	return alloc->free_async_space;
+}
+
+unsigned long
+binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
+				 struct binder_buffer *buffer,
+				 binder_size_t buffer_offset,
+				 const void __user *from,
+				 size_t bytes);
+
+int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
+				struct binder_buffer *buffer,
+				binder_size_t buffer_offset,
+				void *src,
+				size_t bytes);
+
+int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
+				  void *dest,
+				  struct binder_buffer *buffer,
+				  binder_size_t buffer_offset,
+				  size_t bytes);
+
+#if IS_ENABLED(CONFIG_KUNIT)
+void __binder_alloc_init(struct binder_alloc *alloc, struct list_lru *freelist);
+size_t binder_alloc_buffer_size(struct binder_alloc *alloc,
+				struct binder_buffer *buffer);
+#endif
+
+#endif /* _LINUX_BINDER_ALLOC_H */
+
diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h
new file mode 100644
index 000000000..342574bfd
--- /dev/null
+++ b/drivers/android/binder_internal.h
@@ -0,0 +1,597 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _LINUX_BINDER_INTERNAL_H
+#define _LINUX_BINDER_INTERNAL_H
+
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/mutex.h>
+#include <linux/refcount.h>
+#include <linux/stddef.h>
+#include <linux/types.h>
+#include <linux/uidgid.h>
+#include <uapi/linux/android/binderfs.h>
+#include "binder_alloc.h"
+#include "dbitmap.h"
+
+struct binder_context {
+	struct binder_node *binder_context_mgr_node;
+	struct mutex context_mgr_node_lock;
+	kuid_t binder_context_mgr_uid;
+	const char *name;
+};
+
+/**
+ * struct binder_device - information about a binder device node
+ * @hlist:          list of binder devices
+ * @miscdev:        information about a binder character device node
+ * @context:        binder context information
+ * @binderfs_inode: This is the inode of the root dentry of the super block
+ *                  belonging to a binderfs mount.
+ */
+struct binder_device {
+	struct hlist_node hlist;
+	struct miscdevice miscdev;
+	struct binder_context context;
+	struct inode *binderfs_inode;
+	refcount_t ref;
+};
+
+/**
+ * binderfs_mount_opts - mount options for binderfs
+ * @max: maximum number of allocatable binderfs binder devices
+ * @stats_mode: enable binder stats in binderfs.
+ */
+struct binderfs_mount_opts {
+	int max;
+	int stats_mode;
+};
+
+/**
+ * binderfs_info - information about a binderfs mount
+ * @ipc_ns:         The ipc namespace the binderfs mount belongs to.
+ * @control_dentry: This records the dentry of this binderfs mount
+ *                  binder-control device.
+ * @root_uid:       uid that needs to be used when a new binder device is
+ *                  created.
+ * @root_gid:       gid that needs to be used when a new binder device is
+ *                  created.
+ * @mount_opts:     The mount options in use.
+ * @device_count:   The current number of allocated binder devices.
+ * @proc_log_dir:   Pointer to the directory dentry containing process-specific
+ *                  logs.
+ */
+struct binderfs_info {
+	struct ipc_namespace *ipc_ns;
+	struct dentry *control_dentry;
+	kuid_t root_uid;
+	kgid_t root_gid;
+	struct binderfs_mount_opts mount_opts;
+	int device_count;
+	struct dentry *proc_log_dir;
+};
+
+extern const struct file_operations binder_fops;
+
+extern char *binder_devices_param;
+
+#ifdef CONFIG_ANDROID_BINDERFS
+extern bool is_binderfs_device(const struct inode *inode);
+extern struct dentry *binderfs_create_file(struct dentry *dir, const char *name,
+					   const struct file_operations *fops,
+					   void *data);
+#else
+static inline bool is_binderfs_device(const struct inode *inode)
+{
+	return false;
+}
+static inline struct dentry *binderfs_create_file(struct dentry *dir,
+					   const char *name,
+					   const struct file_operations *fops,
+					   void *data)
+{
+	return NULL;
+}
+#endif
+
+#ifdef CONFIG_ANDROID_BINDERFS
+extern int __init init_binderfs(void);
+#else
+static inline int __init init_binderfs(void)
+{
+	return 0;
+}
+#endif
+
+struct binder_debugfs_entry {
+	const char *name;
+	umode_t mode;
+	const struct file_operations *fops;
+	void *data;
+};
+
+extern const struct binder_debugfs_entry binder_debugfs_entries[];
+
+#define binder_for_each_debugfs_entry(entry)	\
+	for ((entry) = binder_debugfs_entries;	\
+	     (entry)->name;			\
+	     (entry)++)
+
+enum binder_stat_types {
+	BINDER_STAT_PROC,
+	BINDER_STAT_THREAD,
+	BINDER_STAT_NODE,
+	BINDER_STAT_REF,
+	BINDER_STAT_DEATH,
+	BINDER_STAT_TRANSACTION,
+	BINDER_STAT_TRANSACTION_COMPLETE,
+	BINDER_STAT_FREEZE,
+	BINDER_STAT_COUNT
+};
+
+struct binder_stats {
+	atomic_t br[_IOC_NR(BR_CLEAR_FREEZE_NOTIFICATION_DONE) + 1];
+	atomic_t bc[_IOC_NR(BC_FREEZE_NOTIFICATION_DONE) + 1];
+	atomic_t obj_created[BINDER_STAT_COUNT];
+	atomic_t obj_deleted[BINDER_STAT_COUNT];
+};
+
+/**
+ * struct binder_work - work enqueued on a worklist
+ * @entry:             node enqueued on list
+ * @type:              type of work to be performed
+ *
+ * There are separate work lists for proc, thread, and node (async).
+ */
+struct binder_work {
+	struct list_head entry;
+
+	enum binder_work_type {
+		BINDER_WORK_TRANSACTION = 1,
+		BINDER_WORK_TRANSACTION_COMPLETE,
+		BINDER_WORK_TRANSACTION_PENDING,
+		BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT,
+		BINDER_WORK_RETURN_ERROR,
+		BINDER_WORK_NODE,
+		BINDER_WORK_DEAD_BINDER,
+		BINDER_WORK_DEAD_BINDER_AND_CLEAR,
+		BINDER_WORK_CLEAR_DEATH_NOTIFICATION,
+		BINDER_WORK_FROZEN_BINDER,
+		BINDER_WORK_CLEAR_FREEZE_NOTIFICATION,
+	} type;
+};
+
+struct binder_error {
+	struct binder_work work;
+	uint32_t cmd;
+};
+
+/**
+ * struct binder_node - binder node bookkeeping
+ * @debug_id:             unique ID for debugging
+ *                        (invariant after initialized)
+ * @lock:                 lock for node fields
+ * @work:                 worklist element for node work
+ *                        (protected by @proc->inner_lock)
+ * @rb_node:              element for proc->nodes tree
+ *                        (protected by @proc->inner_lock)
+ * @dead_node:            element for binder_dead_nodes list
+ *                        (protected by binder_dead_nodes_lock)
+ * @proc:                 binder_proc that owns this node
+ *                        (invariant after initialized)
+ * @refs:                 list of references on this node
+ *                        (protected by @lock)
+ * @internal_strong_refs: used to take strong references when
+ *                        initiating a transaction
+ *                        (protected by @proc->inner_lock if @proc
+ *                        and by @lock)
+ * @local_weak_refs:      weak user refs from local process
+ *                        (protected by @proc->inner_lock if @proc
+ *                        and by @lock)
+ * @local_strong_refs:    strong user refs from local process
+ *                        (protected by @proc->inner_lock if @proc
+ *                        and by @lock)
+ * @tmp_refs:             temporary kernel refs
+ *                        (protected by @proc->inner_lock while @proc
+ *                        is valid, and by binder_dead_nodes_lock
+ *                        if @proc is NULL. During inc/dec and node release
+ *                        it is also protected by @lock to provide safety
+ *                        as the node dies and @proc becomes NULL)
+ * @ptr:                  userspace pointer for node
+ *                        (invariant, no lock needed)
+ * @cookie:               userspace cookie for node
+ *                        (invariant, no lock needed)
+ * @has_strong_ref:       userspace notified of strong ref
+ *                        (protected by @proc->inner_lock if @proc
+ *                        and by @lock)
+ * @pending_strong_ref:   userspace has acked notification of strong ref
+ *                        (protected by @proc->inner_lock if @proc
+ *                        and by @lock)
+ * @has_weak_ref:         userspace notified of weak ref
+ *                        (protected by @proc->inner_lock if @proc
+ *                        and by @lock)
+ * @pending_weak_ref:     userspace has acked notification of weak ref
+ *                        (protected by @proc->inner_lock if @proc
+ *                        and by @lock)
+ * @has_async_transaction: async transaction to node in progress
+ *                        (protected by @lock)
+ * @accept_fds:           file descriptor operations supported for node
+ *                        (invariant after initialized)
+ * @min_priority:         minimum scheduling priority
+ *                        (invariant after initialized)
+ * @txn_security_ctx:     require sender's security context
+ *                        (invariant after initialized)
+ * @async_todo:           list of async work items
+ *                        (protected by @proc->inner_lock)
+ *
+ * Bookkeeping structure for binder nodes.
+ */
+struct binder_node {
+	int debug_id;
+	spinlock_t lock;
+	struct binder_work work;
+	union {
+		struct rb_node rb_node;
+		struct hlist_node dead_node;
+	};
+	struct binder_proc *proc;
+	struct hlist_head refs;
+	int internal_strong_refs;
+	int local_weak_refs;
+	int local_strong_refs;
+	int tmp_refs;
+	binder_uintptr_t ptr;
+	binder_uintptr_t cookie;
+	struct {
+		/*
+		 * bitfield elements protected by
+		 * proc inner_lock
+		 */
+		u8 has_strong_ref:1;
+		u8 pending_strong_ref:1;
+		u8 has_weak_ref:1;
+		u8 pending_weak_ref:1;
+	};
+	struct {
+		/*
+		 * invariant after initialization
+		 */
+		u8 accept_fds:1;
+		u8 txn_security_ctx:1;
+		u8 min_priority;
+	};
+	bool has_async_transaction;
+	struct list_head async_todo;
+};
+
+struct binder_ref_death {
+	/**
+	 * @work: worklist element for death notifications
+	 *        (protected by inner_lock of the proc that
+	 *        this ref belongs to)
+	 */
+	struct binder_work work;
+	binder_uintptr_t cookie;
+};
+
+struct binder_ref_freeze {
+	struct binder_work work;
+	binder_uintptr_t cookie;
+	bool is_frozen:1;
+	bool sent:1;
+	bool resend:1;
+};
+
+/**
+ * struct binder_ref_data - binder_ref counts and id
+ * @debug_id:        unique ID for the ref
+ * @desc:            unique userspace handle for ref
+ * @strong:          strong ref count (debugging only if not locked)
+ * @weak:            weak ref count (debugging only if not locked)
+ *
+ * Structure to hold ref count and ref id information. Since
+ * the actual ref can only be accessed with a lock, this structure
+ * is used to return information about the ref to callers of
+ * ref inc/dec functions.
+ */
+struct binder_ref_data {
+	int debug_id;
+	uint32_t desc;
+	int strong;
+	int weak;
+};
+
+/**
+ * struct binder_ref - struct to track references on nodes
+ * @data:        binder_ref_data containing id, handle, and current refcounts
+ * @rb_node_desc: node for lookup by @data.desc in proc's rb_tree
+ * @rb_node_node: node for lookup by @node in proc's rb_tree
+ * @node_entry:  list entry for node->refs list in target node
+ *               (protected by @node->lock)
+ * @proc:        binder_proc containing ref
+ * @node:        binder_node of target node. When cleaning up a
+ *               ref for deletion in binder_cleanup_ref, a non-NULL
+ *               @node indicates the node must be freed
+ * @death:       pointer to death notification (ref_death) if requested
+ *               (protected by @node->lock)
+ * @freeze:      pointer to freeze notification (ref_freeze) if requested
+ *               (protected by @node->lock)
+ *
+ * Structure to track references from procA to target node (on procB). This
+ * structure is unsafe to access without holding @proc->outer_lock.
+ */
+struct binder_ref {
+	/* Lookups needed: */
+	/*   node + proc => ref (transaction) */
+	/*   desc + proc => ref (transaction, inc/dec ref) */
+	/*   node => refs + procs (proc exit) */
+	struct binder_ref_data data;
+	struct rb_node rb_node_desc;
+	struct rb_node rb_node_node;
+	struct hlist_node node_entry;
+	struct binder_proc *proc;
+	struct binder_node *node;
+	struct binder_ref_death *death;
+	struct binder_ref_freeze *freeze;
+};
+
+/**
+ * struct binder_proc - binder process bookkeeping
+ * @proc_node:            element for binder_procs list
+ * @threads:              rbtree of binder_threads in this proc
+ *                        (protected by @inner_lock)
+ * @nodes:                rbtree of binder nodes associated with
+ *                        this proc ordered by node->ptr
+ *                        (protected by @inner_lock)
+ * @refs_by_desc:         rbtree of refs ordered by ref->desc
+ *                        (protected by @outer_lock)
+ * @refs_by_node:         rbtree of refs ordered by ref->node
+ *                        (protected by @outer_lock)
+ * @waiting_threads:      threads currently waiting for proc work
+ *                        (protected by @inner_lock)
+ * @pid                   PID of group_leader of process
+ *                        (invariant after initialized)
+ * @tsk                   task_struct for group_leader of process
+ *                        (invariant after initialized)
+ * @cred                  struct cred associated with the `struct file`
+ *                        in binder_open()
+ *                        (invariant after initialized)
+ * @deferred_work_node:   element for binder_deferred_list
+ *                        (protected by binder_deferred_lock)
+ * @deferred_work:        bitmap of deferred work to perform
+ *                        (protected by binder_deferred_lock)
+ * @outstanding_txns:     number of transactions to be transmitted before
+ *                        processes in freeze_wait are woken up
+ *                        (protected by @inner_lock)
+ * @is_dead:              process is dead and awaiting free
+ *                        when outstanding transactions are cleaned up
+ *                        (protected by @inner_lock)
+ * @is_frozen:            process is frozen and unable to service
+ *                        binder transactions
+ *                        (protected by @inner_lock)
+ * @sync_recv:            process received sync transactions since last frozen
+ *                        bit 0: received sync transaction after being frozen
+ *                        bit 1: new pending sync transaction during freezing
+ *                        (protected by @inner_lock)
+ * @async_recv:           process received async transactions since last frozen
+ *                        (protected by @inner_lock)
+ * @freeze_wait:          waitqueue of processes waiting for all outstanding
+ *                        transactions to be processed
+ *                        (protected by @inner_lock)
+ * @dmap                  dbitmap to manage available reference descriptors
+ *                        (protected by @outer_lock)
+ * @todo:                 list of work for this process
+ *                        (protected by @inner_lock)
+ * @stats:                per-process binder statistics
+ *                        (atomics, no lock needed)
+ * @delivered_death:      list of delivered death notification
+ *                        (protected by @inner_lock)
+ * @delivered_freeze:     list of delivered freeze notification
+ *                        (protected by @inner_lock)
+ * @max_threads:          cap on number of binder threads
+ *                        (protected by @inner_lock)
+ * @requested_threads:    number of binder threads requested but not
+ *                        yet started. In current implementation, can
+ *                        only be 0 or 1.
+ *                        (protected by @inner_lock)
+ * @requested_threads_started: number binder threads started
+ *                        (protected by @inner_lock)
+ * @tmp_ref:              temporary reference to indicate proc is in use
+ *                        (protected by @inner_lock)
+ * @default_priority:     default scheduler priority
+ *                        (invariant after initialized)
+ * @debugfs_entry:        debugfs node
+ * @alloc:                binder allocator bookkeeping
+ * @context:              binder_context for this proc
+ *                        (invariant after initialized)
+ * @inner_lock:           can nest under outer_lock and/or node lock
+ * @outer_lock:           no nesting under innor or node lock
+ *                        Lock order: 1) outer, 2) node, 3) inner
+ * @binderfs_entry:       process-specific binderfs log file
+ * @oneway_spam_detection_enabled: process enabled oneway spam detection
+ *                        or not
+ *
+ * Bookkeeping structure for binder processes
+ */
+struct binder_proc {
+	struct hlist_node proc_node;
+	struct rb_root threads;
+	struct rb_root nodes;
+	struct rb_root refs_by_desc;
+	struct rb_root refs_by_node;
+	struct list_head waiting_threads;
+	int pid;
+	struct task_struct *tsk;
+	const struct cred *cred;
+	struct hlist_node deferred_work_node;
+	int deferred_work;
+	int outstanding_txns;
+	bool is_dead;
+	bool is_frozen;
+	bool sync_recv;
+	bool async_recv;
+	wait_queue_head_t freeze_wait;
+	struct dbitmap dmap;
+	struct list_head todo;
+	struct binder_stats stats;
+	struct list_head delivered_death;
+	struct list_head delivered_freeze;
+	u32 max_threads;
+	int requested_threads;
+	int requested_threads_started;
+	int tmp_ref;
+	long default_priority;
+	struct dentry *debugfs_entry;
+	struct binder_alloc alloc;
+	struct binder_context *context;
+	spinlock_t inner_lock;
+	spinlock_t outer_lock;
+	struct dentry *binderfs_entry;
+	bool oneway_spam_detection_enabled;
+};
+
+/**
+ * struct binder_thread - binder thread bookkeeping
+ * @proc:                 binder process for this thread
+ *                        (invariant after initialization)
+ * @rb_node:              element for proc->threads rbtree
+ *                        (protected by @proc->inner_lock)
+ * @waiting_thread_node:  element for @proc->waiting_threads list
+ *                        (protected by @proc->inner_lock)
+ * @pid:                  PID for this thread
+ *                        (invariant after initialization)
+ * @looper:               bitmap of looping state
+ *                        (only accessed by this thread)
+ * @looper_needs_return:  looping thread needs to exit driver
+ *                        (no lock needed)
+ * @transaction_stack:    stack of in-progress transactions for this thread
+ *                        (protected by @proc->inner_lock)
+ * @todo:                 list of work to do for this thread
+ *                        (protected by @proc->inner_lock)
+ * @process_todo:         whether work in @todo should be processed
+ *                        (protected by @proc->inner_lock)
+ * @return_error:         transaction errors reported by this thread
+ *                        (only accessed by this thread)
+ * @reply_error:          transaction errors reported by target thread
+ *                        (protected by @proc->inner_lock)
+ * @ee:                   extended error information from this thread
+ *                        (protected by @proc->inner_lock)
+ * @wait:                 wait queue for thread work
+ * @stats:                per-thread statistics
+ *                        (atomics, no lock needed)
+ * @tmp_ref:              temporary reference to indicate thread is in use
+ *                        (atomic since @proc->inner_lock cannot
+ *                        always be acquired)
+ * @is_dead:              thread is dead and awaiting free
+ *                        when outstanding transactions are cleaned up
+ *                        (protected by @proc->inner_lock)
+ *
+ * Bookkeeping structure for binder threads.
+ */
+struct binder_thread {
+	struct binder_proc *proc;
+	struct rb_node rb_node;
+	struct list_head waiting_thread_node;
+	int pid;
+	int looper;              /* only modified by this thread */
+	bool looper_need_return; /* can be written by other thread */
+	struct binder_transaction *transaction_stack;
+	struct list_head todo;
+	bool process_todo;
+	struct binder_error return_error;
+	struct binder_error reply_error;
+	struct binder_extended_error ee;
+	wait_queue_head_t wait;
+	struct binder_stats stats;
+	atomic_t tmp_ref;
+	bool is_dead;
+};
+
+/**
+ * struct binder_txn_fd_fixup - transaction fd fixup list element
+ * @fixup_entry:          list entry
+ * @file:                 struct file to be associated with new fd
+ * @offset:               offset in buffer data to this fixup
+ * @target_fd:            fd to use by the target to install @file
+ *
+ * List element for fd fixups in a transaction. Since file
+ * descriptors need to be allocated in the context of the
+ * target process, we pass each fd to be processed in this
+ * struct.
+ */
+struct binder_txn_fd_fixup {
+	struct list_head fixup_entry;
+	struct file *file;
+	size_t offset;
+	int target_fd;
+};
+
+struct binder_transaction {
+	int debug_id;
+	struct binder_work work;
+	struct binder_thread *from;
+	pid_t from_pid;
+	pid_t from_tid;
+	struct binder_transaction *from_parent;
+	struct binder_proc *to_proc;
+	struct binder_thread *to_thread;
+	struct binder_transaction *to_parent;
+	unsigned is_async:1;
+	unsigned is_reply:1;
+
+	struct binder_buffer *buffer;
+	unsigned int    code;
+	unsigned int    flags;
+	long    priority;
+	long    saved_priority;
+	kuid_t  sender_euid;
+	ktime_t start_time;
+	struct list_head fd_fixups;
+	binder_uintptr_t security_ctx;
+	/**
+	 * @lock:  protects @from, @to_proc, and @to_thread
+	 *
+	 * @from, @to_proc, and @to_thread can be set to NULL
+	 * during thread teardown
+	 */
+	spinlock_t lock;
+};
+
+/**
+ * struct binder_object - union of flat binder object types
+ * @hdr:   generic object header
+ * @fbo:   binder object (nodes and refs)
+ * @fdo:   file descriptor object
+ * @bbo:   binder buffer pointer
+ * @fdao:  file descriptor array
+ *
+ * Used for type-independent object copies
+ */
+struct binder_object {
+	union {
+		struct binder_object_header hdr;
+		struct flat_binder_object fbo;
+		struct binder_fd_object fdo;
+		struct binder_buffer_object bbo;
+		struct binder_fd_array_object fdao;
+	};
+};
+
+/**
+ * Add a binder device to binder_devices
+ * @device: the new binder device to add to the global list
+ */
+void binder_add_device(struct binder_device *device);
+
+/**
+ * Remove a binder device to binder_devices
+ * @device: the binder device to remove from the global list
+ */
+void binder_remove_device(struct binder_device *device);
+
+#if IS_ENABLED(CONFIG_KUNIT)
+vm_fault_t binder_vm_fault(struct vm_fault *vmf);
+#endif
+
+#endif /* _LINUX_BINDER_INTERNAL_H */
diff --git a/drivers/android/binder_netlink.c b/drivers/android/binder_netlink.c
new file mode 100644
index 000000000..81e8432b5
--- /dev/null
+++ b/drivers/android/binder_netlink.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+/* Do not edit directly, auto-generated from: */
+/*	Documentation/netlink/specs/binder.yaml */
+/* YNL-GEN kernel source */
+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
+
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include "binder_netlink.h"
+
+#include <uapi/linux/android/binder_netlink.h>
+
+/* Ops table for binder */
+static const struct genl_split_ops binder_nl_ops[] = {
+};
+
+static const struct genl_multicast_group binder_nl_mcgrps[] = {
+	[BINDER_NLGRP_REPORT] = { "report", },
+};
+
+struct genl_family binder_nl_family __ro_after_init = {
+	.name		= BINDER_FAMILY_NAME,
+	.version	= BINDER_FAMILY_VERSION,
+	.netnsok	= true,
+	.parallel_ops	= true,
+	.module		= THIS_MODULE,
+	.split_ops	= binder_nl_ops,
+	.n_split_ops	= ARRAY_SIZE(binder_nl_ops),
+	.mcgrps		= binder_nl_mcgrps,
+	.n_mcgrps	= ARRAY_SIZE(binder_nl_mcgrps),
+};
diff --git a/drivers/android/binder_netlink.h b/drivers/android/binder_netlink.h
new file mode 100644
index 000000000..57399942a
--- /dev/null
+++ b/drivers/android/binder_netlink.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+/* Do not edit directly, auto-generated from: */
+/*	Documentation/netlink/specs/binder.yaml */
+/* YNL-GEN kernel header */
+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
+
+#ifndef _LINUX_BINDER_GEN_H
+#define _LINUX_BINDER_GEN_H
+
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include <uapi/linux/android/binder_netlink.h>
+
+enum {
+	BINDER_NLGRP_REPORT,
+};
+
+extern struct genl_family binder_nl_family;
+
+#endif /* _LINUX_BINDER_GEN_H */
diff --git a/drivers/android/binder_trace.h b/drivers/android/binder_trace.h
new file mode 100644
index 000000000..fa5eb61cf
--- /dev/null
+++ b/drivers/android/binder_trace.h
@@ -0,0 +1,448 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 Google, Inc.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM binder
+
+#if !defined(_BINDER_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _BINDER_TRACE_H
+
+#include <linux/tracepoint.h>
+
+struct binder_buffer;
+struct binder_node;
+struct binder_proc;
+struct binder_alloc;
+struct binder_ref_data;
+struct binder_thread;
+struct binder_transaction;
+
+TRACE_EVENT(binder_ioctl,
+	TP_PROTO(unsigned int cmd, unsigned long arg),
+	TP_ARGS(cmd, arg),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, cmd)
+		__field(unsigned long, arg)
+	),
+	TP_fast_assign(
+		__entry->cmd = cmd;
+		__entry->arg = arg;
+	),
+	TP_printk("cmd=0x%x arg=0x%lx", __entry->cmd, __entry->arg)
+);
+
+DECLARE_EVENT_CLASS(binder_function_return_class,
+	TP_PROTO(int ret),
+	TP_ARGS(ret),
+	TP_STRUCT__entry(
+		__field(int, ret)
+	),
+	TP_fast_assign(
+		__entry->ret = ret;
+	),
+	TP_printk("ret=%d", __entry->ret)
+);
+
+#define DEFINE_BINDER_FUNCTION_RETURN_EVENT(name)	\
+DEFINE_EVENT(binder_function_return_class, name,	\
+	TP_PROTO(int ret), \
+	TP_ARGS(ret))
+
+DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_ioctl_done);
+DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_write_done);
+DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_read_done);
+
+TRACE_EVENT(binder_wait_for_work,
+	TP_PROTO(bool proc_work, bool transaction_stack, bool thread_todo),
+	TP_ARGS(proc_work, transaction_stack, thread_todo),
+
+	TP_STRUCT__entry(
+		__field(bool, proc_work)
+		__field(bool, transaction_stack)
+		__field(bool, thread_todo)
+	),
+	TP_fast_assign(
+		__entry->proc_work = proc_work;
+		__entry->transaction_stack = transaction_stack;
+		__entry->thread_todo = thread_todo;
+	),
+	TP_printk("proc_work=%d transaction_stack=%d thread_todo=%d",
+		  __entry->proc_work, __entry->transaction_stack,
+		  __entry->thread_todo)
+);
+
+TRACE_EVENT(binder_txn_latency_free,
+	TP_PROTO(struct binder_transaction *t,
+		 int from_proc, int from_thread,
+		 int to_proc, int to_thread),
+	TP_ARGS(t, from_proc, from_thread, to_proc, to_thread),
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, from_proc)
+		__field(int, from_thread)
+		__field(int, to_proc)
+		__field(int, to_thread)
+		__field(unsigned int, code)
+		__field(unsigned int, flags)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->from_proc = from_proc;
+		__entry->from_thread = from_thread;
+		__entry->to_proc = to_proc;
+		__entry->to_thread = to_thread;
+		__entry->code = t->code;
+		__entry->flags = t->flags;
+	),
+	TP_printk("transaction=%d from %d:%d to %d:%d flags=0x%x code=0x%x",
+		  __entry->debug_id, __entry->from_proc, __entry->from_thread,
+		  __entry->to_proc, __entry->to_thread, __entry->code,
+		  __entry->flags)
+);
+
+TRACE_EVENT(binder_transaction,
+	TP_PROTO(bool reply, struct binder_transaction *t,
+		 struct binder_node *target_node),
+	TP_ARGS(reply, t, target_node),
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, target_node)
+		__field(int, to_proc)
+		__field(int, to_thread)
+		__field(int, reply)
+		__field(unsigned int, code)
+		__field(unsigned int, flags)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->target_node = target_node ? target_node->debug_id : 0;
+		__entry->to_proc = t->to_proc->pid;
+		__entry->to_thread = t->to_thread ? t->to_thread->pid : 0;
+		__entry->reply = reply;
+		__entry->code = t->code;
+		__entry->flags = t->flags;
+	),
+	TP_printk("transaction=%d dest_node=%d dest_proc=%d dest_thread=%d reply=%d flags=0x%x code=0x%x",
+		  __entry->debug_id, __entry->target_node,
+		  __entry->to_proc, __entry->to_thread,
+		  __entry->reply, __entry->flags, __entry->code)
+);
+
+TRACE_EVENT(binder_transaction_received,
+	TP_PROTO(struct binder_transaction *t),
+	TP_ARGS(t),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+	),
+	TP_printk("transaction=%d", __entry->debug_id)
+);
+
+TRACE_EVENT(binder_transaction_node_to_ref,
+	TP_PROTO(struct binder_transaction *t, struct binder_node *node,
+		 struct binder_ref_data *rdata),
+	TP_ARGS(t, node, rdata),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, node_debug_id)
+		__field(binder_uintptr_t, node_ptr)
+		__field(int, ref_debug_id)
+		__field(uint32_t, ref_desc)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->node_debug_id = node->debug_id;
+		__entry->node_ptr = node->ptr;
+		__entry->ref_debug_id = rdata->debug_id;
+		__entry->ref_desc = rdata->desc;
+	),
+	TP_printk("transaction=%d node=%d src_ptr=0x%016llx ==> dest_ref=%d dest_desc=%d",
+		  __entry->debug_id, __entry->node_debug_id,
+		  (u64)__entry->node_ptr,
+		  __entry->ref_debug_id, __entry->ref_desc)
+);
+
+TRACE_EVENT(binder_transaction_ref_to_node,
+	TP_PROTO(struct binder_transaction *t, struct binder_node *node,
+		 struct binder_ref_data *rdata),
+	TP_ARGS(t, node, rdata),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, ref_debug_id)
+		__field(uint32_t, ref_desc)
+		__field(int, node_debug_id)
+		__field(binder_uintptr_t, node_ptr)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->ref_debug_id = rdata->debug_id;
+		__entry->ref_desc = rdata->desc;
+		__entry->node_debug_id = node->debug_id;
+		__entry->node_ptr = node->ptr;
+	),
+	TP_printk("transaction=%d node=%d src_ref=%d src_desc=%d ==> dest_ptr=0x%016llx",
+		  __entry->debug_id, __entry->node_debug_id,
+		  __entry->ref_debug_id, __entry->ref_desc,
+		  (u64)__entry->node_ptr)
+);
+
+TRACE_EVENT(binder_transaction_ref_to_ref,
+	TP_PROTO(struct binder_transaction *t, struct binder_node *node,
+		 struct binder_ref_data *src_ref,
+		 struct binder_ref_data *dest_ref),
+	TP_ARGS(t, node, src_ref, dest_ref),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, node_debug_id)
+		__field(int, src_ref_debug_id)
+		__field(uint32_t, src_ref_desc)
+		__field(int, dest_ref_debug_id)
+		__field(uint32_t, dest_ref_desc)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->node_debug_id = node->debug_id;
+		__entry->src_ref_debug_id = src_ref->debug_id;
+		__entry->src_ref_desc = src_ref->desc;
+		__entry->dest_ref_debug_id = dest_ref->debug_id;
+		__entry->dest_ref_desc = dest_ref->desc;
+	),
+	TP_printk("transaction=%d node=%d src_ref=%d src_desc=%d ==> dest_ref=%d dest_desc=%d",
+		  __entry->debug_id, __entry->node_debug_id,
+		  __entry->src_ref_debug_id, __entry->src_ref_desc,
+		  __entry->dest_ref_debug_id, __entry->dest_ref_desc)
+);
+
+TRACE_EVENT(binder_transaction_fd_send,
+	TP_PROTO(struct binder_transaction *t, int fd, size_t offset),
+	TP_ARGS(t, fd, offset),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, fd)
+		__field(size_t, offset)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->fd = fd;
+		__entry->offset = offset;
+	),
+	TP_printk("transaction=%d src_fd=%d offset=%zu",
+		  __entry->debug_id, __entry->fd, __entry->offset)
+);
+
+TRACE_EVENT(binder_transaction_fd_recv,
+	TP_PROTO(struct binder_transaction *t, int fd, size_t offset),
+	TP_ARGS(t, fd, offset),
+
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(int, fd)
+		__field(size_t, offset)
+	),
+	TP_fast_assign(
+		__entry->debug_id = t->debug_id;
+		__entry->fd = fd;
+		__entry->offset = offset;
+	),
+	TP_printk("transaction=%d dest_fd=%d offset=%zu",
+		  __entry->debug_id, __entry->fd, __entry->offset)
+);
+
+DECLARE_EVENT_CLASS(binder_buffer_class,
+	TP_PROTO(struct binder_buffer *buf),
+	TP_ARGS(buf),
+	TP_STRUCT__entry(
+		__field(int, debug_id)
+		__field(size_t, data_size)
+		__field(size_t, offsets_size)
+		__field(size_t, extra_buffers_size)
+	),
+	TP_fast_assign(
+		__entry->debug_id = buf->debug_id;
+		__entry->data_size = buf->data_size;
+		__entry->offsets_size = buf->offsets_size;
+		__entry->extra_buffers_size = buf->extra_buffers_size;
+	),
+	TP_printk("transaction=%d data_size=%zd offsets_size=%zd extra_buffers_size=%zd",
+		  __entry->debug_id, __entry->data_size, __entry->offsets_size,
+		  __entry->extra_buffers_size)
+);
+
+DEFINE_EVENT(binder_buffer_class, binder_transaction_alloc_buf,
+	TP_PROTO(struct binder_buffer *buffer),
+	TP_ARGS(buffer));
+
+DEFINE_EVENT(binder_buffer_class, binder_transaction_buffer_release,
+	TP_PROTO(struct binder_buffer *buffer),
+	TP_ARGS(buffer));
+
+DEFINE_EVENT(binder_buffer_class, binder_transaction_failed_buffer_release,
+	TP_PROTO(struct binder_buffer *buffer),
+	TP_ARGS(buffer));
+
+DEFINE_EVENT(binder_buffer_class, binder_transaction_update_buffer_release,
+	     TP_PROTO(struct binder_buffer *buffer),
+	     TP_ARGS(buffer));
+
+TRACE_EVENT(binder_update_page_range,
+	TP_PROTO(struct binder_alloc *alloc, bool allocate,
+		 unsigned long start, unsigned long end),
+	TP_ARGS(alloc, allocate, start, end),
+	TP_STRUCT__entry(
+		__field(int, proc)
+		__field(bool, allocate)
+		__field(size_t, offset)
+		__field(size_t, size)
+	),
+	TP_fast_assign(
+		__entry->proc = alloc->pid;
+		__entry->allocate = allocate;
+		__entry->offset = start - alloc->vm_start;
+		__entry->size = end - start;
+	),
+	TP_printk("proc=%d allocate=%d offset=%zu size=%zu",
+		  __entry->proc, __entry->allocate,
+		  __entry->offset, __entry->size)
+);
+
+DECLARE_EVENT_CLASS(binder_lru_page_class,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index),
+	TP_STRUCT__entry(
+		__field(int, proc)
+		__field(size_t, page_index)
+	),
+	TP_fast_assign(
+		__entry->proc = alloc->pid;
+		__entry->page_index = page_index;
+	),
+	TP_printk("proc=%d page_index=%zu",
+		  __entry->proc, __entry->page_index)
+);
+
+DEFINE_EVENT(binder_lru_page_class, binder_alloc_lru_start,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_alloc_lru_end,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_free_lru_start,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_free_lru_end,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_alloc_page_start,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_alloc_page_end,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_unmap_user_start,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_unmap_user_end,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_unmap_kernel_start,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+DEFINE_EVENT(binder_lru_page_class, binder_unmap_kernel_end,
+	TP_PROTO(const struct binder_alloc *alloc, size_t page_index),
+	TP_ARGS(alloc, page_index));
+
+TRACE_EVENT(binder_command,
+	TP_PROTO(uint32_t cmd),
+	TP_ARGS(cmd),
+	TP_STRUCT__entry(
+		__field(uint32_t, cmd)
+	),
+	TP_fast_assign(
+		__entry->cmd = cmd;
+	),
+	TP_printk("cmd=0x%x %s",
+		  __entry->cmd,
+		  _IOC_NR(__entry->cmd) < ARRAY_SIZE(binder_command_strings) ?
+			  binder_command_strings[_IOC_NR(__entry->cmd)] :
+			  "unknown")
+);
+
+TRACE_EVENT(binder_return,
+	TP_PROTO(uint32_t cmd),
+	TP_ARGS(cmd),
+	TP_STRUCT__entry(
+		__field(uint32_t, cmd)
+	),
+	TP_fast_assign(
+		__entry->cmd = cmd;
+	),
+	TP_printk("cmd=0x%x %s",
+		  __entry->cmd,
+		  _IOC_NR(__entry->cmd) < ARRAY_SIZE(binder_return_strings) ?
+			  binder_return_strings[_IOC_NR(__entry->cmd)] :
+			  "unknown")
+);
+
+TRACE_EVENT(binder_netlink_report,
+	TP_PROTO(const char *context,
+		 struct binder_transaction *t,
+		 u32 data_size,
+		 u32 error),
+	TP_ARGS(context, t, data_size, error),
+	TP_STRUCT__entry(
+		__field(const char *, context)
+		__field(u32, error)
+		__field(int, from_pid)
+		__field(int, from_tid)
+		__field(int, to_pid)
+		__field(int, to_tid)
+		__field(bool, is_reply)
+		__field(unsigned int, flags)
+		__field(unsigned int, code)
+		__field(size_t, data_size)
+	),
+	TP_fast_assign(
+		__entry->context = context;
+		__entry->error = error;
+		__entry->from_pid = t->from_pid;
+		__entry->from_tid = t->from_tid;
+		__entry->to_pid = t->to_proc ? t->to_proc->pid : 0;
+		__entry->to_tid = t->to_thread ? t->to_thread->pid : 0;
+		__entry->is_reply = t->is_reply;
+		__entry->flags = t->flags;
+		__entry->code = t->code;
+		__entry->data_size = data_size;
+	),
+	TP_printk("from %d:%d to %d:%d context=%s error=%d is_reply=%d flags=0x%x code=0x%x size=%zu",
+		  __entry->from_pid, __entry->from_tid,
+		  __entry->to_pid, __entry->to_tid,
+		  __entry->context, __entry->error, __entry->is_reply,
+		  __entry->flags, __entry->code, __entry->data_size)
+);
+
+#endif /* _BINDER_TRACE_H */
+
+#undef TRACE_INCLUDE_PATH
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE binder_trace
+#include <trace/define_trace.h>
diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c
new file mode 100644
index 000000000..361d69f75
--- /dev/null
+++ b/drivers/android/binderfs.c
@@ -0,0 +1,786 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/compiler_types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/fsnotify.h>
+#include <linux/gfp.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/ipc_namespace.h>
+#include <linux/kdev_t.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/namei.h>
+#include <linux/magic.h>
+#include <linux/major.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/mount.h>
+#include <linux/fs_parser.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/spinlock_types.h>
+#include <linux/stddef.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/user_namespace.h>
+#include <linux/xarray.h>
+#include <uapi/linux/android/binder.h>
+#include <uapi/linux/android/binderfs.h>
+
+#include "binder_internal.h"
+
+#define FIRST_INODE 1
+#define SECOND_INODE 2
+#define INODE_OFFSET 3
+#define BINDERFS_MAX_MINOR (1U << MINORBITS)
+/* Ensure that the initial ipc namespace always has devices available. */
+#define BINDERFS_MAX_MINOR_CAPPED (BINDERFS_MAX_MINOR - 4)
+
+static dev_t binderfs_dev;
+static DEFINE_MUTEX(binderfs_minors_mutex);
+static DEFINE_IDA(binderfs_minors);
+
+enum binderfs_param {
+	Opt_max,
+	Opt_stats_mode,
+};
+
+enum binderfs_stats_mode {
+	binderfs_stats_mode_unset,
+	binderfs_stats_mode_global,
+};
+
+struct binder_features {
+	bool oneway_spam_detection;
+	bool extended_error;
+	bool freeze_notification;
+	bool transaction_report;
+};
+
+static const struct constant_table binderfs_param_stats[] = {
+	{ "global", binderfs_stats_mode_global },
+	{}
+};
+
+static const struct fs_parameter_spec binderfs_fs_parameters[] = {
+	fsparam_u32("max",	Opt_max),
+	fsparam_enum("stats",	Opt_stats_mode, binderfs_param_stats),
+	{}
+};
+
+static struct binder_features binder_features = {
+	.oneway_spam_detection = true,
+	.extended_error = true,
+	.freeze_notification = true,
+	.transaction_report = true,
+};
+
+static inline struct binderfs_info *BINDERFS_SB(const struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+bool is_binderfs_device(const struct inode *inode)
+{
+	if (inode->i_sb->s_magic == BINDERFS_SUPER_MAGIC)
+		return true;
+
+	return false;
+}
+
+/**
+ * binderfs_binder_device_create - allocate inode from super block of a
+ *                                 binderfs mount
+ * @ref_inode: inode from which the super block will be taken
+ * @userp:     buffer to copy information about new device for userspace to
+ * @req:       struct binderfs_device as copied from userspace
+ *
+ * This function allocates a new binder_device and reserves a new minor
+ * number for it.
+ * Minor numbers are limited and tracked globally in binderfs_minors. The
+ * function will stash a struct binder_device for the specific binder
+ * device in i_private of the inode.
+ * It will go on to allocate a new inode from the super block of the
+ * filesystem mount, stash a struct binder_device in its i_private field
+ * and attach a dentry to that inode.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+static int binderfs_binder_device_create(struct inode *ref_inode,
+					 struct binderfs_device __user *userp,
+					 struct binderfs_device *req)
+{
+	int minor, ret;
+	struct dentry *dentry, *root;
+	struct binder_device *device;
+	char *name = NULL;
+	struct inode *inode = NULL;
+	struct super_block *sb = ref_inode->i_sb;
+	struct binderfs_info *info = sb->s_fs_info;
+#if defined(CONFIG_IPC_NS)
+	bool use_reserve = (info->ipc_ns == &init_ipc_ns);
+#else
+	bool use_reserve = true;
+#endif
+
+	/* Reserve new minor number for the new device. */
+	mutex_lock(&binderfs_minors_mutex);
+	if (++info->device_count <= info->mount_opts.max)
+		minor = ida_alloc_max(&binderfs_minors,
+				      use_reserve ? BINDERFS_MAX_MINOR - 1 :
+						    BINDERFS_MAX_MINOR_CAPPED - 1,
+				      GFP_KERNEL);
+	else
+		minor = -ENOSPC;
+	if (minor < 0) {
+		--info->device_count;
+		mutex_unlock(&binderfs_minors_mutex);
+		return minor;
+	}
+	mutex_unlock(&binderfs_minors_mutex);
+
+	ret = -ENOMEM;
+	device = kzalloc_obj(*device);
+	if (!device)
+		goto err;
+
+	inode = new_inode(sb);
+	if (!inode)
+		goto err;
+
+	inode->i_ino = minor + INODE_OFFSET;
+	simple_inode_init_ts(inode);
+	init_special_inode(inode, S_IFCHR | 0600,
+			   MKDEV(MAJOR(binderfs_dev), minor));
+	inode->i_fop = &binder_fops;
+	inode->i_uid = info->root_uid;
+	inode->i_gid = info->root_gid;
+
+	req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */
+	name = kstrdup(req->name, GFP_KERNEL);
+	if (!name)
+		goto err;
+
+	refcount_set(&device->ref, 1);
+	device->binderfs_inode = inode;
+	device->context.binder_context_mgr_uid = INVALID_UID;
+	device->context.name = name;
+	device->miscdev.name = name;
+	device->miscdev.minor = minor;
+	mutex_init(&device->context.context_mgr_node_lock);
+
+	req->major = MAJOR(binderfs_dev);
+	req->minor = minor;
+
+	if (userp && copy_to_user(userp, req, sizeof(*req))) {
+		ret = -EFAULT;
+		goto err;
+	}
+
+	root = sb->s_root;
+	dentry = simple_start_creating(root, name);
+	if (IS_ERR(dentry)) {
+		ret = PTR_ERR(dentry);
+		goto err;
+	}
+	inode->i_private = device;
+	d_make_persistent(dentry, inode);
+	fsnotify_create(root->d_inode, dentry);
+	simple_done_creating(dentry);
+
+	binder_add_device(device);
+
+	return 0;
+
+err:
+	kfree(name);
+	kfree(device);
+	mutex_lock(&binderfs_minors_mutex);
+	--info->device_count;
+	ida_free(&binderfs_minors, minor);
+	mutex_unlock(&binderfs_minors_mutex);
+	iput(inode);
+
+	return ret;
+}
+
+/**
+ * binder_ctl_ioctl - handle binder device node allocation requests
+ * @file: The file pointer for the binder-control device node.
+ * @cmd: The ioctl command.
+ * @arg: The ioctl argument.
+ *
+ * The request handler for the binder-control device. All requests operate on
+ * the binderfs mount the binder-control device resides in:
+ * - BINDER_CTL_ADD
+ *   Allocate a new binder device.
+ *
+ * Return: %0 on success, negative errno on failure.
+ */
+static long binder_ctl_ioctl(struct file *file, unsigned int cmd,
+			     unsigned long arg)
+{
+	int ret = -EINVAL;
+	struct inode *inode = file_inode(file);
+	struct binderfs_device __user *device = (struct binderfs_device __user *)arg;
+	struct binderfs_device device_req;
+
+	switch (cmd) {
+	case BINDER_CTL_ADD:
+		ret = copy_from_user(&device_req, device, sizeof(device_req));
+		if (ret) {
+			ret = -EFAULT;
+			break;
+		}
+
+		ret = binderfs_binder_device_create(inode, device, &device_req);
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+static void binderfs_evict_inode(struct inode *inode)
+{
+	struct binder_device *device = inode->i_private;
+	struct binderfs_info *info = BINDERFS_SB(inode->i_sb);
+
+	clear_inode(inode);
+
+	if (!S_ISCHR(inode->i_mode) || !device)
+		return;
+
+	mutex_lock(&binderfs_minors_mutex);
+	--info->device_count;
+	ida_free(&binderfs_minors, device->miscdev.minor);
+	mutex_unlock(&binderfs_minors_mutex);
+
+	if (refcount_dec_and_test(&device->ref)) {
+		binder_remove_device(device);
+		kfree(device->context.name);
+		kfree(device);
+	}
+}
+
+static int binderfs_fs_context_parse_param(struct fs_context *fc,
+					   struct fs_parameter *param)
+{
+	int opt;
+	struct binderfs_mount_opts *ctx = fc->fs_private;
+	struct fs_parse_result result;
+
+	opt = fs_parse(fc, binderfs_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_max:
+		if (result.uint_32 > BINDERFS_MAX_MINOR)
+			return invalfc(fc, "Bad value for '%s'", param->key);
+
+		ctx->max = result.uint_32;
+		break;
+	case Opt_stats_mode:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		ctx->stats_mode = result.uint_32;
+		break;
+	default:
+		return invalfc(fc, "Unsupported parameter '%s'", param->key);
+	}
+
+	return 0;
+}
+
+static int binderfs_fs_context_reconfigure(struct fs_context *fc)
+{
+	struct binderfs_mount_opts *ctx = fc->fs_private;
+	struct binderfs_info *info = BINDERFS_SB(fc->root->d_sb);
+
+	if (info->mount_opts.stats_mode != ctx->stats_mode)
+		return invalfc(fc, "Binderfs stats mode cannot be changed during a remount");
+
+	info->mount_opts.stats_mode = ctx->stats_mode;
+	info->mount_opts.max = ctx->max;
+	return 0;
+}
+
+static int binderfs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct binderfs_info *info = BINDERFS_SB(root->d_sb);
+
+	if (info->mount_opts.max <= BINDERFS_MAX_MINOR)
+		seq_printf(seq, ",max=%d", info->mount_opts.max);
+
+	switch (info->mount_opts.stats_mode) {
+	case binderfs_stats_mode_unset:
+		break;
+	case binderfs_stats_mode_global:
+		seq_printf(seq, ",stats=global");
+		break;
+	}
+
+	return 0;
+}
+
+static const struct super_operations binderfs_super_ops = {
+	.evict_inode    = binderfs_evict_inode,
+	.show_options	= binderfs_show_options,
+	.statfs         = simple_statfs,
+};
+
+static inline bool is_binderfs_control_device(const struct dentry *dentry)
+{
+	struct binderfs_info *info = dentry->d_sb->s_fs_info;
+
+	return info->control_dentry == dentry;
+}
+
+static int binderfs_rename(struct mnt_idmap *idmap,
+			   struct inode *old_dir, struct dentry *old_dentry,
+			   struct inode *new_dir, struct dentry *new_dentry,
+			   unsigned int flags)
+{
+	if (is_binderfs_control_device(old_dentry) ||
+	    is_binderfs_control_device(new_dentry))
+		return -EPERM;
+
+	return simple_rename(idmap, old_dir, old_dentry, new_dir,
+			     new_dentry, flags);
+}
+
+static int binderfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	if (is_binderfs_control_device(dentry))
+		return -EPERM;
+
+	return simple_unlink(dir, dentry);
+}
+
+static const struct file_operations binder_ctl_fops = {
+	.owner		= THIS_MODULE,
+	.open		= nonseekable_open,
+	.unlocked_ioctl	= binder_ctl_ioctl,
+	.compat_ioctl	= binder_ctl_ioctl,
+	.llseek		= noop_llseek,
+};
+
+/**
+ * binderfs_binder_ctl_create - create a new binder-control device
+ * @sb: super block of the binderfs mount
+ *
+ * This function creates a new binder-control device node in the binderfs mount
+ * referred to by @sb.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+static int binderfs_binder_ctl_create(struct super_block *sb)
+{
+	int minor, ret;
+	struct dentry *dentry;
+	struct binder_device *device;
+	struct inode *inode = NULL;
+	struct dentry *root = sb->s_root;
+	struct binderfs_info *info = sb->s_fs_info;
+#if defined(CONFIG_IPC_NS)
+	bool use_reserve = (info->ipc_ns == &init_ipc_ns);
+#else
+	bool use_reserve = true;
+#endif
+
+	device = kzalloc_obj(*device);
+	if (!device)
+		return -ENOMEM;
+
+	ret = -ENOMEM;
+	inode = new_inode(sb);
+	if (!inode)
+		goto out;
+
+	/* Reserve a new minor number for the new device. */
+	mutex_lock(&binderfs_minors_mutex);
+	minor = ida_alloc_max(&binderfs_minors,
+			      use_reserve ? BINDERFS_MAX_MINOR - 1 :
+					    BINDERFS_MAX_MINOR_CAPPED - 1,
+			      GFP_KERNEL);
+	mutex_unlock(&binderfs_minors_mutex);
+	if (minor < 0) {
+		ret = minor;
+		goto out;
+	}
+
+	inode->i_ino = SECOND_INODE;
+	simple_inode_init_ts(inode);
+	init_special_inode(inode, S_IFCHR | 0600,
+			   MKDEV(MAJOR(binderfs_dev), minor));
+	inode->i_fop = &binder_ctl_fops;
+	inode->i_uid = info->root_uid;
+	inode->i_gid = info->root_gid;
+
+	refcount_set(&device->ref, 1);
+	device->binderfs_inode = inode;
+	device->miscdev.minor = minor;
+
+	dentry = d_alloc_name(root, "binder-control");
+	if (!dentry)
+		goto out;
+
+	inode->i_private = device;
+	info->control_dentry = dentry;
+	d_make_persistent(dentry, inode);
+	dput(dentry);
+
+	return 0;
+
+out:
+	kfree(device);
+	iput(inode);
+
+	return ret;
+}
+
+static const struct inode_operations binderfs_dir_inode_operations = {
+	.lookup = simple_lookup,
+	.rename = binderfs_rename,
+	.unlink = binderfs_unlink,
+};
+
+static struct inode *binderfs_make_inode(struct super_block *sb, int mode)
+{
+	struct inode *ret;
+
+	ret = new_inode(sb);
+	if (ret) {
+		ret->i_ino = iunique(sb, BINDERFS_MAX_MINOR + INODE_OFFSET);
+		ret->i_mode = mode;
+		simple_inode_init_ts(ret);
+	}
+	return ret;
+}
+
+struct dentry *binderfs_create_file(struct dentry *parent, const char *name,
+				    const struct file_operations *fops,
+				    void *data)
+{
+	struct dentry *dentry;
+	struct inode *new_inode, *parent_inode;
+	struct super_block *sb;
+
+	parent_inode = d_inode(parent);
+
+	dentry = simple_start_creating(parent, name);
+	if (IS_ERR(dentry))
+		return dentry;
+
+	sb = parent_inode->i_sb;
+	new_inode = binderfs_make_inode(sb, S_IFREG | 0444);
+	if (!new_inode) {
+		simple_done_creating(dentry);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	new_inode->i_fop = fops;
+	new_inode->i_private = data;
+	d_make_persistent(dentry, new_inode);
+	fsnotify_create(parent_inode, dentry);
+	simple_done_creating(dentry);
+	return dentry; // borrowed
+}
+
+static struct dentry *binderfs_create_dir(struct dentry *parent,
+					  const char *name)
+{
+	struct dentry *dentry;
+	struct inode *new_inode, *parent_inode;
+	struct super_block *sb;
+
+	parent_inode = d_inode(parent);
+
+	dentry = simple_start_creating(parent, name);
+	if (IS_ERR(dentry))
+		return dentry;
+
+	sb = parent_inode->i_sb;
+	new_inode = binderfs_make_inode(sb, S_IFDIR | 0755);
+	if (!new_inode) {
+		simple_done_creating(dentry);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	new_inode->i_fop = &simple_dir_operations;
+	new_inode->i_op = &simple_dir_inode_operations;
+
+	set_nlink(new_inode, 2);
+	d_make_persistent(dentry, new_inode);
+	inc_nlink(parent_inode);
+	fsnotify_mkdir(parent_inode, dentry);
+	simple_done_creating(dentry);
+	return dentry;
+}
+
+static int binder_features_show(struct seq_file *m, void *unused)
+{
+	bool *feature = m->private;
+
+	seq_printf(m, "%d\n", *feature);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(binder_features);
+
+static int init_binder_features(struct super_block *sb)
+{
+	struct dentry *dentry, *dir;
+
+	dir = binderfs_create_dir(sb->s_root, "features");
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+
+	dentry = binderfs_create_file(dir, "oneway_spam_detection",
+				      &binder_features_fops,
+				      &binder_features.oneway_spam_detection);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	dentry = binderfs_create_file(dir, "extended_error",
+				      &binder_features_fops,
+				      &binder_features.extended_error);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	dentry = binderfs_create_file(dir, "freeze_notification",
+				      &binder_features_fops,
+				      &binder_features.freeze_notification);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	dentry = binderfs_create_file(dir, "transaction_report",
+				      &binder_features_fops,
+				      &binder_features.transaction_report);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	return 0;
+}
+
+static int init_binder_logs(struct super_block *sb)
+{
+	struct dentry *binder_logs_root_dir, *dentry, *proc_log_dir;
+	const struct binder_debugfs_entry *db_entry;
+	struct binderfs_info *info;
+	int ret = 0;
+
+	binder_logs_root_dir = binderfs_create_dir(sb->s_root,
+						   "binder_logs");
+	if (IS_ERR(binder_logs_root_dir)) {
+		ret = PTR_ERR(binder_logs_root_dir);
+		goto out;
+	}
+
+	binder_for_each_debugfs_entry(db_entry) {
+		dentry = binderfs_create_file(binder_logs_root_dir,
+					      db_entry->name,
+					      db_entry->fops,
+					      db_entry->data);
+		if (IS_ERR(dentry)) {
+			ret = PTR_ERR(dentry);
+			goto out;
+		}
+	}
+
+	proc_log_dir = binderfs_create_dir(binder_logs_root_dir, "proc");
+	if (IS_ERR(proc_log_dir)) {
+		ret = PTR_ERR(proc_log_dir);
+		goto out;
+	}
+	info = sb->s_fs_info;
+	info->proc_log_dir = proc_log_dir;
+
+out:
+	return ret;
+}
+
+static int binderfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	int ret;
+	struct binderfs_info *info;
+	struct binderfs_mount_opts *ctx = fc->fs_private;
+	struct inode *inode = NULL;
+	struct binderfs_device device_info = {};
+	const char *name;
+	size_t len;
+
+	sb->s_blocksize = PAGE_SIZE;
+	sb->s_blocksize_bits = PAGE_SHIFT;
+
+	/*
+	 * The binderfs filesystem can be mounted by userns root in a
+	 * non-initial userns. By default such mounts have the SB_I_NODEV flag
+	 * set in s_iflags to prevent security issues where userns root can
+	 * just create random device nodes via mknod() since it owns the
+	 * filesystem mount. But binderfs does not allow to create any files
+	 * including devices nodes. The only way to create binder devices nodes
+	 * is through the binder-control device which userns root is explicitly
+	 * allowed to do. So removing the SB_I_NODEV flag from s_iflags is both
+	 * necessary and safe.
+	 */
+	sb->s_iflags &= ~SB_I_NODEV;
+	sb->s_iflags |= SB_I_NOEXEC;
+	sb->s_magic = BINDERFS_SUPER_MAGIC;
+	sb->s_op = &binderfs_super_ops;
+	sb->s_time_gran = 1;
+
+	sb->s_fs_info = kzalloc_obj(struct binderfs_info);
+	if (!sb->s_fs_info)
+		return -ENOMEM;
+	info = sb->s_fs_info;
+
+	info->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns);
+
+	info->root_gid = make_kgid(sb->s_user_ns, 0);
+	if (!gid_valid(info->root_gid))
+		info->root_gid = GLOBAL_ROOT_GID;
+	info->root_uid = make_kuid(sb->s_user_ns, 0);
+	if (!uid_valid(info->root_uid))
+		info->root_uid = GLOBAL_ROOT_UID;
+	info->mount_opts.max = ctx->max;
+	info->mount_opts.stats_mode = ctx->stats_mode;
+
+	inode = new_inode(sb);
+	if (!inode)
+		return -ENOMEM;
+
+	inode->i_ino = FIRST_INODE;
+	inode->i_fop = &simple_dir_operations;
+	inode->i_mode = S_IFDIR | 0755;
+	simple_inode_init_ts(inode);
+	inode->i_op = &binderfs_dir_inode_operations;
+	set_nlink(inode, 2);
+
+	sb->s_root = d_make_root(inode);
+	if (!sb->s_root)
+		return -ENOMEM;
+
+	ret = binderfs_binder_ctl_create(sb);
+	if (ret)
+		return ret;
+
+	name = binder_devices_param;
+	for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) {
+		strscpy(device_info.name, name, len + 1);
+		ret = binderfs_binder_device_create(inode, NULL, &device_info);
+		if (ret)
+			return ret;
+		name += len;
+		if (*name == ',')
+			name++;
+	}
+
+	ret = init_binder_features(sb);
+	if (ret)
+		return ret;
+
+	if (info->mount_opts.stats_mode == binderfs_stats_mode_global)
+		return init_binder_logs(sb);
+
+	return 0;
+}
+
+static int binderfs_fs_context_get_tree(struct fs_context *fc)
+{
+	return get_tree_nodev(fc, binderfs_fill_super);
+}
+
+static void binderfs_fs_context_free(struct fs_context *fc)
+{
+	struct binderfs_mount_opts *ctx = fc->fs_private;
+
+	kfree(ctx);
+}
+
+static const struct fs_context_operations binderfs_fs_context_ops = {
+	.free		= binderfs_fs_context_free,
+	.get_tree	= binderfs_fs_context_get_tree,
+	.parse_param	= binderfs_fs_context_parse_param,
+	.reconfigure	= binderfs_fs_context_reconfigure,
+};
+
+static int binderfs_init_fs_context(struct fs_context *fc)
+{
+	struct binderfs_mount_opts *ctx;
+
+	ctx = kzalloc_obj(struct binderfs_mount_opts);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->max = BINDERFS_MAX_MINOR;
+	ctx->stats_mode = binderfs_stats_mode_unset;
+
+	fc->fs_private = ctx;
+	fc->ops = &binderfs_fs_context_ops;
+
+	return 0;
+}
+
+static void binderfs_kill_super(struct super_block *sb)
+{
+	struct binderfs_info *info = sb->s_fs_info;
+
+	/*
+	 * During inode eviction struct binderfs_info is needed.
+	 * So first wipe the super_block then free struct binderfs_info.
+	 */
+	kill_anon_super(sb);
+
+	if (info && info->ipc_ns)
+		put_ipc_ns(info->ipc_ns);
+
+	kfree(info);
+}
+
+static struct file_system_type binder_fs_type = {
+	.name			= "binder",
+	.init_fs_context	= binderfs_init_fs_context,
+	.parameters		= binderfs_fs_parameters,
+	.kill_sb		= binderfs_kill_super,
+	.fs_flags		= FS_USERNS_MOUNT,
+};
+
+int __init init_binderfs(void)
+{
+	int ret;
+	const char *name;
+	size_t len;
+
+	/* Verify that the default binderfs device names are valid. */
+	name = binder_devices_param;
+	for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) {
+		if (len > BINDERFS_MAX_NAME)
+			return -E2BIG;
+		name += len;
+		if (*name == ',')
+			name++;
+	}
+
+	/* Allocate new major number for binderfs. */
+	ret = alloc_chrdev_region(&binderfs_dev, 0, BINDERFS_MAX_MINOR,
+				  "binder");
+	if (ret)
+		return ret;
+
+	ret = register_filesystem(&binder_fs_type);
+	if (ret) {
+		unregister_chrdev_region(binderfs_dev, BINDERFS_MAX_MINOR);
+		return ret;
+	}
+
+	return ret;
+}
diff --git a/drivers/android/dbitmap.h b/drivers/android/dbitmap.h
new file mode 100644
index 000000000..c7299ce8b
--- /dev/null
+++ b/drivers/android/dbitmap.h
@@ -0,0 +1,169 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2024 Google LLC
+ *
+ * dbitmap - dynamically sized bitmap library.
+ *
+ * Used by the binder driver to optimize the allocation of the smallest
+ * available descriptor ID. Each bit in the bitmap represents the state
+ * of an ID.
+ *
+ * A dbitmap can grow or shrink as needed. This part has been designed
+ * considering that users might need to briefly release their locks in
+ * order to allocate memory for the new bitmap. These operations then,
+ * are verified to determine if the grow or shrink is sill valid.
+ *
+ * This library does not provide protection against concurrent access
+ * by itself. Binder uses the proc->outer_lock for this purpose.
+ */
+
+#ifndef _LINUX_DBITMAP_H
+#define _LINUX_DBITMAP_H
+#include <linux/bitmap.h>
+
+#define NBITS_MIN	BITS_PER_TYPE(unsigned long)
+
+struct dbitmap {
+	unsigned int nbits;
+	unsigned long *map;
+};
+
+static inline int dbitmap_enabled(struct dbitmap *dmap)
+{
+	return !!dmap->nbits;
+}
+
+static inline void dbitmap_free(struct dbitmap *dmap)
+{
+	dmap->nbits = 0;
+	kfree(dmap->map);
+	dmap->map = NULL;
+}
+
+/* Returns the nbits that a dbitmap can shrink to, 0 if not possible. */
+static inline unsigned int dbitmap_shrink_nbits(struct dbitmap *dmap)
+{
+	unsigned int bit;
+
+	if (dmap->nbits <= NBITS_MIN)
+		return 0;
+
+	/*
+	 * Determine if the bitmap can shrink based on the position of
+	 * its last set bit. If the bit is within the first quarter of
+	 * the bitmap then shrinking is possible. In this case, the
+	 * bitmap should shrink to half its current size.
+	 */
+	bit = find_last_bit(dmap->map, dmap->nbits);
+	if (bit < (dmap->nbits >> 2))
+		return dmap->nbits >> 1;
+
+	/* find_last_bit() returns dmap->nbits when no bits are set. */
+	if (bit == dmap->nbits)
+		return NBITS_MIN;
+
+	return 0;
+}
+
+/* Replace the internal bitmap with a new one of different size */
+static inline void
+dbitmap_replace(struct dbitmap *dmap, unsigned long *new, unsigned int nbits)
+{
+	bitmap_copy(new, dmap->map, min(dmap->nbits, nbits));
+	kfree(dmap->map);
+	dmap->map = new;
+	dmap->nbits = nbits;
+}
+
+static inline void
+dbitmap_shrink(struct dbitmap *dmap, unsigned long *new, unsigned int nbits)
+{
+	if (!new)
+		return;
+
+	/*
+	 * Verify that shrinking to @nbits is still possible. The @new
+	 * bitmap might have been allocated without locks, so this call
+	 * could now be outdated. In this case, free @new and move on.
+	 */
+	if (!dbitmap_enabled(dmap) || dbitmap_shrink_nbits(dmap) != nbits) {
+		kfree(new);
+		return;
+	}
+
+	dbitmap_replace(dmap, new, nbits);
+}
+
+/* Returns the nbits that a dbitmap can grow to. */
+static inline unsigned int dbitmap_grow_nbits(struct dbitmap *dmap)
+{
+	return dmap->nbits << 1;
+}
+
+static inline void
+dbitmap_grow(struct dbitmap *dmap, unsigned long *new, unsigned int nbits)
+{
+	/*
+	 * Verify that growing to @nbits is still possible. The @new
+	 * bitmap might have been allocated without locks, so this call
+	 * could now be outdated. In this case, free @new and move on.
+	 */
+	if (!dbitmap_enabled(dmap) || nbits <= dmap->nbits) {
+		kfree(new);
+		return;
+	}
+
+	/*
+	 * Check for ENOMEM after confirming the grow operation is still
+	 * required. This ensures we only disable the dbitmap when it's
+	 * necessary. Once the dbitmap is disabled, binder will fallback
+	 * to slow_desc_lookup_olocked().
+	 */
+	if (!new) {
+		dbitmap_free(dmap);
+		return;
+	}
+
+	dbitmap_replace(dmap, new, nbits);
+}
+
+/*
+ * Finds and sets the next zero bit in the bitmap. Upon success @bit
+ * is populated with the index and 0 is returned. Otherwise, -ENOSPC
+ * is returned to indicate that a dbitmap_grow() is needed.
+ */
+static inline int
+dbitmap_acquire_next_zero_bit(struct dbitmap *dmap, unsigned long offset,
+			      unsigned long *bit)
+{
+	unsigned long n;
+
+	n = find_next_zero_bit(dmap->map, dmap->nbits, offset);
+	if (n == dmap->nbits)
+		return -ENOSPC;
+
+	*bit = n;
+	set_bit(n, dmap->map);
+
+	return 0;
+}
+
+static inline void
+dbitmap_clear_bit(struct dbitmap *dmap, unsigned long bit)
+{
+	clear_bit(bit, dmap->map);
+}
+
+static inline int dbitmap_init(struct dbitmap *dmap)
+{
+	dmap->map = bitmap_zalloc(NBITS_MIN, GFP_KERNEL);
+	if (!dmap->map) {
+		dmap->nbits = 0;
+		return -ENOMEM;
+	}
+
+	dmap->nbits = NBITS_MIN;
+
+	return 0;
+}
+#endif
diff --git a/drivers/android/tests/.kunitconfig b/drivers/android/tests/.kunitconfig
new file mode 100644
index 000000000..39b76bab9
--- /dev/null
+++ b/drivers/android/tests/.kunitconfig
@@ -0,0 +1,7 @@
+#
+# Copyright 2025 Google LLC.
+#
+
+CONFIG_KUNIT=y
+CONFIG_ANDROID_BINDER_IPC=y
+CONFIG_ANDROID_BINDER_ALLOC_KUNIT_TEST=y
diff --git a/drivers/android/tests/Makefile b/drivers/android/tests/Makefile
new file mode 100644
index 000000000..27268418e
--- /dev/null
+++ b/drivers/android/tests/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright 2025 Google LLC.
+#
+
+obj-$(CONFIG_ANDROID_BINDER_ALLOC_KUNIT_TEST)	+= binder_alloc_kunit.o
diff --git a/drivers/android/tests/binder_alloc_kunit.c b/drivers/android/tests/binder_alloc_kunit.c
new file mode 100644
index 000000000..7f9cc003b
--- /dev/null
+++ b/drivers/android/tests/binder_alloc_kunit.c
@@ -0,0 +1,572 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test cases for binder allocator code.
+ *
+ * Copyright 2025 Google LLC.
+ * Author: Tiffany Yang <ynaffit@google.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <kunit/test.h>
+#include <linux/anon_inodes.h>
+#include <linux/err.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/seq_buf.h>
+#include <linux/sizes.h>
+
+#include "../binder_alloc.h"
+#include "../binder_internal.h"
+
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+
+#define BINDER_MMAP_SIZE SZ_128K
+
+#define BUFFER_NUM 5
+#define BUFFER_MIN_SIZE (PAGE_SIZE / 8)
+
+#define FREESEQ_BUFLEN ((3 * BUFFER_NUM) + 1)
+
+#define ALIGN_TYPE_STRLEN (12)
+
+#define ALIGNMENTS_BUFLEN (((ALIGN_TYPE_STRLEN + 6) * BUFFER_NUM) + 1)
+
+#define PRINT_ALL_CASES (0)
+
+/* 5^5 alignment combinations * 2 places to share pages * 5! free sequences */
+#define TOTAL_EXHAUSTIVE_CASES (3125 * 2 * 120)
+
+/**
+ * enum buf_end_align_type - Page alignment of a buffer
+ * end with regard to the end of the previous buffer.
+ *
+ * In the pictures below, buf2 refers to the buffer we
+ * are aligning. buf1 refers to previous buffer by addr.
+ * Symbol [ means the start of a buffer, ] means the end
+ * of a buffer, and | means page boundaries.
+ */
+enum buf_end_align_type {
+	/**
+	 * @SAME_PAGE_UNALIGNED: The end of this buffer is on
+	 * the same page as the end of the previous buffer and
+	 * is not page aligned. Examples:
+	 * buf1 ][ buf2 ][ ...
+	 * buf1 ]|[ buf2 ][ ...
+	 */
+	SAME_PAGE_UNALIGNED = 0,
+	/**
+	 * @SAME_PAGE_ALIGNED: When the end of the previous buffer
+	 * is not page aligned, the end of this buffer is on the
+	 * same page as the end of the previous buffer and is page
+	 * aligned. When the previous buffer is page aligned, the
+	 * end of this buffer is aligned to the next page boundary.
+	 * Examples:
+	 * buf1 ][ buf2 ]| ...
+	 * buf1 ]|[ buf2 ]| ...
+	 */
+	SAME_PAGE_ALIGNED,
+	/**
+	 * @NEXT_PAGE_UNALIGNED: The end of this buffer is on
+	 * the page next to the end of the previous buffer and
+	 * is not page aligned. Examples:
+	 * buf1 ][ buf2 | buf2 ][ ...
+	 * buf1 ]|[ buf2 | buf2 ][ ...
+	 */
+	NEXT_PAGE_UNALIGNED,
+	/**
+	 * @NEXT_PAGE_ALIGNED: The end of this buffer is on
+	 * the page next to the end of the previous buffer and
+	 * is page aligned. Examples:
+	 * buf1 ][ buf2 | buf2 ]| ...
+	 * buf1 ]|[ buf2 | buf2 ]| ...
+	 */
+	NEXT_PAGE_ALIGNED,
+	/**
+	 * @NEXT_NEXT_UNALIGNED: The end of this buffer is on
+	 * the page that follows the page after the end of the
+	 * previous buffer and is not page aligned. Examples:
+	 * buf1 ][ buf2 | buf2 | buf2 ][ ...
+	 * buf1 ]|[ buf2 | buf2 | buf2 ][ ...
+	 */
+	NEXT_NEXT_UNALIGNED,
+	/**
+	 * @LOOP_END: The number of enum values in &buf_end_align_type.
+	 * It is used for controlling loop termination.
+	 */
+	LOOP_END,
+};
+
+static const char *const buf_end_align_type_strs[LOOP_END] = {
+	[SAME_PAGE_UNALIGNED] = "SP_UNALIGNED",
+	[SAME_PAGE_ALIGNED]   = " SP_ALIGNED ",
+	[NEXT_PAGE_UNALIGNED] = "NP_UNALIGNED",
+	[NEXT_PAGE_ALIGNED]   = " NP_ALIGNED ",
+	[NEXT_NEXT_UNALIGNED] = "NN_UNALIGNED",
+};
+
+struct binder_alloc_test_case_info {
+	char alignments[ALIGNMENTS_BUFLEN];
+	struct seq_buf alignments_sb;
+	size_t *buffer_sizes;
+	int *free_sequence;
+	bool front_pages;
+};
+
+static void stringify_free_seq(struct kunit *test, int *seq, struct seq_buf *sb)
+{
+	int i;
+
+	for (i = 0; i < BUFFER_NUM; i++)
+		seq_buf_printf(sb, "[%d]", seq[i]);
+
+	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(sb));
+}
+
+static void stringify_alignments(struct kunit *test, int *alignments,
+				 struct seq_buf *sb)
+{
+	int i;
+
+	for (i = 0; i < BUFFER_NUM; i++)
+		seq_buf_printf(sb, "[ %d:%s ]", i,
+			       buf_end_align_type_strs[alignments[i]]);
+
+	KUNIT_EXPECT_FALSE(test, seq_buf_has_overflowed(sb));
+}
+
+static bool check_buffer_pages_allocated(struct kunit *test,
+					 struct binder_alloc *alloc,
+					 struct binder_buffer *buffer,
+					 size_t size)
+{
+	unsigned long page_addr;
+	unsigned long end;
+	int page_index;
+
+	end = PAGE_ALIGN(buffer->user_data + size);
+	page_addr = buffer->user_data;
+	for (; page_addr < end; page_addr += PAGE_SIZE) {
+		page_index = (page_addr - alloc->vm_start) / PAGE_SIZE;
+		if (!alloc->pages[page_index] ||
+		    !list_empty(page_to_lru(alloc->pages[page_index]))) {
+			kunit_err(test, "expect alloc but is %s at page index %d\n",
+				  alloc->pages[page_index] ?
+				  "lru" : "free", page_index);
+			return false;
+		}
+	}
+	return true;
+}
+
+static unsigned long binder_alloc_test_alloc_buf(struct kunit *test,
+						 struct binder_alloc *alloc,
+						 struct binder_buffer *buffers[],
+						 size_t *sizes, int *seq)
+{
+	unsigned long failures = 0;
+	int i;
+
+	for (i = 0; i < BUFFER_NUM; i++) {
+		buffers[i] = binder_alloc_new_buf(alloc, sizes[i], 0, 0, 0);
+		if (IS_ERR(buffers[i]) ||
+		    !check_buffer_pages_allocated(test, alloc, buffers[i], sizes[i]))
+			failures++;
+	}
+
+	return failures;
+}
+
+static unsigned long binder_alloc_test_free_buf(struct kunit *test,
+						struct binder_alloc *alloc,
+						struct binder_buffer *buffers[],
+						size_t *sizes, int *seq, size_t end)
+{
+	unsigned long failures = 0;
+	int i;
+
+	for (i = 0; i < BUFFER_NUM; i++)
+		binder_alloc_free_buf(alloc, buffers[seq[i]]);
+
+	for (i = 0; i <= (end - 1) / PAGE_SIZE; i++) {
+		if (list_empty(page_to_lru(alloc->pages[i]))) {
+			kunit_err(test, "expect lru but is %s at page index %d\n",
+				  alloc->pages[i] ? "alloc" : "free", i);
+			failures++;
+		}
+	}
+
+	return failures;
+}
+
+static unsigned long binder_alloc_test_free_page(struct kunit *test,
+						 struct binder_alloc *alloc)
+{
+	unsigned long failures = 0;
+	unsigned long count;
+	int i;
+
+	while ((count = list_lru_count(alloc->freelist))) {
+		list_lru_walk(alloc->freelist, binder_alloc_free_page,
+			      NULL, count);
+	}
+
+	for (i = 0; i < (alloc->buffer_size / PAGE_SIZE); i++) {
+		if (alloc->pages[i]) {
+			kunit_err(test, "expect free but is %s at page index %d\n",
+				  list_empty(page_to_lru(alloc->pages[i])) ?
+				  "alloc" : "lru", i);
+			failures++;
+		}
+	}
+
+	return failures;
+}
+
+/* Executes one full test run for the given test case. */
+static bool binder_alloc_test_alloc_free(struct kunit *test,
+					 struct binder_alloc *alloc,
+					 struct binder_alloc_test_case_info *tc,
+					 size_t end)
+{
+	unsigned long pages = PAGE_ALIGN(end) / PAGE_SIZE;
+	struct binder_buffer *buffers[BUFFER_NUM];
+	unsigned long failures;
+	bool failed = false;
+
+	failures = binder_alloc_test_alloc_buf(test, alloc, buffers,
+					       tc->buffer_sizes,
+					       tc->free_sequence);
+	failed = failed || failures;
+	KUNIT_EXPECT_EQ_MSG(test, failures, 0,
+			    "Initial allocation failed: %lu/%u buffers with errors",
+			    failures, BUFFER_NUM);
+
+	failures = binder_alloc_test_free_buf(test, alloc, buffers,
+					      tc->buffer_sizes,
+					      tc->free_sequence, end);
+	failed = failed || failures;
+	KUNIT_EXPECT_EQ_MSG(test, failures, 0,
+			    "Initial buffers not freed correctly: %lu/%lu pages not on lru list",
+			    failures, pages);
+
+	/* Allocate from lru. */
+	failures = binder_alloc_test_alloc_buf(test, alloc, buffers,
+					       tc->buffer_sizes,
+					       tc->free_sequence);
+	failed = failed || failures;
+	KUNIT_EXPECT_EQ_MSG(test, failures, 0,
+			    "Reallocation failed: %lu/%u buffers with errors",
+			    failures, BUFFER_NUM);
+
+	failures = list_lru_count(alloc->freelist);
+	failed = failed || failures;
+	KUNIT_EXPECT_EQ_MSG(test, failures, 0,
+			    "lru list should be empty after reallocation but still has %lu pages",
+			    failures);
+
+	failures = binder_alloc_test_free_buf(test, alloc, buffers,
+					      tc->buffer_sizes,
+					      tc->free_sequence, end);
+	failed = failed || failures;
+	KUNIT_EXPECT_EQ_MSG(test, failures, 0,
+			    "Reallocated buffers not freed correctly: %lu/%lu pages not on lru list",
+			    failures, pages);
+
+	failures = binder_alloc_test_free_page(test, alloc);
+	failed = failed || failures;
+	KUNIT_EXPECT_EQ_MSG(test, failures, 0,
+			    "Failed to clean up allocated pages: %lu/%lu pages still installed",
+			    failures, (alloc->buffer_size / PAGE_SIZE));
+
+	return failed;
+}
+
+static bool is_dup(int *seq, int index, int val)
+{
+	int i;
+
+	for (i = 0; i < index; i++) {
+		if (seq[i] == val)
+			return true;
+	}
+	return false;
+}
+
+/* Generate BUFFER_NUM factorial free orders. */
+static void permute_frees(struct kunit *test, struct binder_alloc *alloc,
+			  struct binder_alloc_test_case_info *tc,
+			  unsigned long *runs, unsigned long *failures,
+			  int index, size_t end)
+{
+	bool case_failed;
+	int i;
+
+	if (index == BUFFER_NUM) {
+		DECLARE_SEQ_BUF(freeseq_sb, FREESEQ_BUFLEN);
+
+		case_failed = binder_alloc_test_alloc_free(test, alloc, tc, end);
+		*runs += 1;
+		*failures += case_failed;
+
+		if (case_failed || PRINT_ALL_CASES) {
+			stringify_free_seq(test, tc->free_sequence,
+					   &freeseq_sb);
+			kunit_err(test, "case %lu: [%s] | %s - %s - %s", *runs,
+				  case_failed ? "FAILED" : "PASSED",
+				  tc->front_pages ? "front" : "back ",
+				  seq_buf_str(&tc->alignments_sb),
+				  seq_buf_str(&freeseq_sb));
+		}
+
+		return;
+	}
+	for (i = 0; i < BUFFER_NUM; i++) {
+		if (is_dup(tc->free_sequence, index, i))
+			continue;
+		tc->free_sequence[index] = i;
+		permute_frees(test, alloc, tc, runs, failures, index + 1, end);
+	}
+}
+
+static void gen_buf_sizes(struct kunit *test,
+			  struct binder_alloc *alloc,
+			  struct binder_alloc_test_case_info *tc,
+			  size_t *end_offset, unsigned long *runs,
+			  unsigned long *failures)
+{
+	size_t last_offset, offset = 0;
+	size_t front_sizes[BUFFER_NUM];
+	size_t back_sizes[BUFFER_NUM];
+	int seq[BUFFER_NUM] = {0};
+	int i;
+
+	tc->free_sequence = seq;
+	for (i = 0; i < BUFFER_NUM; i++) {
+		last_offset = offset;
+		offset = end_offset[i];
+		front_sizes[i] = offset - last_offset;
+		back_sizes[BUFFER_NUM - i - 1] = front_sizes[i];
+	}
+	back_sizes[0] += alloc->buffer_size - end_offset[BUFFER_NUM - 1];
+
+	/*
+	 * Buffers share the first or last few pages.
+	 * Only BUFFER_NUM - 1 buffer sizes are adjustable since
+	 * we need one giant buffer before getting to the last page.
+	 */
+	tc->front_pages = true;
+	tc->buffer_sizes = front_sizes;
+	permute_frees(test, alloc, tc, runs, failures, 0,
+		      end_offset[BUFFER_NUM - 1]);
+
+	tc->front_pages = false;
+	tc->buffer_sizes = back_sizes;
+	permute_frees(test, alloc, tc, runs, failures, 0, alloc->buffer_size);
+}
+
+static void gen_buf_offsets(struct kunit *test, struct binder_alloc *alloc,
+			    size_t *end_offset, int *alignments,
+			    unsigned long *runs, unsigned long *failures,
+			    int index)
+{
+	size_t end, prev;
+	int align;
+
+	if (index == BUFFER_NUM) {
+		struct binder_alloc_test_case_info tc = {0};
+
+		seq_buf_init(&tc.alignments_sb, tc.alignments,
+			     ALIGNMENTS_BUFLEN);
+		stringify_alignments(test, alignments, &tc.alignments_sb);
+
+		gen_buf_sizes(test, alloc, &tc, end_offset, runs, failures);
+		return;
+	}
+	prev = index == 0 ? 0 : end_offset[index - 1];
+	end = prev;
+
+	BUILD_BUG_ON(BUFFER_MIN_SIZE * BUFFER_NUM >= PAGE_SIZE);
+
+	for (align = SAME_PAGE_UNALIGNED; align < LOOP_END; align++) {
+		if (align % 2)
+			end = ALIGN(end, PAGE_SIZE);
+		else
+			end += BUFFER_MIN_SIZE;
+		end_offset[index] = end;
+		alignments[index] = align;
+		gen_buf_offsets(test, alloc, end_offset, alignments, runs,
+				failures, index + 1);
+	}
+}
+
+struct binder_alloc_test {
+	struct binder_alloc alloc;
+	struct list_lru binder_test_freelist;
+	struct file *filp;
+	unsigned long mmap_uaddr;
+};
+
+static void binder_alloc_test_init_freelist(struct kunit *test)
+{
+	struct binder_alloc_test *priv = test->priv;
+
+	KUNIT_EXPECT_PTR_EQ(test, priv->alloc.freelist,
+			    &priv->binder_test_freelist);
+}
+
+static void binder_alloc_test_mmap(struct kunit *test)
+{
+	struct binder_alloc_test *priv = test->priv;
+	struct binder_alloc *alloc = &priv->alloc;
+	struct binder_buffer *buf;
+	struct rb_node *n;
+
+	KUNIT_EXPECT_EQ(test, alloc->mapped, true);
+	KUNIT_EXPECT_EQ(test, alloc->buffer_size, BINDER_MMAP_SIZE);
+
+	n = rb_first(&alloc->allocated_buffers);
+	KUNIT_EXPECT_PTR_EQ(test, n, NULL);
+
+	n = rb_first(&alloc->free_buffers);
+	buf = rb_entry(n, struct binder_buffer, rb_node);
+	KUNIT_EXPECT_EQ(test, binder_alloc_buffer_size(alloc, buf),
+			BINDER_MMAP_SIZE);
+	KUNIT_EXPECT_TRUE(test, list_is_last(&buf->entry, &alloc->buffers));
+}
+
+/**
+ * binder_alloc_exhaustive_test() - Exhaustively test alloc and free of buffer pages.
+ * @test: The test context object.
+ *
+ * Allocate BUFFER_NUM buffers to cover all page alignment cases,
+ * then free them in all orders possible. Check that pages are
+ * correctly allocated, put onto lru when buffers are freed, and
+ * are freed when binder_alloc_free_page() is called.
+ */
+static void binder_alloc_exhaustive_test(struct kunit *test)
+{
+	struct binder_alloc_test *priv = test->priv;
+	size_t end_offset[BUFFER_NUM];
+	int alignments[BUFFER_NUM];
+	unsigned long failures = 0;
+	unsigned long runs = 0;
+
+	gen_buf_offsets(test, &priv->alloc, end_offset, alignments, &runs,
+			&failures, 0);
+
+	KUNIT_EXPECT_EQ(test, runs, TOTAL_EXHAUSTIVE_CASES);
+	KUNIT_EXPECT_EQ(test, failures, 0);
+}
+
+/* ===== End test cases ===== */
+
+static void binder_alloc_test_vma_close(struct vm_area_struct *vma)
+{
+	struct binder_alloc *alloc = vma->vm_private_data;
+
+	binder_alloc_vma_close(alloc);
+}
+
+static const struct vm_operations_struct binder_alloc_test_vm_ops = {
+	.close = binder_alloc_test_vma_close,
+	.fault = binder_vm_fault,
+};
+
+static int binder_alloc_test_mmap_handler(struct file *filp,
+					  struct vm_area_struct *vma)
+{
+	struct binder_alloc *alloc = filp->private_data;
+
+	vm_flags_mod(vma, VM_DONTCOPY | VM_MIXEDMAP, VM_MAYWRITE);
+
+	vma->vm_ops = &binder_alloc_test_vm_ops;
+	vma->vm_private_data = alloc;
+
+	return binder_alloc_mmap_handler(alloc, vma);
+}
+
+static const struct file_operations binder_alloc_test_fops = {
+	.mmap = binder_alloc_test_mmap_handler,
+};
+
+static int binder_alloc_test_init(struct kunit *test)
+{
+	struct binder_alloc_test *priv;
+	int ret;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	test->priv = priv;
+
+	ret = list_lru_init(&priv->binder_test_freelist);
+	if (ret) {
+		kunit_err(test, "Failed to initialize test freelist\n");
+		return ret;
+	}
+
+	/* __binder_alloc_init requires mm to be attached */
+	ret = kunit_attach_mm();
+	if (ret) {
+		kunit_err(test, "Failed to attach mm\n");
+		return ret;
+	}
+	__binder_alloc_init(&priv->alloc, &priv->binder_test_freelist);
+
+	priv->filp = anon_inode_getfile("binder_alloc_kunit",
+					&binder_alloc_test_fops, &priv->alloc,
+					O_RDWR | O_CLOEXEC);
+	if (IS_ERR_OR_NULL(priv->filp)) {
+		kunit_err(test, "Failed to open binder alloc test driver file\n");
+		return priv->filp ? PTR_ERR(priv->filp) : -ENOMEM;
+	}
+
+	priv->mmap_uaddr = kunit_vm_mmap(test, priv->filp, 0, BINDER_MMAP_SIZE,
+					 PROT_READ, MAP_PRIVATE | MAP_NORESERVE,
+					 0);
+	if (!priv->mmap_uaddr) {
+		kunit_err(test, "Could not map the test's transaction memory\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void binder_alloc_test_exit(struct kunit *test)
+{
+	struct binder_alloc_test *priv = test->priv;
+
+	/* Close the backing file to make sure binder_alloc_vma_close runs */
+	if (!IS_ERR_OR_NULL(priv->filp))
+		fput(priv->filp);
+
+	if (priv->alloc.mm)
+		binder_alloc_deferred_release(&priv->alloc);
+
+	/* Make sure freelist is empty */
+	KUNIT_EXPECT_EQ(test, list_lru_count(&priv->binder_test_freelist), 0);
+	list_lru_destroy(&priv->binder_test_freelist);
+}
+
+static struct kunit_case binder_alloc_test_cases[] = {
+	KUNIT_CASE(binder_alloc_test_init_freelist),
+	KUNIT_CASE(binder_alloc_test_mmap),
+	KUNIT_CASE_SLOW(binder_alloc_exhaustive_test),
+	{}
+};
+
+static struct kunit_suite binder_alloc_test_suite = {
+	.name = "binder_alloc",
+	.test_cases = binder_alloc_test_cases,
+	.init = binder_alloc_test_init,
+	.exit = binder_alloc_test_exit,
+};
+
+kunit_test_suite(binder_alloc_test_suite);
+
+MODULE_AUTHOR("Tiffany Yang <ynaffit@google.com>");
+MODULE_DESCRIPTION("Binder Alloc KUnit tests");
+MODULE_LICENSE("GPL");