Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEADgrafted

Changes:

Make expedited grace periods expedite normal RCU callbacks

Miscellaneous fixes:
 * Improve diagnostic output with character task states.
 * Mark accesses to inform KCSAN of concurrency design.
 * Move from kmalloc() to kmalloc_obj().
 * Documentation updates.
 * Improve handling of RCU deferred quiescent states.
 * Clean up unused function arguments and structure fields.
 * Reduce show_rcu_gp_kthreads() stack space.

Tasks RCU updates:
 * Clean up after SRCU re-implementation of Tasks Trace RCU.
 * Mark accesses to inform KCSAN of concurrency design.
 * Add ->lazy_timer status to diagnostic output.
 * Remove an unnecessary memory barrier.
 * Fix a data race, courtesy of KCSAN.
 * Documentation updates.
 * Convert cond_resched_tasks_rcu_qs() from macro to static inline
   function.

SRCU updates:
 * Add Rust helpers for SRCU.
 * Avoid losing queued work at cleanup_srcu_struct() time.

Torture-test updates:
 * Preparation work for immediate RCU priority deboosting.
 * Test RCU readers from real interrupt handlers (as opposed to softirq).
 * Simplify code through use of cpumask_next_wrap().
 * Improve diagnostic output with character task states.
 * Add rcutorture.nwriters parameter to allow lightweight stall testing,
   and rcutorture.stall_only to make doing so easier.
 * Test an RCU Tasks Trace grace period implying an RCU grace period.
 * Make RCU Tasks Trace torturing track reader batches.
 * Fix a data race, courtesy of KCSAN.
 * Plug a shuffle_tmp_mask memory leak on kthread spawn failure.

1 files changed, 189 insertions, 0 deletions

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 */
+