Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 1348 insertions, 0 deletions

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
new file mode 100644
index 000000000..9d9842fc5
--- /dev/null
+++ b/drivers/base/devres.c
@@ -0,0 +1,1348 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * drivers/base/devres.c - device resource management
+ *
+ * Copyright (c) 2006  SUSE Linux Products GmbH
+ * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/percpu.h>
+
+#include <asm/sections.h>
+
+#include "base.h"
+#include "trace.h"
+
+struct devres {
+	struct devres_node		node;
+	dr_release_t			release;
+	/*
+	 * Some archs want to perform DMA into kmalloc caches
+	 * and need a guaranteed alignment larger than
+	 * the alignment of a 64-bit integer.
+	 * Thus we use ARCH_DMA_MINALIGN for data[] which will force the same
+	 * alignment for struct devres when allocated by kmalloc().
+	 */
+	u8 __aligned(ARCH_DMA_MINALIGN) data[];
+};
+
+struct devres_group {
+	struct devres_node		node[2];
+	void				*id;
+	int				color;
+	/* -- 8 pointers */
+};
+
+void devres_node_init(struct devres_node *node,
+		      dr_node_release_t release,
+		      dr_node_free_t free_node)
+{
+	INIT_LIST_HEAD(&node->entry);
+	node->release = release;
+	node->free_node = free_node;
+}
+
+static inline void free_node(struct devres_node *node)
+{
+	node->free_node(node);
+}
+
+void devres_set_node_dbginfo(struct devres_node *node, const char *name,
+			     size_t size)
+{
+	node->name = name;
+	node->size = size;
+}
+
+#ifdef CONFIG_DEBUG_DEVRES
+static int log_devres = 0;
+module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
+
+static void devres_dbg(struct device *dev, struct devres_node *node,
+		       const char *op)
+{
+	if (unlikely(log_devres))
+		dev_err(dev, "DEVRES %3s %p %s (%zu bytes)\n",
+			op, node, node->name, node->size);
+}
+#else /* CONFIG_DEBUG_DEVRES */
+#define devres_dbg(dev, node, op)	do {} while (0)
+#endif /* CONFIG_DEBUG_DEVRES */
+
+static void devres_log(struct device *dev, struct devres_node *node,
+		       const char *op)
+{
+	trace_devres_log(dev, op, node, node->name, node->size);
+	devres_dbg(dev, node, op);
+}
+
+/*
+ * Release functions for devres group.  These callbacks are used only
+ * for identification.
+ */
+static void group_open_release(struct device *dev, struct devres_node *node)
+{
+	/* noop */
+}
+
+static void group_close_release(struct device *dev, struct devres_node *node)
+{
+	/* noop */
+}
+
+static struct devres_group *node_to_group(struct devres_node *node)
+{
+	if (node->release == &group_open_release)
+		return container_of(node, struct devres_group, node[0]);
+	if (node->release == &group_close_release)
+		return container_of(node, struct devres_group, node[1]);
+	return NULL;
+}
+
+static bool check_dr_size(size_t size, size_t *tot_size)
+{
+	/* We must catch any near-SIZE_MAX cases that could overflow. */
+	if (unlikely(check_add_overflow(sizeof(struct devres),
+					size, tot_size)))
+		return false;
+
+	/* Actually allocate the full kmalloc bucket size. */
+	*tot_size = kmalloc_size_roundup(*tot_size);
+
+	return true;
+}
+
+static void dr_node_release(struct device *dev, struct devres_node *node)
+{
+	struct devres *dr = container_of(node, struct devres, node);
+
+	dr->release(dev, dr->data);
+}
+
+static void dr_node_free(struct devres_node *node)
+{
+	struct devres *dr = container_of(node, struct devres, node);
+
+	kfree(dr);
+}
+
+static __always_inline struct devres *alloc_dr(dr_release_t release,
+					       size_t size, gfp_t gfp, int nid)
+{
+	size_t tot_size;
+	struct devres *dr;
+
+	if (!check_dr_size(size, &tot_size))
+		return NULL;
+
+	dr = kmalloc_node_track_caller(tot_size, gfp, nid);
+	if (unlikely(!dr))
+		return NULL;
+
+	/* No need to clear memory twice */
+	if (!(gfp & __GFP_ZERO))
+		memset(dr, 0, offsetof(struct devres, data));
+
+	devres_node_init(&dr->node, dr_node_release, dr_node_free);
+	dr->release = release;
+	return dr;
+}
+
+static void add_dr(struct device *dev, struct devres_node *node)
+{
+	devres_log(dev, node, "ADD");
+	BUG_ON(!list_empty(&node->entry));
+	list_add_tail(&node->entry, &dev->devres_head);
+}
+
+static void replace_dr(struct device *dev,
+		       struct devres_node *old, struct devres_node *new)
+{
+	devres_log(dev, old, "REPLACE");
+	BUG_ON(!list_empty(&new->entry));
+	list_replace(&old->entry, &new->entry);
+}
+
+/**
+ * __devres_alloc_node - Allocate device resource data
+ * @release: Release function devres will be associated with
+ * @size: Allocation size
+ * @gfp: Allocation flags
+ * @nid: NUMA node
+ * @name: Name of the resource
+ *
+ * Allocate devres of @size bytes.  The allocated area is zeroed, then
+ * associated with @release.  The returned pointer can be passed to
+ * other devres_*() functions.
+ *
+ * RETURNS:
+ * Pointer to allocated devres on success, NULL on failure.
+ */
+void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
+			  const char *name)
+{
+	struct devres *dr;
+
+	dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
+	if (unlikely(!dr))
+		return NULL;
+	devres_set_node_dbginfo(&dr->node, name, size);
+	return dr->data;
+}
+EXPORT_SYMBOL_GPL(__devres_alloc_node);
+
+/**
+ * devres_for_each_res - Resource iterator
+ * @dev: Device to iterate resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ * @fn: Function to be called for each matched resource.
+ * @data: Data for @fn, the 3rd parameter of @fn
+ *
+ * Call @fn for each devres of @dev which is associated with @release
+ * and for which @match returns 1.
+ *
+ * RETURNS:
+ * 	void
+ */
+void devres_for_each_res(struct device *dev, dr_release_t release,
+			dr_match_t match, void *match_data,
+			void (*fn)(struct device *, void *, void *),
+			void *data)
+{
+	struct devres_node *node;
+	struct devres_node *tmp;
+
+	if (!fn)
+		return;
+
+	guard(spinlock_irqsave)(&dev->devres_lock);
+	list_for_each_entry_safe_reverse(node, tmp,
+			&dev->devres_head, entry) {
+		struct devres *dr = container_of(node, struct devres, node);
+
+		if (node->release != dr_node_release)
+			continue;
+		if (dr->release != release)
+			continue;
+		if (match && !match(dev, dr->data, match_data))
+			continue;
+		fn(dev, dr->data, data);
+	}
+}
+EXPORT_SYMBOL_GPL(devres_for_each_res);
+
+static inline void free_dr(struct devres *dr)
+{
+	free_node(&dr->node);
+}
+
+/**
+ * devres_free - Free device resource data
+ * @res: Pointer to devres data to free
+ *
+ * Free devres created with devres_alloc().
+ */
+void devres_free(void *res)
+{
+	if (res) {
+		struct devres *dr = container_of(res, struct devres, data);
+
+		BUG_ON(!list_empty(&dr->node.entry));
+		free_dr(dr);
+	}
+}
+EXPORT_SYMBOL_GPL(devres_free);
+
+void devres_node_add(struct device *dev, struct devres_node *node)
+{
+	guard(spinlock_irqsave)(&dev->devres_lock);
+
+	add_dr(dev, node);
+}
+
+/**
+ * devres_add - Register device resource
+ * @dev: Device to add resource to
+ * @res: Resource to register
+ *
+ * Register devres @res to @dev.  @res should have been allocated
+ * using devres_alloc().  On driver detach, the associated release
+ * function will be invoked and devres will be freed automatically.
+ */
+void devres_add(struct device *dev, void *res)
+{
+	struct devres *dr = container_of(res, struct devres, data);
+
+	devres_node_add(dev, &dr->node);
+}
+EXPORT_SYMBOL_GPL(devres_add);
+
+static struct devres *find_dr(struct device *dev, dr_release_t release,
+			      dr_match_t match, void *match_data)
+{
+	struct devres_node *node;
+
+	list_for_each_entry_reverse(node, &dev->devres_head, entry) {
+		struct devres *dr = container_of(node, struct devres, node);
+
+		if (node->release != dr_node_release)
+			continue;
+		if (dr->release != release)
+			continue;
+		if (match && !match(dev, dr->data, match_data))
+			continue;
+		return dr;
+	}
+
+	return NULL;
+}
+
+/**
+ * devres_find - Find device resource
+ * @dev: Device to lookup resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev which is associated with @release
+ * and for which @match returns 1.  If @match is NULL, it's considered
+ * to match all.
+ *
+ * RETURNS:
+ * Pointer to found devres, NULL if not found.
+ */
+void *devres_find(struct device *dev, dr_release_t release,
+		  dr_match_t match, void *match_data)
+{
+	struct devres *dr;
+
+	guard(spinlock_irqsave)(&dev->devres_lock);
+	dr = find_dr(dev, release, match, match_data);
+	if (dr)
+		return dr->data;
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(devres_find);
+
+/**
+ * devres_get - Find devres, if non-existent, add one atomically
+ * @dev: Device to lookup or add devres for
+ * @new_res: Pointer to new initialized devres to add if not found
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev which has the same release function
+ * as @new_res and for which @match return 1.  If found, @new_res is
+ * freed; otherwise, @new_res is added atomically.
+ *
+ * RETURNS:
+ * Pointer to found or added devres.
+ */
+void *devres_get(struct device *dev, void *new_res,
+		 dr_match_t match, void *match_data)
+{
+	struct devres *new_dr = container_of(new_res, struct devres, data);
+	struct devres *dr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+	dr = find_dr(dev, new_dr->release, match, match_data);
+	if (!dr) {
+		add_dr(dev, &new_dr->node);
+		dr = new_dr;
+		new_res = NULL;
+	}
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	devres_free(new_res);
+
+	return dr->data;
+}
+EXPORT_SYMBOL_GPL(devres_get);
+
+bool devres_node_remove(struct device *dev, struct devres_node *node)
+{
+	struct devres_node *__node;
+
+	guard(spinlock_irqsave)(&dev->devres_lock);
+	list_for_each_entry_reverse(__node, &dev->devres_head, entry) {
+		if (__node == node) {
+			list_del_init(&node->entry);
+			devres_log(dev, node, "REM");
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/**
+ * devres_remove - Find a device resource and remove it
+ * @dev: Device to find resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev associated with @release and for
+ * which @match returns 1.  If @match is NULL, it's considered to
+ * match all.  If found, the resource is removed atomically and
+ * returned.
+ *
+ * RETURNS:
+ * Pointer to removed devres on success, NULL if not found.
+ */
+void *devres_remove(struct device *dev, dr_release_t release,
+		    dr_match_t match, void *match_data)
+{
+	struct devres *dr;
+
+	guard(spinlock_irqsave)(&dev->devres_lock);
+	dr = find_dr(dev, release, match, match_data);
+	if (dr) {
+		list_del_init(&dr->node.entry);
+		devres_log(dev, &dr->node, "REM");
+		return dr->data;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(devres_remove);
+
+/**
+ * devres_destroy - Find a device resource and destroy it
+ * @dev: Device to find resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev associated with @release and for
+ * which @match returns 1.  If @match is NULL, it's considered to
+ * match all.  If found, the resource is removed atomically and freed.
+ *
+ * Note that the release function for the resource will not be called,
+ * only the devres-allocated data will be freed.  The caller becomes
+ * responsible for freeing any other data.
+ *
+ * RETURNS:
+ * 0 if devres is found and freed, -ENOENT if not found.
+ */
+int devres_destroy(struct device *dev, dr_release_t release,
+		   dr_match_t match, void *match_data)
+{
+	void *res;
+
+	res = devres_remove(dev, release, match, match_data);
+	if (unlikely(!res))
+		return -ENOENT;
+
+	devres_free(res);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devres_destroy);
+
+
+/**
+ * devres_release - Find a device resource and destroy it, calling release
+ * @dev: Device to find resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev associated with @release and for
+ * which @match returns 1.  If @match is NULL, it's considered to
+ * match all.  If found, the resource is removed atomically, the
+ * release function called and the resource freed.
+ *
+ * RETURNS:
+ * 0 if devres is found and freed, -ENOENT if not found.
+ */
+int devres_release(struct device *dev, dr_release_t release,
+		   dr_match_t match, void *match_data)
+{
+	void *res;
+
+	res = devres_remove(dev, release, match, match_data);
+	if (unlikely(!res))
+		return -ENOENT;
+
+	(*release)(dev, res);
+	devres_free(res);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devres_release);
+
+static int remove_nodes(struct device *dev,
+			struct list_head *first, struct list_head *end,
+			struct list_head *todo)
+{
+	struct devres_node *node, *n;
+	int cnt = 0, nr_groups = 0;
+
+	/* First pass - move normal devres entries to @todo and clear
+	 * devres_group colors.
+	 */
+	node = list_entry(first, struct devres_node, entry);
+	list_for_each_entry_safe_from(node, n, end, entry) {
+		struct devres_group *grp;
+
+		grp = node_to_group(node);
+		if (grp) {
+			/* clear color of group markers in the first pass */
+			grp->color = 0;
+			nr_groups++;
+		} else {
+			/* regular devres entry */
+			if (&node->entry == first)
+				first = first->next;
+			list_move_tail(&node->entry, todo);
+			cnt++;
+		}
+	}
+
+	if (!nr_groups)
+		return cnt;
+
+	/* Second pass - Scan groups and color them.  A group gets
+	 * color value of two iff the group is wholly contained in
+	 * [current node, end). That is, for a closed group, both opening
+	 * and closing markers should be in the range, while just the
+	 * opening marker is enough for an open group.
+	 */
+	node = list_entry(first, struct devres_node, entry);
+	list_for_each_entry_safe_from(node, n, end, entry) {
+		struct devres_group *grp;
+
+		grp = node_to_group(node);
+		BUG_ON(!grp || list_empty(&grp->node[0].entry));
+
+		grp->color++;
+		if (list_empty(&grp->node[1].entry))
+			grp->color++;
+
+		BUG_ON(grp->color <= 0 || grp->color > 2);
+		if (grp->color == 2) {
+			/* No need to update current node or end. The removed
+			 * nodes are always before both.
+			 */
+			list_move_tail(&grp->node[0].entry, todo);
+			list_del_init(&grp->node[1].entry);
+		}
+	}
+
+	return cnt;
+}
+
+static void release_nodes(struct device *dev, struct list_head *todo)
+{
+	struct devres_node *node, *tmp;
+
+	list_for_each_entry_safe_reverse(node, tmp, todo, entry) {
+		devres_log(dev, node, "REL");
+		node->release(dev, node);
+		free_node(node);
+	}
+}
+
+/**
+ * devres_release_all - Release all managed resources
+ * @dev: Device to release resources for
+ *
+ * Release all resources associated with @dev.  This function is
+ * called on driver detach.
+ */
+int devres_release_all(struct device *dev)
+{
+	unsigned long flags;
+	LIST_HEAD(todo);
+	int cnt;
+
+	/* Looks like an uninitialized device structure */
+	if (WARN_ON(dev->devres_head.next == NULL))
+		return -ENODEV;
+
+	/* Nothing to release if list is empty */
+	if (list_empty(&dev->devres_head))
+		return 0;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+	cnt = remove_nodes(dev, dev->devres_head.next, &dev->devres_head, &todo);
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+	release_nodes(dev, &todo);
+	return cnt;
+}
+
+static void devres_group_free(struct devres_node *node)
+{
+	struct devres_group *grp = container_of(node, struct devres_group, node[0]);
+
+	kfree(grp);
+}
+
+/**
+ * devres_open_group - Open a new devres group
+ * @dev: Device to open devres group for
+ * @id: Separator ID
+ * @gfp: Allocation flags
+ *
+ * Open a new devres group for @dev with @id.  For @id, using a
+ * pointer to an object which won't be used for another group is
+ * recommended.  If @id is NULL, address-wise unique ID is created.
+ *
+ * RETURNS:
+ * ID of the new group, NULL on failure.
+ */
+void *devres_open_group(struct device *dev, void *id, gfp_t gfp)
+{
+	struct devres_group *grp;
+
+	grp = kmalloc_obj(*grp, gfp);
+	if (unlikely(!grp))
+		return NULL;
+
+	devres_node_init(&grp->node[0], &group_open_release, devres_group_free);
+	devres_node_init(&grp->node[1], &group_close_release, NULL);
+	devres_set_node_dbginfo(&grp->node[0], "grp<", 0);
+	devres_set_node_dbginfo(&grp->node[1], "grp>", 0);
+	grp->id = grp;
+	if (id)
+		grp->id = id;
+	grp->color = 0;
+
+	devres_node_add(dev, &grp->node[0]);
+	return grp->id;
+}
+EXPORT_SYMBOL_GPL(devres_open_group);
+
+/*
+ * Find devres group with ID @id.  If @id is NULL, look for the latest open
+ * group.
+ */
+static struct devres_group *find_group(struct device *dev, void *id)
+{
+	struct devres_node *node;
+
+	list_for_each_entry_reverse(node, &dev->devres_head, entry) {
+		struct devres_group *grp;
+
+		if (node->release != &group_open_release)
+			continue;
+
+		grp = container_of(node, struct devres_group, node[0]);
+
+		if (id) {
+			if (grp->id == id)
+				return grp;
+		} else if (list_empty(&grp->node[1].entry))
+			return grp;
+	}
+
+	return NULL;
+}
+
+/**
+ * devres_close_group - Close a devres group
+ * @dev: Device to close devres group for
+ * @id: ID of target group, can be NULL
+ *
+ * Close the group identified by @id.  If @id is NULL, the latest open
+ * group is selected.
+ */
+void devres_close_group(struct device *dev, void *id)
+{
+	struct devres_group *grp;
+
+	guard(spinlock_irqsave)(&dev->devres_lock);
+	grp = find_group(dev, id);
+	if (grp)
+		add_dr(dev, &grp->node[1]);
+	else
+		WARN_ON(1);
+}
+EXPORT_SYMBOL_GPL(devres_close_group);
+
+/**
+ * devres_remove_group - Remove a devres group
+ * @dev: Device to remove group for
+ * @id: ID of target group, can be NULL
+ *
+ * Remove the group identified by @id.  If @id is NULL, the latest
+ * open group is selected.  Note that removing a group doesn't affect
+ * any other resources.
+ */
+void devres_remove_group(struct device *dev, void *id)
+{
+	struct devres_group *grp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+
+	grp = find_group(dev, id);
+	if (grp) {
+		list_del_init(&grp->node[0].entry);
+		list_del_init(&grp->node[1].entry);
+		devres_log(dev, &grp->node[0], "REM");
+	} else
+		WARN_ON(1);
+
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+	kfree(grp);
+}
+EXPORT_SYMBOL_GPL(devres_remove_group);
+
+/**
+ * devres_release_group - Release resources in a devres group
+ * @dev: Device to release group for
+ * @id: ID of target group, can be NULL
+ *
+ * Release all resources in the group identified by @id.  If @id is
+ * NULL, the latest open group is selected.  The selected group and
+ * groups properly nested inside the selected group are removed.
+ *
+ * RETURNS:
+ * The number of released non-group resources.
+ */
+int devres_release_group(struct device *dev, void *id)
+{
+	struct devres_group *grp;
+	unsigned long flags;
+	LIST_HEAD(todo);
+	int cnt = 0;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+	grp = find_group(dev, id);
+	if (grp) {
+		struct list_head *first = &grp->node[0].entry;
+		struct list_head *end = &dev->devres_head;
+
+		if (!list_empty(&grp->node[1].entry))
+			end = grp->node[1].entry.next;
+
+		cnt = remove_nodes(dev, first, end, &todo);
+	} else if (list_empty(&dev->devres_head)) {
+		/*
+		 * dev is probably dying via devres_release_all(): groups
+		 * have already been removed and are on the process of
+		 * being released - don't touch and don't warn.
+		 */
+	} else {
+		WARN_ON(1);
+	}
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+	release_nodes(dev, &todo);
+
+	return cnt;
+}
+EXPORT_SYMBOL_GPL(devres_release_group);
+
+/*
+ * Custom devres actions allow inserting a simple function call
+ * into the teardown sequence.
+ */
+
+struct action_devres {
+	void *data;
+	void (*action)(void *);
+};
+
+struct devres_action {
+	struct devres_node node;
+	struct action_devres action;
+};
+
+static int devm_action_match(struct devres_action *devres, struct action_devres *target)
+{
+	return devres->action.action == target->action &&
+	       devres->action.data == target->data;
+}
+
+static void devm_action_release(struct device *dev, struct devres_node *node)
+{
+	struct devres_action *devres = container_of(node, struct devres_action, node);
+
+	devres->action.action(devres->action.data);
+}
+
+static void devm_action_free(struct devres_node *node)
+{
+	struct devres_action *action = container_of(node, struct devres_action, node);
+
+	kfree(action);
+}
+
+/**
+ * __devm_add_action() - add a custom action to list of managed resources
+ * @dev: Device that owns the action
+ * @action: Function that should be called
+ * @data: Pointer to data passed to @action implementation
+ * @name: Name of the resource (for debugging purposes)
+ *
+ * This adds a custom action to the list of managed resources so that
+ * it gets executed as part of standard resource unwinding.
+ */
+int __devm_add_action(struct device *dev, void (*action)(void *), void *data, const char *name)
+{
+	struct devres_action *devres;
+
+	devres = kzalloc_obj(*devres);
+	if (!devres)
+		return -ENOMEM;
+
+	devres_node_init(&devres->node, devm_action_release, devm_action_free);
+	devres_set_node_dbginfo(&devres->node, name, sizeof(*devres));
+
+	devres->action.data = data;
+	devres->action.action = action;
+
+	devres_node_add(dev, &devres->node);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__devm_add_action);
+
+static struct devres_action *devres_action_find(struct device *dev,
+						void (*action)(void *),
+						void *data)
+{
+	struct devres_node *node;
+	struct action_devres target = {
+		.data = data,
+		.action = action,
+	};
+
+	list_for_each_entry_reverse(node, &dev->devres_head, entry) {
+		struct devres_action *dr = container_of(node, struct devres_action, node);
+
+		if (node->release != devm_action_release)
+			continue;
+		if (devm_action_match(dr, &target))
+			return dr;
+	}
+
+	return NULL;
+}
+
+bool devm_is_action_added(struct device *dev, void (*action)(void *), void *data)
+{
+	guard(spinlock_irqsave)(&dev->devres_lock);
+
+	return !!devres_action_find(dev, action, data);
+}
+EXPORT_SYMBOL_GPL(devm_is_action_added);
+
+static struct devres_action *remove_action(struct device *dev,
+					   void (*action)(void *),
+					   void *data)
+{
+	struct devres_action *dr;
+
+	guard(spinlock_irqsave)(&dev->devres_lock);
+
+	dr = devres_action_find(dev, action, data);
+	if (!dr)
+		return ERR_PTR(-ENOENT);
+
+	list_del_init(&dr->node.entry);
+	devres_log(dev, &dr->node, "REM");
+
+	return dr;
+}
+
+/**
+ * devm_remove_action_nowarn() - removes previously added custom action
+ * @dev: Device that owns the action
+ * @action: Function implementing the action
+ * @data: Pointer to data passed to @action implementation
+ *
+ * Removes instance of @action previously added by devm_add_action().
+ * Both action and data should match one of the existing entries.
+ *
+ * In contrast to devm_remove_action(), this function does not WARN() if no
+ * entry could have been found.
+ *
+ * This should only be used if the action is contained in an object with
+ * independent lifetime management, e.g. the Devres rust abstraction.
+ *
+ * Causing the warning from regular driver code most likely indicates an abuse
+ * of the devres API.
+ *
+ * Returns: 0 on success, -ENOENT if no entry could have been found.
+ */
+int devm_remove_action_nowarn(struct device *dev,
+			      void (*action)(void *),
+			      void *data)
+{
+	struct devres_action *dr;
+
+	dr = remove_action(dev, action, data);
+	if (IS_ERR(dr))
+		return PTR_ERR(dr);
+
+	kfree(dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_remove_action_nowarn);
+
+/**
+ * devm_release_action() - release previously added custom action
+ * @dev: Device that owns the action
+ * @action: Function implementing the action
+ * @data: Pointer to data passed to @action implementation
+ *
+ * Releases and removes instance of @action previously added by
+ * devm_add_action().  Both action and data should match one of the
+ * existing entries.
+ */
+void devm_release_action(struct device *dev, void (*action)(void *), void *data)
+{
+	struct devres_action *dr;
+
+	dr = remove_action(dev, action, data);
+	if (WARN_ON(IS_ERR(dr)))
+		return;
+
+	dr->action.action(dr->action.data);
+
+	kfree(dr);
+}
+EXPORT_SYMBOL_GPL(devm_release_action);
+
+/*
+ * Managed kmalloc/kfree
+ */
+static void devm_kmalloc_release(struct device *dev, void *res)
+{
+	/* noop */
+}
+
+static int devm_kmalloc_match(struct device *dev, void *res, void *data)
+{
+	return res == data;
+}
+
+/**
+ * devm_kmalloc - Resource-managed kmalloc
+ * @dev: Device to allocate memory for
+ * @size: Allocation size
+ * @gfp: Allocation gfp flags
+ *
+ * Managed kmalloc.  Memory allocated with this function is
+ * automatically freed on driver detach.  Like all other devres
+ * resources, guaranteed alignment is unsigned long long.
+ *
+ * RETURNS:
+ * Pointer to allocated memory on success, NULL on failure.
+ */
+void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
+{
+	struct devres *dr;
+
+	if (unlikely(!size))
+		return ZERO_SIZE_PTR;
+
+	/* use raw alloc_dr for kmalloc caller tracing */
+	dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
+	if (unlikely(!dr))
+		return NULL;
+
+	/*
+	 * This is named devm_kzalloc_release for historical reasons
+	 * The initial implementation did not support kmalloc, only kzalloc
+	 */
+	devres_set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
+	devres_add(dev, dr->data);
+	return dr->data;
+}
+EXPORT_SYMBOL_GPL(devm_kmalloc);
+
+/**
+ * devm_krealloc - Resource-managed krealloc()
+ * @dev: Device to re-allocate memory for
+ * @ptr: Pointer to the memory chunk to re-allocate
+ * @new_size: New allocation size
+ * @gfp: Allocation gfp flags
+ *
+ * Managed krealloc(). Resizes the memory chunk allocated with devm_kmalloc().
+ * Behaves similarly to regular krealloc(): if @ptr is NULL or ZERO_SIZE_PTR,
+ * it's the equivalent of devm_kmalloc(). If new_size is zero, it frees the
+ * previously allocated memory and returns ZERO_SIZE_PTR. This function doesn't
+ * change the order in which the release callback for the re-alloc'ed devres
+ * will be called (except when falling back to devm_kmalloc() or when freeing
+ * resources when new_size is zero). The contents of the memory are preserved
+ * up to the lesser of new and old sizes.
+ */
+void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
+{
+	size_t total_new_size, total_old_size;
+	struct devres *old_dr, *new_dr;
+	unsigned long flags;
+
+	if (unlikely(!new_size)) {
+		devm_kfree(dev, ptr);
+		return ZERO_SIZE_PTR;
+	}
+
+	if (unlikely(ZERO_OR_NULL_PTR(ptr)))
+		return devm_kmalloc(dev, new_size, gfp);
+
+	if (WARN_ON(is_kernel_rodata((unsigned long)ptr)))
+		/*
+		 * We cannot reliably realloc a const string returned by
+		 * devm_kstrdup_const().
+		 */
+		return NULL;
+
+	if (!check_dr_size(new_size, &total_new_size))
+		return NULL;
+
+	total_old_size = ksize(container_of(ptr, struct devres, data));
+	if (total_old_size == 0) {
+		WARN(1, "Pointer doesn't point to dynamically allocated memory.");
+		return NULL;
+	}
+
+	/*
+	 * If new size is smaller or equal to the actual number of bytes
+	 * allocated previously - just return the same pointer.
+	 */
+	if (total_new_size <= total_old_size)
+		return ptr;
+
+	/*
+	 * Otherwise: allocate new, larger chunk. We need to allocate before
+	 * taking the lock as most probably the caller uses GFP_KERNEL.
+	 * alloc_dr() will call check_dr_size() to reserve extra memory
+	 * for struct devres automatically, so size @new_size user request
+	 * is delivered to it directly as devm_kmalloc() does.
+	 */
+	new_dr = alloc_dr(devm_kmalloc_release,
+			  new_size, gfp, dev_to_node(dev));
+	if (!new_dr)
+		return NULL;
+
+	devres_set_node_dbginfo(&new_dr->node, "devm_krealloc_release", new_size);
+
+	/*
+	 * The spinlock protects the linked list against concurrent
+	 * modifications but not the resource itself.
+	 */
+	spin_lock_irqsave(&dev->devres_lock, flags);
+
+	old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
+	if (!old_dr) {
+		spin_unlock_irqrestore(&dev->devres_lock, flags);
+		free_dr(new_dr);
+		WARN(1, "Memory chunk not managed or managed by a different device.");
+		return NULL;
+	}
+
+	replace_dr(dev, &old_dr->node, &new_dr->node);
+
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+	/*
+	 * We can copy the memory contents after releasing the lock as we're
+	 * no longer modifying the list links.
+	 */
+	memcpy(new_dr->data, old_dr->data,
+	       total_old_size - offsetof(struct devres, data));
+	/*
+	 * Same for releasing the old devres - it's now been removed from the
+	 * list. This is also the reason why we must not use devm_kfree() - the
+	 * links are no longer valid.
+	 */
+	free_dr(old_dr);
+
+	return new_dr->data;
+}
+EXPORT_SYMBOL_GPL(devm_krealloc);
+
+/**
+ * devm_kstrdup - Allocate resource managed space and
+ *                copy an existing string into that.
+ * @dev: Device to allocate memory for
+ * @s: the string to duplicate
+ * @gfp: the GFP mask used in the devm_kmalloc() call when
+ *       allocating memory
+ * RETURNS:
+ * Pointer to allocated string on success, NULL on failure.
+ */
+char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
+{
+	if (!s)
+		return NULL;
+
+	return devm_kmemdup(dev, s, strlen(s) + 1, gfp);
+}
+EXPORT_SYMBOL_GPL(devm_kstrdup);
+
+/**
+ * devm_kstrdup_const - resource managed conditional string duplication
+ * @dev: device for which to duplicate the string
+ * @s: the string to duplicate
+ * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ *
+ * Strings allocated by devm_kstrdup_const will be automatically freed when
+ * the associated device is detached.
+ *
+ * RETURNS:
+ * Source string if it is in .rodata section otherwise it falls back to
+ * devm_kstrdup.
+ */
+const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
+{
+	if (is_kernel_rodata((unsigned long)s))
+		return s;
+
+	return devm_kstrdup(dev, s, gfp);
+}
+EXPORT_SYMBOL_GPL(devm_kstrdup_const);
+
+/**
+ * devm_kvasprintf - Allocate resource managed space and format a string
+ *		     into that.
+ * @dev: Device to allocate memory for
+ * @gfp: the GFP mask used in the devm_kmalloc() call when
+ *       allocating memory
+ * @fmt: The printf()-style format string
+ * @ap: Arguments for the format string
+ * RETURNS:
+ * Pointer to allocated string on success, NULL on failure.
+ */
+char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
+		      va_list ap)
+{
+	unsigned int len;
+	char *p;
+	va_list aq;
+
+	va_copy(aq, ap);
+	len = vsnprintf(NULL, 0, fmt, aq);
+	va_end(aq);
+
+	p = devm_kmalloc(dev, len+1, gfp);
+	if (!p)
+		return NULL;
+
+	vsnprintf(p, len+1, fmt, ap);
+
+	return p;
+}
+EXPORT_SYMBOL(devm_kvasprintf);
+
+/**
+ * devm_kasprintf - Allocate resource managed space and format a string
+ *		    into that.
+ * @dev: Device to allocate memory for
+ * @gfp: the GFP mask used in the devm_kmalloc() call when
+ *       allocating memory
+ * @fmt: The printf()-style format string
+ * @...: Arguments for the format string
+ * RETURNS:
+ * Pointer to allocated string on success, NULL on failure.
+ */
+char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
+{
+	va_list ap;
+	char *p;
+
+	va_start(ap, fmt);
+	p = devm_kvasprintf(dev, gfp, fmt, ap);
+	va_end(ap);
+
+	return p;
+}
+EXPORT_SYMBOL_GPL(devm_kasprintf);
+
+/**
+ * devm_kfree - Resource-managed kfree
+ * @dev: Device this memory belongs to
+ * @p: Memory to free
+ *
+ * Free memory allocated with devm_kmalloc().
+ */
+void devm_kfree(struct device *dev, const void *p)
+{
+	int rc;
+
+	/*
+	 * Special cases: pointer to a string in .rodata returned by
+	 * devm_kstrdup_const() or NULL/ZERO ptr.
+	 */
+	if (unlikely(is_kernel_rodata((unsigned long)p) || ZERO_OR_NULL_PTR(p)))
+		return;
+
+	rc = devres_destroy(dev, devm_kmalloc_release,
+			    devm_kmalloc_match, (void *)p);
+	WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_kfree);
+
+/**
+ * devm_kmemdup - Resource-managed kmemdup
+ * @dev: Device this memory belongs to
+ * @src: Memory region to duplicate
+ * @len: Memory region length
+ * @gfp: GFP mask to use
+ *
+ * Duplicate region of a memory using resource managed kmalloc
+ */
+void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
+{
+	void *p;
+
+	p = devm_kmalloc(dev, len, gfp);
+	if (p)
+		memcpy(p, src, len);
+
+	return p;
+}
+EXPORT_SYMBOL_GPL(devm_kmemdup);
+
+/**
+ * devm_kmemdup_const - conditionally duplicate and manage a region of memory
+ *
+ * @dev: Device this memory belongs to
+ * @src: memory region to duplicate
+ * @len: memory region length,
+ * @gfp: GFP mask to use
+ *
+ * Return: source address if it is in .rodata or the return value of kmemdup()
+ * to which the function falls back otherwise.
+ */
+const void *
+devm_kmemdup_const(struct device *dev, const void *src, size_t len, gfp_t gfp)
+{
+	if (is_kernel_rodata((unsigned long)src))
+		return src;
+
+	return devm_kmemdup(dev, src, len, gfp);
+}
+EXPORT_SYMBOL_GPL(devm_kmemdup_const);
+
+struct pages_devres {
+	unsigned long addr;
+	unsigned int order;
+};
+
+static int devm_pages_match(struct device *dev, void *res, void *p)
+{
+	struct pages_devres *devres = res;
+	struct pages_devres *target = p;
+
+	return devres->addr == target->addr;
+}
+
+static void devm_pages_release(struct device *dev, void *res)
+{
+	struct pages_devres *devres = res;
+
+	free_pages(devres->addr, devres->order);
+}
+
+/**
+ * devm_get_free_pages - Resource-managed __get_free_pages
+ * @dev: Device to allocate memory for
+ * @gfp_mask: Allocation gfp flags
+ * @order: Allocation size is (1 << order) pages
+ *
+ * Managed get_free_pages.  Memory allocated with this function is
+ * automatically freed on driver detach.
+ *
+ * RETURNS:
+ * Address of allocated memory on success, 0 on failure.
+ */
+
+unsigned long devm_get_free_pages(struct device *dev,
+				  gfp_t gfp_mask, unsigned int order)
+{
+	struct pages_devres *devres;
+	unsigned long addr;
+
+	addr = __get_free_pages(gfp_mask, order);
+
+	if (unlikely(!addr))
+		return 0;
+
+	devres = devres_alloc(devm_pages_release,
+			      sizeof(struct pages_devres), GFP_KERNEL);
+	if (unlikely(!devres)) {
+		free_pages(addr, order);
+		return 0;
+	}
+
+	devres->addr = addr;
+	devres->order = order;
+
+	devres_add(dev, devres);
+	return addr;
+}
+EXPORT_SYMBOL_GPL(devm_get_free_pages);
+
+/**
+ * devm_free_pages - Resource-managed free_pages
+ * @dev: Device this memory belongs to
+ * @addr: Memory to free
+ *
+ * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
+ * there is no need to supply the @order.
+ */
+void devm_free_pages(struct device *dev, unsigned long addr)
+{
+	struct pages_devres devres = { .addr = addr };
+
+	WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
+			       &devres));
+}
+EXPORT_SYMBOL_GPL(devm_free_pages);
+
+static void devm_percpu_release(struct device *dev, void *pdata)
+{
+	void __percpu *p;
+
+	p = *(void __percpu **)pdata;
+	free_percpu(p);
+}
+
+/**
+ * __devm_alloc_percpu - Resource-managed alloc_percpu
+ * @dev: Device to allocate per-cpu memory for
+ * @size: Size of per-cpu memory to allocate
+ * @align: Alignment of per-cpu memory to allocate
+ *
+ * Managed alloc_percpu. Per-cpu memory allocated with this function is
+ * automatically freed on driver detach.
+ *
+ * RETURNS:
+ * Pointer to allocated memory on success, NULL on failure.
+ */
+void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
+		size_t align)
+{
+	void *p;
+	void __percpu *pcpu;
+
+	pcpu = __alloc_percpu(size, align);
+	if (!pcpu)
+		return NULL;
+
+	p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
+	if (!p) {
+		free_percpu(pcpu);
+		return NULL;
+	}
+
+	*(void __percpu **)p = pcpu;
+
+	devres_add(dev, p);
+
+	return pcpu;
+}
+EXPORT_SYMBOL_GPL(__devm_alloc_percpu);