1 files changed, 63 insertions, 28 deletions

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index 3df0025d12aa..ff55e1bcfa30 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -85,7 +85,7 @@ static void group_close_release(struct device *dev, void *res)
 	/* noop */
 }
 
-static struct devres_group * node_to_group(struct devres_node *node)
+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]);
@@ -107,8 +107,8 @@ static bool check_dr_size(size_t size, size_t *tot_size)
 	return true;
 }
 
-static __always_inline struct devres * alloc_dr(dr_release_t release,
-						size_t size, gfp_t gfp, int nid)
+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;
@@ -283,8 +283,8 @@ static struct devres *find_dr(struct device *dev, dr_release_t release,
  * 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)
+void *devres_find(struct device *dev, dr_release_t release,
+		  dr_match_t match, void *match_data)
 {
 	struct devres *dr;
 	unsigned long flags;
@@ -313,8 +313,8 @@ EXPORT_SYMBOL_GPL(devres_find);
  * RETURNS:
  * Pointer to found or added devres.
  */
-void * devres_get(struct device *dev, void *new_res,
-		  dr_match_t match, void *match_data)
+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;
@@ -349,8 +349,8 @@ EXPORT_SYMBOL_GPL(devres_get);
  * 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)
+void *devres_remove(struct device *dev, dr_release_t release,
+		    dr_match_t match, void *match_data)
 {
 	struct devres *dr;
 	unsigned long flags;
@@ -549,7 +549,7 @@ int devres_release_all(struct device *dev)
  * RETURNS:
  * ID of the new group, NULL on failure.
  */
-void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
+void *devres_open_group(struct device *dev, void *id, gfp_t gfp)
 {
 	struct devres_group *grp;
 	unsigned long flags;
@@ -567,6 +567,7 @@ void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
 	grp->id = grp;
 	if (id)
 		grp->id = id;
+	grp->color = 0;
 
 	spin_lock_irqsave(&dev->devres_lock, flags);
 	add_dr(dev, &grp->node[0]);
@@ -575,8 +576,11 @@ void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
 }
 EXPORT_SYMBOL_GPL(devres_open_group);
 
-/* Find devres group with ID @id.  If @id is NULL, look for the latest. */
-static struct devres_group * find_group(struct device *dev, void *id)
+/*
+ * 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;
 
@@ -686,6 +690,13 @@ int devres_release_group(struct device *dev, void *id)
 		spin_unlock_irqrestore(&dev->devres_lock, flags);
 
 		release_nodes(dev, &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.
+		 */
+		spin_unlock_irqrestore(&dev->devres_lock, flags);
 	} else {
 		WARN_ON(1);
 		spin_unlock_irqrestore(&dev->devres_lock, flags);
@@ -748,26 +759,50 @@ int __devm_add_action(struct device *dev, void (*action)(void *), void *data, co
 }
 EXPORT_SYMBOL_GPL(__devm_add_action);
 
+bool devm_is_action_added(struct device *dev, void (*action)(void *), void *data)
+{
+	struct action_devres devres = {
+		.data = data,
+		.action = action,
+	};
+
+	return devres_find(dev, devm_action_release, devm_action_match, &devres);
+}
+EXPORT_SYMBOL_GPL(devm_is_action_added);
+
 /**
- * devm_remove_action() - removes previously added custom action
+ * 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.
  */
-void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
+int devm_remove_action_nowarn(struct device *dev,
+			      void (*action)(void *),
+			      void *data)
 {
 	struct action_devres devres = {
 		.data = data,
 		.action = action,
 	};
 
-	WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
-			       &devres));
+	return devres_destroy(dev, devm_action_release, devm_action_match,
+			      &devres);
 }
-EXPORT_SYMBOL_GPL(devm_remove_action);
+EXPORT_SYMBOL_GPL(devm_remove_action_nowarn);
 
 /**
  * devm_release_action() - release previously added custom action
@@ -896,9 +931,12 @@ void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
 	/*
 	 * 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,
-			  total_new_size, gfp, dev_to_node(dev));
+			  new_size, gfp, dev_to_node(dev));
 	if (!new_dr)
 		return NULL;
 
@@ -949,17 +987,10 @@ EXPORT_SYMBOL_GPL(devm_krealloc);
  */
 char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
 {
-	size_t size;
-	char *buf;
-
 	if (!s)
 		return NULL;
 
-	size = strlen(s) + 1;
-	buf = devm_kmalloc(dev, size, gfp);
-	if (buf)
-		memcpy(buf, s, size);
-	return buf;
+	return devm_kmemdup(dev, s, strlen(s) + 1, gfp);
 }
 EXPORT_SYMBOL_GPL(devm_kstrdup);
 
@@ -1222,7 +1253,11 @@ EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
  */
 void devm_free_percpu(struct device *dev, void __percpu *pdata)
 {
-	WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
-			       (__force void *)pdata));
+	/*
+	 * Use devres_release() to prevent memory leakage as
+	 * devm_free_pages() does.
+	 */
+	WARN_ON(devres_release(dev, devm_percpu_release, devm_percpu_match,
+			       (void *)(__force unsigned long)pdata));
 }
 EXPORT_SYMBOL_GPL(devm_free_percpu);