[PATCH 0/5] devres: provide and use devm_krealloc()

[PATCH 0/5] devres: provide and use devm_krealloc()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Regular krealloc() obviously can't work with managed memory. This series
implements devm_krealloc() and adds the first user with hope that this
helper will be adopted by other drivers currently using non-managed
krealloc().

Some cosmetic changes to the code modified by main patches are included.

Bartosz Golaszewski (5):
  devres: remove stray space from devm_kmalloc() definition
  devres: move the size check from alloc_dr() into a separate function
  device: remove 'extern' attribute from function prototypes in device.h
  devres: provide devm_krealloc()
  hwmon: pmbus: use more devres helpers

 .../driver-api/driver-model/devres.rst        |   1 +
 drivers/base/devres.c                         |  58 ++++-
 drivers/hwmon/pmbus/pmbus_core.c              |  27 +--
 include/linux/device.h                        | 225 +++++++++---------
 4 files changed, 173 insertions(+), 138 deletions(-)

-- 
2.26.1

[PATCH 1/5] devres: remove stray space from devm_kmalloc() definition

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Use the preferred coding style for functions returning pointers.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/base/devres.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index 0bbb328bd17f..c34327219c34 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -807,7 +807,7 @@ static int devm_kmalloc_match(struct device *dev, void *res, void *data)
  * RETURNS:
  * Pointer to allocated memory on success, NULL on failure.
  */
-void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
+void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
 {
 	struct devres *dr;
 
-- 
2.26.1

[PATCH 2/5] devres: move the size check from alloc_dr() into a separate function

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

We will perform the same size check in devm_krealloc(). Move the relevant
code into a separate helper.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/base/devres.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index c34327219c34..1df1fb10b2d9 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -89,15 +89,23 @@ static struct devres_group * node_to_group(struct devres_node *node)
 	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;
+
+	return true;
+}
+
 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;
 
-	/* We must catch any near-SIZE_MAX cases that could overflow. */
-	if (unlikely(check_add_overflow(sizeof(struct devres), size,
-					&tot_size)))
+	if (!check_dr_size(size, &tot_size))
 		return NULL;
 
 	dr = kmalloc_node_track_caller(tot_size, gfp, nid);
-- 
2.26.1

[PATCH 3/5] device: remove 'extern' attribute from function prototypes in device.h

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Functions are declared 'extern' implicitly by the compiler. There's no
reason to prepend every prototype with it. Remove the 'extern' keyword
from all function declarations in linux/device.h.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 include/linux/device.h | 223 ++++++++++++++++++++---------------------
 1 file changed, 107 insertions(+), 116 deletions(-)

diff --git a/include/linux/device.h b/include/linux/device.h
index 15460a5ac024..9cadb647cacc 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -145,68 +145,66 @@ ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
 	struct device_attribute dev_attr_##_name =		\
 		__ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store)
 
-extern int device_create_file(struct device *device,
-			      const struct device_attribute *entry);
-extern void device_remove_file(struct device *dev,
-			       const struct device_attribute *attr);
-extern bool device_remove_file_self(struct device *dev,
-				    const struct device_attribute *attr);
-extern int __must_check device_create_bin_file(struct device *dev,
+int device_create_file(struct device *device,
+		       const struct device_attribute *entry);
+void device_remove_file(struct device *dev,
+			const struct device_attribute *attr);
+bool device_remove_file_self(struct device *dev,
+			     const struct device_attribute *attr);
+int __must_check device_create_bin_file(struct device *dev,
 					const struct bin_attribute *attr);
-extern void device_remove_bin_file(struct device *dev,
-				   const struct bin_attribute *attr);
+void device_remove_bin_file(struct device *dev,
+			    const struct bin_attribute *attr);
 
 /* device resource management */
 typedef void (*dr_release_t)(struct device *dev, void *res);
 typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
 
 #ifdef CONFIG_DEBUG_DEVRES
-extern void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
-				 int nid, const char *name) __malloc;
+void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
+			  int nid, const char *name) __malloc;
 #define devres_alloc(release, size, gfp) \
 	__devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)
 #define devres_alloc_node(release, size, gfp, nid) \
 	__devres_alloc_node(release, size, gfp, nid, #release)
 #else
-extern void *devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,
-			       int nid) __malloc;
+void *devres_alloc_node(dr_release_t release, size_t size,
+			gfp_t gfp, int nid) __malloc;
 static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
 {
 	return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);
 }
 #endif
 
-extern 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);
-extern void devres_free(void *res);
-extern void devres_add(struct device *dev, void *res);
-extern void *devres_find(struct device *dev, dr_release_t release,
-			 dr_match_t match, void *match_data);
-extern void *devres_get(struct device *dev, void *new_res,
-			dr_match_t match, void *match_data);
-extern void *devres_remove(struct device *dev, dr_release_t release,
-			   dr_match_t match, void *match_data);
-extern int devres_destroy(struct device *dev, dr_release_t release,
-			  dr_match_t match, void *match_data);
-extern int devres_release(struct device *dev, dr_release_t release,
-			  dr_match_t match, void *match_data);
+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);
+void devres_free(void *res);
+void devres_add(struct device *dev, void *res);
+void *devres_find(struct device *dev, dr_release_t release,
+		  dr_match_t match, void *match_data);
+void *devres_get(struct device *dev, void *new_res,
+		 dr_match_t match, void *match_data);
+void *devres_remove(struct device *dev, dr_release_t release,
+		    dr_match_t match, void *match_data);
+int devres_destroy(struct device *dev, dr_release_t release,
+		   dr_match_t match, void *match_data);
+int devres_release(struct device *dev, dr_release_t release,
+		   dr_match_t match, void *match_data);
 
 /* devres group */
-extern void * __must_check devres_open_group(struct device *dev, void *id,
-					     gfp_t gfp);
-extern void devres_close_group(struct device *dev, void *id);
-extern void devres_remove_group(struct device *dev, void *id);
-extern int devres_release_group(struct device *dev, void *id);
+void * __must_check devres_open_group(struct device *dev, void *id, gfp_t gfp);
+void devres_close_group(struct device *dev, void *id);
+void devres_remove_group(struct device *dev, void *id);
+int devres_release_group(struct device *dev, void *id);
 
 /* managed devm_k.alloc/kfree for device drivers */
-extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
-extern __printf(3, 0)
-char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
-		      va_list ap) __malloc;
-extern __printf(3, 4)
-char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...) __malloc;
+void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
+__printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
+				     const char *fmt, va_list ap) __malloc;
+__printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
+				    const char *fmt, ...) __malloc;
 static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
 {
 	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);
@@ -226,16 +224,14 @@ static inline void *devm_kcalloc(struct device *dev,
 {
 	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
 }
-extern void devm_kfree(struct device *dev, const void *p);
-extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
-extern const char *devm_kstrdup_const(struct device *dev,
-				      const char *s, gfp_t gfp);
-extern void *devm_kmemdup(struct device *dev, const void *src, size_t len,
-			  gfp_t gfp);
+void devm_kfree(struct device *dev, const void *p);
+char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
+const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp);
+void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp);
 
-extern unsigned long devm_get_free_pages(struct device *dev,
-					 gfp_t gfp_mask, unsigned int order);
-extern void devm_free_pages(struct device *dev, unsigned long addr);
+unsigned long devm_get_free_pages(struct device *dev,
+				  gfp_t gfp_mask, unsigned int order);
+void devm_free_pages(struct device *dev, unsigned long addr);
 
 void __iomem *devm_ioremap_resource(struct device *dev,
 				    const struct resource *res);
@@ -651,8 +647,7 @@ static inline const char *dev_name(const struct device *dev)
 	return kobject_name(&dev->kobj);
 }
 
-extern __printf(2, 3)
-int dev_set_name(struct device *dev, const char *name, ...);
+__printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...);
 
 #ifdef CONFIG_NUMA
 static inline int dev_to_node(struct device *dev)
@@ -809,39 +804,38 @@ static inline bool dev_has_sync_state(struct device *dev)
 /*
  * High level routines for use by the bus drivers
  */
-extern int __must_check device_register(struct device *dev);
-extern void device_unregister(struct device *dev);
-extern void device_initialize(struct device *dev);
-extern int __must_check device_add(struct device *dev);
-extern void device_del(struct device *dev);
-extern int device_for_each_child(struct device *dev, void *data,
-		     int (*fn)(struct device *dev, void *data));
-extern int device_for_each_child_reverse(struct device *dev, void *data,
-		     int (*fn)(struct device *dev, void *data));
-extern struct device *device_find_child(struct device *dev, void *data,
-				int (*match)(struct device *dev, void *data));
-extern struct device *device_find_child_by_name(struct device *parent,
-						const char *name);
-extern int device_rename(struct device *dev, const char *new_name);
-extern int device_move(struct device *dev, struct device *new_parent,
-		       enum dpm_order dpm_order);
-extern int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
-extern const char *device_get_devnode(struct device *dev,
-				      umode_t *mode, kuid_t *uid, kgid_t *gid,
-				      const char **tmp);
+int __must_check device_register(struct device *dev);
+void device_unregister(struct device *dev);
+void device_initialize(struct device *dev);
+int __must_check device_add(struct device *dev);
+void device_del(struct device *dev);
+int device_for_each_child(struct device *dev, void *data,
+			  int (*fn)(struct device *dev, void *data));
+int device_for_each_child_reverse(struct device *dev, void *data,
+				  int (*fn)(struct device *dev, void *data));
+struct device *device_find_child(struct device *dev, void *data,
+				 int (*match)(struct device *dev, void *data));
+struct device *device_find_child_by_name(struct device *parent,
+					 const char *name);
+int device_rename(struct device *dev, const char *new_name);
+int device_move(struct device *dev, struct device *new_parent,
+		enum dpm_order dpm_order);
+int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid);
+const char *device_get_devnode(struct device *dev, umode_t *mode, kuid_t *uid,
+			       kgid_t *gid, const char **tmp);
 
 static inline bool device_supports_offline(struct device *dev)
 {
 	return dev->bus && dev->bus->offline && dev->bus->online;
 }
 
-extern void lock_device_hotplug(void);
-extern void unlock_device_hotplug(void);
-extern int lock_device_hotplug_sysfs(void);
-extern int device_offline(struct device *dev);
-extern int device_online(struct device *dev);
-extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
-extern void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
+void lock_device_hotplug(void);
+void unlock_device_hotplug(void);
+int lock_device_hotplug_sysfs(void);
+int device_offline(struct device *dev);
+int device_online(struct device *dev);
+void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
+void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2);
 
 static inline int dev_num_vf(struct device *dev)
@@ -854,14 +848,13 @@ static inline int dev_num_vf(struct device *dev)
 /*
  * Root device objects for grouping under /sys/devices
  */
-extern struct device *__root_device_register(const char *name,
-					     struct module *owner);
+struct device *__root_device_register(const char *name, struct module *owner);
 
 /* This is a macro to avoid include problems with THIS_MODULE */
 #define root_device_register(name) \
 	__root_device_register(name, THIS_MODULE)
 
-extern void root_device_unregister(struct device *root);
+void root_device_unregister(struct device *root);
 
 static inline void *dev_get_platdata(const struct device *dev)
 {
@@ -872,33 +865,31 @@ static inline void *dev_get_platdata(const struct device *dev)
  * Manual binding of a device to driver. See drivers/base/bus.c
  * for information on use.
  */
-extern int __must_check device_bind_driver(struct device *dev);
-extern void device_release_driver(struct device *dev);
-extern int  __must_check device_attach(struct device *dev);
-extern int __must_check driver_attach(struct device_driver *drv);
-extern void device_initial_probe(struct device *dev);
-extern int __must_check device_reprobe(struct device *dev);
+int __must_check device_bind_driver(struct device *dev);
+void device_release_driver(struct device *dev);
+int  __must_check device_attach(struct device *dev);
+int __must_check driver_attach(struct device_driver *drv);
+void device_initial_probe(struct device *dev);
+int __must_check device_reprobe(struct device *dev);
 
-extern bool device_is_bound(struct device *dev);
+bool device_is_bound(struct device *dev);
 
 /*
  * Easy functions for dynamically creating devices on the fly
  */
-extern __printf(5, 6)
-struct device *device_create(struct class *cls, struct device *parent,
-			     dev_t devt, void *drvdata,
-			     const char *fmt, ...);
-extern __printf(6, 7)
-struct device *device_create_with_groups(struct class *cls,
-			     struct device *parent, dev_t devt, void *drvdata,
-			     const struct attribute_group **groups,
-			     const char *fmt, ...);
-extern void device_destroy(struct class *cls, dev_t devt);
-
-extern int __must_check device_add_groups(struct device *dev,
-					const struct attribute_group **groups);
-extern void device_remove_groups(struct device *dev,
-				 const struct attribute_group **groups);
+__printf(5, 6) struct device *
+device_create(struct class *cls, struct device *parent, dev_t devt,
+	      void *drvdata, const char *fmt, ...);
+__printf(6, 7) struct device *
+device_create_with_groups(struct class *cls, struct device *parent, dev_t devt,
+			  void *drvdata, const struct attribute_group **groups,
+			  const char *fmt, ...);
+void device_destroy(struct class *cls, dev_t devt);
+
+int __must_check device_add_groups(struct device *dev,
+				   const struct attribute_group **groups);
+void device_remove_groups(struct device *dev,
+			  const struct attribute_group **groups);
 
 static inline int __must_check device_add_group(struct device *dev,
 					const struct attribute_group *grp)
@@ -916,14 +907,14 @@ static inline void device_remove_group(struct device *dev,
 	return device_remove_groups(dev, groups);
 }
 
-extern int __must_check devm_device_add_groups(struct device *dev,
+int __must_check devm_device_add_groups(struct device *dev,
 					const struct attribute_group **groups);
-extern void devm_device_remove_groups(struct device *dev,
-				      const struct attribute_group **groups);
-extern int __must_check devm_device_add_group(struct device *dev,
-					const struct attribute_group *grp);
-extern void devm_device_remove_group(struct device *dev,
-				     const struct attribute_group *grp);
+void devm_device_remove_groups(struct device *dev,
+			       const struct attribute_group **groups);
+int __must_check devm_device_add_group(struct device *dev,
+				       const struct attribute_group *grp);
+void devm_device_remove_group(struct device *dev,
+			      const struct attribute_group *grp);
 
 /*
  * Platform "fixup" functions - allow the platform to have their say
@@ -940,21 +931,21 @@ extern int (*platform_notify_remove)(struct device *dev);
  * get_device - atomically increment the reference count for the device.
  *
  */
-extern struct device *get_device(struct device *dev);
-extern void put_device(struct device *dev);
-extern bool kill_device(struct device *dev);
+struct device *get_device(struct device *dev);
+void put_device(struct device *dev);
+bool kill_device(struct device *dev);
 
 #ifdef CONFIG_DEVTMPFS
-extern int devtmpfs_mount(void);
+int devtmpfs_mount(void);
 #else
 static inline int devtmpfs_mount(void) { return 0; }
 #endif
 
 /* drivers/base/power/shutdown.c */
-extern void device_shutdown(void);
+void device_shutdown(void);
 
 /* debugging and troubleshooting/diagnostic helpers. */
-extern const char *dev_driver_string(const struct device *dev);
+const char *dev_driver_string(const struct device *dev);
 
 /* Device links interface. */
 struct device_link *device_link_add(struct device *consumer,
-- 
2.26.1

[PATCH 4/5] devres: provide devm_krealloc()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Implement the managed variant of krealloc(). This function works with
all memory allocated by devm_kmalloc() (or devres functions using it
implicitly like devm_kmemdup(), devm_kstrdup() etc.).

Managed realloc'ed chunks can be manually released with devm_kfree().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 .../driver-api/driver-model/devres.rst        |  1 +
 drivers/base/devres.c                         | 42 +++++++++++++++++++
 include/linux/device.h                        |  2 +
 3 files changed, 45 insertions(+)

diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index e0b58c392e4f..0a2572c3813c 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -352,6 +352,7 @@ MEM
   devm_kfree()
   devm_kmalloc()
   devm_kmalloc_array()
+  devm_krealloc()
   devm_kmemdup()
   devm_kstrdup()
   devm_kvasprintf()
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index 1df1fb10b2d9..baf41a290356 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -834,6 +834,48 @@ void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
 }
 EXPORT_SYMBOL_GPL(devm_kmalloc);
 
+void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
+{
+	struct devres *old_dr, *new_dr;
+	struct list_head old_head;
+	unsigned long flags;
+	void *ret = NULL;
+	size_t tot_size;
+
+	if (unlikely(!new_size)) {
+		devm_kfree(dev, ptr);
+		return ZERO_SIZE_PTR;
+	}
+
+	if (unlikely(!ptr))
+		return devm_kmalloc(dev, new_size, gfp);
+
+	if (!check_dr_size(new_size, &tot_size))
+		return NULL;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+
+	old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
+	if (WARN_ONCE(!old_dr, "Memory chunk not managed or managed by a different device"))
+		goto out;
+
+	old_head = old_dr->node.entry;
+
+	new_dr = krealloc(old_dr, tot_size, gfp);
+	if (!new_dr)
+		goto out;
+
+	if (new_dr != old_dr)
+		list_replace(&old_head, &new_dr->node.entry);
+
+	ret = new_dr->data;
+
+out:
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_krealloc);
+
 /**
  * devm_kstrdup - Allocate resource managed space and
  *                copy an existing string into that.
diff --git a/include/linux/device.h b/include/linux/device.h
index 9cadb647cacc..228063c6392c 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -201,6 +201,8 @@ int devres_release_group(struct device *dev, void *id);
 
 /* managed devm_k.alloc/kfree for device drivers */
 void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
+void *devm_krealloc(struct device *dev, void *ptr, size_t size,
+		    gfp_t gfp) __must_check;
 __printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
 				     const char *fmt, va_list ap) __malloc;
 __printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
-- 
2.26.1

[PATCH 5/5] hwmon: pmbus: use more devres helpers

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Shrink pmbus code by using devm_hwmon_device_register_with_groups()
and devm_krealloc() instead of their non-managed variants.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/hwmon/pmbus/pmbus_core.c | 27 +++++++++------------------
 1 file changed, 9 insertions(+), 18 deletions(-)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index a420877ba533..af74504647b8 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -1022,9 +1022,9 @@ static int pmbus_add_attribute(struct pmbus_data *data, struct attribute *attr)
 {
 	if (data->num_attributes >= data->max_attributes - 1) {
 		int new_max_attrs = data->max_attributes + PMBUS_ATTR_ALLOC_SIZE;
-		void *new_attrs = krealloc(data->group.attrs,
-					   new_max_attrs * sizeof(void *),
-					   GFP_KERNEL);
+		void *new_attrs = devm_krealloc(data->dev, data->group.attrs,
+						new_max_attrs * sizeof(void *),
+						GFP_KERNEL);
 		if (!new_attrs)
 			return -ENOMEM;
 		data->group.attrs = new_attrs;
@@ -2538,7 +2538,7 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
 
 	ret = pmbus_find_attributes(client, data);
 	if (ret)
-		goto out_kfree;
+		return ret;
 
 	/*
 	 * If there are no attributes, something is wrong.
@@ -2546,35 +2546,27 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
 	 */
 	if (!data->num_attributes) {
 		dev_err(dev, "No attributes found\n");
-		ret = -ENODEV;
-		goto out_kfree;
+		return -ENODEV;
 	}
 
 	data->groups[0] = &data->group;
 	memcpy(data->groups + 1, info->groups, sizeof(void *) * groups_num);
-	data->hwmon_dev = hwmon_device_register_with_groups(dev, client->name,
-							    data, data->groups);
+	data->hwmon_dev = devm_hwmon_device_register_with_groups(dev,
+					client->name, data, data->groups);
 	if (IS_ERR(data->hwmon_dev)) {
-		ret = PTR_ERR(data->hwmon_dev);
 		dev_err(dev, "Failed to register hwmon device\n");
-		goto out_kfree;
+		return PTR_ERR(data->hwmon_dev);
 	}
 
 	ret = pmbus_regulator_register(data);
 	if (ret)
-		goto out_unregister;
+		return ret;
 
 	ret = pmbus_init_debugfs(client, data);
 	if (ret)
 		dev_warn(dev, "Failed to register debugfs\n");
 
 	return 0;
-
-out_unregister:
-	hwmon_device_unregister(data->hwmon_dev);
-out_kfree:
-	kfree(data->group.attrs);
-	return ret;
 }
 EXPORT_SYMBOL_GPL(pmbus_do_probe);
 
@@ -2585,7 +2577,6 @@ int pmbus_do_remove(struct i2c_client *client)
 	debugfs_remove_recursive(data->debugfs);
 
 	hwmon_device_unregister(data->hwmon_dev);
-	kfree(data->group.attrs);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(pmbus_do_remove);
-- 
2.26.1

Re: [PATCH 5/5] hwmon: pmbus: use more devres helpers

[Guenter Roeck]

On Fri, Jun 26, 2020 at 06:55:35PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> Shrink pmbus code by using devm_hwmon_device_register_with_groups()
> and devm_krealloc() instead of their non-managed variants.
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  drivers/hwmon/pmbus/pmbus_core.c | 27 +++++++++------------------
>  1 file changed, 9 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index a420877ba533..af74504647b8 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -1022,9 +1022,9 @@ static int pmbus_add_attribute(struct pmbus_data *data, struct attribute *attr)
>  {
>  	if (data->num_attributes >= data->max_attributes - 1) {
>  		int new_max_attrs = data->max_attributes + PMBUS_ATTR_ALLOC_SIZE;
> -		void *new_attrs = krealloc(data->group.attrs,
> -					   new_max_attrs * sizeof(void *),
> -					   GFP_KERNEL);
> +		void *new_attrs = devm_krealloc(data->dev, data->group.attrs,
> +						new_max_attrs * sizeof(void *),
> +						GFP_KERNEL);
>  		if (!new_attrs)
>  			return -ENOMEM;
>  		data->group.attrs = new_attrs;
> @@ -2538,7 +2538,7 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
>  
>  	ret = pmbus_find_attributes(client, data);
>  	if (ret)
> -		goto out_kfree;
> +		return ret;
>  
>  	/*
>  	 * If there are no attributes, something is wrong.
> @@ -2546,35 +2546,27 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
>  	 */
>  	if (!data->num_attributes) {
>  		dev_err(dev, "No attributes found\n");
> -		ret = -ENODEV;
> -		goto out_kfree;
> +		return -ENODEV;
>  	}
>  
>  	data->groups[0] = &data->group;
>  	memcpy(data->groups + 1, info->groups, sizeof(void *) * groups_num);
> -	data->hwmon_dev = hwmon_device_register_with_groups(dev, client->name,
> -							    data, data->groups);
> +	data->hwmon_dev = devm_hwmon_device_register_with_groups(dev,
> +					client->name, data, data->groups);
>  	if (IS_ERR(data->hwmon_dev)) {
> -		ret = PTR_ERR(data->hwmon_dev);
>  		dev_err(dev, "Failed to register hwmon device\n");
> -		goto out_kfree;
> +		return PTR_ERR(data->hwmon_dev);
>  	}
>  
>  	ret = pmbus_regulator_register(data);
>  	if (ret)
> -		goto out_unregister;
> +		return ret;
>  
>  	ret = pmbus_init_debugfs(client, data);
>  	if (ret)
>  		dev_warn(dev, "Failed to register debugfs\n");
>  
>  	return 0;
> -
> -out_unregister:
> -	hwmon_device_unregister(data->hwmon_dev);
> -out_kfree:
> -	kfree(data->group.attrs);
> -	return ret;
>  }
>  EXPORT_SYMBOL_GPL(pmbus_do_probe);
>  
> @@ -2585,7 +2577,6 @@ int pmbus_do_remove(struct i2c_client *client)
>  	debugfs_remove_recursive(data->debugfs);
>  
>  	hwmon_device_unregister(data->hwmon_dev);

This is now wrong.

> -	kfree(data->group.attrs);
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(pmbus_do_remove);
> -- 
> 2.26.1
>