Commit 64c862a8 authored by Joe Perches's avatar Joe Perches Committed by Greg Kroah-Hartman
Browse files

devres: add kernel standard devm_k.alloc functions 



Currently, devm_ managed memory only supports kzalloc.

Convert the devm_kzalloc implementation to devm_kmalloc and remove the
complete memset to 0 but still set the initial struct devres header and
whatever padding before data to 0.

Add the other normal alloc variants as static inlines with __GFP_ZERO
added to the gfp flag where appropriate:

	devm_kzalloc
	devm_kcalloc
	devm_kmalloc_array

Add gfp.h to device.h for the newly added static inlines.

akpm: the current API forces us to replace kmalloc() with kzalloc() when
performing devm_ conversions.  This adds a relatively minor overhead.
More significantly, it will defeat kmemcheck used-uninitialized checking,
and for a particular driver, losing used-uninitialised checking for their
core controlling data structures will significantly degrade kmemcheck
usefulness.

Signed-off-by: default avatarJoe Perches <joe@perches.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Sangjung Woo <sangjung.woo@samsung.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d723a92d

drivers/base/devres.c

+16 −11
Original line number Diff line number Diff line
@@ -91,7 +91,8 @@ static __always_inline struct devres * alloc_dr(dr_release_t release, 
	if (unlikely(!dr))

		return NULL;



	memset(dr, 0, tot_size);

	memset(dr, 0, offsetof(struct devres, data));



	INIT_LIST_HEAD(&dr->node.entry);

	dr->node.release = release;

	return dr;
@@ -745,58 +746,62 @@ void devm_remove_action(struct device *dev, void (*action)(void *), void *data) 
EXPORT_SYMBOL_GPL(devm_remove_action);



/*

 * Managed kzalloc/kfree

 * Managed kmalloc/kfree

 */

static void devm_kzalloc_release(struct device *dev, void *res)

static void devm_kmalloc_release(struct device *dev, void *res)

{

	/* noop */

}



static int devm_kzalloc_match(struct device *dev, void *res, void *data)

static int devm_kmalloc_match(struct device *dev, void *res, void *data)

{

	return res == data;

}



/**

 * devm_kzalloc - Resource-managed kzalloc

 * devm_kmalloc - Resource-managed kmalloc

 * @dev: Device to allocate memory for

 * @size: Allocation size

 * @gfp: Allocation gfp flags

 *

 * Managed kzalloc.  Memory allocated with this function is

 * 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_kzalloc(struct device *dev, size_t size, gfp_t gfp)

void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)

{

	struct devres *dr;



	/* use raw alloc_dr for kmalloc caller tracing */

	dr = alloc_dr(devm_kzalloc_release, size, gfp);

	dr = alloc_dr(devm_kmalloc_release, size, gfp);

	if (unlikely(!dr))

		return NULL;



	/*

	 * This is named devm_kzalloc_release for historical reasons

	 * The initial implementation did not support kmalloc, only kzalloc

	 */

	set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);

	devres_add(dev, dr->data);

	return dr->data;

}

EXPORT_SYMBOL_GPL(devm_kzalloc);

EXPORT_SYMBOL_GPL(devm_kmalloc);



/**

 * devm_kfree - Resource-managed kfree

 * @dev: Device this memory belongs to

 * @p: Memory to free

 *

 * Free memory allocated with devm_kzalloc().

 * Free memory allocated with devm_kmalloc().

 */

void devm_kfree(struct device *dev, void *p)

{

	int rc;



	rc = devres_destroy(dev, devm_kzalloc_release, devm_kzalloc_match, p);

	rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, p);

	WARN_ON(rc);

}

EXPORT_SYMBOL_GPL(devm_kfree);

include/linux/device.h

+19 −2
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/atomic.h>

#include <linux/ratelimit.h>

#include <linux/uidgid.h>

#include <linux/gfp.h>

#include <asm/device.h>



struct device;
@@ -606,8 +607,24 @@ 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);



/* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */

extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);

/* managed devm_k.alloc/kfree for device drivers */

extern void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp);

static inline void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)

{

	return devm_kmalloc(dev, size, gfp | __GFP_ZERO);

}

static inline void *devm_kmalloc_array(struct device *dev,

				       size_t n, size_t size, gfp_t flags)

{

	if (size != 0 && n > SIZE_MAX / size)

		return NULL;

	return devm_kmalloc(dev, n * size, flags);

}

static inline void *devm_kcalloc(struct device *dev,

				 size_t n, size_t size, gfp_t flags)

{

	return devm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);

}

extern void devm_kfree(struct device *dev, void *p);



void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res);

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