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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: Joe Perches <joe@perches.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Sangjung Woo <sangjung.woo@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Joe Perches 2013-10-11 13:11:38 -07:00 committed by Greg Kroah-Hartman
parent d723a92dd4
commit 64c862a839
2 changed files with 35 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/base/devres.c
View File

@ -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);

21
include/linux/device.h
View File

@ -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);