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Commit a8c0f9a4 authored by Pekka Enberg's avatar Pekka Enberg Committed by Linus Torvalds
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[PATCH] slab: introduce kmem_cache_zalloc allocator 



Introduce a memory-zeroing variant of kmem_cache_alloc.  The allocator
already exits in XFS and there are potential users for it so this patch
makes the allocator available for the general public.

Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 871751e2

include/linux/slab.h

+2 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ extern kmem_cache_t *kmem_cache_create(const char *, size_t, size_t, unsigned lo 
extern int kmem_cache_destroy(kmem_cache_t *);

extern int kmem_cache_shrink(kmem_cache_t *);

extern void *kmem_cache_alloc(kmem_cache_t *, gfp_t);

extern void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);

extern void kmem_cache_free(kmem_cache_t *, void *);

extern unsigned int kmem_cache_size(kmem_cache_t *);

extern const char *kmem_cache_name(kmem_cache_t *);
@@ -156,6 +157,7 @@ struct kmem_cache *kmem_cache_create(const char *c, size_t, size_t, 
	void (*)(void *, struct kmem_cache *, unsigned long));

int kmem_cache_destroy(struct kmem_cache *c);

void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags);

void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);

void kmem_cache_free(struct kmem_cache *c, void *b);

const char *kmem_cache_name(struct kmem_cache *);

void *kmalloc(size_t size, gfp_t flags);

mm/slab.c

+17 −0
Original line number Diff line number Diff line
@@ -3107,6 +3107,23 @@ void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) 
}

EXPORT_SYMBOL(kmem_cache_alloc);



/**

 * kmem_cache_alloc - Allocate an object. The memory is set to zero.

 * @cache: The cache to allocate from.

 * @flags: See kmalloc().

 *

 * Allocate an object from this cache and set the allocated memory to zero.

 * The flags are only relevant if the cache has no available objects.

 */

void *kmem_cache_zalloc(struct kmem_cache *cache, gfp_t flags)

{

	void *ret = __cache_alloc(cache, flags, __builtin_return_address(0));

	if (ret)

		memset(ret, 0, obj_size(cache));

	return ret;

}

EXPORT_SYMBOL(kmem_cache_zalloc);



/**

 * kmem_ptr_validate - check if an untrusted pointer might

 *	be a slab entry.

mm/slob.c

+10 −0
Original line number Diff line number Diff line
@@ -294,6 +294,16 @@ void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags) 
}

EXPORT_SYMBOL(kmem_cache_alloc);



void *kmem_cache_zalloc(struct kmem_cache *c, gfp_t flags)

{

	void *ret = kmem_cache_alloc(c, flags);

	if (ret)

		memset(ret, 0, c->size);



	return ret;

}

EXPORT_SYMBOL(kmem_cache_zalloc);



void kmem_cache_free(struct kmem_cache *c, void *b)

{

	if (c->dtor)