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 <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 871751e2
......@@ -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);
......@@ -3107,6 +3107,23 @@ void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
* 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;
* kmem_ptr_validate - check if an untrusted pointer might
* be a slab entry.
......@@ -294,6 +294,16 @@ void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags)
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;
void kmem_cache_free(struct kmem_cache *c, void *b)
if (c->dtor)
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