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authorChristoph Lameter <clameter@sgi.com>2007-07-17 04:03:22 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-17 10:23:01 -0700
commit6cb8f91320d3e720351c21741da795fed580b21b (patch)
treec9f73c8b82cd0f6c534939b8b9f36e8615b0ab2d /mm/slub.c
parentef2ad80c7d255ed0449eda947c2d700635b7e0f5 (diff)
Slab allocators: consistent ZERO_SIZE_PTR support and NULL result semantics
Define ZERO_OR_NULL_PTR macro to be able to remove the checks from the allocators. Move ZERO_SIZE_PTR related stuff into slab.h. Make ZERO_SIZE_PTR work for all slab allocators and get rid of the WARN_ON_ONCE(size == 0) that is still remaining in SLAB. Make slub return NULL like the other allocators if a too large memory segment is requested via __kmalloc. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slub.c')
-rw-r--r--mm/slub.c29
1 files changed, 16 insertions, 13 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 1b0a95d75dbb..548d78df81e1 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2270,10 +2270,11 @@ static struct kmem_cache *get_slab(size_t size, gfp_t flags)
int index = kmalloc_index(size);
if (!index)
- return NULL;
+ return ZERO_SIZE_PTR;
/* Allocation too large? */
- BUG_ON(index < 0);
+ if (index < 0)
+ return NULL;
#ifdef CONFIG_ZONE_DMA
if ((flags & SLUB_DMA)) {
@@ -2314,9 +2315,10 @@ void *__kmalloc(size_t size, gfp_t flags)
{
struct kmem_cache *s = get_slab(size, flags);
- if (s)
- return slab_alloc(s, flags, -1, __builtin_return_address(0));
- return ZERO_SIZE_PTR;
+ if (ZERO_OR_NULL_PTR(s))
+ return s;
+
+ return slab_alloc(s, flags, -1, __builtin_return_address(0));
}
EXPORT_SYMBOL(__kmalloc);
@@ -2325,9 +2327,10 @@ void *__kmalloc_node(size_t size, gfp_t flags, int node)
{
struct kmem_cache *s = get_slab(size, flags);
- if (s)
- return slab_alloc(s, flags, node, __builtin_return_address(0));
- return ZERO_SIZE_PTR;
+ if (ZERO_OR_NULL_PTR(s))
+ return s;
+
+ return slab_alloc(s, flags, node, __builtin_return_address(0));
}
EXPORT_SYMBOL(__kmalloc_node);
#endif
@@ -2378,7 +2381,7 @@ void kfree(const void *x)
* this comparison would be true for all "negative" pointers
* (which would cover the whole upper half of the address space).
*/
- if ((unsigned long)x <= (unsigned long)ZERO_SIZE_PTR)
+ if (ZERO_OR_NULL_PTR(x))
return;
page = virt_to_head_page(x);
@@ -2687,8 +2690,8 @@ void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller)
{
struct kmem_cache *s = get_slab(size, gfpflags);
- if (!s)
- return ZERO_SIZE_PTR;
+ if (ZERO_OR_NULL_PTR(s))
+ return s;
return slab_alloc(s, gfpflags, -1, caller);
}
@@ -2698,8 +2701,8 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
{
struct kmem_cache *s = get_slab(size, gfpflags);
- if (!s)
- return ZERO_SIZE_PTR;
+ if (ZERO_OR_NULL_PTR(s))
+ return s;
return slab_alloc(s, gfpflags, node, caller);
}