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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/slob.c
parentef2ad80c7d255ed0449eda947c2d700635b7e0f5 (diff)
downloadlinux-6cb8f91320d3e720351c21741da795fed580b21b.tar.gz
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/slob.c')
-rw-r--r--mm/slob.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/mm/slob.c b/mm/slob.c
index 154e7bdf3544..41d32c3c0be4 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -347,7 +347,7 @@ static void slob_free(void *block, int size)
 	slobidx_t units;
 	unsigned long flags;
 
-	if (!block)
+	if (ZERO_OR_NULL_PTR(block))
 		return;
 	BUG_ON(!size);
 
@@ -424,10 +424,13 @@ out:
 
 void *__kmalloc_node(size_t size, gfp_t gfp, int node)
 {
+	unsigned int *m;
 	int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN);
 
 	if (size < PAGE_SIZE - align) {
-		unsigned int *m;
+		if (!size)
+			return ZERO_SIZE_PTR;
+
 		m = slob_alloc(size + align, gfp, align, node);
 		if (m)
 			*m = size;
@@ -450,7 +453,7 @@ void kfree(const void *block)
 {
 	struct slob_page *sp;
 
-	if (!block)
+	if (ZERO_OR_NULL_PTR(block))
 		return;
 
 	sp = (struct slob_page *)virt_to_page(block);
@@ -468,7 +471,7 @@ size_t ksize(const void *block)
 {
 	struct slob_page *sp;
 
-	if (!block)
+	if (ZERO_OR_NULL_PTR(block))
 		return 0;
 
 	sp = (struct slob_page *)virt_to_page(block);