From 6cb8f91320d3e720351c21741da795fed580b21b Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 17 Jul 2007 04:03:22 -0700 Subject: 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 Acked-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slob.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'mm/slob.c') 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); -- cgit v1.2.3-55-g7522