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Commit 6286ae97 authored by Christoph Lameter's avatar Christoph Lameter Committed by Pekka Enberg
Browse files

slab: Return NULL for oversized allocations 



The inline path seems to have changed the SLAB behavior for very large
kmalloc allocations with  commit e3366016 ("slab: Use common
kmalloc_index/kmalloc_size functions"). This patch restores the old
behavior but also adds diagnostics so that we can figure where in the
code these large allocations occur.

Reported-and-tested-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
Link: http://lkml.kernel.org/r/201305040348.CIF81716.OStQOHFJMFLOVF@I-love.SAKURA.ne.jp


[ penberg@kernel.org: use WARN_ON_ONCE ]
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent 14e50c6a

include/linux/slab_def.h

+6 −0
Original line number Diff line number Diff line
@@ -126,6 +126,9 @@ static __always_inline void *kmalloc(size_t size, gfp_t flags) 
		if (!size)

			return ZERO_SIZE_PTR;



		if (WARN_ON_ONCE(size > KMALLOC_MAX_SIZE))

			return NULL;



		i = kmalloc_index(size);



#ifdef CONFIG_ZONE_DMA
@@ -172,6 +175,9 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node) 
		if (!size)

			return ZERO_SIZE_PTR;



		if (WARN_ON_ONCE(size > KMALLOC_MAX_SIZE))

			return NULL;



		i = kmalloc_index(size);



#ifdef CONFIG_ZONE_DMA

mm/slab_common.c

+3 −0
Original line number Diff line number Diff line
@@ -373,6 +373,9 @@ struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags) 
{

	int index;



	if (WARN_ON_ONCE(size > KMALLOC_MAX_SIZE))

		return NULL;



	if (size <= 192) {

		if (!size)

			return ZERO_SIZE_PTR;