slab: Return NULL for oversized allocations (6286ae97) · Commits · 戴 / test

The inline path seems to have changed the SLAB behavior for very large kmalloc allocations with commit ("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:

Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by:

Christoph 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:

Pekka Enberg <penberg@kernel.org>

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;

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