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[PATCH] Fix GFP_HIGHMEM slab panic

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As reported by Martin J. Bligh <mbligh@google.com>, we let through some
non-slab bits to slab allocation through __get_vm_area_node when doing a
vmalloc.

I haven't been able to reproduce this, although I understand why it
happens: vmalloc allocates memory with

GFP_KERNEL | __GFP_HIGHMEM

and commit 52fd24ca1db3a741f144bbc229beefe044202cac resulted in the same
flags are passed down to cache_alloc_refill, causing the BUG.  The
following patch fixes it.

Note that when calling kmalloc_node, I am masking off __GFP_HIGHMEM with
GFP_LEVEL_MASK, whereas __vmalloc_area_node does the same with

~(__GFP_HIGHMEM | __GFP_ZERO).

IMHO, using GFP_LEVEL_MASK is preferable, but either should fix this
problem.

Signed-off-by: Giridhar Pemmasani (pgiri@yahoo.com)
Cc: Martin J. Bligh <mbligh@google.com>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Giridhar Pemmasani 2006-10-29 04:46:55 -08:00 committed by Linus Torvalds
parent 2da6dc2886
commit 5211e6e6c6
1 changed files with 1 additions and 1 deletions
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2
mm/vmalloc.c
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@ -182,7 +182,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long fl
addr = ALIGN(start, align);
size = PAGE_ALIGN(size);
area = kmalloc_node(sizeof(*area), gfp_mask, node);
area = kmalloc_node(sizeof(*area), gfp_mask & GFP_LEVEL_MASK, node);
if (unlikely(!area))
return NULL;