[PATCH] Fix GFP_HIGHMEM slab panic
commit5211e6e6c671f0d4b1e1a1023384d20227d8ee65
authorGiridhar Pemmasani <pgiri@yahoo.com>
Sun, 29 Oct 2006 12:46:55 +0000 (29 04:46 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Sun, 29 Oct 2006 16:01:58 +0000 (29 08:01 -0800)
tree437c827044b2ed0a277adc95182985d8a95a8fc0
parent2da6dc28867b6cad6181291ed03093a487587d61
[PATCH] Fix GFP_HIGHMEM slab panic

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>
mm/vmalloc.c