[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>
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 6d381df..46606c1 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -182,7 +182,7 @@
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;