On Tue, 2 Jul 2013 21:49:26 +0900 Tetsuo Handa
<penguin-ker...@i-love.sakura.ne.jp> wrote:
> Some architectures (e.g. powerpc built with CONFIG_PPC_256K_PAGES=y
> CONFIG_FORCE_MAX_ZONEORDER=11) get PAGE_SHIFT + MAX_ORDER > 26.
>
> In 3.10 kernels, CONFIG_LOCKDEP=y with PAGE_SHIFT + MAX_ORDER > 26 makes
> init_lock_keys() dereference beyond kmalloc_caches[26].
> This leads to an unbootable system (kernel panic at initializing SLAB)
> if one of kmalloc_caches[26...PAGE_SHIFT+MAX_ORDER-1] is not NULL.
>
> Fix this by making sure that init_lock_keys() does not dereference beyond
> kmalloc_caches[26] arrays.
Nice, thanks. Pekka, please grab.
From: Christoph Lameter <c...@linux.com>
Subject: slab: fix init_lock_keys
Some architectures (e.g. powerpc built with CONFIG_PPC_256K_PAGES=y
CONFIG_FORCE_MAX_ZONEORDER=11) get PAGE_SHIFT + MAX_ORDER > 26.
In 3.10 kernels, CONFIG_LOCKDEP=y with PAGE_SHIFT + MAX_ORDER > 26 makes
init_lock_keys() dereference beyond kmalloc_caches[26].
This leads to an unbootable system (kernel panic at initializing SLAB)
if one of kmalloc_caches[26...PAGE_SHIFT+MAX_ORDER-1] is not NULL.
Fix this by making sure that init_lock_keys() does not dereference beyond
kmalloc_caches[26] arrays.
Signed-off-by: Christoph Lameter <c...@linux.com>
Reported-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
Cc: Pekka Enberg <penb...@kernel.org>
Cc: <sta...@vger.kernel.org> [3.10.x]
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
---
mm/slab.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/slab.c~slab-fix-init_lock_keys mm/slab.c
--- a/mm/slab.c~slab-fix-init_lock_keys
+++ a/mm/slab.c
@@ -565,7 +565,7 @@ static void init_node_lock_keys(int q)
if (slab_state < UP)
return;
- for (i = 1; i < PAGE_SHIFT + MAX_ORDER; i++) {
+ for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) {
struct kmem_cache_node *n;
struct kmem_cache *cache = kmalloc_caches[i];
_
--
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