Messages in this thread Patch in this message | | | Date | Tue, 2 Jul 2013 12:12:10 -0700 | From | Andrew Morton <> | Subject | Re: [linux-next-20130422] Bug in SLAB? |
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On Tue, 2 Jul 2013 21:49:26 +0900 Tetsuo Handa <penguin-kernel@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 <cl@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 <cl@linux.com> Reported-by: Tetsuo Handa <penguin-kernel@I-Love.SAKURA.ne.jp> Cc: Pekka Enberg <penberg@kernel.org> Cc: <stable@vger.kernel.org> [3.10.x] Signed-off-by: Andrew Morton <akpm@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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