From 0f8f8094d28eb53368ac09186ea6b3a324cc7d44 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 2 Jul 2013 12:12:10 -0700 Subject: [PATCH] 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 Reported-by: Tetsuo Handa Cc: Pekka Enberg Cc: [3.10.x] Signed-off-by: Andrew Morton Signed-off-by: Pekka Enberg --- mm/slab.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slab.c b/mm/slab.c index 4a907a072669..9bf225162fcb 100644 --- a/mm/slab.c +++ b/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]; -- 2.39.5