From e54d62790b19f7e7ce494b5ff3386ee1c5c4d3e3 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 4 Mar 2014 17:13:47 -0500 Subject: [PATCH] slab_common: fix the check for duplicate slab names The patch dd4c21b12c36524570d912fbf9984bb12097db14 is supposed to fix the problem where kmem_cache_create incorrectly reports duplicate cache name and fails. The problem is described in the header of that patch. However, the patch doesn't really fix the problem because of these reasons: * the logic to test for debugging is reversed. It was intended to perform the check only if slub debugging is enabled (which implies that caches with the same parameters are not merged). Therefore, there should be #if !defined(CONFIG_SLUB) || defined(CONFIG_SLUB_DEBUG_ON) The current code has the condition reversed and performs the test if debugging is disabled. * slub debugging may be enabled or disabled based on kernel command line, CONFIG_SLUB_DEBUG_ON is just the default settings. Therefore the test based on definition of CONFIG_SLUB_DEBUG_ON is unreliable. This patch fixes the problem by removing the test "!defined(CONFIG_SLUB_DEBUG_ON)". Therefore, duplicate names are never checked if the SLUB allocator is used. Note to stable kernel maintainers: when backporint this patch, please backport also the patch dd4c21b12c36524570d912fbf9984bb12097db14. Acked-by: David Rientjes Acked-by: Christoph Lameter Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org # 3.6+ Signed-off-by: Pekka Enberg --- mm/slab_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index 102cc6fca3d39..b810fba0095d3 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -55,7 +55,7 @@ static int kmem_cache_sanity_check(const char *name, size_t size) continue; } -#if !defined(CONFIG_SLUB) || !defined(CONFIG_SLUB_DEBUG_ON) +#if !defined(CONFIG_SLUB) if (!strcmp(s->name, name)) { pr_err("%s (%s): Cache name already exists.\n", __func__, name); -- 2.39.5