slub: convert SLAB_DEBUG_FREE to SLAB_CONSISTENCY_CHECKS

SLAB_DEBUG_FREE allows expensive consistency checks at free to be turned
on or off.  Expand its use to be able to turn off all consistency
checks.  This gives a nice speed up if you only want features such as
poisoning or tracing.

Credit to Mathias Krause for the original work which inspired this
series

Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/mm/slab.h b/mm/slab.h
index e880bbe..b793436 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -125,7 +125,7 @@ static inline unsigned long kmem_cache_flags(unsigned long object_size,
 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
 #elif defined(CONFIG_SLUB_DEBUG)
 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
-			  SLAB_TRACE | SLAB_DEBUG_FREE)
+			  SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
 #else
 #define SLAB_DEBUG_FLAGS (0)
 #endif
@@ -311,7 +311,8 @@ static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
 	 * to not do even the assignment. In that case, slab_equal_or_root
 	 * will also be a constant.
 	 */
-	if (!memcg_kmem_enabled() && !unlikely(s->flags & SLAB_DEBUG_FREE))
+	if (!memcg_kmem_enabled() &&
+	    !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
 		return s;
 
 	page = virt_to_head_page(x);