slab: add a flag to prevent debug_free checks on a kmem_cache

This is a preperatory patch for the debugobjects infrastructure.  The flag
prevents debug_free checks on kmem_caches.  This is necessary to avoid
resursive calls into a debug mechanism which uses a kmem_cache itself.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/slab.h b/include/linux/slab.h
index f62caaad94e0..6d03c954f641 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -29,6 +29,13 @@
 #define SLAB_MEM_SPREAD         0x00100000UL    /* Spread some memory over cpuset */
 #define SLAB_TRACE              0x00200000UL    /* Trace allocations and frees */
 
+/* Flag to prevent checks on free */
+#ifdef CONFIG_DEBUG_OBJECTS
+# define SLAB_DEBUG_OBJECTS     0x00400000UL
+#else
+# define SLAB_DEBUG_OBJECTS     0x00000000UL
+#endif
+
 /* The following flags affect the page allocator grouping pages by mobility */
 #define SLAB_RECLAIM_ACCOUNT    0x00020000UL            /* Objects are reclaimable */
 #define SLAB_TEMPORARY          SLAB_RECLAIM_ACCOUNT    /* Objects are short-lived */