SLUB Debug: Fix check for super sized slabs (>512k 64bit, >256k 32bit)

SLUB Debug: Fix check for super sized slabs (>512k 64bit, >256k 32bit)

[Christoph Lameter]

The check for super sized slabs where we can no longer move the free 
pointer behind the object for debugging purposes etc is accessing a field 
that is not setup yet. We must use objsize here since the size of the slab 
has not been determined yet.

The effect of this is that a global slab shrink via "slabinfo -s" will 
show errors about offsets being wrong if booted with slub_debug. 
Potentially there are other troubles with huge slabs under slub_debug 
because the calculated free pointer offset is truncated.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

---
 mm/slub.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: slub/mm/slub.c
===================================================================
--- slub.orig/mm/slub.c	2007-05-18 10:14:05.000000000 -0700
+++ slub/mm/slub.c	2007-05-18 10:14:13.000000000 -0700
@@ -946,7 +946,7 @@ static void kmem_cache_open_debug_check(
 	 * Debugging or ctor may create a need to move the free
 	 * pointer. Fail if this happens.
 	 */
-	if (s->size >= 65535 * sizeof(void *)) {
+	if (s->objsize >= 65535 * sizeof(void *)) {
 		BUG_ON(s->flags & (SLAB_RED_ZONE | SLAB_POISON |
 				SLAB_STORE_USER | SLAB_DESTROY_BY_RCU));
 		BUG_ON(s->ctor);

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