From: J. R. Okajima <hooanon05@yahoo.co.jp>
Date: Wed, 2 Dec 2009 07:55:50 +0000 (+0900)
Subject: slab, kmemleak: pass the correct pointer to kmemleak_erase()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ddbf2e8366f2a7fa3419be418cfd83a914d2527f;p=mv-sheeva.git

slab, kmemleak: pass the correct pointer to kmemleak_erase()

In ____cache_alloc(), the variable 'ac' may be changed after
cache_alloc_refill() and the following kmemleak_erase() may get an incorrect
pointer. Update 'ac' after cache_alloc_refill() unconditionally.

See the following URL for the discussion of this patch:

 http://marc.info/?l=linux-kernel&m=125873373124187&w=2

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
---

diff --git a/mm/slab.c b/mm/slab.c
index 4e61449d794..66e90477a4b 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3103,6 +3103,11 @@ static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
 	} else {
 		STATS_INC_ALLOCMISS(cachep);
 		objp = cache_alloc_refill(cachep, flags);
+		/*
+		 * the 'ac' may be updated by cache_alloc_refill(),
+		 * and kmemleak_erase() requires its correct value.
+		 */
+		ac = cpu_cache_get(cachep);
 	}
 	/*
 	 * To avoid a false negative, if an object that is in one of the