From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Date: Tue, 21 Apr 2009 19:24:41 +0000 (-0700)
Subject: memcg: use rcu_dereference to access mm->owner
X-Git-Tag: v2.6.30-rc3~23
X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=e638c1394010859a015a3b533ee452d768e62cea

memcg: use rcu_dereference to access mm->owner

mm->owner should be accessed with rcu_dereference().

Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 18146c9..a9e3b76 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -75,7 +75,7 @@ int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)
 {
 	struct mem_cgroup *mem;
 	rcu_read_lock();
-	mem = mem_cgroup_from_task((mm)->owner);
+	mem = mem_cgroup_from_task(rcu_dereference((mm)->owner));
 	rcu_read_unlock();
 	return cgroup == mem;
 }