+ memcontrol-rcu_read_lock-to-protect-mm_match_cgroup.patch added to -mm tree

+ memcontrol-rcu_read_lock-to-protect-mm_match_cgroup.patch added to -mm tree

[akpm]

The patch titled
     memcontrol: rcu_read_lock() to protect mm_match_cgroup()
has been added to the -mm tree.  Its filename is
     memcontrol-rcu_read_lock-to-protect-mm_match_cgroup.patch

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------------------------------------------------------
Subject: memcontrol: rcu_read_lock() to protect mm_match_cgroup()
From: Lai Jiangshan <laijs@cn.fujitsu.com>

mm_match_cgroup() calls cgroup_subsys_state().

We must use rcu_read_lock() to protect cgroup_subsys_state().

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/memcontrol.h |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff -puN include/linux/memcontrol.h~memcontrol-rcu_read_lock-to-protect-mm_match_cgroup include/linux/memcontrol.h
--- a/include/linux/memcontrol.h~memcontrol-rcu_read_lock-to-protect-mm_match_cgroup
+++ a/include/linux/memcontrol.h
@@ -61,8 +61,15 @@ int task_in_mem_cgroup(struct task_struc
 
 extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 
-#define mm_match_cgroup(mm, cgroup)	\
-	((cgroup) == mem_cgroup_from_task((mm)->owner))
+static inline
+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);
+	rcu_read_unlock();
+	return cgroup == mem;
+}
 
 extern int
 mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr);
_

Patches currently in -mm which might be from laijs@cn.fujitsu.com are

origin.patch
linux-next.patch
kprobes-bugfix-try_module_get-even-if-calling_mod-is-null.patch
cgroups-add-lock-for-child-cgroups-in-cgroup_post_fork.patch
cgroups-fix-cgroup_iter_next-bug.patch
cgroups-dont-put-struct-cgroupfs_root-protected-by-rcu.patch
cgroups-use-task_lock-for-access-tsk-cgroups-safe-in-cgroup_clone.patch
cgroups-call-find_css_set-safely-in-cgroup_attach_task.patch
devcgroup-use-list_for_each_entry_rcu.patch
memcontrol-rcu_read_lock-to-protect-mm_match_cgroup.patch
cpuset-rcu_read_lock-to-protect-task_cs.patch