Commit 2e4d4091 authored Jan 07, 2009 by Lai Jiangshan Committed by Linus Torvalds Jan 08, 2009

memcontrol: rcu_read_lock() to protect mm_match_cgroup()



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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 18f59ea7

include/linux/memcontrol.h

+9 −2

Original line number	Diff line number	Diff line
		@@ -61,8 +61,15 @@ int task_in_mem_cgroup(struct task_struct task, const struct mem_cgroup mem);

		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);