From 2e4d40915fb85207fe48cfc31201824ec6d7426e Mon Sep 17 00:00:00 2001 From: Lai Jiangshan <laijs@cn.fujitsu.com> Date: Wed, 7 Jan 2009 18:08:07 -0800 Subject: [PATCH] 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> --- include/linux/memcontrol.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 472efd09118c..2de6504e01fb 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -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); -- GitLab