From 523fb486bfd94e3a3b16a42bcb21b1959cf14df8 Mon Sep 17 00:00:00 2001 From: Li Zefan <lizf@cn.fujitsu.com> Date: Wed, 23 Mar 2011 16:42:48 -0700 Subject: [PATCH] cpuset: hold callback_mutex in cpuset_post_clone() Chaning cpuset->mems/cpuset->cpus should be protected under callback_mutex. cpuset_clone() doesn't follow this rule. It's ok because it's called when creating and initializing a cgroup, but we'd better hold the lock to avoid subtil break in the future. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- kernel/cpuset.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index e472fe139192..33eee16addb8 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1840,8 +1840,10 @@ static void cpuset_post_clone(struct cgroup_subsys *ss, cs = cgroup_cs(cgroup); parent_cs = cgroup_cs(parent); + mutex_lock(&callback_mutex); cs->mems_allowed = parent_cs->mems_allowed; cpumask_copy(cs->cpus_allowed, parent_cs->cpus_allowed); + mutex_unlock(&callback_mutex); return; }