From: Lai Jiangshan <laijs@cn.fujitsu.com>
Date: Thu, 8 Jan 2009 02:08:39 +0000 (-0800)
Subject: cpuset: rcu_read_lock() to protect task_cs()
X-Git-Tag: v2.6.29-rc1~87
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=13337714f3b0307dc7f75ef5d83ecf0db2abbd65;p=pandora-kernel.git

cpuset: rcu_read_lock() to protect task_cs()

task_cs() calls task_subsys_state().

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

It's correct that top_cpuset is never freed, but cgroup_subsys_state()
accesses css_set, this css_set maybe freed when task_cs() called.

We use use rcu_read_lock() to protect it.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Cc: 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>
---

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