Messages in this thread Patch in this message | | | Date | Fri, 21 Nov 2008 16:49:40 +0800 | From | Lai Jiangshan <> | Subject | [PATCH] cpuset: rcu_read_lock() to protect task_cs() even we don't dereference to task_cs()'s return value |
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task_cs() calls cgroup_subsys_state().
we must use rcu_read_lock() to protect cgroup_subsys_state().
in current_cpuset_is_being_rebound(), we don't dereference to task_cs()'s return value, but task_cs() accesses css_set, this css_set maybe freed when task_cs() called.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 3e00526..e0e087e 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1141,7 +1136,11 @@ done: int current_cpuset_is_being_rebound(void) { - return task_cs(current) == cpuset_being_rebound; + struct cpuset *cs; + rcu_read_lock(); + cs = task_cs(current); + rcu_read_unlock(); + return cs == cpuset_being_rebound; } static int update_relax_domain_level(struct cpuset *cs, s64 val)
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