path: root/kernel/freezer.c
diff options
authorTejun Heo <tj@kernel.org>2011-11-21 12:32:26 -0800
committerTejun Heo <tj@kernel.org>2011-11-21 12:32:26 -0800
commit37ad8aca94a1da2112a7c56151390914e80d1113 (patch)
treedaf5f8956aa7fa7b8d3e15aaf67dd3d6fc6f2375 /kernel/freezer.c
parent5ece3eae4cdb968c269e0bc7e2c0e2b223552025 (diff)
freezer: use lock_task_sighand() in fake_signal_wake_up()
cgroup_freezer calls freeze_task() without holding tasklist_lock and, if the task is exiting, its ->sighand may be gone by the time fake_signal_wake_up() is called. Use lock_task_sighand() instead of accessing ->sighand directly. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Paul Menage <paul@paulmenage.org>
Diffstat (limited to 'kernel/freezer.c')
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/freezer.c b/kernel/freezer.c
index c3496c6a91b2..389549f0a94e 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -93,9 +93,10 @@ static void fake_signal_wake_up(struct task_struct *p)
unsigned long flags;
- spin_lock_irqsave(&p->sighand->siglock, flags);
- signal_wake_up(p, 0);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ if (lock_task_sighand(p, &flags)) {
+ signal_wake_up(p, 0);
+ unlock_task_sighand(p, &flags);
+ }

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