Messages in this thread Patch in this message | | | Date | Mon, 31 Oct 2011 15:35:26 -0700 | From | Tejun Heo <> | Subject | [PATCH 19/17] freezer: use lock_task_sighand() in fake_signal_wake_up() |
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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> --- kernel/freezer.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/freezer.c b/kernel/freezer.c index 10f9840..a9c18c7 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, 1); - spin_unlock_irqrestore(&p->sighand->siglock, flags); + if (lock_task_sighand(p, &flags)) { + signal_wake_up(p, 1); + unlock_task_sighand(p, &flags); + } } /** -- 1.7.3.1
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