| Message ID | 20110829140621.GE18871@mtj.dyndns.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 08/29, Tejun Heo wrote: > > --- work.orig/kernel/freezer.c > +++ work/kernel/freezer.c > @@ -103,9 +103,10 @@ static void fake_signal_wake_up(struct t > { > 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); > + } Yes, this looks correct. Oleg.
Index: work/kernel/freezer.c =================================================================== --- work.orig/kernel/freezer.c +++ work/kernel/freezer.c @@ -103,9 +103,10 @@ static void fake_signal_wake_up(struct t { 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); + } } /**
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> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Paul Menage <paul@paulmenage.org> --- kernel/freezer.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)