Hello, On Thu, Sep 08, 2011 at 07:59:26PM +0200, Oleg Nesterov wrote: > > Indeed, nice catch. This one actually is pretty dangerous. We > > probably want to make a separate fix for this and backport it to > > -stable? > > And I forgot to mention that wait_event_freezable_timeout() doesn't > handle -ERESTARTSYS at all. > > But I don't think -stable needs this fix. According to grep, nobody > check the returned value, and none of the callers plays with signals. Ah, no user, okay. > > Yeap, with freezable_with_signal gone, this looks correct & simpler to > > me > > I don't really understand this... set_freezable_with_signal() has a > lot of problems, yes... But even if it wasn't removed this fix makes > sense anyway, afaics. > > If freezable_with_signal caller does wait_event_freezable_timeout(), > __retval becomes -ERESTARTSYS after freeze_task(). The next iteration > will return 0 with the KERN_ERR message from schedule_timeout(). Hmmm... but with the change, if a kthread gets TIF_SIGPENDING from freezer and then thawed, it would not enter try_to_freeze() and thus won't clear TIF_SIGPENDING. The original code was racy too but the window would be much larger afterwards. Anyways, this doesn't matter anymore. > > but it would be nice if you can sprinkle some documentation while > > at it. :) > > But they already have the comment ;) What can I add? Proper /** - */ comment w/ return value documentation? :P Thanks. -- tejun _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
