Eric Dumazet <eric.duma...@gmail.com> wrote: > On Wed, 2013-01-02 at 18:40 +0000, Eric Wong wrote: > > Eric Dumazet <eric.duma...@gmail.com> wrote: > > > It seems the real problem is the epi->event.events = event->events; > > > which is done without taking ep->lock > > > > Yes. I am hoping it is possible to do it without a lock there, > > but your change is more obviously correct. > > > > > While a smp_mb() could reduce the race window, I believe there is still > > > a race, and the following patch would close it. > > > > I'm not an experienced kernel hacker, can you describe where the race > > would be? > > It would be for example in ep_send_events_proc() doing : > > if (epi->event.events & EPOLLONESHOT) > epi->event.events &= EP_PRIVATE_BITS; > > And this could happen at the same time.
That modification in ep_send_events_proc() is protected by ep->mtx (as is ep_modify()), though. Maybe there are other places, but I don't see it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
