On Tue, 2014-06-17 at 00:28 +0200, Thomas Gleixner wrote: > On Tue, 17 Jun 2014, Thomas Gleixner wrote: > > On Mon, 16 Jun 2014, Darren Hart wrote: > > > On Wed, 2014-06-11 at 20:45 +0000, Thomas Gleixner wrote: > > > In wake_futex_pi we verify ownership by matching pi_state->owner == > > > current, but here the only test is the TID value, which is set by > > > userspace - which we don't trust... > > > > > > I'm trying to determine if it matters in this case... if there are no > > > waiters, is the pi_state still around? If so, it does indeed matter, and > > > we should be verifying. > > > > Erm. The whole point of this patch is to do: > > > > - Find existing state first and handle it. > > > > - If no state exists and TID == current, take it > > > > - Otherwise create state > > Duh, that was the lock path. But here the point is: > > - Find existing state first and handle it. > > - If no state exists and TID == current, release it >
Right, I understood your meaning, and I withdraw the concern. > The retry is obvious, right? Yes. -- Darren Hart Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
