On Fri, 30 Sep 2016, Waiman Long wrote: > + WRITE_ONCE(state->owner, current); > + preempt_disable(); > + for (;;) { > + ret = futex_trylock(uaddr, vpid, &uval, true);
Did you actually read what I said? You CANNOT access userspace in a preempt disabled region without disabling pagefaults and handle the resulting wreckage yourself. End of review. tglx