On Wed, Apr 25, 2018 at 3:22 PM, Oleg Nesterov <o...@redhat.com> wrote: > On 04/24, Daniel Vetter wrote: >> >> wait_event_killabel doesn't check for fatal_signal_pending before calling >> schedule, so definitely has a nice race there. > > This is fine. See the signal_pending_state() check in __schedule(). > > And this doesn't differ from wait_event_interruptible(), it too doesn't > check signal_pending(), we rely on schedule() which must not block if the > caller is signalled/killed. > > The problem is that it is not clear what should fatal_signal_pending() or > even signal_pending() mean after exit_signals().
Uh, I was totally thrown off in all the wait_event* macros and somehow landed in the _locked variants, which all need to recheck before they drop the lock, for efficiency reasons. See do_wait_intr(). Sorry for the confusion. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch
