On Mon, Jan 29, 2024 at 02:41:11PM +0100, Christian Brauner wrote: > On Mon, Jan 29, 2024 at 12:23:15PM +0100, Oleg Nesterov wrote: > > --- a/kernel/signal.c > > +++ b/kernel/signal.c > > @@ -2051,7 +2051,8 @@ bool do_notify_parent(struct task_struct *tsk, int sig) > > WARN_ON_ONCE(!tsk->ptrace && > > (tsk->group_leader != tsk || !thread_group_empty(tsk))); > > /* > > - * tsk is a group leader and has no threads, wake up the pidfd waiters. > > + * tsk is a group leader and has no threads, wake up the !PIDFD_THREAD > > + * waiters. > > */ > > if (thread_group_empty(tsk)) > > do_notify_pidfd(tsk); > > @@ -3926,6 +3927,7 @@ SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig, > > prepare_kill_siginfo(sig, &kinfo); > > } > > > > + /* TODO: respect PIDFD_THREAD */ > > So I've been thinking about this at the end of last week. Do we need to > give userspace a way to send a thread-group wide signal even when a > PIDFD_THREAD pidfd is passed? Or should we just not worry about this > right now and wait until someone needs this? I don't need it currently, but it would have been handy for some of the tests I wrote. Should I fix those up and send them too on top of Oleg's v2? Tycho
