On 03/06, Christian Brauner wrote:
>
> Back when we implemented support for PIDFD_THREAD we ended up with the
> decision that if userspace holds:
>
> pidfd_leader_thread = pidfd_open(<thread-group-leader-pid>, PIDFD_THREAD)
>
> that exit notification is not strictly defined if a non-thread-group
> leader thread execs:
Yes, this was even documented in commit 64bef697d33b ...
> --- a/kernel/exit.c
> +++ b/kernel/exit.c
> @@ -745,8 +745,11 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
> /*
> * sub-thread or delay_group_leader(), wake up the
> * PIDFD_THREAD waiters.
> + *
> + * The thread-group leader will be taken over by the execing
> + * task so don't cause spurious wakeups.
> */
> - if (!thread_group_empty(tsk))
> + if (!thread_group_empty(tsk) && (tsk->signal->notify_count >= 0))
> do_notify_pidfd(tsk);
>
> if (unlikely(tsk->ptrace)) {
perhaps... but this won't help if the leader exits and that another
thread does exec?
