From: Oleg Nesterov Date: Mon, 5 Feb 2024 14:13:48 +0000 (+0100) Subject: pidfd: change do_notify_pidfd() to use __wake_up(poll_to_key(EPOLLIN)) X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9ed52108f6478a6a805c0c15a3f70aabba07247e;p=linux.git pidfd: change do_notify_pidfd() to use __wake_up(poll_to_key(EPOLLIN)) rather than wake_up_all(). This way do_notify_pidfd() won't wakeup the POLLHUP-only waiters which wait for pid_task() == NULL. TODO: - as Christian pointed out, this asks for the new wake_up_all_poll() helper, it can already have other users. - we can probably discriminate the PIDFD_THREAD and non-PIDFD_THREAD waiters, but this needs more work. See https://lore.kernel.org/all/20240205140848.GA15853@redhat.com/ Signed-off-by: Oleg Nesterov Link: https://lore.kernel.org/r/20240205141348.GA16539@redhat.com Reviewed-by: Tycho Andersen Signed-off-by: Christian Brauner --- diff --git a/kernel/signal.c b/kernel/signal.c index 9b40109f0c564..c3fac06937e28 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2021,11 +2021,12 @@ ret: void do_notify_pidfd(struct task_struct *task) { - struct pid *pid; + struct pid *pid = task_pid(task); WARN_ON(task->exit_state == 0); - pid = task_pid(task); - wake_up_all(&pid->wait_pidfd); + + __wake_up(&pid->wait_pidfd, TASK_NORMAL, 0, + poll_to_key(EPOLLIN | EPOLLRDNORM)); } /*