Re: [PATCH 1/3] seccomp: interrupt SECCOMP_IOCTL_NOTIF_RECV when all users have exited

Oleg Nesterov
2024-05-23T09:00:36Z

Hi Andrei,

the patch looks good to me even if I don't really understand what
SECCOMP_IOCTL_NOTIF_RECV does. But let me ask a stupid question,

On 05/23, Andrei Vagin wrote:
>
> The change is based on the 'commit 99cdb8b9a573 ("seccomp: notify about
> unused filter")' which implemented (E)POLLHUP notifications.

To me this patch fixes the commit above, because without this change

> @@ -1466,7 +1466,7 @@ static int recv_wake_function(wait_queue_entry_t *wait, unsigned int mode, int s
> void *key)
> {
> /* Avoid a wakeup if event not interesting for us. */
> - if (key && !(key_to_poll(key) & (EPOLLIN | EPOLLERR)))
> + if (key && !(key_to_poll(key) & (EPOLLIN | EPOLLERR | EPOLLHUP)))

__seccomp_filter_orphan() -> wake_up_poll(&orig->wqh, EPOLLHUP) won't
wakeup the task sleeping in recv_wait_event(), right ?

In any case, FWIW

Reviewed-by: Oleg Nesterov <oleg@redhat.com>