Re: [RFC PATCH 1/8] signal: Dequeue SIGKILL even if SIGNAL_GROUP_EXIT/group_exec_task is set

From: Oleg Nesterov
Date: Mon May 22 2023 - 09:31:58 EST


On 05/18, Eric W. Biederman wrote:
>
> void recalc_sigpending(void)
> {
> - if (!recalc_sigpending_tsk(current) && !freezing(current))
> + if ((!recalc_sigpending_tsk(current) && !freezing(current)) ||
> + ((current->signal->flags & SIGNAL_GROUP_EXIT) &&
> + !__fatal_signal_pending(current)))
> clear_thread_flag(TIF_SIGPENDING);
>
> }
> @@ -1043,6 +1045,13 @@ static void complete_signal(int sig, struct task_struct *p, enum pid_type type)
> * This signal will be fatal to the whole group.
> */
> if (!sig_kernel_coredump(sig)) {
> + /*
> + * The signal is being short circuit delivered
> + * don't it pending.
> + */
> + if (type != PIDTYPE_PID) {
> + sigdelset(&t->signal->shared_pending, sig);
> +
> /*
> * Start a group exit and wake everybody up.
> * This way we don't have other threads

Eric, sorry. I fail to understand this patch.

How can it help? And whom?

Perhaps we can discuss it in the context of the new series from Mike?

Oleg.