Re: [PATCH] signal: trace_signal_deliver when signal_group_exit

From: Oleg Nesterov
Date: Sat Apr 20 2019 - 07:23:06 EST


On 04/20, Zhenliang Wei wrote:
>
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -2441,6 +2441,8 @@ bool get_signal(struct ksignal *ksig)
> if (signal_group_exit(signal)) {
> ksig->info.si_signo = signr = SIGKILL;
> sigdelset(&current->pending.signal, SIGKILL);
> + trace_signal_deliver(signr, &ksig->info,
> + &sighand->action[signr - 1]);

Well, in this case ksig->info is not fully initialized for TP_STORE_SIGINFO()
which reads si_errno/si_code...

How about

trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO, SIG_DFL)

?

We know that action[SIGKILL] must be SIG_DFL.

And SEND_SIG_NOINFO matches the fact that SIGKILL doesn't have any info,
collect_signal() sets SI_USER and clears si_errno in this case.

Oleg.