From 2d5a42141c9ba258f3db4b3f809b4ec766927ba2 Mon Sep 17 00:00:00 2001
From: claudio <claudio@openbsd.org>
Date: Wed, 9 Oct 2024 08:39:49 +0000
Subject: [PATCH] Convert prsignal() into a real function

Also do not use ps_mainproc as the thread the signal is send to. Sending
a signal to ps_mainproc may not work reliably if it already exited. Use
TAILQ_FIRST(&pr->ps_threads) instead but first check that the process has
not yet entered exit1().

OK mpi@
---
 sys/kern/kern_sig.c | 12 +++++++++++-
 sys/sys/signalvar.h |  4 ++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 8f8ab6405f6..ae226ed639b 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sig.c,v 1.339 2024/10/01 08:28:34 claudio Exp $	*/
+/*	$OpenBSD: kern_sig.c,v 1.340 2024/10/09 08:39:49 claudio Exp $	*/
 /*	$NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $	*/
 
 /*
@@ -901,6 +901,16 @@ psignal(struct proc *p, int signum)
 	ptsignal(p, signum, SPROCESS);
 }
 
+void
+prsignal(struct process *pr, int signum)
+{
+	/* Ignore signal if the target process is exiting */
+	if (pr->ps_flags & PS_EXITING) {
+		return;
+	}
+	ptsignal(TAILQ_FIRST(&pr->ps_threads), signum, SPROCESS);
+}
+
 /*
  * type = SPROCESS	process signal, can be diverted (sigwait())
  * type = STHREAD	thread signal, but should be propagated if unhandled
diff --git a/sys/sys/signalvar.h b/sys/sys/signalvar.h
index 3912d92623b..a8c6168f7ef 100644
--- a/sys/sys/signalvar.h
+++ b/sys/sys/signalvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: signalvar.h,v 1.54 2022/05/13 15:32:00 claudio Exp $	*/
+/*	$OpenBSD: signalvar.h,v 1.55 2024/10/09 08:39:49 claudio Exp $	*/
 /*	$NetBSD: signalvar.h,v 1.17 1996/04/22 01:23:31 christos Exp $	*/
 
 /*
@@ -114,7 +114,7 @@ void	pgsigio(struct sigio_ref *sir, int sig, int checkctty);
 void	pgsignal(struct pgrp *pgrp, int sig, int checkctty);
 void	psignal(struct proc *p, int sig);
 void	ptsignal(struct proc *p, int sig, enum signal_type type);
-#define prsignal(pr,sig)	ptsignal((pr)->ps_mainproc, (sig), SPROCESS)
+void	prsignal(struct process *pr, int sig);
 void	trapsignal(struct proc *p, int sig, u_long code, int type,
 	    union sigval val);
 __dead void sigexit(struct proc *, int);
-- 
2.20.1