From 3a16673c2ffffc4349bcd56176c191a0d83d7a57 Mon Sep 17 00:00:00 2001
From: claudio <claudio@openbsd.org>
Date: Wed, 16 Aug 2023 07:55:52 +0000
Subject: [PATCH] Move SCHED_LOCK after sleep_signal_check.

sleep_signal_check() is there to look for pending signals / single thread
requests which were posted before sleep_setup() finished. Once p_stat
is set to SSLEEP the wakeup and delivery of signals is taken care of
by ptsignal and single_thread_set().

Moving the SCHED_LOCK further down allows to cleanup cursig() and to
remove a SCHED_LOCK recursion in single_thread_check().

OK mpi@
---
 sys/kern/kern_sig.c   | 15 +++++----------
 sys/kern/kern_synch.c |  4 ++--
 2 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index eaa726642a0..af0e0d7f4eb 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sig.c,v 1.312 2023/08/13 15:53:31 claudio Exp $	*/
+/*	$OpenBSD: kern_sig.c,v 1.313 2023/08/16 07:55:52 claudio Exp $	*/
 /*	$NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $	*/
 
 /*
@@ -1251,7 +1251,6 @@ cursig(struct proc *p, struct sigctx *sctx)
 {
 	struct process *pr = p->p_p;
 	int signum, mask, prop;
-	int dolock = (p->p_flag & P_SINTR) == 0;
 	sigset_t ps_siglist;
 	int s;
 
@@ -1294,11 +1293,9 @@ cursig(struct proc *p, struct sigctx *sctx)
 			single_thread_set(p, SINGLE_SUSPEND, 0);
 			pr->ps_xsig = signum;
 
-			if (dolock)
-				SCHED_LOCK(s);
+			SCHED_LOCK(s);
 			proc_stop(p, 1);
-			if (dolock)
-				SCHED_UNLOCK(s);
+			SCHED_UNLOCK(s);
 
 			/*
 			 * re-take the signal before releasing
@@ -1371,11 +1368,9 @@ cursig(struct proc *p, struct sigctx *sctx)
 				    prop & SA_TTYSTOP))
 					break;	/* == ignore */
 				pr->ps_xsig = signum;
-				if (dolock)
-					SCHED_LOCK(s);
+				SCHED_LOCK(s);
 				proc_stop(p, 1);
-				if (dolock)
-					SCHED_UNLOCK(s);
+				SCHED_UNLOCK(s);
 				break;
 			} else if (prop & SA_IGNORE) {
 				/*
diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index 591fa77a736..624bf52b2b5 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_synch.c,v 1.197 2023/08/14 08:33:24 mpi Exp $	*/
+/*	$OpenBSD: kern_synch.c,v 1.198 2023/08/16 07:55:52 claudio Exp $	*/
 /*	$NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $	*/
 
 /*
@@ -373,7 +373,6 @@ sleep_finish(int timo, int do_sleep)
 		timeout_add(&p->p_sleep_to, timo);
 	}
 
-	SCHED_LOCK(s);
 	if (catch != 0) {
 		/*
 		 * We put ourselves on the sleep queue and start our
@@ -390,6 +389,7 @@ sleep_finish(int timo, int do_sleep)
 		}
 	}
 
+	SCHED_LOCK(s);
 	/*
 	 * If the wakeup happens while going to sleep, p->p_wchan
 	 * will be NULL. In that case unwind immediately but still
-- 
2.20.1