From cd735d8f5a7c1f56d99f9d5e6535696d1e8484c3 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Mon, 16 Oct 2017 20:15:19 +0000
Subject: [PATCH] Improve assertion that an ignored or blocked signal is not
 delivered.

Split two conditions into separate asserts.  Print additional details,
like the signal number and action value.

Reviewed by:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
---
 sys/kern/kern_sig.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index d3bccd0dd1c..e0bc937b6e8 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -3030,8 +3030,10 @@ postsig(int sig)
 		/*
 		 * If we get here, the signal must be caught.
 		 */
-		KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig),
-		    ("postsig action"));
+		KASSERT(action != SIG_IGN, ("postsig action %p", action));
+		KASSERT(!SIGISMEMBER(td->td_sigmask, sig),
+		    ("postsig action: blocked sig %d", sig));
+
 		/*
 		 * Set the new mask value and also defer further
 		 * occurrences of this signal.