From 5ebe96648bcec067b428315b455b16b6b026df06 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Mon, 12 Jul 2010 10:14:24 +0000
Subject: [PATCH] For xsi_sigpause(3), remove the supplied signal from the
 process mask during sigpause(2) call. It was backward. Check that the signal
 number is valid.

Reported by:	Garrett Cooper <yanegomi gmail com>
MFC after:	1 week
---
 lib/libc/compat-43/sigcompat.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/lib/libc/compat-43/sigcompat.c b/lib/libc/compat-43/sigcompat.c
index c3ba30a41f4..6841eeb2461 100644
--- a/lib/libc/compat-43/sigcompat.c
+++ b/lib/libc/compat-43/sigcompat.c
@@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$");
 
 #include "namespace.h"
 #include <sys/param.h>
+#include <errno.h>
 #include <signal.h>
 #include <string.h>
 #include "un-namespace.h"
@@ -111,9 +112,16 @@ int
 xsi_sigpause(int sig)
 {
 	sigset_t set;
+	int error;
 
-	sigemptyset(&set);
-	sigaddset(&set, sig);
+	if (!_SIG_VALID(sig)) {
+		errno = EINVAL;
+		return (-1);
+	}
+	error = _sigprocmask(SIG_BLOCK, NULL, &set);
+	if (error != 0)
+		return (error);
+	sigdelset(&set, sig);
 	return (_sigsuspend(&set));
 }