From: tholo <tholo@openbsd.org>
Date: Sat, 29 Mar 1997 20:28:20 +0000 (+0000)
Subject: Avoid infinite loops; from NetBSD PR 3285
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=c0edfbda20a6dbb1d064a67a57081e52d533023a;p=openbsd

Avoid infinite loops; from NetBSD PR 3285
---

diff --git a/sbin/dmesg/dmesg.c b/sbin/dmesg/dmesg.c
index 9e63bd76a53..e0475239c82 100644
--- a/sbin/dmesg/dmesg.c
+++ b/sbin/dmesg/dmesg.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dmesg.c,v 1.4 1997/01/15 23:41:10 millert Exp $	*/
+/*	$OpenBSD: dmesg.c,v 1.5 1997/03/29 20:28:20 tholo Exp $	*/
 /*	$NetBSD: dmesg.c,v 1.8 1995/03/18 14:54:49 cgd Exp $	*/
 
 /*-
@@ -44,7 +44,7 @@ static char copyright[] =
 #if 0
 static char sccsid[] = "@(#)dmesg.c	8.1 (Berkeley) 6/5/93";
 #else
-static char rcsid[] = "$OpenBSD: dmesg.c,v 1.4 1997/01/15 23:41:10 millert Exp $";
+static char rcsid[] = "$OpenBSD: dmesg.c,v 1.5 1997/03/29 20:28:20 tholo Exp $";
 #endif
 #endif /* not lint */
 
@@ -129,10 +129,10 @@ main(argc, argv)
 	 * The message buffer is circular; start at the read pointer, and
 	 * go to the write pointer - 1.
 	 */
-	p = cur.msg_bufc + cur.msg_bufx;
-	ep = cur.msg_bufc + cur.msg_bufx - 1;
-	for (newl = skip = 0; p != ep; ++p) {
-		if (p == cur.msg_bufc + MSG_BSIZE)
+	p = ep = cur.msg_bufc + (cur.msg_bufx - 1 + MSG_BSIZE) % MSG_BSIZE;
+	newl = skip = 0;
+	do {
+		if (++p == cur.msg_bufc + MSG_BSIZE)
 			p = cur.msg_bufc;
 		ch = *p;
 		/* Skip "\n<.*>" syslog sequences. */
@@ -153,7 +153,7 @@ main(argc, argv)
 			(void)putchar(buf[0]);
 		else
 			(void)printf("%s", buf);
-	}
+	} while (p != ep);
 	if (!newl)
 		(void)putchar('\n');
 	exit(0);