[src/trunk]: src/sys/dev/ic avoid undefined behavior

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0e5633c328bf
branches:  trunk
changeset: 787688:0e5633c328bf
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Jun 28 14:48:17 2013 +0000

description:
avoid undefined behavior
http://m00nbsd.net/ae123a9bae03f7dde5c6d654412daf5a.html

diffstat:

 sys/dev/ic/opl.c |  9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diffs (30 lines):

diff -r 6841d1f997f2 -r 0e5633c328bf sys/dev/ic/opl.c
--- a/sys/dev/ic/opl.c  Fri Jun 28 14:46:44 2013 +0000
+++ b/sys/dev/ic/opl.c  Fri Jun 28 14:48:17 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: opl.c,v 1.39 2012/04/09 10:18:16 plunky Exp $  */
+/*     $NetBSD: opl.c,v 1.40 2013/06/28 14:48:17 christos Exp $        */
 
 /*
  * Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: opl.c,v 1.39 2012/04/09 10:18:16 plunky Exp $");
+__KERNEL_RCSID(0, "$NetBSD: opl.c,v 1.40 2013/06/28 14:48:17 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -158,8 +158,9 @@
        mutex_exit(sc->lock);
 
        sc->syn.mets = &opl3_midi;
-       snprintf(sc->syn.name, sizeof(sc->syn.name), "%sYamaha OPL%d",
-           sc->syn.name, sc->model);
+       size_t len = strlen(sc->syn.name);
+       snprintf(sc->syn.name + len, sizeof(sc->syn.name) - len, "Yamaha OPL%d",
+           sc->model);
        sc->syn.data = sc;
        sc->syn.nvoice = sc->model == OPL_2 ? OPL2_NVOICE : OPL3_NVOICE;
        sc->syn.lock = sc->lock;