[src/trunk]: src/sys/net bpf_filter: remove unnecessary memset(), add a comment.

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

details:   https://anonhg.NetBSD.org/src/rev/9be311816b02
branches:  trunk
changeset: 780666:9be311816b02
user:      rmind <rmind%NetBSD.org@localhost>
date:      Thu Aug 02 20:13:24 2012 +0000

description:
bpf_filter: remove unnecessary memset(), add a comment.

diffstat:

 sys/net/bpf_filter.c |  9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diffs (30 lines):

diff -r 1b5dc8311aa2 -r 9be311816b02 sys/net/bpf_filter.c
--- a/sys/net/bpf_filter.c      Thu Aug 02 16:06:58 2012 +0000
+++ b/sys/net/bpf_filter.c      Thu Aug 02 20:13:24 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bpf_filter.c,v 1.51 2012/08/01 23:24:29 rmind Exp $    */
+/*     $NetBSD: bpf_filter.c,v 1.52 2012/08/02 20:13:24 rmind Exp $    */
 
 /*-
  * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: bpf_filter.c,v 1.51 2012/08/01 23:24:29 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bpf_filter.c,v 1.52 2012/08/02 20:13:24 rmind Exp $");
 
 #if 0
 #if !(defined(lint) || defined(KERNEL))
@@ -149,7 +149,10 @@
                return (u_int)-1;
        }
 
-       memset(mem, 0, sizeof(mem));
+       /*
+        * Note: safe to leave memwords uninitialised, as the validation
+        * step ensures that it will not be read, if it was not written.
+        */
        A = 0;
        X = 0;
        --pc;