[src/trunk]: src/sys/net Use IFADDR_WRITER_FOREACH instead of IFADDR_READER_F...

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9adc9717384a
branches:  trunk
changeset: 357990:9adc9717384a
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Thu Dec 07 01:23:53 2017 +0000

description:
Use IFADDR_WRITER_FOREACH instead of IFADDR_READER_FOREACH

At that point no other one modifies the list so IFADDR_READER_FOREACH
is unnecessary. Use of IFADDR_READER_FOREACH is harmless in general though,
if we try to detect contract violations of pserialize, using it violates
the contract. So avoid using it makes life easy.

diffstat:

 sys/net/if.c |  10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diffs (32 lines):

diff -r 523b9d5bdde6 -r 9adc9717384a sys/net/if.c
--- a/sys/net/if.c      Thu Dec 07 00:38:38 2017 +0000
+++ b/sys/net/if.c      Thu Dec 07 01:23:53 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if.c,v 1.406 2017/12/06 09:54:47 ozaki-r Exp $ */
+/*     $NetBSD: if.c,v 1.407 2017/12/07 01:23:53 ozaki-r Exp $ */
 
 /*-
  * Copyright (c) 1999, 2000, 2001, 2008 The NetBSD Foundation, Inc.
@@ -90,7 +90,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.406 2017/12/06 09:54:47 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.407 2017/12/07 01:23:53 ozaki-r Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_inet.h"
@@ -1378,9 +1378,11 @@
 again:
        /*
         * At this point, no other one tries to remove ifa in the list,
-        * so we don't need to take a lock or psref.
+        * so we don't need to take a lock or psref.  Avoid using
+        * IFADDR_READER_FOREACH to pass over an inspection of contract
+        * violations of pserialize.
         */
-       IFADDR_READER_FOREACH(ifa, ifp) {
+       IFADDR_WRITER_FOREACH(ifa, ifp) {
                family = ifa->ifa_addr->sa_family;
 #ifdef IFAREF_DEBUG
                printf("if_detach: ifaddr %p, family %d, refcnt %d\n",