[src/trunk]: src/sys/net Ensure that nobody references a rtentry that is pass...

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

details:   https://anonhg.NetBSD.org/src/rev/4c3408f8d939
branches:  trunk
changeset: 821597:4c3408f8d939
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Fri Feb 10 13:48:06 2017 +0000

description:
Ensure that nobody references a rtentry that is passed to rt_setgate

diffstat:

 sys/net/route.c |  30 +++++++++++++++++++++---------
 1 files changed, 21 insertions(+), 9 deletions(-)

diffs (53 lines):

diff -r 86b14cb36b3d -r 4c3408f8d939 sys/net/route.c
--- a/sys/net/route.c   Fri Feb 10 13:44:47 2017 +0000
+++ b/sys/net/route.c   Fri Feb 10 13:48:06 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: route.c,v 1.189 2017/02/10 13:44:47 ozaki-r Exp $      */
+/*     $NetBSD: route.c,v 1.190 2017/02/10 13:48:06 ozaki-r Exp $      */
 
 /*-
  * Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
@@ -97,7 +97,7 @@
 #endif
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.189 2017/02/10 13:44:47 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.190 2017/02/10 13:48:06 ozaki-r Exp $");
 
 #include <sys/param.h>
 #ifdef RTFLUSH_DEBUG
@@ -918,15 +918,27 @@
                         * Smash the current notion of the gateway to
                         * this destination.  Should check about netmask!!!
                         */
-                       /*
-                        * FIXME NOMPSAFE: the rtentry is updated with the existence
-                        * of refeferences of it.
-                        */
-                       error = rt_setgate(rt, gateway);
+#ifdef NET_MPSAFE
+                       KASSERT(!cpu_softintr_p());
+
+                       error = rt_update_prepare(rt);
                        if (error == 0) {
-                               rt->rt_flags |= RTF_MODIFIED;
-                               flags |= RTF_MODIFIED;
+#endif
+                               error = rt_setgate(rt, gateway);
+                               if (error == 0) {
+                                       rt->rt_flags |= RTF_MODIFIED;
+                                       flags |= RTF_MODIFIED;
+                               }
+#ifdef NET_MPSAFE
+                               rt_update_finish(rt);
+                       } else {
+                               /*
+                                * If error != 0, the rtentry is being
+                                * destroyed, so doing nothing doesn't
+                                * matter.
+                                */
                        }
+#endif
                        stat = &rtstat.rts_newgateway;
                }
        } else