[src/netbsd-8]: src/sys/net Pull up following revision(s) (requested by chris...

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

details:   https://anonhg.NetBSD.org/src/rev/3d1f6ed05454
branches:  netbsd-8
changeset: 434558:3d1f6ed05454
user:      snj <snj%NetBSD.org@localhost>
date:      Sat Jan 13 22:10:55 2018 +0000

description:
Pull up following revision(s) (requested by christos in ticket #496):
        sys/net/route.c: revision 1.202-1.203
        sys/net/route.h: revision 1.117
Use a queue of deferred entries to delete routes instead of a fixed stack
of 10. Otherwise we can overflow in route deletions from the rexmit timer.
--
Don't stomp past the end of the array! need __arraycount not sizeof()
Found by chuq, while debugging the sdf.org crashes
Restructure a bit for readability.

diffstat:

 sys/net/route.c |  51 ++++++++++++++++++++++-----------------------------
 sys/net/route.h |   5 +++--
 2 files changed, 25 insertions(+), 31 deletions(-)

diffs (120 lines):

diff -r 3bde419caabe -r 3d1f6ed05454 sys/net/route.c
--- a/sys/net/route.c   Sat Jan 13 21:57:11 2018 +0000
+++ b/sys/net/route.c   Sat Jan 13 22:10:55 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: route.c,v 1.194.6.3 2017/10/24 08:55:55 snj Exp $      */
+/*     $NetBSD: route.c,v 1.194.6.4 2018/01/13 22:10:55 snj 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 1.194.6.3 2017/10/24 08:55:55 snj Exp $");
+__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.194.6.4 2018/01/13 22:10:55 snj Exp $");
 
 #include <sys/param.h>
 #ifdef RTFLUSH_DEBUG
@@ -255,7 +255,7 @@
        struct workqueue        *wq;
        struct work             wk;
        kmutex_t                lock;
-       struct rtentry          *queue[10];
+       SLIST_HEAD(, rtentry)   queue;
 } rt_free_global __cacheline_aligned;
 
 /* psref for rtentry */
@@ -458,6 +458,8 @@
 #endif
 
        mutex_init(&rt_free_global.lock, MUTEX_DEFAULT, IPL_SOFTNET);
+       SLIST_INIT(&rt_free_global.queue);
+
        rt_psref_class = psref_class_create("rtentry", IPL_SOFTNET);
 
        error = workqueue_create(&rt_free_global.wq, "rt_free",
@@ -686,23 +688,20 @@
 static void
 rt_free_work(struct work *wk, void *arg)
 {
-       int i;
-       struct rtentry *rt;
+
+       for (;;) {
+               struct rtentry *rt;
 
-restart:
-       mutex_enter(&rt_free_global.lock);
-       for (i = 0; i < sizeof(rt_free_global.queue); i++) {
-               if (rt_free_global.queue[i] == NULL)
-                       continue;
-               rt = rt_free_global.queue[i];
-               rt_free_global.queue[i] = NULL;
+               mutex_enter(&rt_free_global.lock);
+               if ((rt = SLIST_FIRST(&rt_free_global.queue)) == NULL) {
+                       mutex_exit(&rt_free_global.lock);
+                       return;
+               }
+               SLIST_REMOVE_HEAD(&rt_free_global.queue, rt_free);
                mutex_exit(&rt_free_global.lock);
-
                atomic_dec_uint(&rt->rt_refcnt);
                _rt_free(rt);
-               goto restart;
        }
-       mutex_exit(&rt_free_global.lock);
 }
 
 void
@@ -710,23 +709,17 @@
 {
 
        KASSERT(rt->rt_refcnt > 0);
-       if (!rt_wait_ok()) {
-               int i;
-               mutex_enter(&rt_free_global.lock);
-               for (i = 0; i < sizeof(rt_free_global.queue); i++) {
-                       if (rt_free_global.queue[i] == NULL) {
-                               rt_free_global.queue[i] = rt;
-                               break;
-                       }
-               }
-               KASSERT(i < sizeof(rt_free_global.queue));
-               rt_ref(rt);
-               mutex_exit(&rt_free_global.lock);
-               workqueue_enqueue(rt_free_global.wq, &rt_free_global.wk, NULL);
-       } else {
+       if (rt_wait_ok()) {
                atomic_dec_uint(&rt->rt_refcnt);
                _rt_free(rt);
+               return;
        }
+
+       mutex_enter(&rt_free_global.lock);
+       rt_ref(rt);
+       SLIST_INSERT_HEAD(&rt_free_global.queue, rt, rt_free);
+       mutex_exit(&rt_free_global.lock);
+       workqueue_enqueue(rt_free_global.wq, &rt_free_global.wk, NULL);
 }
 
 #ifdef NET_MPSAFE
diff -r 3bde419caabe -r 3d1f6ed05454 sys/net/route.h
--- a/sys/net/route.h   Sat Jan 13 21:57:11 2018 +0000
+++ b/sys/net/route.h   Sat Jan 13 22:10:55 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: route.h,v 1.112.4.2 2017/10/24 08:55:55 snj Exp $      */
+/*     $NetBSD: route.h,v 1.112.4.3 2018/01/13 22:10:55 snj Exp $      */
 
 /*
  * Copyright (c) 1980, 1986, 1993
@@ -124,7 +124,8 @@
        struct  sockaddr *rt_tag;       /* route tagging info */
 #ifdef _KERNEL
        kcondvar_t rt_cv;
-       struct psref_target     rt_psref;
+       struct psref_target rt_psref;
+       SLIST_ENTRY(rtentry) rt_free;   /* queue of deferred frees */
 #endif
 };