Module Name:    src
Committed By:   snj
Date:           Sat Feb  3 22:07:26 UTC 2018

Modified Files:
        src/sys/net [netbsd-8]: route.c rtsock.c
        src/sys/netinet [netbsd-8]: in.c tcp_subr.c tcp_timer.c tcp_timer.h
            tcp_var.h
        src/sys/netinet6 [netbsd-8]: in6.c

Log Message:
Pull up following revision(s) (requested by ozaki-r in ticket #514):
        sys/net/route.c: 1.205
        sys/net/rtsock.c: 1.237-1.238
        sys/netinet/in.c: 1.215
        sys/netinet/tcp_subr.c: 1.272
        sys/netinet/tcp_timer.c: 1.93
        sys/netinet/tcp_timer.h: 1.29
        sys/netinet/tcp_var.h: 1.182
        sys/netinet6/in6.c: 1.258
Remove extra pserialize_perform from in_purgeaddr
It's already performed in ifa_remove. Note so there (in in6_unlink_ifa too).
Release rt_so_mtx on updating a rtentry to avoid a deadlock with route_intr
The deadlock happened only if NET_MPSAFE on.
Run tcp_slowtimo in workqueue if NET_MPSAFE
If NET_MPSAFE is enabled, we have to avoid taking softnet_lock in softint as
much as possible to prevent any softint handlers including callout handlers
such as tcp_slowtimo from sticking on softnet_lock because it results in
undesired delays of executing subsequent softint handlers.
NFCI for !NET_MPSAFE
Fix a return value of rt_update_prepare
Callers expect it to be an errno.
Fix another deadlock
When waiting for a route update to finish, a waiter has to release its reference
to the route to avoid a deadlock. Because a updater tries to wait for references
to a target route (except for a reference by the updater itself) to be released.


To generate a diff of this commit:
cvs rdiff -u -r1.194.6.4 -r1.194.6.5 src/sys/net/route.c
cvs rdiff -u -r1.213.2.5 -r1.213.2.6 src/sys/net/rtsock.c
cvs rdiff -u -r1.203.2.6 -r1.203.2.7 src/sys/netinet/in.c
cvs rdiff -u -r1.270 -r1.270.6.1 src/sys/netinet/tcp_subr.c
cvs rdiff -u -r1.91 -r1.91.8.1 src/sys/netinet/tcp_timer.c
cvs rdiff -u -r1.28 -r1.28.48.1 src/sys/netinet/tcp_timer.h
cvs rdiff -u -r1.177.10.1 -r1.177.10.2 src/sys/netinet/tcp_var.h
cvs rdiff -u -r1.245.2.5 -r1.245.2.6 src/sys/netinet6/in6.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: src/sys/net/route.c
diff -u src/sys/net/route.c:1.194.6.4 src/sys/net/route.c:1.194.6.5
--- src/sys/net/route.c:1.194.6.4	Sat Jan 13 22:10:55 2018
+++ src/sys/net/route.c	Sat Feb  3 22:07:26 2018
@@ -1,4 +1,4 @@
-/*	$NetBSD: route.c,v 1.194.6.4 2018/01/13 22:10:55 snj Exp $	*/
+/*	$NetBSD: route.c,v 1.194.6.5 2018/02/03 22:07:26 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 1.194.6.4 2018/01/13 22:10:55 snj Exp $");
+__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.194.6.5 2018/02/03 22:07:26 snj Exp $");
 
 #include <sys/param.h>
 #ifdef RTFLUSH_DEBUG
@@ -747,7 +747,7 @@ rt_update_prepare(struct rtentry *rt)
 	/* If the entry is being destroyed, don't proceed the update. */
 	if (!ISSET(rt->rt_flags, RTF_UP)) {
 		RT_UNLOCK();
-		return -1;
+		return ESRCH;
 	}
 	rt->rt_flags |= RTF_UPDATING;
 	RT_UNLOCK();

Index: src/sys/net/rtsock.c
diff -u src/sys/net/rtsock.c:1.213.2.5 src/sys/net/rtsock.c:1.213.2.6
--- src/sys/net/rtsock.c:1.213.2.5	Tue Jan  2 10:30:10 2018
+++ src/sys/net/rtsock.c	Sat Feb  3 22:07:26 2018
@@ -1,4 +1,4 @@
-/*	$NetBSD: rtsock.c,v 1.213.2.5 2018/01/02 10:30:10 snj Exp $	*/
+/*	$NetBSD: rtsock.c,v 1.213.2.6 2018/02/03 22:07:26 snj Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rtsock.c,v 1.213.2.5 2018/01/02 10:30:10 snj Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rtsock.c,v 1.213.2.6 2018/02/03 22:07:26 snj Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -82,6 +82,7 @@ __KERNEL_RCSID(0, "$NetBSD: rtsock.c,v 1
 #include <sys/kauth.h>
 #include <sys/kmem.h>
 #include <sys/intr.h>
+#include <sys/condvar.h>
 
 #include <net/if.h>
 #include <net/if_llatbl.h>
@@ -187,6 +188,9 @@ struct routecb {
 static struct rawcbhead rt_rawcb;
 #ifdef NET_MPSAFE
 static kmutex_t *rt_so_mtx;
+
+static bool rt_updating = false;
+static kcondvar_t rt_update_cv;
 #endif
 
 static void
@@ -1002,11 +1006,37 @@ COMPATNAME(route_output)(struct mbuf *m,
 
 		case RTM_CHANGE:
 #ifdef NET_MPSAFE
+			/*
+			 * Release rt_so_mtx to avoid a deadlock with route_intr
+			 * and also serialize updating routes to avoid another.
+			 */
+			if (rt_updating) {
+				/* Release to allow the updater to proceed */
+				rt_unref(rt);
+				rt = NULL;
+			}
+			while (rt_updating) {
+				error = cv_wait_sig(&rt_update_cv, rt_so_mtx);
+				if (error != 0)
+					goto flush;
+			}
+			if (rt == NULL) {
+				error = rtrequest1(RTM_GET, &info, &rt);
+				if (error != 0)
+					goto flush;
+			}
+			rt_updating = true;
+			mutex_exit(rt_so_mtx);
+
 			error = rt_update_prepare(rt);
 			if (error == 0) {
 				error = route_output_change(rt, &info, rtm);
 				rt_update_finish(rt);
 			}
+
+			mutex_enter(rt_so_mtx);
+			rt_updating = false;
+			cv_broadcast(&rt_update_cv);
 #else
 			error = route_output_change(rt, &info, rtm);
 #endif
@@ -2105,6 +2135,8 @@ COMPATNAME(route_init)(void)
 #endif
 #ifdef NET_MPSAFE
 	rt_so_mtx = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
+
+	cv_init(&rt_update_cv, "rtsock_cv");
 #endif
 
 	sysctl_net_route_setup(NULL);

Index: src/sys/netinet/in.c
diff -u src/sys/netinet/in.c:1.203.2.6 src/sys/netinet/in.c:1.203.2.7
--- src/sys/netinet/in.c:1.203.2.6	Sat Jan 13 05:45:06 2018
+++ src/sys/netinet/in.c	Sat Feb  3 22:07:26 2018
@@ -1,4 +1,4 @@
-/*	$NetBSD: in.c,v 1.203.2.6 2018/01/13 05:45:06 snj Exp $	*/
+/*	$NetBSD: in.c,v 1.203.2.7 2018/02/03 22:07:26 snj Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -91,7 +91,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: in.c,v 1.203.2.6 2018/01/13 05:45:06 snj Exp $");
+__KERNEL_RCSID(0, "$NetBSD: in.c,v 1.203.2.7 2018/02/03 22:07:26 snj Exp $");
 
 #include "arp.h"
 
@@ -855,9 +855,7 @@ in_purgeaddr(struct ifaddr *ifa)
 	TAILQ_REMOVE(&in_ifaddrhead, ia, ia_list);
 	IN_ADDRLIST_WRITER_REMOVE(ia);
 	ifa_remove(ifp, &ia->ia_ifa);
-#ifdef NET_MPSAFE
-	pserialize_perform(in_ifaddrhash_psz);
-#endif
+	/* Assume ifa_remove called pserialize_perform and psref_destroy */
 	mutex_exit(&in_ifaddr_lock);
 	IN_ADDRHASH_ENTRY_DESTROY(ia);
 	IN_ADDRLIST_ENTRY_DESTROY(ia);

Index: src/sys/netinet/tcp_subr.c
diff -u src/sys/netinet/tcp_subr.c:1.270 src/sys/netinet/tcp_subr.c:1.270.6.1
--- src/sys/netinet/tcp_subr.c:1.270	Fri Mar  3 07:13:06 2017
+++ src/sys/netinet/tcp_subr.c	Sat Feb  3 22:07:26 2018
@@ -1,4 +1,4 @@
-/*	$NetBSD: tcp_subr.c,v 1.270 2017/03/03 07:13:06 ozaki-r Exp $	*/
+/*	$NetBSD: tcp_subr.c,v 1.270.6.1 2018/02/03 22:07:26 snj Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -91,7 +91,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.270 2017/03/03 07:13:06 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.270.6.1 2018/02/03 22:07:26 snj Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -388,8 +388,6 @@ struct mowner tcp_sock_rx_mowner = MOWNE
 struct mowner tcp_sock_tx_mowner = MOWNER_INIT("tcp", "sock tx");
 #endif
 
-callout_t tcp_slowtimo_ch;
-
 static int
 do_tcpinit(void)
 {
@@ -430,8 +428,7 @@ do_tcpinit(void)
 
 	vtw_earlyinit();
 
-	callout_init(&tcp_slowtimo_ch, CALLOUT_MPSAFE);
-	callout_reset(&tcp_slowtimo_ch, 1, tcp_slowtimo, NULL);
+	tcp_slowtimo_init();
 
 	return 0;
 }

Index: src/sys/netinet/tcp_timer.c
diff -u src/sys/netinet/tcp_timer.c:1.91 src/sys/netinet/tcp_timer.c:1.91.8.1
--- src/sys/netinet/tcp_timer.c:1.91	Mon Jul 25 00:10:38 2016
+++ src/sys/netinet/tcp_timer.c	Sat Feb  3 22:07:26 2018
@@ -1,4 +1,4 @@
-/*	$NetBSD: tcp_timer.c,v 1.91 2016/07/25 00:10:38 knakahara Exp $	*/
+/*	$NetBSD: tcp_timer.c,v 1.91.8.1 2018/02/03 22:07:26 snj Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -93,11 +93,12 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tcp_timer.c,v 1.91 2016/07/25 00:10:38 knakahara Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tcp_timer.c,v 1.91.8.1 2018/02/03 22:07:26 snj Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
 #include "opt_tcp_debug.h"
+#include "opt_net_mpsafe.h"
 #endif
 
 #include <sys/param.h>
@@ -108,6 +109,8 @@ __KERNEL_RCSID(0, "$NetBSD: tcp_timer.c,
 #include <sys/protosw.h>
 #include <sys/errno.h>
 #include <sys/kernel.h>
+#include <sys/callout.h>
+#include <sys/workqueue.h>
 
 #include <net/if.h>
 
@@ -149,6 +152,15 @@ u_int	tcp_keepcnt = 0;		/* max idle prob
 
 int	tcp_maxpersistidle = 0;		/* max idle time in persist */
 
+static callout_t	tcp_slowtimo_ch;
+#ifdef NET_MPSAFE
+static struct workqueue	*tcp_slowtimo_wq;
+static struct work	tcp_slowtimo_wk;
+#endif
+
+static void tcp_slowtimo_work(struct work *, void *);
+static void tcp_slowtimo(void *);
+
 /*
  * Time to delay the ACK.  This is initialized in tcp_init(), unless
  * its patched.
@@ -193,6 +205,21 @@ tcp_timer_init(void)
 		tcp_delack_ticks = TCP_DELACK_TICKS;
 }
 
+void
+tcp_slowtimo_init(void)
+{
+#ifdef NET_MPSAFE
+	int error;
+
+	error = workqueue_create(&tcp_slowtimo_wq, "tcp_slowtimo",
+	    tcp_slowtimo_work, NULL, PRI_SOFTNET, IPL_SOFTNET, WQ_MPSAFE);
+	if (error != 0)
+		panic("%s: workqueue_create failed (%d)\n", __func__, error);
+#endif
+	callout_init(&tcp_slowtimo_ch, CALLOUT_MPSAFE);
+	callout_reset(&tcp_slowtimo_ch, 1, tcp_slowtimo, NULL);
+}
+
 /*
  * Callout to process delayed ACKs for a TCPCB.
  */
@@ -229,8 +256,8 @@ tcp_delack(void *arg)
  * Updates the timers in all active tcb's and
  * causes finite state machine actions if timers expire.
  */
-void
-tcp_slowtimo(void *arg)
+static void
+tcp_slowtimo_work(struct work *wk, void *arg)
 {
 
 	mutex_enter(softnet_lock);
@@ -241,6 +268,17 @@ tcp_slowtimo(void *arg)
 	callout_schedule(&tcp_slowtimo_ch, hz / PR_SLOWHZ);
 }
 
+static void
+tcp_slowtimo(void *arg)
+{
+
+#ifdef NET_MPSAFE
+	workqueue_enqueue(tcp_slowtimo_wq, &tcp_slowtimo_wk, NULL);
+#else
+	tcp_slowtimo_work(NULL, NULL);
+#endif
+}
+
 /*
  * Cancel all timers for TCP tp.
  */

Index: src/sys/netinet/tcp_timer.h
diff -u src/sys/netinet/tcp_timer.h:1.28 src/sys/netinet/tcp_timer.h:1.28.48.1
--- src/sys/netinet/tcp_timer.h:1.28	Tue May 24 18:37:52 2011
+++ src/sys/netinet/tcp_timer.h	Sat Feb  3 22:07:26 2018
@@ -1,4 +1,4 @@
-/*	$NetBSD: tcp_timer.h,v 1.28 2011/05/24 18:37:52 gdt Exp $	*/
+/*	$NetBSD: tcp_timer.h,v 1.28.48.1 2018/02/03 22:07:26 snj Exp $	*/
 
 /*-
  * Copyright (c) 2001, 2005 The NetBSD Foundation, Inc.
@@ -190,6 +190,7 @@ extern int tcp_ttl;			/* time to live fo
 extern const int tcp_backoff[];
 
 void	tcp_timer_init(void);
+void	tcp_slowtimo_init(void);
 #endif
 
 #endif /* !_NETINET_TCP_TIMER_H_ */

Index: src/sys/netinet/tcp_var.h
diff -u src/sys/netinet/tcp_var.h:1.177.10.1 src/sys/netinet/tcp_var.h:1.177.10.2
--- src/sys/netinet/tcp_var.h:1.177.10.1	Sat Oct 21 19:43:54 2017
+++ src/sys/netinet/tcp_var.h	Sat Feb  3 22:07:26 2018
@@ -1,4 +1,4 @@
-/*	$NetBSD: tcp_var.h,v 1.177.10.1 2017/10/21 19:43:54 snj Exp $	*/
+/*	$NetBSD: tcp_var.h,v 1.177.10.2 2018/02/03 22:07:26 snj Exp $	*/
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -959,8 +959,6 @@ void	 tcp_setpersist(struct tcpcb *);
 int	 tcp_signature_compute(struct mbuf *, struct tcphdr *, int, int,
 	    int, u_char *, u_int);
 #endif
-void	 tcp_slowtimo(void *);
-extern callout_t tcp_slowtimo_ch;
 void	 tcp_fasttimo(void);
 struct mbuf *
 	 tcp_template(struct tcpcb *);

Index: src/sys/netinet6/in6.c
diff -u src/sys/netinet6/in6.c:1.245.2.5 src/sys/netinet6/in6.c:1.245.2.6
--- src/sys/netinet6/in6.c:1.245.2.5	Tue Jan  2 10:56:58 2018
+++ src/sys/netinet6/in6.c	Sat Feb  3 22:07:26 2018
@@ -1,4 +1,4 @@
-/*	$NetBSD: in6.c,v 1.245.2.5 2018/01/02 10:56:58 snj Exp $	*/
+/*	$NetBSD: in6.c,v 1.245.2.6 2018/02/03 22:07:26 snj Exp $	*/
 /*	$KAME: in6.c,v 1.198 2001/07/18 09:12:38 itojun Exp $	*/
 
 /*
@@ -62,7 +62,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: in6.c,v 1.245.2.5 2018/01/02 10:56:58 snj Exp $");
+__KERNEL_RCSID(0, "$NetBSD: in6.c,v 1.245.2.6 2018/02/03 22:07:26 snj Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -1423,6 +1423,7 @@ in6_unlink_ifa(struct in6_ifaddr *ia, st
 	mutex_enter(&in6_ifaddr_lock);
 	IN6_ADDRLIST_WRITER_REMOVE(ia);
 	ifa_remove(ifp, &ia->ia_ifa);
+	/* Assume ifa_remove called pserialize_perform and psref_destroy */
 	mutex_exit(&in6_ifaddr_lock);
 
 	/*

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