Thu Dec 7 01:23:53 2017 UTC ()
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.


(ozaki-r)
diff -r1.406 -r1.407 src/sys/net/if.c
cvs diff -r1.406 -r1.407 src/sys/net/if.c (expand / switch to unified diff)

--- src/sys/net/if.c 2017/12/06 09:54:47 1.406
+++ src/sys/net/if.c 2017/12/07 01:23:53 1.407
@@ -1,14 +1,14 @@ @@ -1,14 +1,14 @@
1/* $NetBSD: if.c,v 1.406 2017/12/06 09:54:47 ozaki-r Exp $ */ 1/* $NetBSD: if.c,v 1.407 2017/12/07 01:23:53 ozaki-r Exp $ */
2 2
3/*- 3/*-
4 * Copyright (c) 1999, 2000, 2001, 2008 The NetBSD Foundation, Inc. 4 * Copyright (c) 1999, 2000, 2001, 2008 The NetBSD Foundation, Inc.
5 * All rights reserved. 5 * All rights reserved.
6 * 6 *
7 * This code is derived from software contributed to The NetBSD Foundation 7 * This code is derived from software contributed to The NetBSD Foundation
8 * by William Studenmund and Jason R. Thorpe. 8 * by William Studenmund and Jason R. Thorpe.
9 * 9 *
10 * Redistribution and use in source and binary forms, with or without 10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions 11 * modification, are permitted provided that the following conditions
12 * are met: 12 * are met:
13 * 1. Redistributions of source code must retain the above copyright 13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer. 14 * notice, this list of conditions and the following disclaimer.
@@ -80,27 +80,27 @@ @@ -80,27 +80,27 @@
80 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 80 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
81 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 81 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
82 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 82 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
83 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 83 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
84 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 84 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
85 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 85 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
86 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 86 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
87 * SUCH DAMAGE. 87 * SUCH DAMAGE.
88 * 88 *
89 * @(#)if.c 8.5 (Berkeley) 1/9/95 89 * @(#)if.c 8.5 (Berkeley) 1/9/95
90 */ 90 */
91 91
92#include <sys/cdefs.h> 92#include <sys/cdefs.h>
93__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.406 2017/12/06 09:54:47 ozaki-r Exp $"); 93__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.407 2017/12/07 01:23:53 ozaki-r Exp $");
94 94
95#if defined(_KERNEL_OPT) 95#if defined(_KERNEL_OPT)
96#include "opt_inet.h" 96#include "opt_inet.h"
97#include "opt_ipsec.h" 97#include "opt_ipsec.h"
98 98
99#include "opt_atalk.h" 99#include "opt_atalk.h"
100#include "opt_natm.h" 100#include "opt_natm.h"
101#include "opt_wlan.h" 101#include "opt_wlan.h"
102#include "opt_net_mpsafe.h" 102#include "opt_net_mpsafe.h"
103#endif 103#endif
104 104
105#include <sys/param.h> 105#include <sys/param.h>
106#include <sys/mbuf.h> 106#include <sys/mbuf.h>
@@ -1368,29 +1368,31 @@ if_detach(struct ifnet *ifp) @@ -1368,29 +1368,31 @@ if_detach(struct ifnet *ifp)
1368 * 1368 *
1369 * pr_usrreq calls can remove an arbitrary number of ifaddrs 1369 * pr_usrreq calls can remove an arbitrary number of ifaddrs
1370 * from the list, including our "cursor", ifa. For safety, 1370 * from the list, including our "cursor", ifa. For safety,
1371 * and to honor the TAILQ abstraction, I just restart the 1371 * and to honor the TAILQ abstraction, I just restart the
1372 * loop after each removal. Note that the loop will exit 1372 * loop after each removal. Note that the loop will exit
1373 * when all of the remaining ifaddrs belong to the AF_LINK 1373 * when all of the remaining ifaddrs belong to the AF_LINK
1374 * family. I am counting on the historical fact that at 1374 * family. I am counting on the historical fact that at
1375 * least one pr_usrreq in each address domain removes at 1375 * least one pr_usrreq in each address domain removes at
1376 * least one ifaddr. 1376 * least one ifaddr.
1377 */ 1377 */
1378again: 1378again:
1379 /* 1379 /*
1380 * At this point, no other one tries to remove ifa in the list, 1380 * At this point, no other one tries to remove ifa in the list,
1381 * so we don't need to take a lock or psref. 1381 * so we don't need to take a lock or psref. Avoid using
 1382 * IFADDR_READER_FOREACH to pass over an inspection of contract
 1383 * violations of pserialize.
1382 */ 1384 */
1383 IFADDR_READER_FOREACH(ifa, ifp) { 1385 IFADDR_WRITER_FOREACH(ifa, ifp) {
1384 family = ifa->ifa_addr->sa_family; 1386 family = ifa->ifa_addr->sa_family;
1385#ifdef IFAREF_DEBUG 1387#ifdef IFAREF_DEBUG
1386 printf("if_detach: ifaddr %p, family %d, refcnt %d\n", 1388 printf("if_detach: ifaddr %p, family %d, refcnt %d\n",
1387 ifa, family, ifa->ifa_refcnt); 1389 ifa, family, ifa->ifa_refcnt);
1388 if (last_ifa != NULL && ifa == last_ifa) 1390 if (last_ifa != NULL && ifa == last_ifa)
1389 panic("if_detach: loop detected"); 1391 panic("if_detach: loop detected");
1390 last_ifa = ifa; 1392 last_ifa = ifa;
1391#endif 1393#endif
1392 if (family == AF_LINK) 1394 if (family == AF_LINK)
1393 continue; 1395 continue;
1394 dp = pffinddomain(family); 1396 dp = pffinddomain(family);
1395 KASSERTMSG(dp != NULL, "no domain for AF %d", family); 1397 KASSERTMSG(dp != NULL, "no domain for AF %d", family);
1396 /* 1398 /*