[src/trunk]: src/sys/netipsec Don't call key_ismyaddr, which may sleep, in a ...

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

details:   https://anonhg.NetBSD.org/src/rev/563a13715c77
branches:  trunk
changeset: 992293:563a13715c77
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Thu Aug 23 01:55:38 2018 +0000

description:
Don't call key_ismyaddr, which may sleep, in a pserialize read section

Use mutex here instead of pserialize because using mutex is simpler than
using psz+ref, which is another solution, and key_checkspidup isn't called in
any performance-sensitive paths.

diffstat:

 sys/netipsec/key.c |  14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diffs (50 lines):

diff -r d123b75e7141 -r 563a13715c77 sys/netipsec/key.c
--- a/sys/netipsec/key.c        Thu Aug 23 01:25:22 2018 +0000
+++ b/sys/netipsec/key.c        Thu Aug 23 01:55:38 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: key.c,v 1.256 2018/07/04 19:20:25 christos Exp $       */
+/*     $NetBSD: key.c,v 1.257 2018/08/23 01:55:38 ozaki-r Exp $        */
 /*     $FreeBSD: key.c,v 1.3.2.3 2004/02/14 22:23:23 bms Exp $ */
 /*     $KAME: key.c,v 1.191 2001/06/27 10:46:49 sakane Exp $   */
 
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: key.c,v 1.256 2018/07/04 19:20:25 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: key.c,v 1.257 2018/08/23 01:55:38 ozaki-r Exp $");
 
 /*
  * This code is referred to RFC 2367
@@ -3455,7 +3455,6 @@
 {
        struct secashead *sah;
        struct secasvar *sav;
-       int s;
 
        /* check address family */
        if (saidx->src.sa.sa_family != saidx->dst.sa.sa_family) {
@@ -3466,18 +3465,19 @@
        }
 
        /* check all SAD */
-       s = pserialize_read_enter();
-       SAHLIST_READER_FOREACH(sah) {
+       /* key_ismyaddr may sleep, so use mutex, not pserialize, here. */
+       mutex_enter(&key_sad.lock);
+       SAHLIST_WRITER_FOREACH(sah) {
                if (!key_ismyaddr((struct sockaddr *)&sah->saidx.dst))
                        continue;
                sav = key_getsavbyspi(sah, spi);
                if (sav != NULL) {
-                       pserialize_read_exit(s);
                        KEY_SA_UNREF(&sav);
+                       mutex_exit(&key_sad.lock);
                        return true;
                }
        }
-       pserialize_read_exit(s);
+       mutex_exit(&key_sad.lock);
 
        return false;
 }