[src/trunk]: src/sys/net Fix locking order since IFNET_LOCK must be held

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

details:   https://anonhg.NetBSD.org/src/rev/7bdf241eb38b
branches:  trunk
changeset: 1020875:7bdf241eb38b
user:      yamaguchi <yamaguchi%NetBSD.org@localhost>
date:      Mon Apr 26 02:36:45 2021 +0000

description:
Fix locking order since IFNET_LOCK must be held
before acquiring SPPP_LOCK

diffstat:

 sys/net/if_spppsubr.c |  13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)

diffs (51 lines):

diff -r b8dc5c638376 -r 7bdf241eb38b sys/net/if_spppsubr.c
--- a/sys/net/if_spppsubr.c     Mon Apr 26 00:38:23 2021 +0000
+++ b/sys/net/if_spppsubr.c     Mon Apr 26 02:36:45 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_spppsubr.c,v 1.220 2021/04/23 03:36:13 yamaguchi Exp $       */
+/*     $NetBSD: if_spppsubr.c,v 1.221 2021/04/26 02:36:45 yamaguchi Exp $       */
 
 /*
  * Synchronous PPP/Cisco link level subroutines.
@@ -41,7 +41,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.220 2021/04/23 03:36:13 yamaguchi Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.221 2021/04/26 02:36:45 yamaguchi Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_inet.h"
@@ -5542,7 +5542,10 @@
        uint32_t myaddr = 0, hisaddr = 0;
        int s;
 
+       KASSERT(SPPP_WLOCKED(sp));
+       SPPP_UNLOCK(sp);
        IFNET_LOCK(ifp);
+       SPPP_LOCK(sp, RW_WRITER);
 
        /*
         * Pick the first AF_INET address from the list,
@@ -5614,7 +5617,10 @@
        struct sockaddr_in *si, *dest;
        int s;
 
+       KASSERT(SPPP_WLOCKED(sp));
+       SPPP_UNLOCK(sp);
        IFNET_LOCK(ifp);
+       SPPP_LOCK(sp, RW_WRITER);
 
        /*
         * Pick the first AF_INET address from the list,
@@ -5740,7 +5746,10 @@
        int s;
        struct psref psref;
 
+       KASSERT(SPPP_WLOCKED(sp));
+       SPPP_UNLOCK(sp);
        IFNET_LOCK(ifp);
+       SPPP_LOCK(sp, RW_WRITER);
 
        /*
         * Pick the first link-local AF_INET6 address from the list,