[src/trunk]: src/sys/net Fix order in rollback case; switch if_ipsec to atomi...

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

details:   https://anonhg.NetBSD.org/src/rev/53ccb02f9af8
branches:  trunk
changeset: 1006943:53ccb02f9af8
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sat Feb 01 02:57:55 2020 +0000

description:
Fix order in rollback case; switch if_ipsec to atomic_load/store_*.

diffstat:

 sys/net/if_ipsec.c |  14 ++++++--------
 sys/net/if_ipsec.h |   5 ++---
 2 files changed, 8 insertions(+), 11 deletions(-)

diffs (89 lines):

diff -r 5fc1b24a1c44 -r 53ccb02f9af8 sys/net/if_ipsec.c
--- a/sys/net/if_ipsec.c        Sat Feb 01 02:57:45 2020 +0000
+++ b/sys/net/if_ipsec.c        Sat Feb 01 02:57:55 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_ipsec.c,v 1.26 2020/01/29 04:34:10 thorpej Exp $  */
+/*     $NetBSD: if_ipsec.c,v 1.27 2020/02/01 02:57:55 riastradh Exp $  */
 
 /*
  * Copyright (c) 2017 Internet Initiative Japan Inc.
@@ -27,13 +27,14 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_ipsec.c,v 1.26 2020/01/29 04:34:10 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_ipsec.c,v 1.27 2020/02/01 02:57:55 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
 #endif
 
 #include <sys/param.h>
+#include <sys/atomic.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
 #include <sys/mbuf.h>
@@ -1130,7 +1131,6 @@
        if_ipsec_copy_variant(nullvar, ovar);
        if_ipsec_clear_config(nullvar);
        psref_target_init(&nullvar->iv_psref, iv_psref_class);
-       membar_producer();
        /*
         * (2-3) Swap variant include its SPs.
         */
@@ -1236,7 +1236,6 @@
        if_ipsec_copy_variant(nullvar, ovar);
        if_ipsec_clear_config(nullvar);
        psref_target_init(&nullvar->iv_psref, iv_psref_class);
-       membar_producer();
        /*
         * (2-3) Swap variant include its SPs.
         */
@@ -1323,7 +1322,6 @@
        if_ipsec_copy_variant(nullvar, ovar);
        if_ipsec_clear_config(nullvar);
        psref_target_init(&nullvar->iv_psref, iv_psref_class);
-       membar_producer();
        /*
         * (2-3) Swap variant include its SPs.
         */
@@ -1894,16 +1892,16 @@
         * we stop packet processing while replacing SPs, that is, we set
         * "null" config variant to sc->ipsec_var.
         */
-       sc->ipsec_var = nullvar;
+       atomic_store_release(&sc->ipsec_var, nullvar);
        pserialize_perform(sc->ipsec_psz);
        psref_target_destroy(&ovar->iv_psref, iv_psref_class);
 
        error = if_ipsec_replace_sp(sc, ovar, nvar);
        if (!error)
-               sc->ipsec_var = nvar;
+               atomic_store_release(&sc->ipsec_var, nvar);
        else {
-               sc->ipsec_var = ovar; /* rollback */
                psref_target_init(&ovar->iv_psref, iv_psref_class);
+               atomic_store_release(&sc->ipsec_var, ovar); /* rollback */
        }
 
        pserialize_perform(sc->ipsec_psz);
diff -r 5fc1b24a1c44 -r 53ccb02f9af8 sys/net/if_ipsec.h
--- a/sys/net/if_ipsec.h        Sat Feb 01 02:57:45 2020 +0000
+++ b/sys/net/if_ipsec.h        Sat Feb 01 02:57:55 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_ipsec.h,v 1.6 2019/11/01 04:28:14 knakahara Exp $  */
+/*     $NetBSD: if_ipsec.h,v 1.7 2020/02/01 02:57:55 riastradh Exp $  */
 
 /*
  * Copyright (c) 2017 Internet Initiative Japan Inc.
@@ -165,9 +165,8 @@
        int s;
 
        s = pserialize_read_enter();
-       var = sc->ipsec_var;
+       var = atomic_load_consume(&sc->ipsec_var);
        KASSERT(var != NULL);
-       membar_datadep_consumer();
        psref_acquire(psref, &var->iv_psref, iv_psref_class);
        pserialize_read_exit(s);