Module Name: src
Committed By: riastradh
Date: Mon Jul 29 16:01:13 UTC 2024
Modified Files:
src/sys/net: if_wg.c
Log Message:
wg(4): Omit needless atomic_load.
wgs_local_index is only ever written to while only one thread has
access to it and it is not in the thmap -- before it is published in
wg_get_session_index, and after it is unpublished in
wg_destroy_session. So no need for atomic_load -- it is stable if we
observe it in thmap_get result.
(Of course this is only for an assertion, which if tripped obviously
indicates a violation of our assumptions. But if that happens, well,
in the worst case we'll see a weird assertion message claiming that
the index is not equal to itself, which from which we can conclude
there must have been a concurrent update, which is good enough to
help diagnose that problem without any atomic_load.)
Tidying some of the changes for:
PR kern/55729: net/if_wg/t_misc:wg_rekey test case fails
PR kern/56252: wg(4) state machine has race conditions
PR kern/58463: if_wg does not work when idle.
To generate a diff of this commit:
cvs rdiff -u -r1.119 -r1.120 src/sys/net/if_wg.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/if_wg.c
diff -u src/sys/net/if_wg.c:1.119 src/sys/net/if_wg.c:1.120
--- src/sys/net/if_wg.c:1.119 Mon Jul 29 16:00:41 2024
+++ src/sys/net/if_wg.c Mon Jul 29 16:01:13 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: if_wg.c,v 1.119 2024/07/29 16:00:41 riastradh Exp $ */
+/* $NetBSD: if_wg.c,v 1.120 2024/07/29 16:01:13 riastradh Exp $ */
/*
* Copyright (C) Ryota Ozaki <ozaki.ry...@gmail.com>
@@ -41,7 +41,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.119 2024/07/29 16:00:41 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.120 2024/07/29 16:01:13 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_altq_enabled.h"
@@ -2490,11 +2490,9 @@ wg_lookup_session_by_index(struct wg_sof
int s = pserialize_read_enter();
wgs = thmap_get(wg->wg_sessions_byindex, &index, sizeof index);
if (wgs != NULL) {
- uint32_t oindex __diagused =
- atomic_load_relaxed(&wgs->wgs_local_index);
- KASSERTMSG(index == oindex,
+ KASSERTMSG(index == wgs->wgs_local_index,
"index=%"PRIx32" wgs->wgs_local_index=%"PRIx32,
- index, oindex);
+ index, wgs->wgs_local_index);
psref_acquire(psref, &wgs->wgs_psref, wg_psref_class);
}
pserialize_read_exit(s);
