From: Simon Wunderlich <sw@simonwunderlich.de>
To: netdev@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>,
b.a.t.m.a.n@lists.open-mesh.org,
Sven Eckelmann <sven@narfation.org>,
stable@kernel.org, Simon Wunderlich <sw@simonwunderlich.de>
Subject: [PATCH net 08/15] batman-adv: tp_meter: annotate last_recv_time access with READ/WRITE_ONCE
Date: Fri, 19 Jun 2026 09:00:38 +0200 [thread overview]
Message-ID: <20260619070045.438101-9-sw@simonwunderlich.de> (raw)
In-Reply-To: <20260619070045.438101-1-sw@simonwunderlich.de>
From: Sven Eckelmann <sven@narfation.org>
The last_recv_time field for batadv_tp_receiver tracks the jiffies value of
the most recent activity and is used to detect timeouts. These accesses are
not consistently protected by a lock, so READ_ONCE/WRITE_ONCE must be used
to prevent data races caused by compiler optimizations.
Cc: stable@kernel.org
Fixes: 33a3bb4a3345 ("batman-adv: throughput meter implementation")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
net/batman-adv/tp_meter.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c
index 259ac8c307359..fb87fa141e32a 100644
--- a/net/batman-adv/tp_meter.c
+++ b/net/batman-adv/tp_meter.c
@@ -1290,7 +1290,7 @@ static void batadv_tp_receiver_shutdown(struct timer_list *t)
bat_priv = tp_vars->common.bat_priv;
/* if there is recent activity rearm the timer */
- if (!batadv_has_timed_out(tp_vars->last_recv_time,
+ if (!batadv_has_timed_out(READ_ONCE(tp_vars->last_recv_time),
BATADV_TP_RECV_TIMEOUT)) {
/* reset the receiver shutdown timer */
batadv_tp_reset_receiver_timer(tp_vars);
@@ -1532,7 +1532,7 @@ batadv_tp_init_recv(struct batadv_priv *bat_priv,
tp_vars = batadv_tp_list_find_receiver_session(bat_priv, icmp->orig,
icmp->session);
if (tp_vars) {
- tp_vars->last_recv_time = jiffies;
+ WRITE_ONCE(tp_vars->last_recv_time, jiffies);
goto out_unlock;
}
@@ -1562,7 +1562,7 @@ batadv_tp_init_recv(struct batadv_priv *bat_priv,
kref_get(&tp_vars->common.refcount);
timer_setup(&tp_vars->common.timer, batadv_tp_receiver_shutdown, 0);
- tp_vars->last_recv_time = jiffies;
+ WRITE_ONCE(tp_vars->last_recv_time, jiffies);
kref_get(&tp_vars->common.refcount);
hlist_add_head_rcu(&tp_vars->common.list, &bat_priv->tp_receiver_list);
@@ -1613,7 +1613,7 @@ static void batadv_tp_recv_msg(struct batadv_priv *bat_priv,
goto out;
}
- tp_vars->last_recv_time = jiffies;
+ WRITE_ONCE(tp_vars->last_recv_time, jiffies);
}
/* if the packet is a duplicate, it may be the case that an ACK has been
--
2.47.3
next prev parent reply other threads:[~2026-06-19 7:00 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-19 7:00 [PATCH net 00/15] pull request: batman-adv 2026-06-19 Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 01/15] batman-adv: gw: don't deselect gateway with active hardif Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 02/15] batman-adv: ensure bcast is writable before modifying TTL Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 03/15] batman-adv: fix (m|b)cast csum after decrementing TTL Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 04/15] batman-adv: frag: ensure fragment is writable before modifying TTL Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 05/15] batman-adv: frag: avoid underflow of TTL Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 06/15] batman-adv: v: prevent OGM aggregation on disabled hardif Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 07/15] batman-adv: tp_meter: restrict number of unacked list entries Simon Wunderlich
2026-06-19 7:00 ` Simon Wunderlich [this message]
2026-06-19 7:00 ` [PATCH net 09/15] batman-adv: tp_meter: prevent parallel modifications of last_recv Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 10/15] batman-adv: tp_meter: handle overlapping packets Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 11/15] batman-adv: tt: don't merge change entries with different VIDs Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 12/15] batman-adv: tt: track roam count per VID Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 13/15] batman-adv: dat: prevent false sharing between VLANs Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 14/15] batman-adv: tvlv: enforce 2-byte alignment Simon Wunderlich
2026-06-19 7:00 ` [PATCH net 15/15] batman-adv: tvlv: avoid race of cifsnotfound handler state Simon Wunderlich
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