This is a note to let you know that I've just added the patch titled
net: mscc: ocelot: improve handling of TX timestamp for unknown skb
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-mscc-ocelot-improve-handling-of-tx-timestamp-for.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 14debaad48994d49905113ff4ec1edc07e2d6da5
Author: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Date: Thu Dec 5 16:55:16 2024 +0200
net: mscc: ocelot: improve handling of TX timestamp for unknown skb
[ Upstream commit b6fba4b3f0becb794e274430f3a0839d8ba31262 ]
This condition, theoretically impossible to trigger, is not really
handled well. By "continuing", we are skipping the write to SYS_PTP_NXT
which advances the timestamp FIFO to the next entry. So we are reading
the same FIFO entry all over again, printing stack traces and eventually
killing the kernel.
No real problem has been observed here. This is part of a larger rework
of the timestamp IRQ procedure, with this logical change split out into
a patch of its own. We will need to "goto next_ts" for other conditions
as well.
Fixes: 9fde506e0c53 ("net: mscc: ocelot: warn when a PTP IRQ is raised for an unknown skb")
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Link: https://patch.msgid.link/20241205145519.1236778-3-vladimir.oltean@xxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/mscc/ocelot_ptp.c b/drivers/net/ethernet/mscc/ocelot_ptp.c
index 3c22652879ac..1386fb2ff4a9 100644
--- a/drivers/net/ethernet/mscc/ocelot_ptp.c
+++ b/drivers/net/ethernet/mscc/ocelot_ptp.c
@@ -790,7 +790,7 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
spin_unlock_irqrestore(&port->tx_skbs.lock, flags);
if (WARN_ON(!skb_match))
- continue;
+ goto next_ts;
if (!ocelot_validate_ptp_skb(skb_match, seqid)) {
dev_err_ratelimited(ocelot->dev,
@@ -808,7 +808,7 @@ void ocelot_get_txtstamp(struct ocelot *ocelot)
shhwtstamps.hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
skb_complete_tx_timestamp(skb_match, &shhwtstamps);
- /* Next ts */
+next_ts:
ocelot_write(ocelot, SYS_PTP_NXT_PTP_NXT, SYS_PTP_NXT);
}
}
