6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Vladimir Oltean vladimir.oltean@nxp.com
[ 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@nxp.com Link: https://patch.msgid.link/20241205145519.1236778-3-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mscc/ocelot_ptp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
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); } }