Re: [PATCH net] net: stmmac: initialize ptp_lock at probe time
From: Maxime Chevallier <maxime.chevallier@bootlin.com>
Date: 2026-09-04 11:30:49
Also in:
linux-arm-kernel
Hi, On 9/4/26 12:32, Lorenzo Bianconi wrote:
priv->ptp_lock is only initialized in stmmac_ptp_register(), which runs
during __stmmac_open(). However, the lock is also used while the
interface is down and has never been opened: tc_taprio_configure()
invokes the PTP gettime64() callback to compute the EST base time when
offloading a TAPRIO schedule, and stmmac_get_time() takes
priv->ptp_lock. Using an uninitialized rwlock is undefined behaviour.
Move the rwlock_init() to __stmmac_dvr_probe(), together with the other
private locks, so that ptp_lock is always valid regardless of the
interface state.
Fixes: b60189e0392f ("net: stmmac: Integrate EST with TAPRIO scheduler API")
Signed-off-by: Lorenzo Bianconi <redacted>Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Maxime
quoted hunk ↗ jump to hunk
--- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 1 + drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c | 1 - 2 files changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 24656b35350b..5fe7e95fdd34 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c@@ -8025,6 +8025,7 @@ static int __stmmac_dvr_probe(struct device *device, stmmac_napi_add(ndev); mutex_init(&priv->lock); + rwlock_init(&priv->ptp_lock); stmmac_fpe_init(priv);diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c index 960249960004..3bfcc9760dce 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c@@ -365,7 +365,6 @@ void stmmac_ptp_register(struct stmmac_priv *priv) if (priv->plat->crosststamp) priv->ptp_clock_ops.getcrosststamp = stmmac_getcrosststamp; - rwlock_init(&priv->ptp_lock); mutex_init(&priv->aux_ts_lock); priv->ptp_clock = ptp_clock_register(&priv->ptp_clock_ops,--- base-commit: 641d03105cc0d2437e32fdeec164f91a4ccef6c4 change-id: 20260904-stmmac-fix-ptp-clock-init-b8eba4328243 Best regards,