net: dsa: sja1105: reject other RX filters than HWTSTAMP_FILTER_PTP_V2_L2_EVENT

This is all that we can support timestamping, so we shouldn't accept
anything else. Also see sja1105_hwtstamp_get().

To avoid erroring out in an inconsistent state, operate on copies of
priv->hwts_rx_en and priv->hwts_tx_en, and write them back when nothing
else can fail anymore.

Fixes: a602afd200f5 ("net: dsa: sja1105: Expose PTP timestamping ioctls to userspace")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250318115716.2124395-3-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/dsa/sja1105/sja1105_ptp.c b/drivers/net/dsa/sja1105/sja1105_ptp.c
index a1f4ca6ad888f1b643a201e6925e835a9be9f132..08b45fdd1d2482b0f1f922aae4ff18db8e279f09 100644 (file)
--- a/drivers/net/dsa/sja1105/sja1105_ptp.c
+++ b/drivers/net/dsa/sja1105/sja1105_ptp.c
@@ -61,17 +61,21 @@ enum sja1105_ptp_clk_mode {
 int sja1105_hwtstamp_set(struct dsa_switch *ds, int port, struct ifreq *ifr)
 {
        struct sja1105_private *priv = ds->priv;
+       unsigned long hwts_tx_en, hwts_rx_en;
        struct hwtstamp_config config;
 
        if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
                return -EFAULT;
 
+       hwts_tx_en = priv->hwts_tx_en;
+       hwts_rx_en = priv->hwts_rx_en;
+
        switch (config.tx_type) {
        case HWTSTAMP_TX_OFF:
-               priv->hwts_tx_en &= ~BIT(port);
+               hwts_tx_en &= ~BIT(port);
                break;
        case HWTSTAMP_TX_ON:
-               priv->hwts_tx_en |= BIT(port);
+               hwts_tx_en |= BIT(port);
                break;
        default:
                return -ERANGE;
@@ -79,15 +83,21 @@ int sja1105_hwtstamp_set(struct dsa_switch *ds, int port, struct ifreq *ifr)
 
        switch (config.rx_filter) {
        case HWTSTAMP_FILTER_NONE:
-               priv->hwts_rx_en &= ~BIT(port);
+               hwts_rx_en &= ~BIT(port);
                break;
-       default:
-               priv->hwts_rx_en |= BIT(port);
+       case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
+               hwts_rx_en |= BIT(port);
                break;
+       default:
+               return -ERANGE;
        }
 
        if (copy_to_user(ifr->ifr_data, &config, sizeof(config)))
                return -EFAULT;
+
+       priv->hwts_tx_en = hwts_tx_en;
+       priv->hwts_rx_en = hwts_rx_en;
+
        return 0;
 }