phy: phy_ethtool_ksettings_get: Lock the phy for consistency

The PHY structure should be locked while copying information out if
it, otherwise there is no guarantee of self consistency. Without the
lock the PHY state machine could be updating the structure.

Fixes: 2d55173e ("phy: add generic function to support ksetting support")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy.c

@@ -299,6 +299,7 @@ EXPORT_SYMBOL(phy_ethtool_ksettings_set);
 void phy_ethtool_ksettings_get(struct phy_device *phydev,
 			       struct ethtool_link_ksettings *cmd)
 {
+	mutex_lock(&phydev->lock);
 	linkmode_copy(cmd->link_modes.supported, phydev->supported);
 	linkmode_copy(cmd->link_modes.advertising, phydev->advertising);
 	linkmode_copy(cmd->link_modes.lp_advertising, phydev->lp_advertising);
@@ -317,6 +318,7 @@ void phy_ethtool_ksettings_get(struct phy_device *phydev,
 	cmd->base.autoneg = phydev->autoneg;
 	cmd->base.eth_tp_mdix_ctrl = phydev->mdix_ctrl;
 	cmd->base.eth_tp_mdix = phydev->mdix;
+	mutex_unlock(&phydev->lock);
 }
 EXPORT_SYMBOL(phy_ethtool_ksettings_get);