From 2db2d9d1ac37222cd9cd9b59bfd7f9cea3bd2457 Mon Sep 17 00:00:00 2001 From: Ioana Ciornei Date: Tue, 28 May 2019 20:38:08 +0300 Subject: [PATCH] net: phy: Guard against the presence of a netdev A prerequisite for PHYLIB to work in the absence of a struct net_device is to not access pointers to it. Changes are needed in the following areas: - Printing: In some places netdev_err was replaced with phydev_err. - Incrementing reference count to the parent MDIO bus driver: If there is no net device, then the reference count should definitely be incremented since there is no chance that it was an Ethernet driver who registered the MDIO bus. - Sysfs links are not created in case there is no attached_dev. - No netif_carrier_off is done if there is no attached_dev. Signed-off-by: Ioana Ciornei Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/phy/phy_device.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 8fd1bf37718b..da3bf3f70d63 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1138,6 +1138,9 @@ static void phy_sysfs_create_links(struct phy_device *phydev) struct net_device *dev = phydev->attached_dev; int err; + if (!dev) + return; + err = sysfs_create_link(&phydev->mdio.dev.kobj, &dev->dev.kobj, "attached_dev"); if (err) @@ -1176,9 +1179,9 @@ static void phy_sysfs_create_links(struct phy_device *phydev) int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, u32 flags, phy_interface_t interface) { - struct module *ndev_owner = dev->dev.parent->driver->owner; struct mii_bus *bus = phydev->mdio.bus; struct device *d = &phydev->mdio.dev; + struct module *ndev_owner = NULL; bool using_genphy = false; int err; @@ -1187,8 +1190,10 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, * our own module->refcnt here, otherwise we would not be able to * unload later on. */ + if (dev) + ndev_owner = dev->dev.parent->driver->owner; if (ndev_owner != bus->owner && !try_module_get(bus->owner)) { - dev_err(&dev->dev, "failed to get the bus module\n"); + phydev_err(phydev, "failed to get the bus module\n"); return -EIO; } @@ -1207,7 +1212,7 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, } if (!try_module_get(d->driver->owner)) { - dev_err(&dev->dev, "failed to get the device driver module\n"); + phydev_err(phydev, "failed to get the device driver module\n"); err = -EIO; goto error_put_device; } @@ -1228,8 +1233,10 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, } phydev->phy_link_change = phy_link_change; - phydev->attached_dev = dev; - dev->phydev = phydev; + if (dev) { + phydev->attached_dev = dev; + dev->phydev = phydev; + } /* Some Ethernet drivers try to connect to a PHY device before * calling register_netdevice() -> netdev_register_kobject() and @@ -1252,7 +1259,8 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, /* Initial carrier state is off as the phy is about to be * (re)initialized. */ - netif_carrier_off(phydev->attached_dev); + if (dev) + netif_carrier_off(phydev->attached_dev); /* Do initial configuration here, now that * we have certain key parameters @@ -1358,16 +1366,19 @@ EXPORT_SYMBOL_GPL(phy_driver_is_genphy_10g); void phy_detach(struct phy_device *phydev) { struct net_device *dev = phydev->attached_dev; - struct module *ndev_owner = dev->dev.parent->driver->owner; + struct module *ndev_owner = NULL; struct mii_bus *bus; if (phydev->sysfs_links) { - sysfs_remove_link(&dev->dev.kobj, "phydev"); + if (dev) + sysfs_remove_link(&dev->dev.kobj, "phydev"); sysfs_remove_link(&phydev->mdio.dev.kobj, "attached_dev"); } phy_suspend(phydev); - phydev->attached_dev->phydev = NULL; - phydev->attached_dev = NULL; + if (dev) { + phydev->attached_dev->phydev = NULL; + phydev->attached_dev = NULL; + } phydev->phylink = NULL; phy_led_triggers_unregister(phydev); @@ -1390,6 +1401,8 @@ void phy_detach(struct phy_device *phydev) bus = phydev->mdio.bus; put_device(&phydev->mdio.dev); + if (dev) + ndev_owner = dev->dev.parent->driver->owner; if (ndev_owner != bus->owner) module_put(bus->owner); -- 2.30.2