Commit 2db2d9d1 authored by Ioana Ciornei's avatar Ioana Ciornei Committed by David S. Miller
Browse files

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: default avatarIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: default avatarVladimir Oltean <olteanv@gmail.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 53cfca2d

drivers/net/phy/phy_device.c

+23 −10
Original line number Diff line number Diff line
@@ -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;

	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
@@ -1252,6 +1259,7 @@ 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.

	 */

	if (dev)

		netif_carrier_off(phydev->attached_dev);



	/* Do initial configuration here, now that
@@ -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) {

		if (dev)

			sysfs_remove_link(&dev->dev.kobj, "phydev");

		sysfs_remove_link(&phydev->mdio.dev.kobj, "attached_dev");

	}

	phy_suspend(phydev);

	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);

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