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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 <ioana.ciornei@nxp.com>
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ioana Ciornei 2019-05-28 20:38:08 +03:00 committed by David S. Miller
parent 53cfca2d6b
commit 2db2d9d1ac
1 changed files with 23 additions and 10 deletions
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33
drivers/net/phy/phy_device.c
View File

@ -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);