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Commit 7322967b authored by Russell King's avatar Russell King Committed by David S. Miller
Browse files

phy: add proper phy struct device refcounting 



Take a refcount on the phy struct device when the phy device is attached
to a network device, and drop it after it's detached.  This ensures that
a refcount is held on the phy device while the device is being used by
a network device, thereby preventing the phy_device from being
unexpectedly kfree()'d by phy_device_release().

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3e3aaf64

drivers/net/phy/phy_device.c

+12 −0
Original line number Original line Diff line number Diff line
@@ -578,6 +578,7 @@ EXPORT_SYMBOL(phy_init_hw); 
 *     generic driver is used.  The phy_device is given a ptr to

 *     generic driver is used.  The phy_device is given a ptr to

 *     the attaching device, and given a callback for link status

 *     the attaching device, and given a callback for link status

 *     change.  The phy_device is returned to the attaching driver.

 *     change.  The phy_device is returned to the attaching driver.

 *     This function takes a reference on the phy device.

 */

 */

int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,

int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,

		      u32 flags, phy_interface_t interface)

		      u32 flags, phy_interface_t interface)
@@ -591,6 +592,8 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, 
		return -EIO;

		return -EIO;

	}

	}





	get_device(d);



	/* Assume that if there is no driver, that it doesn't

	/* Assume that if there is no driver, that it doesn't

	 * exist, and we should use the genphy driver.

	 * exist, and we should use the genphy driver.

	 */

	 */
@@ -636,6 +639,7 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev, 
	return err;

	return err;





error:

error:

	put_device(d);

	module_put(bus->owner);

	module_put(bus->owner);

	return err;

	return err;

}

}
@@ -679,6 +683,9 @@ EXPORT_SYMBOL(phy_attach); 
/**

/**

 * phy_detach - detach a PHY device from its network device

 * phy_detach - detach a PHY device from its network device

 * @phydev: target phy_device struct

 * @phydev: target phy_device struct

 *

 * This detaches the phy device from its network device and the phy

 * driver, and drops the reference count taken in phy_attach_direct().

 */

 */

void phy_detach(struct phy_device *phydev)

void phy_detach(struct phy_device *phydev)

{

{
@@ -701,8 +708,13 @@ void phy_detach(struct phy_device *phydev) 
		}

		}

	}

	}





	/*

	 * The phydev might go away on the put_device() below, so avoid

	 * a use-after-free bug by reading the underlying bus first.

	 */

	bus = phydev->bus;

	bus = phydev->bus;





	put_device(&phydev->dev);

	module_put(bus->owner);

	module_put(bus->owner);

}

}

EXPORT_SYMBOL(phy_detach);

EXPORT_SYMBOL(phy_detach);