net: fix net_device refcounting

of_find_net_device_by_node() uses class_find_device() internally to
lookup the corresponding network device.  class_find_device() returns
a reference to the embedded struct device, with its refcount
incremented.

Add a comment to the definition in net/core/net-sysfs.c indicating the
need to drop this refcount, and fix the DSA code to drop this refcount
when the OF-generated platform data is cleaned up and freed.  Also
arrange for the ref to be dropped when handling errors.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Russell King 2015-09-24 20:36:33 +01:00 committed by David S. Miller
parent 38737e490d
commit 9861f72074
2 changed files with 13 additions and 1 deletions

View File

@ -1481,6 +1481,15 @@ static int of_dev_node_match(struct device *dev, const void *data)
return ret == 0 ? dev->of_node == data : ret;
}
/*
* of_find_net_device_by_node - lookup the net device for the device node
* @np: OF device node
*
* Looks up the net_device structure corresponding with the device node.
* If successful, returns a pointer to the net_device with the embedded
* struct device refcount incremented by one, or NULL on failure. The
* refcount must be dropped when done with the net_device.
*/
struct net_device *of_find_net_device_by_node(struct device_node *np)
{
struct device *dev;

View File

@ -679,7 +679,7 @@ static int dsa_of_probe(struct device *dev)
pd = kzalloc(sizeof(*pd), GFP_KERNEL);
if (!pd) {
ret = -ENOMEM;
goto out_put_mdio;
goto out_put_ethernet;
}
dev->platform_data = pd;
@ -773,6 +773,8 @@ static int dsa_of_probe(struct device *dev)
out_free:
kfree(pd);
dev->platform_data = NULL;
out_put_ethernet:
put_device(&ethernet_dev->dev);
out_put_mdio:
put_device(&mdio_bus->dev);
return ret;
@ -786,6 +788,7 @@ static void dsa_of_remove(struct device *dev)
return;
dsa_of_free_platform_data(pd);
put_device(&pd->of_netdev->dev);
kfree(pd);
}
#else