[PATCH net-next v5 02/10] net: free_netdev: exit earlier if dummy

Breno Leitao
2024-04-10T13:18:20Z

For dummy devices, exit earlier at free_netdev() instead of executing
the whole function. This is necessary, because dummy devices are
special, and shouldn't have the second part of the function executed.

Otherwise reg_state, which is NETREG_DUMMY, will be overwritten and
there will be no way to identify that this is a dummy device. Also, this
device do not need the final put_device(), since dummy devices are not
registered (through register_netdevice()), where the device reference is
increased (at netdev_register_kobject()/device_add()).

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
---
net/core/dev.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 987039ffa63c..c74b42bc6888 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -11060,7 +11060,8 @@ void free_netdev(struct net_device *dev)
phy_link_topo_destroy(dev->link_topo);

/* Compatibility with error handling in drivers */
- if (dev->reg_state == NETREG_UNINITIALIZED) {
+ if (dev->reg_state == NETREG_UNINITIALIZED ||
+ dev->reg_state == NETREG_DUMMY) {
netdev_freemem(dev);
return;
}
--
2.43.0