diff mbox series

[net-next,v4,1/9] net: free_netdev: exit earlier if dummy

Message ID 20240409125738.1824983-2-leitao@debian.org (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series allocate dummy device dynamically | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next, async
netdev/apply fail Patch does not apply to net-next-1

Commit Message

Breno Leitao April 9, 2024, 12:57 p.m. UTC
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 for dummy devices, 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(-)

Comments

Jakub Kicinski April 10, 2024, 1:46 a.m. UTC | #1
On Tue,  9 Apr 2024 05:57:15 -0700 Breno Leitao wrote:
> 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 for dummy devices, 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()).

There's a small fuzz when applying due to the phy topo changes
landing, please rebase, the CI didn't ingest it right.
diff mbox series

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index 92f5bddbc2de..bf0a335781aa 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -11051,7 +11051,8 @@  void free_netdev(struct net_device *dev)
 	dev->xdp_bulkq = NULL;
 
 	/*  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;
 	}