[PATCH 5.10 012/105] net: move net_set_todo inside rollback_registered()

Greg Kroah-Hartman
2022-07-27T16:48:07Z

From: Fedor Pchelkin <pchelkin@ispras.ru>

From: Jakub Kicinski <kuba@kernel.org>

commit 2014beea7eb165c745706b13659a0f1d0a9a2a61 upstream.

Commit 93ee31f14f6f ("[NET]: Fix free_netdev on register_netdev
failure.") moved net_set_todo() outside of rollback_registered()
so that rollback_registered() can be used in the failure path of
register_netdevice() but without risking a double free.

Since commit cf124db566e6 ("net: Fix inconsistent teardown and
release of private netdev state."), however, we have a better
way of handling that condition, since destructors don't call
free_netdev() directly.

After the change in commit c269a24ce057 ("net: make free_netdev()
more lenient with unregistering devices") we can now move
net_set_todo() back.

Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/core/dev.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9595,8 +9595,10 @@ static void rollback_registered_many(str

synchronize_net();

- list_for_each_entry(dev, head, unreg_list)
+ list_for_each_entry(dev, head, unreg_list) {
dev_put(dev);
+ net_set_todo(dev);
+ }
}

static void rollback_registered(struct net_device *dev)
@@ -10147,7 +10149,6 @@ int register_netdevice(struct net_device
/* Expect explicit free_netdev() on failure */
dev->needs_free_netdev = false;
rollback_registered(dev);
- net_set_todo(dev);
goto out;
}
/*
@@ -10755,8 +10756,6 @@ void unregister_netdevice_queue(struct n
list_move_tail(&dev->unreg_list, head);
} else {
rollback_registered(dev);
- /* Finish processing unregister after unlock */
- net_set_todo(dev);
}
}
EXPORT_SYMBOL(unregister_netdevice_queue);
@@ -10770,12 +10769,8 @@ EXPORT_SYMBOL(unregister_netdevice_queue
*/
void unregister_netdevice_many(struct list_head *head)
{
- struct net_device *dev;
-
if (!list_empty(head)) {
rollback_registered_many(head);
- list_for_each_entry(dev, head, unreg_list)
- net_set_todo(dev);
list_del(head);
}
}