On 08.09.22 05:04, Ziyang Xuan wrote:
Now, register_netdevice_notifier() and register_pernet_subsys() are both
after can_proto_register(). It can create CAN_BCM socket and process socket
once can_proto_register() successfully, so it is possible missing notifier
event or proc node creation because notifier or bcm proc directory is not
registered or created yet. Although this is a low probability scenario, it
is not impossible.
Move register_pernet_subsys() and register_netdevice_notifier() to the
front of can_proto_register(). In addition, register_pernet_subsys() and
register_netdevice_notifier() may fail, check their results are necessary.
Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
---
net/can/bcm.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/net/can/bcm.c b/net/can/bcm.c
index e60161bec850..e2783156bfd1 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -1744,15 +1744,27 @@ static int __init bcm_module_init(void)
pr_info("can: broadcast manager protocol\n");
+ err = register_pernet_subsys(&canbcm_pernet_ops);
+ if (err)
+ return err;
Analogue to your patch for the CAN_RAW socket here (which has been
applied to can-next right now) ...
https://lore.kernel.org/linux-can/7af9401f0d2d9fed36c1667b5ac9b8df8f8b87ee.1661584485.git.william.xuanziyang@xxxxxxxxxx/T/#u
... I'm not sure whether this is the right sequence to acquire the
different resources here.
E.g. in ipsec_pfkey_init() in af_key.c
https://elixir.bootlin.com/linux/v5.19.7/source/net/key/af_key.c#L3887
proto_register() is executed before register_pernet_subsys()
Which seems to be more natural to me.
Best regards,
Oliver
+
+ err = register_netdevice_notifier(&canbcm_notifier);
+ if (err)
+ goto register_notifier_failed;
+
err = can_proto_register(&bcm_can_proto);
if (err < 0) {
printk(KERN_ERR "can: registration of bcm protocol failed\n");
- return err;
+ goto register_proto_failed;
}
- register_pernet_subsys(&canbcm_pernet_ops);
- register_netdevice_notifier(&canbcm_notifier);
return 0;
+
+register_proto_failed:
+ unregister_netdevice_notifier(&canbcm_notifier);
+register_notifier_failed:
+ unregister_pernet_subsys(&canbcm_pernet_ops);
+ return err;
}
static void __exit bcm_module_exit(void)
