Messages in this thread | | | Date | Thu, 8 Sep 2022 09:10:15 +0200 | Subject | Re: [PATCH 1/2] can: bcm: registration process optimization in bcm_module_init() | From | Oliver Hartkopp <> |
| |
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@huawei.com> > --- > 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@huawei.com/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)
| |