Re: [PATCH net v2] hsr: Handle failures in module init

[Shigeru Yoshida <syoshida@redhat.com>]

On Fri, 15 Mar 2024 13:04:52 +0100, Felix Maurer wrote:
> A failure during registration of the netdev notifier was not handled at
> all. A failure during netlink initialization did not unregister the netdev
> notifier.
> 
> Handle failures of netdev notifier registration and netlink initialization.
> Both functions should only return negative values on failure and thereby
> lead to the hsr module not being loaded.
> 
> Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
> Signed-off-by: Felix Maurer <fmaurer@redhat.com>

The patch LGTM. Module initialization errors are handled
correctly. Netdev notifier is correctly unregistered when netlink
initialization fails.

Reviewed-by: Shigeru Yoshida <syoshida@redhat.com>

> ---
>  net/hsr/hsr_main.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/net/hsr/hsr_main.c b/net/hsr/hsr_main.c
> index cb83c8feb746..9756e657bab9 100644
> --- a/net/hsr/hsr_main.c
> +++ b/net/hsr/hsr_main.c
> @@ -148,14 +148,21 @@ static struct notifier_block hsr_nb = {
>  
>  static int __init hsr_init(void)
>  {
> -	int res;
> +	int err;
>  
>  	BUILD_BUG_ON(sizeof(struct hsr_tag) != HSR_HLEN);
>  
> -	register_netdevice_notifier(&hsr_nb);
> -	res = hsr_netlink_init();
> +	err = register_netdevice_notifier(&hsr_nb);
> +	if (err)
> +		return err;
> +
> +	err = hsr_netlink_init();
> +	if (err) {
> +		unregister_netdevice_notifier(&hsr_nb);
> +		return err;
> +	}
>  
> -	return res;
> +	return 0;
>  }
>  
>  static void __exit hsr_exit(void)
> -- 
> 2.44.0
> 
>