> On 1 Sep 2018, at 6:06, YueHaibing <yuehaibing@xxxxxxxxxx> wrote:
>
> Fixes gcc '-Wunused-but-set-variable' warning:
>
> drivers/net/net_failover.c: In function 'net_failover_slave_unregister':
> drivers/net/net_failover.c:598:35: warning:
> variable 'primary_dev' set but not used [-Wunused-but-set-variable]
>
> There should check the validity of 'slave_dev'.
>
> Fixes: cfc80d9a1163 ("net: Introduce net_failover driver")
> Suggested-by: Samudrala, Sridhar <sridhar.samudrala@xxxxxxxxx>
> Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
> ---
> drivers/net/net_failover.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/net/net_failover.c b/drivers/net/net_failover.c
> index 7ae1856..af1ece8 100644
> --- a/drivers/net/net_failover.c
> +++ b/drivers/net/net_failover.c
> @@ -602,6 +602,9 @@ static int net_failover_slave_unregister(struct net_device *slave_dev,
> nfo_info = netdev_priv(failover_dev);
> primary_dev = rtnl_dereference(nfo_info->primary_dev);
> standby_dev = rtnl_dereference(nfo_info->standby_dev);
> +
> + if (slave_dev != primary_dev && slave_dev != standby_dev)
> + return -ENODEV;
As this condition signals a bug, I think we should instead:
if (WARN_ON_ONCE((slave_dev != primary_dev) && (slave_dev != standby_dev))
return -ENODEV;
>
> vlan_vids_del_by_dev(slave_dev, failover_dev);
> dev_uc_unsync(slave_dev, failover_dev);
>
