RE: [PATCH net-next v6 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[Emeel Hakim <ehakim@nvidia.com>]

> -----Original Message-----
> From: Sabrina Dubroca <sd@queasysnail.net>
> Sent: Sunday, 8 January 2023 1:05
> To: Emeel Hakim <ehakim@nvidia.com>
> Cc: netdev@vger.kernel.org; Raed Salem <raeds@nvidia.com>;
> davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> pabeni@redhat.com; atenart@kernel.org
> Subject: Re: [PATCH net-next v6 1/2] macsec: add support for
> IFLA_MACSEC_OFFLOAD in macsec_changelink
> 
> External email: Use caution opening links or attachments
> 
> 
> 2023-01-06, 15:35:50 +0200, ehakim@nvidia.com wrote:
> [...]
> > +static int macsec_upd_offload(struct sk_buff *skb, struct genl_info
> > +*info) {
> > +     struct nlattr *tb_offload[MACSEC_OFFLOAD_ATTR_MAX + 1];
> > +     struct nlattr **attrs = info->attrs;
> > +     enum macsec_offload offload;
> > +     struct net_device *dev;
> > +     int ret;
> > +
> > +     if (!attrs[MACSEC_ATTR_IFINDEX])
> > +             return -EINVAL;
> > +
> > +     if (!attrs[MACSEC_ATTR_OFFLOAD])
> > +             return -EINVAL;
> > +
> > +     if (nla_parse_nested_deprecated(tb_offload, MACSEC_OFFLOAD_ATTR_MAX,
> > +                                     attrs[MACSEC_ATTR_OFFLOAD],
> > +                                     macsec_genl_offload_policy, NULL))
> > +             return -EINVAL;
> > +
> > +     dev = get_dev_from_nl(genl_info_net(info), attrs);
> > +     if (IS_ERR(dev))
> > +             return PTR_ERR(dev);
> > +
> > +     if (!tb_offload[MACSEC_OFFLOAD_ATTR_TYPE])
> > +             return -EINVAL;
> > +
> > +     offload = nla_get_u8(tb_offload[MACSEC_OFFLOAD_ATTR_TYPE]);
> > +
> > +     rtnl_lock();
> 
> Why are you putting rtnl_lock() back down here? You just moved it above
> get_dev_from_nl with commit f3b4a00f0f62 ("net: macsec: fix net device access
> prior to holding a lock"), now you're pretty much reverting that fix.

Ack will fix.

> > +
> > +     ret = macsec_update_offload(dev, offload);
> >
> > -rollback:
> > -     macsec->offload = prev_offload;
> > -out:
> >       rtnl_unlock();
> > +
> >       return ret;
> >  }
> >
> 
> --
> Sabrina