On Sat, 25 Nov 2017 00:24:50 +0100, Daniel Borkmann wrote:
> > +static void dev_xdp_uninstall(struct net_device *dev)
> > +{
> > + struct netdev_bpf xdp;
> > + bpf_op_t ndo_bpf;
>
> Can you add a comment here stating that generic XDP does not
> need to be handled since we drop the prog from free_netdev()?
> Potentially we could also drop the generic one from here, that
> way we'd make no difference and have a dev_xdp_install() and
> one dev_xdp_uninstall() for all kind of attach types. Given
> generic XDP should simulate native XDP anyway, probably better
> to just do that.
I will move the freeing of generic XDP here and add a simple test to
the last patch. Thanks!
> > + ndo_bpf = dev->netdev_ops->ndo_bpf;
> > + if (!ndo_bpf)
> > + return;
> > +
> > + __dev_xdp_query(dev, ndo_bpf, &xdp);
> > + if (xdp.prog_attached == XDP_ATTACHED_NONE)
> > + return;
> > +
> > + /* Program removal should always succeed */
> > + WARN_ON(dev_xdp_install(dev, ndo_bpf, NULL, xdp.prog_flags, NULL));
> > +}
