[xdp-hints] Re: [PATCH bpf-next v5 07/17] bpf: XDP metadata RX kfuncs

[Stanislav Fomichev <sdf@google.com>]

On Thu, Dec 22, 2022 at 4:31 PM Martin KaFai Lau <martin.lau@linux.dev> wrote:
>
> On 12/20/22 2:20 PM, Stanislav Fomichev wrote:
> > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> > index bafcb7a3ae6f..6d81b14361e3 100644
> > --- a/kernel/bpf/core.c
> > +++ b/kernel/bpf/core.c
> > @@ -2097,6 +2097,14 @@ bool bpf_prog_map_compatible(struct bpf_map *map,
> >       if (fp->kprobe_override)
> >               return false;
> >
> > +     /* XDP programs inserted into maps are not guaranteed to run on
> > +      * a particular netdev (and can run outside driver context entirely
> > +      * in the case of devmap and cpumap). Until device checks
> > +      * are implemented, prohibit adding dev-bound programs to program maps.
> > +      */
> > +     if (bpf_prog_is_dev_bound(fp->aux))
> > +             return false;
> > +
>
> There is a recent change in the same function in the bpf tree, commit
> 1c123c567fb1. fyi.

Thanks for the heads up; looks like it won't conflict, right?

> [ ... ]
>
> > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> > index fdfdcab4a59d..320451a0be3e 100644
> > --- a/kernel/bpf/verifier.c
> > +++ b/kernel/bpf/verifier.c
> > @@ -2081,6 +2081,22 @@ static struct btf *find_kfunc_desc_btf(struct bpf_verifier_env *env, s16 offset)
> >       return btf_vmlinux ?: ERR_PTR(-ENOENT);
> >   }
> >
> > +int bpf_dev_bound_kfunc_check(struct bpf_verifier_env *env,
> > +                           struct bpf_prog_aux *prog_aux)
>
> nit. Move the dev bound related function to offload.c. &env->log can be passed
> instead of env and then use bpf_log().

Sure, SG!

> Others lgtm.
>