Re: [PATCH v3 bpf-next 1/3] bpf: introduce new VFS based BPF kfuncs

[Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>]

On Fri, Jul 26, 2024 at 1:56 AM Matt Bobrowski <mattbobrowski@xxxxxxxxxx> wrote:
> +
> +static int bpf_fs_kfuncs_filter(const struct bpf_prog *prog, u32 kfunc_id)
> +{
> +       if (!btf_id_set8_contains(&bpf_fs_kfunc_set_ids, kfunc_id) ||
> +           prog->type == BPF_PROG_TYPE_LSM)
> +               return 0;
> +       return -EACCES;
> +}
> +
> +static const struct btf_kfunc_id_set bpf_fs_kfunc_set = {
> +       .owner = THIS_MODULE,
> +       .set = &bpf_fs_kfunc_set_ids,
> +       .filter = bpf_fs_kfuncs_filter,
> +};
> +
> +static int __init bpf_fs_kfuncs_init(void)
> +{
> +       return register_btf_kfunc_id_set(BPF_PROG_TYPE_LSM, &bpf_fs_kfunc_set);
> +}

Aside from buf__sz <= 0 that Christian spotted
the bpf_fs_kfuncs_filter() is a watery water.
It's doing a redundant check that is already covered by

register_btf_kfunc_id_set(BPF_PROG_TYPE_LSM,...

I'll remove it while applying.