Re: [PATCH v13 bpf-next 3/8] libbpf: use layout to compute an unknown kind size

On Fri, Mar 6, 2026 at 3:37 AM Alan Maguire <[email protected]> wrote:
>
> This allows BTF parsing to proceed even if we do not know the
> kind.  Fall back to base BTF layout if layout information is
> not in split BTF.
>
> Signed-off-by: Alan Maguire <[email protected]>
> ---
>  tools/lib/bpf/btf.c | 42 +++++++++++++++++++++++++++++++++---------
>  1 file changed, 33 insertions(+), 9 deletions(-)
>
> diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
> index ae13f9f4df08..9f4d1bd73b4d 100644
> --- a/tools/lib/bpf/btf.c
> +++ b/tools/lib/bpf/btf.c
> @@ -356,7 +356,32 @@ static int btf_parse_layout_sec(struct btf *btf)
>         return 0;
>  }
>
> -static int btf_type_size(const struct btf_type *t)
> +/* for unknown kinds, consult kind layout. */
> +static int btf_type_size_unknown(const struct btf *btf, const struct btf_type *t)
> +{
> +       __u32 layout_kinds = btf->hdr.layout_len / sizeof(struct btf_layout);

(give you are going to resubmit anyways)

nit: l_cnt or something? layout_kinds sounds like it actually contains a content

> +       struct btf_layout *l = btf->layout;
> +       __u16 vlen = btf_vlen(t);
> +       __u32 kind = btf_kind(t);
> +

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