On Wed, Jun 22, 2022 at 10:35 AM Daniel Müller <deso@xxxxxxxxxx> wrote:
>
> This change merges the two existing implementations of the
> bpf_core_types_are_compat() function into relo_core.c, inheriting the
> recursion tracking from the kernel and the usage of
> btf_kind_core_compat() from libbpf. The kernel is left untouched and
> will be adjusted subsequently.
>
> Signed-off-by: Daniel Müller <deso@xxxxxxxxxx>
> ---
I don't feel very strongly about this, but given we are consolidating
kernel and libbpf code, I think it makes sense to do it in one patch.
> tools/lib/bpf/libbpf.c | 72 +-----------------------------------
> tools/lib/bpf/relo_core.c | 78 +++++++++++++++++++++++++++++++++++++++
> tools/lib/bpf/relo_core.h | 2 +
> 3 files changed, 81 insertions(+), 71 deletions(-)
>
[...]
> - default:
> - pr_warn("unexpected kind %s relocated, local [%d], target [%d]\n",
> - btf_kind_str(local_type), local_id, targ_id);
> - return 0;
> - }
> + return bpf_core_types_are_compat_recur(local_btf, local_id, targ_btf, targ_id, INT_MAX);
INT_MAX seems like an overkill, let's just hard-code 32 just like we
have for a local recursion limit here?
> }
>
[...]
> /*
> * Turn bpf_core_relo into a low- and high-level spec representation,
> * validating correctness along the way, as well as calculating resulting
> diff --git a/tools/lib/bpf/relo_core.h b/tools/lib/bpf/relo_core.h
> index 7df0da0..b8998f 100644
> --- a/tools/lib/bpf/relo_core.h
> +++ b/tools/lib/bpf/relo_core.h
> @@ -68,6 +68,8 @@ struct bpf_core_relo_res {
> __u32 new_type_id;
> };
>
> +int bpf_core_types_are_compat_recur(const struct btf *local_btf, __u32 local_id,
> + const struct btf *targ_btf, __u32 targ_id, int level);
Just leave it called __bpf_core_types_are_compat like in kernel, it is
clearly an "internal" version of bpf_core_types_are_compat(), so it's
more proper naming convention.
> int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
> const struct btf *targ_btf, __u32 targ_id);
>
> --
> 2.30.2
>
