Re: [PATCH bpf-next v1 3/4] bpftool: Don't drop a type in the sorted C dump
Eduard Zingerman <[email protected]>
| Newsgroups | org.kernel.vger.bpf |
|---|---|
| Message-ID | <[email protected]> |
On Wed, 2026-08-19 at 17:06 -0700, Ihor Solodrai wrote:
> The C dump sorts types by default, so that generated headers are
> diffable. The sorted dump emits one type fewer than the unsorted dump
> of the same BTF.
>
> dump_btf_c() starts its loop at index 1 to skip the void type at BTF
> type ID 0. That holds for the unsorted dump, where the array index is
> the type ID, but not after qsort(): position 0 is then the lowest ranked
> type, and btf_type_rank() ranks an anonymous enum 0 while void takes the
> default rank of 10. So the enum is skipped, and void is emitted instead
> as a no-op.
>
> Skip by type ID rather than by position.
>
> Fixes: 94133cf24bb3 ("bpftool: Introduce btf c dump sorting")
> Signed-off-by: Ihor Solodrai <[email protected]>
> ---
Acked-by: Eduard Zingerman <[email protected]>
...