Re: [PATCH bpf-next v3 1/3] bpftool: Skip non-autoload programs when generating light skeletons

[Quentin Monnet]

2026-09-18 14:09 UTC+1000 ~ Thiébaud Weksteen <tweek@xxxxxxxxxx>
> When generating a light skeleton (bpftool gen skeleton -L),
> bpf_object__load() skips loading programs marked as non-autoload (e.g.
> SEC("?...")), so the generated loader program only records and populates
> file descriptors for autoloaded programs.
> 
> Previously, bpftool emitted struct bpf_prog_desc fields, link fields,
> and attach/detach/destroy functions for all programs in the BPF object,
> causing the loader program to store subsequent program FDs into
> incorrect skeleton struct fields when non-autoload programs were
> present.
> 
> Furthermore, bpf_object__load() can update a program's autoload status
> during preparation (e.g. for struct_ops programs when resolving kernel
> BTF members or adjusting autoload based on map autocreate settings).
> Move bpf_object__gen_loader() and bpf_object__load() out of gen_trace()
> into do_skeleton() before counting programs and emitting struct fields so
> that struct field declarations and attach/detach/destroy functions all
> observe the final post-load autoload state.
> 
> Skip programs with !bpf_program__autoload(prog) when counting programs
> and generating progs/links struct fields as well as attach, detach, and
> destroy functions for light skeletons.
> 
> Fixes: d510296d331a ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.")
> Signed-off-by: Thiébaud Weksteen <tweek@xxxxxxxxxx>


Reviewed-by: Quentin Monnet <qmo@xxxxxxxxxx>

Thanks!