Re: [PATCH bpf-next v1 04/14] selftests/bpf: Add kfunc set test to resolve_btfids

On Tue, Jun 16, 2026 at 12:07 AM Emil Tsalapatis <[email protected]> wrote:
>
> On Mon Jun 1, 2026 at 6:17 PM EDT, Ihor Solodrai wrote:
> > Extend the resolve_btfids selftest to cover kfunc sets defined with
> > BTF_KFUNCS_START/BTF_KFUNCS_END.
> >
> > The test verifies that resolve_btfids correctly processes BTF_ID_FLAGS,
> > resolves function IDs, and checks the kfunc set is sorted.
> >
> > Signed-off-by: Ihor Solodrai <[email protected]>
>
> Reviewed-by: Emil Tsalapatis <[email protected]>
>
> One nit below.
>
> > ---
> >  .../selftests/bpf/prog_tests/resolve_btfids.c | 56 +++++++++++++++++++
> >  tools/testing/selftests/bpf/progs/btf_data.c  | 10 ++++
> >  2 files changed, 66 insertions(+)
> >
> > diff --git a/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c b/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c
> > index d0e51979d455..f6fd79b9dd23 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c
> > @@ -10,6 +10,10 @@
> >  #include <linux/btf_ids.h>
> >  #include "test_progs.h"
> >
> > +#ifndef KF_FASTCALL
> > +#define KF_FASTCALL (1 << 12)
> > +#endif
> > +
> >  struct symbol {
> >       const char      *name;
> >       int              type;
> > @@ -26,6 +30,17 @@ struct symbol test_symbols[] = {
> >       { "func",    BTF_KIND_FUNC,    -1 },
> >  };
> >
> > +struct kfunc_symbol {
> > +     const char      *name;
> > +     s32              id;
> > +     u32              flags;
> > +};
> > +
> > +static struct kfunc_symbol kfunc_symbols[] = {
> > +     { "kfunc_a", -1, 0 },
> > +     { "kfunc_b", -1, KF_FASTCALL },
> > +};
> > +
> >  /* Align the .BTF_ids section to 4 bytes */
> >  asm (
> >  ".pushsection " BTF_IDS_SECTION " ,\"a\"; \n"
> > @@ -77,7 +92,13 @@ BTF_ID(union,   U)
> >  BTF_ID(func,    func)
> >  BTF_SET_END(test_set)
> >
> > +BTF_KFUNCS_START(test_kfunc_set)
> > +BTF_ID_FLAGS(func, kfunc_a)
> > +BTF_ID_FLAGS(func, kfunc_b, KF_FASTCALL)
> > +BTF_KFUNCS_END(test_kfunc_set)
> > +
> >  #pragma GCC visibility pop
> > +
> >  static int
> >  __resolve_symbol(struct btf *btf, int type_id)
> >  {
> > @@ -108,6 +129,18 @@ __resolve_symbol(struct btf *btf, int type_id)
> >                       test_symbols[i].id = type_id;
> >       }
> >
> > +     if (BTF_INFO_KIND(type->info) == BTF_KIND_FUNC) {
> > +             str = btf__name_by_offset(btf, type->name_off);
> > +             if (str) {
>
> This can be rewritten to collapse the nesting:
> if (BTF_INFO_KIND(type->info) != BTF_KIND_FUNC)
>         return 0;
>
> str = btf__name_by_offset(btf, type->name_off);
> if (!str)
>         return 0;
>
> <the rest>

Thank you for this comment :)

Together we can fight claude habits :)