Re: [PATCH bpf-next v3 2/2] selftests/bpf: Update kfuncs using btf_struct_meta to new variants

[Jiri Olsa <olsajiri@gmail.com>]

On Thu, Mar 19, 2026 at 01:43:35PM -0700, Ihor Solodrai wrote:
> On 3/19/26 5:30 AM, Jiri Olsa wrote:
> > On Wed, Mar 18, 2026 at 04:42:10PM -0700, Ihor Solodrai wrote:
> >> Update selftests to use the new non-_impl kfuncs marked with
> >> KF_IMPLICIT_ARGS by removing redundant declarations and macros from
> >> bpf_experimental.h (the new kfuncs are present in the vmlinux.h) and
> >> updating relevant callsites.
> >>
> >> Fix spin_lock verifier-log matching for lock_id_kptr_preserve by
> >> accepting variable instruction numbers. The calls to kfuncs with
> >> implicit arguments do not have register moves (e.g. r5 = 0)
> >> corresponding to dummy arguments anymore, so the order of instructions
> >> has shifted.
> >>
> >> Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
> >> ---
> >>  .../testing/selftests/bpf/bpf_experimental.h  | 156 +-----------------
> >>  .../selftests/bpf/prog_tests/spin_lock.c      |   5 +-
> >>  .../selftests/bpf/progs/kptr_xchg_inline.c    |   4 +-
> >>  3 files changed, 9 insertions(+), 156 deletions(-)
> >>
> >> diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h
> >> index 44466acf8083..2234bd6bc9d3 100644
> >> --- a/tools/testing/selftests/bpf/bpf_experimental.h
> >> +++ b/tools/testing/selftests/bpf/bpf_experimental.h
> >> @@ -8,156 +8,11 @@
> >>  
> >>  [...]
> >> -
> >> -/* Description
> >> - *	Free an allocated percpu object. All fields of the object that require
> >> - *	destruction will be destructed before the storage is freed.
> >> - *
> >> - *	The 'meta' parameter is rewritten by the verifier, no need for BPF
> >> - *	program to set it.
> >> - * Returns
> >> - *	Void.
> >> - */
> >> -extern void bpf_percpu_obj_drop_impl(void *kptr, void *meta) __ksym;
> >> +/* Convenience macro to wrap over bpf_percpu_obj_new */
> >> +#define bpf_percpu_obj_new(type) ((type __percpu_kptr *)bpf_percpu_obj_new(bpf_core_type_id_local(type)))
> > 
> > nit, seems like a shame to remove all the comments which are still
> > valid, maybe we could leave those externs with comments and just
> > drop the _impl suffix
> 
> I assumed they were copy-pasted from somewhere, but apparently no.
> 
> How about we move the useful comments to kernel/helpers.c, where
> the kfuncs are defined?

sounds good, thanks

jirka