[linux-next-20250324]/tool/bpf/bpftool fails to complie on linux-next-20250324

[Tomas Glozar]

út 25. 3. 2025 v 16:27 odesílatel Quentin Monnet <qmo at kernel.org> napsal:
> Sorry I don't understand the issue, why not simply rename the variable
> that you introduced in tools/build/feature/Makefile at the same time, as
> well? That should solve it, no? This way you don't have to export it
> from the rtla Makefiles. Or am I missing something?
>

If I set BPFTOOL in the rtla makefiles, then it won't propagate to the
feature check, unless exported. I observed feature testing of clang
works, because CLANG is set in tools/scripts/Makefile.include, and did
the same thing for BPFTOOL.

> I think this was the intent.

I see.

> The variable name needs to change either for rtla + probe, or for all
> BPF utilities relying on it, indeed. As far as I can see, this is the
> sched_ext and runqslower utilities as well as the selftests for bpf,
> sched_ext, and hid. I'd argue that the variable has been in use in the
> Makefiles for these tools and selftests for a while, and renaming it
> might produce errors for anyone already using it to pass a specfic
> version of bpftool to try.

That sounds much better than renaming the existing BPFTOOL variable,
thanks for the suggestion. I will send a patch tomorrow and give you a
Suggested-by.

> Note: Not that many dependencies, most of them are optional. For
> bootstrap bpftool we pass -lelf, -lz, sometimes -lzstd.

Noted. I must have been thinking of the entire long list of
dependencies in tools/perf/Makefile.config, completely unrelated to
this. Sorry for the confusion.

Tomas