On Fri, Feb 26, 2021 at 12:23 PM Ilya Leoshkevich [off-list ref] wrote:

Some BPF programs compiled on s390 fail to load, because s390
arch-specific linux headers contain float and double types.

Introduce support for such types by representing them using the new
BTF_KIND_FLOAT. This series deals with libbpf, bpftool, in-kernel BTF
parser as well as selftests and documentation.

There are also pahole and LLVM parts:

* https://github.com/iii-i/dwarves/commit/btf-kind-float-v2
* https://reviews.llvm.org/D83289

...

v6 -> v7: John suggested to add a comment explaining why sanitization
          does not preserve the type name, as well as what effect it has
          on running the code on the older kernels.
          Yonghong has asked to add a comment explaining why we are not
          checking the alignment very precisely in the kernel.
          John suggested to add a bpf_core_field_size test (commit #9).

Applied without patch 9, since it crashes current llvm.
Please work with Yonghong to land llvm support
and resubmit the selftest along with an update to selftest/bpf/README.rst
that needs to explain which llvm commit is needed to pass the test.

Thanks!