[bpf-next,0/6] Add BTF_KIND_FLOAT support

Message

Ilya Leoshkevich Feb. 16, 2021, 1:12 a.m. UTC

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

but they should go in after the libbpf part is integrated.

---

v0: https://lore.kernel.org/bpf/[e-mail]/
v0 -> v1: Per Andrii's suggestion, remove the unnecessary trailing u32.

Based on Alexei's feedback [1] I'm proceeding with the BTF_KIND_FLOAT
approach.

[1] https://lore.kernel.org/bpf/[e-mail]/

Ilya Leoshkevich (6):
  bpf: Add BTF_KIND_FLOAT to uapi
  libbpf: Add BTF_KIND_FLOAT support
  tools/bpftool: Add BTF_KIND_FLOAT support
  bpf: Add BTF_KIND_FLOAT support
  selftest/bpf: Add BTF_KIND_FLOAT tests
  bpf: Document BTF_KIND_FLOAT in btf.rst

 Documentation/bpf/btf.rst                    | 17 +++-
 include/uapi/linux/btf.h                     |  5 +-
 kernel/bpf/btf.c                             | 66 ++++++++++++++-
 tools/bpf/bpftool/btf.c                      |  8 ++
 tools/bpf/bpftool/btf_dumper.c               |  1 +
 tools/include/uapi/linux/btf.h               |  5 +-
 tools/lib/bpf/btf.c                          | 44 ++++++++++
 tools/lib/bpf/btf.h                          |  8 ++
 tools/lib/bpf/btf_dump.c                     |  4 +
 tools/lib/bpf/libbpf.c                       | 29 ++++++-
 tools/lib/bpf/libbpf.map                     |  5 ++
 tools/lib/bpf/libbpf_internal.h              |  2 +
 tools/testing/selftests/bpf/btf_helpers.c    |  4 +
 tools/testing/selftests/bpf/prog_tests/btf.c | 84 ++++++++++++++++++++
 tools/testing/selftests/bpf/test_btf.h       |  3 +
 15 files changed, 276 insertions(+), 9 deletions(-)