[PATCH bpf-next v5 0/3] Normalize enum values in libbpf and bpftool

[Hungyu Lin <dennylin0707@gmail.com>]

This series fixes enum signedness in libbpf and bpftool data dumps
using the shared btf_enum_value() helper suggested by Alexei. It also
uses the helper for enum-backed map fields, where sign extension can
change the requested map_extra value.

Ordinary enums are interpreted according to kflag. When kflag is
clear, values are treated as unsigned, including BTF from producers
that did not record signedness.

The helper returns __u64, consistent with btf_enum64_value(). bpftool
casts to __s64 at signed numeric output. CO-RE relocation handling is
left for a separate change.

Changes in v5:
- Keep patches 1 and 2 and the map_extra test unchanged.
- Adopt the bpftool and libbpf tests posted by Alexei in the v4 review.

Tested on arm64 (Linux 6.12.68, GCC 13.3, Clang 18.1). libbpf and
bpftool build with -Werror under both compilers. With patch 3 alone,
the new bpftool_map_dump/enum and map_extra/enum32_high subtests and
the expanded enum_data subtest in btf_dump fail. With the full series,
all 25 subtests pass. The 22 unchanged existing subtests pass in both
cases.

v4: https://lore.kernel.org/bpf/20261107020725.36675-1-dennylin0707@gmail.com/
v3: https://lore.kernel.org/bpf/20261101103221.51534-1-dennylin0707@gmail.com/

Thanks,
Hungyu

Hungyu Lin (3):
  libbpf: Normalize enum values according to signedness
  bpftool: Preserve unsigned enum values in data dumps
  selftests/bpf: Cover enum signedness in data dumps and map fields

 tools/bpf/bpftool/btf_dumper.c                | 23 ++++--
 tools/lib/bpf/btf.h                           |  6 ++
 tools/lib/bpf/btf_dump.c                      |  2 +-
 tools/lib/bpf/libbpf.c                        |  2 +-
 .../bpf/prog_tests/bpftool_map_dump.c         | 76 +++++++++++++++++++
 .../selftests/bpf/prog_tests/btf_dump.c       | 20 +++++
 .../selftests/bpf/prog_tests/map_extra.c      | 19 +++++
 .../selftests/bpf/progs/test_map_extra.c      | 12 +++
 8 files changed, 150 insertions(+), 10 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/map_extra.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_map_extra.c


base-commit: 3e18218484126afb9da722080659c038cb2256ab
-- 
2.43.0