[PATCH bpf-next 0/5] btf_dedup algorithm and test fixes

[Andrii Nakryiko <andriin@fb.com>]

This patchset fixes a bug in btf_dedup() algorithm, which under specific hash
collision causes infinite loop. It also exposes ability to tune BTF
deduplication table size, with double purpose of allowing applications to
adjust size according to the size of BTF data, as well as allowing a simple way
to force hash collisions by setting table size to 1.

- Patch #1 fixes bug in btf_dedup testing code that's checking strings
- Patch #2 fixes pointer arg formatting in btf.h
- Patch #3 adds option to specify custom dedup table size
- Patch #4 fixes aforementioned bug in btf_dedup
- Patch #5 adds test that validates the fix

Andrii Nakryiko (5):
  selftests/bpf: fix btf_dedup testing code
  libbpf: fix formatting for btf_ext__get_raw_data
  btf: allow to customize dedup hash table size
  btf: fix bug with resolving STRUCT/UNION into corresponding FWD
  selftests/bpf: add btf_dedup test of FWD/STRUCT resolution

 tools/lib/bpf/btf.c                    | 49 ++++++++++++++++----------
 tools/lib/bpf/btf.h                    |  3 +-
 tools/testing/selftests/bpf/.gitignore |  1 +
 tools/testing/selftests/bpf/test_btf.c | 49 ++++++++++++++++++++++++--
 4 files changed, 81 insertions(+), 21 deletions(-)

-- 
2.17.1