Add support for flexible array accesses in a relocatable manner in BPF CO-RE. It's a typical pattern in C, and kernel in particular, to provide a fixed-length struct with zero-sized or dimensionless array at the end. In such cases variable-sized array contents follows immediately after the end of a struct. This patch set adds support for such access pattern by allowing accesses to such arrays. Patch #1 adds libbpf support. Patch #2 adds few test cases for validation. Andrii Nakryiko (2): libbpf: support flexible arrays in CO-RE selftests/bpf: add flexible array relocation tests tools/lib/bpf/libbpf.c | 34 +++++++++++++--- .../selftests/bpf/prog_tests/core_reloc.c | 4 ++ ...f__core_reloc_arrays___equiv_zero_sz_arr.c | 3 ++ ..._core_reloc_arrays___err_bad_zero_sz_arr.c | 3 ++ .../btf__core_reloc_arrays___fixed_arr.c | 3 ++ .../selftests/bpf/progs/core_reloc_types.h | 39 +++++++++++++++++++ .../bpf/progs/test_core_reloc_arrays.c | 8 ++-- 7 files changed, 85 insertions(+), 9 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___equiv_zero_sz_arr.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___err_bad_zero_sz_arr.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___fixed_arr.c -- 2.17.1
