This patch set implements central part of CO-RE (Compile Once - Run Everywhere, see [0] and [1] for slides and video): relocating fields offsets. Most of the details are written down as comments to corresponding parts of the code. Patch #1 adds a bunch of commonly useful btf_xxx helpers to simplify working with BTF types. Patch #2 converts existing libbpf code to these new helpers and removes some of pre-existing ones. Patch #3 adds loading of .BTF.ext offset relocations section and macros to work with its contents. Patch #4 implements CO-RE relocations algorithm in libbpf. Patch #5 introduced BPF_CORE_READ macro, hiding usage of Clang's __builtin_preserve_access_index intrinsic that records offset relocation. Patches #6-#14 adds selftests validating various parts of relocation handling, type compatibility, etc. For all tests to work, you'll need latest Clang/LLVM supporting __builtin_preserve_access_index intrinsic, used for recording offset relocations. Kernel on which selftests run should have BTF information built in (CONFIG_DEBUG_INFO_BTF=y). [0] http://vger.kernel.org/bpfconf2019.html#session-2 [1] http://vger.kernel.org/lpc-bpf2018.html#session-2 v3->v4: - added btf_xxx helpers (Alexei); - switched libbpf code to new helpers; - reduced amount of logging and simplified format in few places (Alexei); - made flavor name parsing logic more strict (exactly three underscores); - no uname() error checking (Alexei); - updated misc tests to reflect latest Clang fixes (Yonghong); v2->v3: - enclose BPF_CORE_READ args in parens (Song); v1->v2: - add offsetofend(), fix btf_ext optional fields checks (Song); - add bpf_core_dump_spec() for logging spec representation; - move special first element processing out of the loop (Song); - typo fixes (Song); - drop BPF_ST | BPF_MEM insn relocation (Alexei); - extracted BPF_CORE_READ into bpf_helpers (Alexei); - added extra tests validating Clang capturing relocs correctly (Yonghong); - switch core_relocs.c to use sub-tests; - updated mods tests after Clang bug was fixed (Yonghong); - fix bug enumerating candidate types; Andrii Nakryiko (14): libbpf: add helpers for working with BTF types libbpf: convert libbpf code to use new btf helpers libbpf: add .BTF.ext offset relocation section loading libbpf: implement BPF CO-RE offset relocation algorithm selftests/bpf: add BPF_CORE_READ relocatable read macro selftests/bpf: add CO-RE relocs testing setup selftests/bpf: add CO-RE relocs struct flavors tests selftests/bpf: add CO-RE relocs nesting tests selftests/bpf: add CO-RE relocs array tests selftests/bpf: add CO-RE relocs enum/ptr/func_proto tests selftests/bpf: add CO-RE relocs modifiers/typedef tests selftests/bpf: add CO-RE relocs ptr-as-array tests selftests/bpf: add CO-RE relocs ints tests selftests/bpf: add CO-RE relocs misc tests tools/lib/bpf/btf.c | 250 ++--- tools/lib/bpf/btf.h | 180 ++++ tools/lib/bpf/btf_dump.c | 136 +-- tools/lib/bpf/libbpf.c | 941 +++++++++++++++++- tools/lib/bpf/libbpf.h | 1 + tools/lib/bpf/libbpf_internal.h | 105 ++ tools/testing/selftests/bpf/bpf_helpers.h | 20 + .../selftests/bpf/prog_tests/core_reloc.c | 386 +++++++ .../bpf/progs/btf__core_reloc_arrays.c | 3 + .../btf__core_reloc_arrays___diff_arr_dim.c | 3 + ...btf__core_reloc_arrays___diff_arr_val_sz.c | 3 + .../btf__core_reloc_arrays___err_non_array.c | 3 + ...btf__core_reloc_arrays___err_too_shallow.c | 3 + .../btf__core_reloc_arrays___err_too_small.c | 3 + ..._core_reloc_arrays___err_wrong_val_type1.c | 3 + ..._core_reloc_arrays___err_wrong_val_type2.c | 3 + .../bpf/progs/btf__core_reloc_flavors.c | 3 + .../btf__core_reloc_flavors__err_wrong_name.c | 3 + .../bpf/progs/btf__core_reloc_ints.c | 3 + .../bpf/progs/btf__core_reloc_ints___bool.c | 3 + .../btf__core_reloc_ints___err_bitfield.c | 3 + .../btf__core_reloc_ints___err_wrong_sz_16.c | 3 + .../btf__core_reloc_ints___err_wrong_sz_32.c | 3 + .../btf__core_reloc_ints___err_wrong_sz_64.c | 3 + .../btf__core_reloc_ints___err_wrong_sz_8.c | 3 + .../btf__core_reloc_ints___reverse_sign.c | 3 + .../bpf/progs/btf__core_reloc_misc.c | 5 + .../bpf/progs/btf__core_reloc_mods.c | 3 + .../progs/btf__core_reloc_mods___mod_swap.c | 3 + .../progs/btf__core_reloc_mods___typedefs.c | 3 + .../bpf/progs/btf__core_reloc_nesting.c | 3 + .../btf__core_reloc_nesting___anon_embed.c | 3 + ...f__core_reloc_nesting___dup_compat_types.c | 5 + ...core_reloc_nesting___err_array_container.c | 3 + ...tf__core_reloc_nesting___err_array_field.c | 3 + ...e_reloc_nesting___err_dup_incompat_types.c | 4 + ...re_reloc_nesting___err_missing_container.c | 3 + ...__core_reloc_nesting___err_missing_field.c | 3 + ..._reloc_nesting___err_nonstruct_container.c | 3 + ...e_reloc_nesting___err_partial_match_dups.c | 4 + .../btf__core_reloc_nesting___err_too_deep.c | 3 + .../btf__core_reloc_nesting___extra_nesting.c | 3 + ..._core_reloc_nesting___struct_union_mixup.c | 3 + .../bpf/progs/btf__core_reloc_primitives.c | 3 + ...f__core_reloc_primitives___diff_enum_def.c | 3 + ..._core_reloc_primitives___diff_func_proto.c | 3 + ...f__core_reloc_primitives___diff_ptr_type.c | 3 + ...tf__core_reloc_primitives___err_non_enum.c | 3 + ...btf__core_reloc_primitives___err_non_int.c | 3 + ...btf__core_reloc_primitives___err_non_ptr.c | 3 + .../bpf/progs/btf__core_reloc_ptr_as_arr.c | 3 + .../btf__core_reloc_ptr_as_arr___diff_sz.c | 3 + .../selftests/bpf/progs/core_reloc_types.h | 667 +++++++++++++ .../bpf/progs/test_core_reloc_arrays.c | 55 + .../bpf/progs/test_core_reloc_flavors.c | 62 ++ .../bpf/progs/test_core_reloc_ints.c | 44 + .../bpf/progs/test_core_reloc_kernel.c | 36 + .../bpf/progs/test_core_reloc_misc.c | 57 ++ .../bpf/progs/test_core_reloc_mods.c | 62 ++ .../bpf/progs/test_core_reloc_nesting.c | 46 + .../bpf/progs/test_core_reloc_primitives.c | 43 + .../bpf/progs/test_core_reloc_ptr_as_arr.c | 30 + 62 files changed, 2979 insertions(+), 280 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/core_reloc.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___diff_arr_dim.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___diff_arr_val_sz.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___err_non_array.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___err_too_shallow.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___err_too_small.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___err_wrong_val_type1.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_arrays___err_wrong_val_type2.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_flavors.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_flavors__err_wrong_name.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___bool.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___err_bitfield.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___err_wrong_sz_16.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___err_wrong_sz_32.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___err_wrong_sz_64.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___err_wrong_sz_8.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ints___reverse_sign.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_misc.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_mods.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_mods___mod_swap.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_mods___typedefs.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___anon_embed.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___dup_compat_types.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___err_array_container.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___err_array_field.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___err_dup_incompat_types.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___err_missing_container.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___err_missing_field.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___err_nonstruct_container.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___err_partial_match_dups.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___err_too_deep.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___extra_nesting.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_nesting___struct_union_mixup.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_primitives.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_primitives___diff_enum_def.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_primitives___diff_func_proto.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_primitives___diff_ptr_type.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_primitives___err_non_enum.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_primitives___err_non_int.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_primitives___err_non_ptr.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ptr_as_arr.c create mode 100644 tools/testing/selftests/bpf/progs/btf__core_reloc_ptr_as_arr___diff_sz.c create mode 100644 tools/testing/selftests/bpf/progs/core_reloc_types.h create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_arrays.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_flavors.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_ints.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_misc.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_mods.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_nesting.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_primitives.c create mode 100644 tools/testing/selftests/bpf/progs/test_core_reloc_ptr_as_arr.c -- 2.17.1
