This patch introduces BPF Type Format (BTF). BTF (BPF Type Format) is the meta data format which describes the data types of BPF program/map. Hence, it basically focus on the C programming language which the modern BPF is primary using. The first use case is to provide a generic pretty print capability for a BPF map.
A modified pahole that can convert dwarf to BTF is here: https://github.com/iamkafai/pahole/tree/btf (Arnaldo, there is some BTF_KIND numbering changes on Apr 18th, d61426c1571) Please see individual patch for details. v5: - Remove BTF_KIND_FLOAT and BTF_KIND_FUNC which are not currently used. They can be added in the future. Some bpf_df_xxx() are removed together. - Add comment in patch 7 to clarify that the new bpffs_map_fops should not be extended further. v4: - Fix warning (remove unneeded semicolon) - Remove a redundant variable (nr_bytes) from btf_int_check_meta() in patch 1. Caught by W=1. v3: - Rebase to bpf-next - Fix sparse warning (by adding static) - Add BTF header logging: btf_verifier_log_hdr() - Fix the alignment test on btf->type_off - Add tests for the BTF header - Lower the max BTF size to 16MB. It should be enough for some time. We could raise it later if it would be needed. v2: - Use kvfree where needed in patch 1 and 2 - Also consider BTF_INT_OFFSET() in the btf_int_check_meta() in patch 1 - Fix an incorrect goto target in map_create() during the btf-error-path in patch 7 - re-org some local vars to keep the rev xmas tree in btf.c Martin KaFai Lau (10): bpf: btf: Introduce BPF Type Format (BTF) bpf: btf: Validate type reference bpf: btf: Check members of struct/union bpf: btf: Add pretty print capability for data with BTF type info bpf: btf: Add BPF_BTF_LOAD command bpf: btf: Add BPF_OBJ_GET_INFO_BY_FD support to BTF fd bpf: btf: Add pretty print support to the basic arraymap bpf: btf: Sync bpf.h and btf.h to tools/ bpf: btf: Add BTF support to libbpf bpf: btf: Add BTF tests include/linux/bpf.h | 20 +- include/linux/btf.h | 48 + include/uapi/linux/bpf.h | 12 + include/uapi/linux/btf.h | 130 ++ kernel/bpf/Makefile | 1 + kernel/bpf/arraymap.c | 50 + kernel/bpf/btf.c | 2064 ++++++++++++++++++++++++++ kernel/bpf/inode.c | 156 +- kernel/bpf/syscall.c | 51 +- tools/include/uapi/linux/bpf.h | 12 + tools/include/uapi/linux/btf.h | 130 ++ tools/lib/bpf/Build | 2 +- tools/lib/bpf/bpf.c | 92 +- tools/lib/bpf/bpf.h | 16 + tools/lib/bpf/btf.c | 374 +++++ tools/lib/bpf/btf.h | 22 + tools/lib/bpf/libbpf.c | 148 +- tools/lib/bpf/libbpf.h | 3 + tools/testing/selftests/bpf/Makefile | 26 +- tools/testing/selftests/bpf/test_btf.c | 1669 +++++++++++++++++++++ tools/testing/selftests/bpf/test_btf_haskv.c | 48 + tools/testing/selftests/bpf/test_btf_nokv.c | 43 + 22 files changed, 5076 insertions(+), 41 deletions(-) create mode 100644 include/linux/btf.h create mode 100644 include/uapi/linux/btf.h create mode 100644 kernel/bpf/btf.c create mode 100644 tools/include/uapi/linux/btf.h create mode 100644 tools/lib/bpf/btf.c create mode 100644 tools/lib/bpf/btf.h create mode 100644 tools/testing/selftests/bpf/test_btf.c create mode 100644 tools/testing/selftests/bpf/test_btf_haskv.c create mode 100644 tools/testing/selftests/bpf/test_btf_nokv.c -- 2.9.5
