Implement error reporting changes discussed in "Libbpf: the road to v1.0" ([0]) document. Libbpf gets a new API, libbpf_set_strict_mode() which accepts a set of flags that turn on a set of libbpf 1.0 changes, that might be potentially breaking. It's possible to opt-in into all current and future 1.0 features by specifying LIBBPF_STRICT_ALL flag. When some of the 1.0 "features" are requested, libbpf APIs might behave differently. In this patch set a first set of changes are implemented, all related to the way libbpf returns errors. See individual patches for details. Patch #1 adds a no-op libbpf_set_strict_mode() functionality to enable updating selftests. Patch #2 gets rid of all the bad code patterns that will break in libbpf 1.0 (exact -1 comparison for low-level APIs, direct IS_ERR() macro usage to check pointer-returning APIs for error, etc). These changes make selftest work in both legacy and 1.0 libbpf modes. Selftests also opt-in into 100% libbpf 1.0 mode to automatically gain all the subsequent changes, which will come in follow up patches. Patch #3 streamlines error reporting for low-level APIs wrapping bpf() syscall. Patch #4 streamlines errors for all the rest APIs. Patch #5 ensures that BPF skeletons propagate errors properly as well, as currently on error some APIs will return NULL with no way of checking exact error code. [0] https://docs.google.com/document/d/1UyjTZuPFWiPFyKk1tV5an11_iaRuec6U-ZESZ54nNTY v1->v2: - move libbpf_set_strict_mode() implementation to patch #1, where it belongs (Alexei); - add acks, slight rewording of commit messages. Andrii Nakryiko (5): libbpf: add libbpf_set_strict_mode() API to turn on libbpf 1.0 behaviors selftests/bpf: turn on libbpf 1.0 mode and fix all IS_ERR checks libbpf: streamline error reporting for low-level APIs libbpf: streamline error reporting for high-level APIs bpftool: set errno on skeleton failures and propagate errors tools/bpf/bpftool/gen.c | 27 +- tools/lib/bpf/Makefile | 1 + tools/lib/bpf/bpf.c | 168 ++++-- tools/lib/bpf/bpf_prog_linfo.c | 18 +- tools/lib/bpf/btf.c | 302 +++++----- tools/lib/bpf/btf_dump.c | 14 +- tools/lib/bpf/libbpf.c | 519 ++++++++++-------- tools/lib/bpf/libbpf.h | 1 + tools/lib/bpf/libbpf.map | 5 + tools/lib/bpf/libbpf_errno.c | 7 +- tools/lib/bpf/libbpf_internal.h | 53 ++ tools/lib/bpf/libbpf_legacy.h | 59 ++ tools/lib/bpf/linker.c | 22 +- tools/lib/bpf/netlink.c | 81 +-- tools/lib/bpf/ringbuf.c | 26 +- tools/testing/selftests/bpf/bench.c | 1 + .../selftests/bpf/benchs/bench_rename.c | 2 +- .../selftests/bpf/benchs/bench_ringbufs.c | 6 +- .../selftests/bpf/benchs/bench_trigger.c | 2 +- .../selftests/bpf/prog_tests/attach_probe.c | 12 +- .../selftests/bpf/prog_tests/bpf_iter.c | 31 +- .../selftests/bpf/prog_tests/bpf_tcp_ca.c | 8 +- tools/testing/selftests/bpf/prog_tests/btf.c | 93 ++-- .../selftests/bpf/prog_tests/btf_dump.c | 8 +- .../selftests/bpf/prog_tests/btf_write.c | 4 +- .../bpf/prog_tests/cg_storage_multi.c | 84 +-- .../bpf/prog_tests/cgroup_attach_multi.c | 2 +- .../selftests/bpf/prog_tests/cgroup_link.c | 14 +- .../bpf/prog_tests/cgroup_skb_sk_lookup.c | 2 +- .../selftests/bpf/prog_tests/check_mtu.c | 2 +- .../selftests/bpf/prog_tests/core_reloc.c | 15 +- .../selftests/bpf/prog_tests/fexit_bpf2bpf.c | 25 +- .../selftests/bpf/prog_tests/flow_dissector.c | 2 +- .../bpf/prog_tests/flow_dissector_reattach.c | 10 +- .../bpf/prog_tests/get_stack_raw_tp.c | 10 +- .../prog_tests/get_stackid_cannot_attach.c | 9 +- .../selftests/bpf/prog_tests/hashmap.c | 9 +- .../selftests/bpf/prog_tests/kfree_skb.c | 19 +- .../selftests/bpf/prog_tests/ksyms_btf.c | 3 +- .../selftests/bpf/prog_tests/link_pinning.c | 7 +- .../selftests/bpf/prog_tests/obj_name.c | 8 +- .../selftests/bpf/prog_tests/perf_branches.c | 4 +- .../selftests/bpf/prog_tests/perf_buffer.c | 2 +- .../bpf/prog_tests/perf_event_stackmap.c | 3 +- .../selftests/bpf/prog_tests/probe_user.c | 7 +- .../selftests/bpf/prog_tests/prog_run_xattr.c | 4 +- .../bpf/prog_tests/raw_tp_test_run.c | 4 +- .../selftests/bpf/prog_tests/rdonly_maps.c | 7 +- .../bpf/prog_tests/reference_tracking.c | 2 +- .../selftests/bpf/prog_tests/resolve_btfids.c | 2 +- .../selftests/bpf/prog_tests/ringbuf_multi.c | 2 +- .../bpf/prog_tests/select_reuseport.c | 53 +- .../selftests/bpf/prog_tests/send_signal.c | 3 +- .../selftests/bpf/prog_tests/sk_lookup.c | 2 +- .../selftests/bpf/prog_tests/sock_fields.c | 14 +- .../selftests/bpf/prog_tests/sockmap_basic.c | 8 +- .../selftests/bpf/prog_tests/sockmap_ktls.c | 2 +- .../selftests/bpf/prog_tests/sockmap_listen.c | 10 +- .../bpf/prog_tests/stacktrace_build_id_nmi.c | 3 +- .../selftests/bpf/prog_tests/stacktrace_map.c | 2 +- .../bpf/prog_tests/stacktrace_map_raw_tp.c | 5 +- .../bpf/prog_tests/tcp_hdr_options.c | 15 +- .../selftests/bpf/prog_tests/test_overhead.c | 12 +- .../bpf/prog_tests/trampoline_count.c | 14 +- .../selftests/bpf/prog_tests/udp_limit.c | 7 +- .../selftests/bpf/prog_tests/xdp_bpf2bpf.c | 2 +- .../selftests/bpf/prog_tests/xdp_link.c | 8 +- tools/testing/selftests/bpf/test_maps.c | 168 +++--- tools/testing/selftests/bpf/test_progs.c | 3 + tools/testing/selftests/bpf/test_progs.h | 9 +- .../selftests/bpf/test_tcpnotify_user.c | 7 +- 71 files changed, 1123 insertions(+), 952 deletions(-) create mode 100644 tools/lib/bpf/libbpf_legacy.h -- 2.30.2
