On 7/1/19 4:58 PM, Andrii Nakryiko wrote: > This patchset adds the following APIs to allow attaching BPF programs to > tracing entities: > - bpf_program__attach_perf_event for attaching to any opened perf event FD, > allowing users full control; > - bpf_program__attach_kprobe for attaching to kernel probes (both entry and > return probes); > - bpf_program__attach_uprobe for attaching to user probes (both entry/return); > - bpf_program__attach_tracepoint for attaching to kernel tracepoints; > - bpf_program__attach_raw_tracepoint for attaching to raw kernel tracepoint > (wrapper around bpf_raw_tracepoint_open); > > This set of APIs makes libbpf more useful for tracing applications. > > All attach APIs return abstract struct bpf_link that encapsulates logic of > detaching BPF program. See patch #2 for details. bpf_assoc was considered as > an alternative name for this opaque "handle", but bpf_link seems to be > appropriate semantically and is nice and short. > > Pre-patch #1 makes internal libbpf_strerror_r helper function work w/ negative > error codes, lifting the burder off callers to keep track of error sign. > Patch #2 adds bpf_link abstraction. > Patch #3 adds attach_perf_event, which is the base for all other APIs. > Patch #4 adds kprobe/uprobe APIs. > Patch #5 adds tracepoint API. > Patch #6 adds raw_tracepoint API. > Patch #7 converts one existing test to use attach_perf_event. > Patch #8 adds new kprobe/uprobe tests. > Patch #9 converts some selftests currently using tracepoint to new APIs. > > v4->v5: > - typo and small nits (Yonghong); > - validate pfd in attach_perf_event (Yonghong); > - parse_uint_from_file fixes (Yonghong); > - check for malloc failure in attach_raw_tracepoint (Yonghong); > - attach_probes selftests clean up fixes (Yonghong); > v3->v4: > - proper errno handling (Stanislav); > - bpf_fd -> prog_fd (Stanislav); > - switch to fprintf (Song); > v2->v3: > - added bpf_link concept (Daniel); > - didn't add generic bpf_link__attach_program for reasons described in [0]; > - dropped Stanislav's Reviewed-by from patches #2-#6, in case he doesn't like > the change; > v1->v2: > - preserve errno before close() call (Stanislav); > - use libbpf_perf_event_disable_and_close in selftest (Stanislav); > - remove unnecessary memset (Stanislav); > > [0] https://lore.kernel.org/bpf/CAEf4BzZ7EM5eP2eaZn7T2Yb5QgVRiwAs+epeLR1g01TTx-6m6Q@xxxxxxxxxxxxxx/ > > Andrii Nakryiko (9): > libbpf: make libbpf_strerror_r agnostic to sign of error > libbpf: introduce concept of bpf_link > libbpf: add ability to attach/detach BPF program to perf event > libbpf: add kprobe/uprobe attach API > libbpf: add tracepoint attach API > libbpf: add raw tracepoint attach API > selftests/bpf: switch test to new attach_perf_event API > selftests/bpf: add kprobe/uprobe selftests > selftests/bpf: convert existing tracepoint tests to new APIs > > tools/lib/bpf/libbpf.c | 367 ++++++++++++++++++ > tools/lib/bpf/libbpf.h | 21 + > tools/lib/bpf/libbpf.map | 8 +- > tools/lib/bpf/str_error.c | 2 +- > .../selftests/bpf/prog_tests/attach_probe.c | 166 ++++++++ > .../bpf/prog_tests/stacktrace_build_id.c | 55 +-- > .../bpf/prog_tests/stacktrace_build_id_nmi.c | 31 +- > .../selftests/bpf/prog_tests/stacktrace_map.c | 43 +- > .../bpf/prog_tests/stacktrace_map_raw_tp.c | 15 +- > .../selftests/bpf/progs/test_attach_probe.c | 55 +++ > 10 files changed, 664 insertions(+), 99 deletions(-) > create mode 100644 tools/testing/selftests/bpf/prog_tests/attach_probe.c > create mode 100644 tools/testing/selftests/bpf/progs/test_attach_probe.c Looks good to me. Ack for the whole series. Acked-by: Yonghong Song <yhs@xxxxxx>
