Hello, I'd like to add bpf_perf_event_read_sample() helper to get the sample data of an perf_event from BPF programs. This enables more sophistigated filtering for the perf samples. Initially I'm thinking of code and data address based filtering. The original discussion can be seen here: https://lore.kernel.org/r/20220823210354.1407473-1-namhyung@xxxxxxxxxx The bpf_perf_event_read_sample() will take a buffer and size to save the data as well as a flag to specify perf sample type. The flag argument should have a single value in the enum perf_event_sample_format like PERF_SAMPLE_IP. If the buffer is NULL, it will return the size of data instead. This is to support variable length data in the future. The first patch adds bpf_prepare_sample() to setup necessary perf sample data before calling the bpf overflow handler for the perf event. The existing logic for callchain moved to the function and it sets IP and ADDR data if they are not set already. The second patch actually adds the bpf_perf_event_read_sample() helper and supports IP and ADDR data. The last patch adds a test code for this. The code is available at 'bpf/perf-sample-v1' branch in git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git Thanks, Namhyung Namhyung Kim (3): perf/core: Prepare sample data before calling BPF bpf: Add bpf_perf_event_read_sample() helper bpf: Add perf_event_read_sample test cases include/uapi/linux/bpf.h | 23 +++ kernel/events/core.c | 40 +++- kernel/trace/bpf_trace.c | 49 +++++ tools/include/uapi/linux/bpf.h | 23 +++ .../selftests/bpf/prog_tests/perf_sample.c | 172 ++++++++++++++++++ .../selftests/bpf/progs/test_perf_sample.c | 28 +++ 6 files changed, 326 insertions(+), 9 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/perf_sample.c create mode 100644 tools/testing/selftests/bpf/progs/test_perf_sample.c base-commit: e39e739ab57399f46167d453bbdb8ef8d57c6488 -- 2.38.1.273.g43a17bfeac-goog
