selftests/bpf: Skip test when perf_event_open returns EOPNOTSUPP

When testing send_signal and stacktrace_build_id_nmi using the riscv sbi
pmu driver without the sscofpmf extension or the riscv legacy pmu driver,
then failures as follows are encountered:

    test_send_signal_common:FAIL:perf_event_open unexpected perf_event_open: actual -1 < expected 0
    #272/3   send_signal/send_signal_nmi:FAIL

    test_stacktrace_build_id_nmi:FAIL:perf_event_open err -1 errno 95
    #304     stacktrace_build_id_nmi:FAIL

The reason is that the above pmu driver or hardware does not support
sampling events, that is, PERF_PMU_CAP_NO_INTERRUPT is set to pmu
capabilities, and then perf_event_open returns EOPNOTSUPP. Since
PERF_PMU_CAP_NO_INTERRUPT is not only set in the riscv-related pmu driver,
it is better to skip testing when this capability is set.

Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240402073029.1299085-1-pulehui@huaweicloud.com

diff --git a/tools/testing/selftests/bpf/prog_tests/send_signal.c b/tools/testing/selftests/bpf/prog_tests/send_signal.c
index b15b343ebb6b12c7badcbf4dfbed88a13b302873..920aee41bd58c0a3a4263cfcb190b7f95ffaa6bf 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/send_signal.c
+++ b/tools/testing/selftests/bpf/prog_tests/send_signal.c
@@ -179,7 +179,7 @@ static void test_send_signal_nmi(bool signal_thread)
        pmu_fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */,
                         -1 /* cpu */, -1 /* group_fd */, 0 /* flags */);
        if (pmu_fd == -1) {
-               if (errno == ENOENT) {
+               if (errno == ENOENT || errno == EOPNOTSUPP) {
                        printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n",
                               __func__);
                        test__skip();

diff --git a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
index 5db9eec24b5bddb9bb6b9150d5a012a7924f1a03..0832fd7874575cb57fec52a8e266101b022823d4 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
+++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
@@ -35,7 +35,7 @@ retry:
        pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
                         0 /* cpu 0 */, -1 /* group id */,
                         0 /* flags */);
-       if (pmu_fd < 0 && errno == ENOENT) {
+       if (pmu_fd < 0 && (errno == ENOENT || errno == EOPNOTSUPP)) {
                printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n", __func__);
                test__skip();
                goto cleanup;