The send_signal/send_signal_tracepoint is pretty flaky, with at least one failure in every ten runs on a few attempts I've tried it: > test_send_signal_common:PASS:pipe_c2p 0 nsec > test_send_signal_common:PASS:pipe_p2c 0 nsec > test_send_signal_common:PASS:fork 0 nsec > test_send_signal_common:PASS:skel_open_and_load 0 nsec > test_send_signal_common:PASS:skel_attach 0 nsec > test_send_signal_common:PASS:pipe_read 0 nsec > test_send_signal_common:PASS:pipe_write 0 nsec > test_send_signal_common:PASS:reading pipe 0 nsec > test_send_signal_common:PASS:reading pipe error: size 0 0 nsec > test_send_signal_common:FAIL:incorrect result unexpected incorrect result: actual 48 != expected 50 > test_send_signal_common:PASS:pipe_write 0 nsec > #139/1 send_signal/send_signal_tracepoint:FAIL The reason does not appear to be a correctness issue in the strict sense. Rather, we merely do not receive the signal we are waiting for within the provided timeout. Let's bump the timeout by a factor of ten. With that change I have not been able to reproduce the failure in 150+ iterations. I am also sneaking in a small simplification to the test_progs test selection logic. Signed-off-by: Daniel Müller <deso@xxxxxxxxxx> --- tools/testing/selftests/bpf/prog_tests/send_signal.c | 2 +- tools/testing/selftests/bpf/test_progs.c | 7 ++----- 2 files changed, 3 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/send_signal.c b/tools/testing/selftests/bpf/prog_tests/send_signal.c index d71226e..d63a20 100644 --- a/tools/testing/selftests/bpf/prog_tests/send_signal.c +++ b/tools/testing/selftests/bpf/prog_tests/send_signal.c @@ -64,7 +64,7 @@ static void test_send_signal_common(struct perf_event_attr *attr, ASSERT_EQ(read(pipe_p2c[0], buf, 1), 1, "pipe_read"); /* wait a little for signal handler */ - for (int i = 0; i < 100000000 && !sigusr1_received; i++) + for (int i = 0; i < 1000000000 && !sigusr1_received; i++) j /= i + j + 1; buf[0] = sigusr1_received ? '2' : '0'; diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index c639f2e..3561c9 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -1604,11 +1604,8 @@ int main(int argc, char **argv) struct prog_test_def *test = &prog_test_defs[i]; test->test_num = i + 1; - if (should_run(&env.test_selector, - test->test_num, test->test_name)) - test->should_run = true; - else - test->should_run = false; + test->should_run = should_run(&env.test_selector, + test->test_num, test->test_name); if ((test->run_test == NULL && test->run_serial_test == NULL) || (test->run_test != NULL && test->run_serial_test != NULL)) { -- 2.30.2