The test_sys_enter_exit test was setting target_pid before attaching the BPF programs, which causes syscalls made during the attach phase to be counted. This is flaky because, apparently, there is no guarantee that both on_enter and on_exit will trigger during the attachment. Move the target_pid assignment to after task_local_storage__attach() so that only explicit sys_gettid() calls are counted. Reported-by: BPF CI Bot (Claude Opus 4.6) Closes: https://github.com/kernel-patches/vmtest/issues/448 Signed-off-by: Ihor Solodrai --- I've been experimenting with running AI on BPF CI to investigate test failures. This is an example of a thing it may come up with. I don't want to spam the list with these, so for starters I'll be relaying only patches that I evaluated and/or tested. The AI generated reports will be posted with "[bpf-ci-bot]" prefix here: https://github.com/kernel-patches/vmtest/issues The goal of this particular application of AI is to make BPF CI more stable, less noisy/flaky, and potentially find and fix more kernel bugs. We'll see how it goes. --- .../selftests/bpf/prog_tests/task_local_storage.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/task_local_storage.c b/tools/testing/selftests/bpf/prog_tests/task_local_storage.c index 7bee33797c71..2820a604aaa6 100644 --- a/tools/testing/selftests/bpf/prog_tests/task_local_storage.c +++ b/tools/testing/selftests/bpf/prog_tests/task_local_storage.c @@ -25,24 +25,28 @@ static void test_sys_enter_exit(void) { struct task_local_storage *skel; + pid_t pid = sys_gettid(); int err; skel = task_local_storage__open_and_load(); if (!ASSERT_OK_PTR(skel, "skel_open_and_load")) return; - skel->bss->target_pid = sys_gettid(); - err = task_local_storage__attach(skel); if (!ASSERT_OK(err, "skel_attach")) goto out; + /* Set target_pid after attach so that syscalls made during + * attach are not counted. + */ + skel->bss->target_pid = pid; + sys_gettid(); sys_gettid(); - /* 3x syscalls: 1x attach and 2x gettid */ - ASSERT_EQ(skel->bss->enter_cnt, 3, "enter_cnt"); - ASSERT_EQ(skel->bss->exit_cnt, 3, "exit_cnt"); + /* 2x gettid syscalls */ + ASSERT_EQ(skel->bss->enter_cnt, 2, "enter_cnt"); + ASSERT_EQ(skel->bss->exit_cnt, 2, "exit_cnt"); ASSERT_EQ(skel->bss->mismatch_cnt, 0, "mismatch_cnt"); out: task_local_storage__destroy(skel); -- 2.53.0