[PATCH bpf-next 11/13] selftests/bpf: Add hit/attach/detach race optimized uprobe test

Jiri Olsa
2024-12-11T13:36:08Z

Adding test that makes sure parallel execution of the uprobe and
attach/detach of optimized uprobe on it works properly.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
.../selftests/bpf/prog_tests/uprobe_syscall.c | 82 +++++++++++++++++++
1 file changed, 82 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
index 1dbc26a1130c..eacd14db8f8d 100644
--- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
+++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c
@@ -532,6 +532,81 @@ static void test_uprobe_usdt(void)
cleanup:
uprobe_optimized__destroy(skel);
}
+
+static bool race_stop;
+
+static void *worker_trigger(void *arg)
+{
+ unsigned long rounds = 0;
+
+ while (!race_stop) {
+ uprobe_test();
+ rounds++;
+ }
+
+ printf("tid %d trigger rounds: %lu\n", gettid(), rounds);
+ return NULL;
+}
+
+static void *worker_attach(void *arg)
+{
+ struct uprobe_optimized *skel;
+ unsigned long rounds = 0;
+
+ skel = uprobe_optimized__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "uprobe_optimized__open_and_load"))
+ goto cleanup;
+
+ while (!race_stop) {
+ skel->links.test_2 = bpf_program__attach_uprobe_multi(skel->progs.test_2, -1,
+ "/proc/self/exe", "uprobe_test_nop5", NULL);
+ if (!ASSERT_OK_PTR(skel->links.test_2, "bpf_program__attach_uprobe_multi"))
+ break;
+ bpf_link__destroy(skel->links.test_2);
+ skel->links.test_2 = NULL;
+ rounds++;
+ }
+
+ printf("tid %d attach rounds: %lu hits: %lu\n", gettid(), rounds, skel->bss->executed);
+
+cleanup:
+ uprobe_optimized__destroy(skel);
+ return NULL;
+}
+
+static void test_uprobe_race(void)
+{
+ int err, i, nr_cpus, nr;
+ pthread_t *threads;
+
+ nr_cpus = libbpf_num_possible_cpus();
+ if (!ASSERT_GE(nr_cpus, 0, "nr_cpus"))
+ return;
+
+ nr = nr_cpus * 2;
+ threads = malloc(sizeof(*threads) * nr);
+ if (!ASSERT_OK_PTR(threads, "malloc"))
+ return;
+
+ for (i = 0; i < nr_cpus; i++) {
+ err = pthread_create(&threads[i], NULL, worker_trigger, NULL);
+ if (!ASSERT_OK(err, "pthread_create"))
+ goto cleanup;
+ }
+
+ for (; i < nr; i++) {
+ err = pthread_create(&threads[i], NULL, worker_attach, NULL);
+ if (!ASSERT_OK(err, "pthread_create"))
+ goto cleanup;
+ }
+
+ sleep(4);
+
+cleanup:
+ race_stop = true;
+ for (i = 0; i < nr; i++)
+ pthread_join(threads[i], NULL);
+}
#else
static void test_uretprobe_regs_equal(void)
{
@@ -567,6 +642,11 @@ static void test_uprobe_usdt(void)
{
test__skip();
}
+
+static void test_uprobe_race(void)
+{
+ test__skip();
+}
#endif

void test_uprobe_syscall(void)
@@ -585,4 +665,6 @@ void test_uprobe_syscall(void)
test_uprobe_multi();
if (test__start_subtest("uprobe_usdt"))
test_uprobe_usdt();
+ if (test__start_subtest("uprobe_race"))
+ test_uprobe_race();
}
--
2.47.0