The result:
$ tools/testing/selftests/bpf/test_progs -t tracing_failure/tracing_deny #468/3 tracing_failure/tracing_deny:OK #468 tracing_failure:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: KaFai Wan kafai.wan@linux.dev Acked-by: Yonghong Song yonghong.song@linux.dev --- .../bpf/prog_tests/tracing_failure.c | 33 +++++++++++++++++++ .../selftests/bpf/progs/tracing_failure.c | 6 ++++ 2 files changed, 39 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/tracing_failure.c b/tools/testing/selftests/bpf/prog_tests/tracing_failure.c index a222df765bc3..39b59276884a 100644 --- a/tools/testing/selftests/bpf/prog_tests/tracing_failure.c +++ b/tools/testing/selftests/bpf/prog_tests/tracing_failure.c @@ -28,10 +28,43 @@ static void test_bpf_spin_lock(bool is_spin_lock) tracing_failure__destroy(skel); }
+static void test_tracing_deny(void) +{ + struct tracing_failure *skel; + char log_buf[256]; + int btf_id, err; + + /* __rcu_read_lock depends on CONFIG_PREEMPT_RCU */ + btf_id = libbpf_find_vmlinux_btf_id("__rcu_read_lock", BPF_TRACE_FENTRY); + if (btf_id <= 0) { + test__skip(); + return; + } + + skel = tracing_failure__open(); + if (!ASSERT_OK_PTR(skel, "tracing_failure__open")) + return; + + bpf_program__set_autoload(skel->progs.tracing_deny, true); + bpf_program__set_log_buf(skel->progs.tracing_deny, log_buf, sizeof(log_buf)); + + err = tracing_failure__load(skel); + if (!ASSERT_ERR(err, "tracing_failure__load")) + goto out; + + ASSERT_HAS_SUBSTR(log_buf, + "Attaching tracing programs to function '__rcu_read_lock' is rejected.", + "log_buf"); +out: + tracing_failure__destroy(skel); +} + void test_tracing_failure(void) { if (test__start_subtest("bpf_spin_lock")) test_bpf_spin_lock(true); if (test__start_subtest("bpf_spin_unlock")) test_bpf_spin_lock(false); + if (test__start_subtest("tracing_deny")) + test_tracing_deny(); } diff --git a/tools/testing/selftests/bpf/progs/tracing_failure.c b/tools/testing/selftests/bpf/progs/tracing_failure.c index d41665d2ec8c..58d2777014e1 100644 --- a/tools/testing/selftests/bpf/progs/tracing_failure.c +++ b/tools/testing/selftests/bpf/progs/tracing_failure.c @@ -18,3 +18,9 @@ int BPF_PROG(test_spin_unlock, struct bpf_spin_lock *lock) { return 0; } + +SEC("?fentry/__rcu_read_lock") +int BPF_PROG(tracing_deny) +{ + return 0; +}