tracing_failure.c

 1// SPDX-License-Identifier: GPL-2.0
 2/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
 3#include <test_progs.h>
 4#include "tracing_failure.skel.h"
 5
 6static void test_bpf_spin_lock(bool is_spin_lock)
 7{
 8	struct tracing_failure *skel;
 9	int err;
10
11	skel = tracing_failure__open();
12	if (!ASSERT_OK_PTR(skel, "tracing_failure__open"))
13		return;
14
15	if (is_spin_lock)
16		bpf_program__set_autoload(skel->progs.test_spin_lock, true);
17	else
18		bpf_program__set_autoload(skel->progs.test_spin_unlock, true);
19
20	err = tracing_failure__load(skel);
21	if (!ASSERT_OK(err, "tracing_failure__load"))
22		goto out;
23
24	err = tracing_failure__attach(skel);
25	ASSERT_ERR(err, "tracing_failure__attach");
26
27out:
28	tracing_failure__destroy(skel);
29}
30
31static void test_tracing_fail_prog(const char *prog_name, const char *exp_msg)
32{
33	struct tracing_failure *skel;
34	struct bpf_program *prog;
35	char log_buf[256];
36	int err;
37
38	skel = tracing_failure__open();
39	if (!ASSERT_OK_PTR(skel, "tracing_failure__open"))
40		return;
41
42	prog = bpf_object__find_program_by_name(skel->obj, prog_name);
43	if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
44		goto out;
45
46	bpf_program__set_autoload(prog, true);
47	bpf_program__set_log_buf(prog, log_buf, sizeof(log_buf));
48
49	err = tracing_failure__load(skel);
50	if (!ASSERT_ERR(err, "tracing_failure__load"))
51		goto out;
52
53	ASSERT_HAS_SUBSTR(log_buf, exp_msg, "log_buf");
54out:
55	tracing_failure__destroy(skel);
56}
57
58static void test_tracing_deny(void)
59{
60	int btf_id;
61
62	/* __rcu_read_lock depends on CONFIG_PREEMPT_RCU */
63	btf_id = libbpf_find_vmlinux_btf_id("__rcu_read_lock", BPF_TRACE_FENTRY);
64	if (btf_id <= 0) {
65		test__skip();
66		return;
67	}
68
69	test_tracing_fail_prog("tracing_deny",
70			       "Attaching tracing programs to function '__rcu_read_lock' is rejected.");
71}
72
73static void test_fexit_noreturns(void)
74{
75	test_tracing_fail_prog("fexit_noreturns",
76			       "Attaching fexit/fmod_ret to __noreturn function 'do_exit' is rejected.");
77}
78
79void test_tracing_failure(void)
80{
81	if (test__start_subtest("bpf_spin_lock"))
82		test_bpf_spin_lock(true);
83	if (test__start_subtest("bpf_spin_unlock"))
84		test_bpf_spin_lock(false);
85	if (test__start_subtest("tracing_deny"))
86		test_tracing_deny();
87	if (test__start_subtest("fexit_noreturns"))
88		test_fexit_noreturns();
89}