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 
test_bpf_spin_lock(bool is_spin_lock)6 static 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 
27 out:
28 	tracing_failure__destroy(skel);
29 }
30 
test_tracing_fail_prog(const char * prog_name,const char * exp_msg)31 static 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");
54 out:
55 	tracing_failure__destroy(skel);
56 }
57 
test_tracing_deny(void)58 static 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 
test_fexit_noreturns(void)73 static 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 
test_tracing_failure(void)79 void 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 }
90