1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
3 
4 #define _GNU_SOURCE
5 #include <sys/wait.h>
6 #include <test_progs.h>
7 #include <unistd.h>
8 
9 #include "task_kfunc_failure.skel.h"
10 #include "task_kfunc_success.skel.h"
11 
12 static size_t log_buf_sz = 1 << 20; /* 1 MB */
13 static char obj_log_buf[1048576];
14 
15 static struct task_kfunc_success *open_load_task_kfunc_skel(void)
16 {
17 	struct task_kfunc_success *skel;
18 	int err;
19 
20 	skel = task_kfunc_success__open();
21 	if (!ASSERT_OK_PTR(skel, "skel_open"))
22 		return NULL;
23 
24 	skel->bss->pid = getpid();
25 
26 	err = task_kfunc_success__load(skel);
27 	if (!ASSERT_OK(err, "skel_load"))
28 		goto cleanup;
29 
30 	return skel;
31 
32 cleanup:
33 	task_kfunc_success__destroy(skel);
34 	return NULL;
35 }
36 
37 static void run_success_test(const char *prog_name)
38 {
39 	struct task_kfunc_success *skel;
40 	int status;
41 	pid_t child_pid;
42 	struct bpf_program *prog;
43 	struct bpf_link *link = NULL;
44 
45 	skel = open_load_task_kfunc_skel();
46 	if (!ASSERT_OK_PTR(skel, "open_load_skel"))
47 		return;
48 
49 	if (!ASSERT_OK(skel->bss->err, "pre_spawn_err"))
50 		goto cleanup;
51 
52 	prog = bpf_object__find_program_by_name(skel->obj, prog_name);
53 	if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
54 		goto cleanup;
55 
56 	link = bpf_program__attach(prog);
57 	if (!ASSERT_OK_PTR(link, "attached_link"))
58 		goto cleanup;
59 
60 	child_pid = fork();
61 	if (!ASSERT_GT(child_pid, -1, "child_pid"))
62 		goto cleanup;
63 	if (child_pid == 0)
64 		_exit(0);
65 	waitpid(child_pid, &status, 0);
66 
67 	ASSERT_OK(skel->bss->err, "post_wait_err");
68 
69 cleanup:
70 	bpf_link__destroy(link);
71 	task_kfunc_success__destroy(skel);
72 }
73 
74 static const char * const success_tests[] = {
75 	"test_task_acquire_release_argument",
76 	"test_task_acquire_release_current",
77 	"test_task_acquire_leave_in_map",
78 	"test_task_xchg_release",
79 	"test_task_get_release",
80 	"test_task_current_acquire_release",
81 	"test_task_from_pid_arg",
82 	"test_task_from_pid_current",
83 	"test_task_from_pid_invalid",
84 };
85 
86 static struct {
87 	const char *prog_name;
88 	const char *expected_err_msg;
89 } failure_tests[] = {
90 	{"task_kfunc_acquire_untrusted", "R1 must be referenced or trusted"},
91 	{"task_kfunc_acquire_fp", "arg#0 pointer type STRUCT task_struct must point"},
92 	{"task_kfunc_acquire_unsafe_kretprobe", "reg type unsupported for arg#0 function"},
93 	{"task_kfunc_acquire_trusted_walked", "R1 must be referenced or trusted"},
94 	{"task_kfunc_acquire_null", "arg#0 pointer type STRUCT task_struct must point"},
95 	{"task_kfunc_acquire_unreleased", "Unreleased reference"},
96 	{"task_kfunc_get_non_kptr_param", "arg#0 expected pointer to map value"},
97 	{"task_kfunc_get_non_kptr_acquired", "arg#0 expected pointer to map value"},
98 	{"task_kfunc_get_null", "arg#0 expected pointer to map value"},
99 	{"task_kfunc_xchg_unreleased", "Unreleased reference"},
100 	{"task_kfunc_get_unreleased", "Unreleased reference"},
101 	{"task_kfunc_release_untrusted", "arg#0 is untrusted_ptr_or_null_ expected ptr_ or socket"},
102 	{"task_kfunc_release_fp", "arg#0 pointer type STRUCT task_struct must point"},
103 	{"task_kfunc_release_null", "arg#0 is ptr_or_null_ expected ptr_ or socket"},
104 	{"task_kfunc_release_unacquired", "release kernel function bpf_task_release expects"},
105 	{"task_kfunc_from_pid_no_null_check", "arg#0 is ptr_or_null_ expected ptr_ or socket"},
106 	{"task_kfunc_from_lsm_task_free", "reg type unsupported for arg#0 function"},
107 };
108 
109 static void verify_fail(const char *prog_name, const char *expected_err_msg)
110 {
111 	LIBBPF_OPTS(bpf_object_open_opts, opts);
112 	struct task_kfunc_failure *skel;
113 	int err, i;
114 
115 	opts.kernel_log_buf = obj_log_buf;
116 	opts.kernel_log_size = log_buf_sz;
117 	opts.kernel_log_level = 1;
118 
119 	skel = task_kfunc_failure__open_opts(&opts);
120 	if (!ASSERT_OK_PTR(skel, "task_kfunc_failure__open_opts"))
121 		goto cleanup;
122 
123 	for (i = 0; i < ARRAY_SIZE(failure_tests); i++) {
124 		struct bpf_program *prog;
125 		const char *curr_name = failure_tests[i].prog_name;
126 
127 		prog = bpf_object__find_program_by_name(skel->obj, curr_name);
128 		if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
129 			goto cleanup;
130 
131 		bpf_program__set_autoload(prog, !strcmp(curr_name, prog_name));
132 	}
133 
134 	err = task_kfunc_failure__load(skel);
135 	if (!ASSERT_ERR(err, "unexpected load success"))
136 		goto cleanup;
137 
138 	if (!ASSERT_OK_PTR(strstr(obj_log_buf, expected_err_msg), "expected_err_msg")) {
139 		fprintf(stderr, "Expected err_msg: %s\n", expected_err_msg);
140 		fprintf(stderr, "Verifier output: %s\n", obj_log_buf);
141 	}
142 
143 cleanup:
144 	task_kfunc_failure__destroy(skel);
145 }
146 
147 void test_task_kfunc(void)
148 {
149 	int i;
150 
151 	for (i = 0; i < ARRAY_SIZE(success_tests); i++) {
152 		if (!test__start_subtest(success_tests[i]))
153 			continue;
154 
155 		run_success_test(success_tests[i]);
156 	}
157 
158 	for (i = 0; i < ARRAY_SIZE(failure_tests); i++) {
159 		if (!test__start_subtest(failure_tests[i].prog_name))
160 			continue;
161 
162 		verify_fail(failure_tests[i].prog_name, failure_tests[i].expected_err_msg);
163 	}
164 }
165