1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
3 
4 #define _GNU_SOURCE
5 #include <cgroup_helpers.h>
6 #include <test_progs.h>
7 
8 #include "cgrp_kfunc_failure.skel.h"
9 #include "cgrp_kfunc_success.skel.h"
10 
11 static size_t log_buf_sz = 1 << 20; /* 1 MB */
12 static char obj_log_buf[1048576];
13 
14 static struct cgrp_kfunc_success *open_load_cgrp_kfunc_skel(void)
15 {
16 	struct cgrp_kfunc_success *skel;
17 	int err;
18 
19 	skel = cgrp_kfunc_success__open();
20 	if (!ASSERT_OK_PTR(skel, "skel_open"))
21 		return NULL;
22 
23 	skel->bss->pid = getpid();
24 
25 	err = cgrp_kfunc_success__load(skel);
26 	if (!ASSERT_OK(err, "skel_load"))
27 		goto cleanup;
28 
29 	return skel;
30 
31 cleanup:
32 	cgrp_kfunc_success__destroy(skel);
33 	return NULL;
34 }
35 
36 static int mkdir_rm_test_dir(void)
37 {
38 	int fd;
39 	const char *cgrp_path = "cgrp_kfunc";
40 
41 	fd = create_and_get_cgroup(cgrp_path);
42 	if (!ASSERT_GT(fd, 0, "mkdir_cgrp_fd"))
43 		return -1;
44 
45 	close(fd);
46 	remove_cgroup(cgrp_path);
47 
48 	return 0;
49 }
50 
51 static void run_success_test(const char *prog_name)
52 {
53 	struct cgrp_kfunc_success *skel;
54 	struct bpf_program *prog;
55 	struct bpf_link *link = NULL;
56 
57 	skel = open_load_cgrp_kfunc_skel();
58 	if (!ASSERT_OK_PTR(skel, "open_load_skel"))
59 		return;
60 
61 	if (!ASSERT_OK(skel->bss->err, "pre_mkdir_err"))
62 		goto cleanup;
63 
64 	prog = bpf_object__find_program_by_name(skel->obj, prog_name);
65 	if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
66 		goto cleanup;
67 
68 	link = bpf_program__attach(prog);
69 	if (!ASSERT_OK_PTR(link, "attached_link"))
70 		goto cleanup;
71 
72 	ASSERT_EQ(skel->bss->invocations, 0, "pre_rmdir_count");
73 	if (!ASSERT_OK(mkdir_rm_test_dir(), "cgrp_mkdir"))
74 		goto cleanup;
75 
76 	ASSERT_EQ(skel->bss->invocations, 1, "post_rmdir_count");
77 	ASSERT_OK(skel->bss->err, "post_rmdir_err");
78 
79 cleanup:
80 	bpf_link__destroy(link);
81 	cgrp_kfunc_success__destroy(skel);
82 }
83 
84 static const char * const success_tests[] = {
85 	"test_cgrp_acquire_release_argument",
86 	"test_cgrp_acquire_leave_in_map",
87 	"test_cgrp_xchg_release",
88 	"test_cgrp_get_release",
89 	"test_cgrp_get_ancestors",
90 };
91 
92 static struct {
93 	const char *prog_name;
94 	const char *expected_err_msg;
95 } failure_tests[] = {
96 	{"cgrp_kfunc_acquire_untrusted", "R1 must be referenced or trusted"},
97 	{"cgrp_kfunc_acquire_fp", "arg#0 pointer type STRUCT cgroup must point"},
98 	{"cgrp_kfunc_acquire_unsafe_kretprobe", "reg type unsupported for arg#0 function"},
99 	{"cgrp_kfunc_acquire_trusted_walked", "R1 must be referenced or trusted"},
100 	{"cgrp_kfunc_acquire_null", "arg#0 pointer type STRUCT cgroup must point"},
101 	{"cgrp_kfunc_acquire_unreleased", "Unreleased reference"},
102 	{"cgrp_kfunc_get_non_kptr_param", "arg#0 expected pointer to map value"},
103 	{"cgrp_kfunc_get_non_kptr_acquired", "arg#0 expected pointer to map value"},
104 	{"cgrp_kfunc_get_null", "arg#0 expected pointer to map value"},
105 	{"cgrp_kfunc_xchg_unreleased", "Unreleased reference"},
106 	{"cgrp_kfunc_get_unreleased", "Unreleased reference"},
107 	{"cgrp_kfunc_release_untrusted", "arg#0 is untrusted_ptr_or_null_ expected ptr_ or socket"},
108 	{"cgrp_kfunc_release_fp", "arg#0 pointer type STRUCT cgroup must point"},
109 	{"cgrp_kfunc_release_null", "arg#0 is ptr_or_null_ expected ptr_ or socket"},
110 	{"cgrp_kfunc_release_unacquired", "release kernel function bpf_cgroup_release expects"},
111 };
112 
113 static void verify_fail(const char *prog_name, const char *expected_err_msg)
114 {
115 	LIBBPF_OPTS(bpf_object_open_opts, opts);
116 	struct cgrp_kfunc_failure *skel;
117 	int err, i;
118 
119 	opts.kernel_log_buf = obj_log_buf;
120 	opts.kernel_log_size = log_buf_sz;
121 	opts.kernel_log_level = 1;
122 
123 	skel = cgrp_kfunc_failure__open_opts(&opts);
124 	if (!ASSERT_OK_PTR(skel, "cgrp_kfunc_failure__open_opts"))
125 		goto cleanup;
126 
127 	for (i = 0; i < ARRAY_SIZE(failure_tests); i++) {
128 		struct bpf_program *prog;
129 		const char *curr_name = failure_tests[i].prog_name;
130 
131 		prog = bpf_object__find_program_by_name(skel->obj, curr_name);
132 		if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
133 			goto cleanup;
134 
135 		bpf_program__set_autoload(prog, !strcmp(curr_name, prog_name));
136 	}
137 
138 	err = cgrp_kfunc_failure__load(skel);
139 	if (!ASSERT_ERR(err, "unexpected load success"))
140 		goto cleanup;
141 
142 	if (!ASSERT_OK_PTR(strstr(obj_log_buf, expected_err_msg), "expected_err_msg")) {
143 		fprintf(stderr, "Expected err_msg: %s\n", expected_err_msg);
144 		fprintf(stderr, "Verifier output: %s\n", obj_log_buf);
145 	}
146 
147 cleanup:
148 	cgrp_kfunc_failure__destroy(skel);
149 }
150 
151 void test_cgrp_kfunc(void)
152 {
153 	int i, err;
154 
155 	err = setup_cgroup_environment();
156 	if (!ASSERT_OK(err, "cgrp_env_setup"))
157 		goto cleanup;
158 
159 	for (i = 0; i < ARRAY_SIZE(success_tests); i++) {
160 		if (!test__start_subtest(success_tests[i]))
161 			continue;
162 
163 		run_success_test(success_tests[i]);
164 	}
165 
166 	for (i = 0; i < ARRAY_SIZE(failure_tests); i++) {
167 		if (!test__start_subtest(failure_tests[i].prog_name))
168 			continue;
169 
170 		verify_fail(failure_tests[i].prog_name, failure_tests[i].expected_err_msg);
171 	}
172 
173 cleanup:
174 	cleanup_cgroup_environment();
175 }
176