1 // SPDX-License-Identifier: GPL-2.0
2
3 /* Based on Christian Brauner's clone3() example */
4
5 #define _GNU_SOURCE
6 #include <errno.h>
7 #include <inttypes.h>
8 #include <linux/types.h>
9 #include <linux/sched.h>
10 #include <stdbool.h>
11 #include <stdint.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <sys/syscall.h>
15 #include <sys/types.h>
16 #include <sys/un.h>
17 #include <sys/wait.h>
18 #include <unistd.h>
19 #include <sched.h>
20
21 #include "../kselftest.h"
22 #include "clone3_selftests.h"
23
24 enum test_mode {
25 CLONE3_ARGS_NO_TEST,
26 CLONE3_ARGS_ALL_0,
27 CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG,
28 CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
29 CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
30 CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
31 };
32
33 static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
34 {
35 struct __clone_args args = {
36 .flags = flags,
37 .exit_signal = SIGCHLD,
38 };
39
40 struct clone_args_extended {
41 struct __clone_args args;
42 __aligned_u64 excess_space[2];
43 } args_ext;
44
45 pid_t pid = -1;
46 int status;
47
48 memset(&args_ext, 0, sizeof(args_ext));
49 if (size > sizeof(struct __clone_args))
50 args_ext.excess_space[1] = 1;
51
52 if (size == 0)
53 size = sizeof(struct __clone_args);
54
55 switch (test_mode) {
56 case CLONE3_ARGS_NO_TEST:
57 /*
58 * Uses default 'flags' and 'SIGCHLD'
59 * assignment.
60 */
61 break;
62 case CLONE3_ARGS_ALL_0:
63 args.flags = 0;
64 args.exit_signal = 0;
65 break;
66 case CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG:
67 args.exit_signal = 0xbadc0ded00000000ULL;
68 break;
69 case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG:
70 args.exit_signal = 0x0000000080000000ULL;
71 break;
72 case CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG:
73 args.exit_signal = 0x0000000000000100ULL;
74 break;
75 case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG:
76 args.exit_signal = 0x00000000000000f0ULL;
77 break;
78 }
79
80 memcpy(&args_ext.args, &args, sizeof(struct __clone_args));
81
82 pid = sys_clone3((struct __clone_args *)&args_ext, size);
83 if (pid < 0) {
84 ksft_print_msg("%s - Failed to create new process\n",
85 strerror(errno));
86 return -errno;
87 }
88
89 if (pid == 0) {
90 ksft_print_msg("I am the child, my PID is %d\n", getpid());
91 _exit(EXIT_SUCCESS);
92 }
93
94 ksft_print_msg("I am the parent (%d). My child's pid is %d\n",
95 getpid(), pid);
96
97 if (waitpid(-1, &status, __WALL) < 0) {
98 ksft_print_msg("waitpid() returned %s\n", strerror(errno));
99 return -errno;
100 }
101 if (!WIFEXITED(status)) {
102 ksft_print_msg("Child did not exit normally, status 0x%x\n",
103 status);
104 return EXIT_FAILURE;
105 }
106 if (WEXITSTATUS(status))
107 return WEXITSTATUS(status);
108
109 return 0;
110 }
111
112 static bool test_clone3(uint64_t flags, size_t size, int expected,
113 enum test_mode test_mode)
114 {
115 int ret;
116
117 ksft_print_msg(
118 "[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n",
119 getpid(), flags, size);
120 ret = call_clone3(flags, size, test_mode);
121 ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n",
122 getpid(), ret, expected);
123 if (ret != expected) {
124 ksft_print_msg(
125 "[%d] Result (%d) is different than expected (%d)\n",
126 getpid(), ret, expected);
127 return false;
128 }
129
130 return true;
131 }
132
133 typedef bool (*filter_function)(void);
134 typedef size_t (*size_function)(void);
135
136 static bool not_root(void)
137 {
138 if (getuid() != 0) {
139 ksft_print_msg("Not running as root\n");
140 return true;
141 }
142
143 return false;
144 }
145
146 static bool no_timenamespace(void)
147 {
148 if (not_root())
149 return true;
150
151 if (!access("/proc/self/ns/time", F_OK))
152 return false;
153
154 ksft_print_msg("Time namespaces are not supported\n");
155 return true;
156 }
157
158 static size_t page_size_plus_8(void)
159 {
160 return getpagesize() + 8;
161 }
162
163 struct test {
164 const char *name;
165 uint64_t flags;
166 size_t size;
167 size_function size_function;
168 int expected;
169 enum test_mode test_mode;
170 filter_function filter;
171 };
172
173 static const struct test tests[] = {
174 {
175 .name = "simple clone3()",
176 .flags = 0,
177 .size = 0,
178 .expected = 0,
179 .test_mode = CLONE3_ARGS_NO_TEST,
180 },
181 {
182 .name = "clone3() in a new PID_NS",
183 .flags = CLONE_NEWPID,
184 .size = 0,
185 .expected = 0,
186 .test_mode = CLONE3_ARGS_NO_TEST,
187 .filter = not_root,
188 },
189 {
190 .name = "CLONE_ARGS_SIZE_VER0",
191 .flags = 0,
192 .size = CLONE_ARGS_SIZE_VER0,
193 .expected = 0,
194 .test_mode = CLONE3_ARGS_NO_TEST,
195 },
196 {
197 .name = "CLONE_ARGS_SIZE_VER0 - 8",
198 .flags = 0,
199 .size = CLONE_ARGS_SIZE_VER0 - 8,
200 .expected = -EINVAL,
201 .test_mode = CLONE3_ARGS_NO_TEST,
202 },
203 {
204 .name = "sizeof(struct clone_args) + 8",
205 .flags = 0,
206 .size = sizeof(struct __clone_args) + 8,
207 .expected = 0,
208 .test_mode = CLONE3_ARGS_NO_TEST,
209 },
210 {
211 .name = "exit_signal with highest 32 bits non-zero",
212 .flags = 0,
213 .size = 0,
214 .expected = -EINVAL,
215 .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG,
216 },
217 {
218 .name = "negative 32-bit exit_signal",
219 .flags = 0,
220 .size = 0,
221 .expected = -EINVAL,
222 .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
223 },
224 {
225 .name = "exit_signal not fitting into CSIGNAL mask",
226 .flags = 0,
227 .size = 0,
228 .expected = -EINVAL,
229 .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
230 },
231 {
232 .name = "NSIG < exit_signal < CSIG",
233 .flags = 0,
234 .size = 0,
235 .expected = -EINVAL,
236 .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
237 },
238 {
239 .name = "Arguments sizeof(struct clone_args) + 8",
240 .flags = 0,
241 .size = sizeof(struct __clone_args) + 8,
242 .expected = 0,
243 .test_mode = CLONE3_ARGS_ALL_0,
244 },
245 {
246 .name = "Arguments sizeof(struct clone_args) + 16",
247 .flags = 0,
248 .size = sizeof(struct __clone_args) + 16,
249 .expected = -E2BIG,
250 .test_mode = CLONE3_ARGS_ALL_0,
251 },
252 {
253 .name = "Arguments sizeof(struct clone_arg) * 2",
254 .flags = 0,
255 .size = sizeof(struct __clone_args) + 16,
256 .expected = -E2BIG,
257 .test_mode = CLONE3_ARGS_ALL_0,
258 },
259 {
260 .name = "Arguments > page size",
261 .flags = 0,
262 .size_function = page_size_plus_8,
263 .expected = -E2BIG,
264 .test_mode = CLONE3_ARGS_NO_TEST,
265 },
266 {
267 .name = "CLONE_ARGS_SIZE_VER0 in a new PID NS",
268 .flags = CLONE_NEWPID,
269 .size = CLONE_ARGS_SIZE_VER0,
270 .expected = 0,
271 .test_mode = CLONE3_ARGS_NO_TEST,
272 .filter = not_root,
273 },
274 {
275 .name = "CLONE_ARGS_SIZE_VER0 - 8 in a new PID NS",
276 .flags = CLONE_NEWPID,
277 .size = CLONE_ARGS_SIZE_VER0 - 8,
278 .expected = -EINVAL,
279 .test_mode = CLONE3_ARGS_NO_TEST,
280 },
281 {
282 .name = "sizeof(struct clone_args) + 8 in a new PID NS",
283 .flags = CLONE_NEWPID,
284 .size = sizeof(struct __clone_args) + 8,
285 .expected = 0,
286 .test_mode = CLONE3_ARGS_NO_TEST,
287 .filter = not_root,
288 },
289 {
290 .name = "Arguments > page size in a new PID NS",
291 .flags = CLONE_NEWPID,
292 .size_function = page_size_plus_8,
293 .expected = -E2BIG,
294 .test_mode = CLONE3_ARGS_NO_TEST,
295 },
296 {
297 .name = "New time NS",
298 .flags = CLONE_NEWTIME,
299 .size = 0,
300 .expected = 0,
301 .test_mode = CLONE3_ARGS_NO_TEST,
302 .filter = no_timenamespace,
303 },
304 {
305 .name = "exit signal (SIGCHLD) in flags",
306 .flags = SIGCHLD,
307 .size = 0,
308 .expected = -EINVAL,
309 .test_mode = CLONE3_ARGS_NO_TEST,
310 },
311 };
312
313 int main(int argc, char *argv[])
314 {
315 size_t size;
316 int i;
317
318 ksft_print_header();
319 ksft_set_plan(ARRAY_SIZE(tests));
320 test_clone3_supported();
321
322 for (i = 0; i < ARRAY_SIZE(tests); i++) {
323 if (tests[i].filter && tests[i].filter()) {
324 ksft_test_result_skip("%s\n", tests[i].name);
325 continue;
326 }
327
328 if (tests[i].size_function)
329 size = tests[i].size_function();
330 else
331 size = tests[i].size;
332
333 ksft_print_msg("Running test '%s'\n", tests[i].name);
334
335 ksft_test_result(test_clone3(tests[i].flags, size,
336 tests[i].expected,
337 tests[i].test_mode),
338 "%s\n", tests[i].name);
339 }
340
341 ksft_finished();
342 }
343
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.