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("Child returned %s\n", strerror(errno)); 99 return -errno; 100 } 101 if (WEXITSTATUS(status)) 102 return WEXITSTATUS(status); 103 104 return 0; 105 } 106 107 static bool test_clone3(uint64_t flags, size_t size, int expected, 108 enum test_mode test_mode) 109 { 110 int ret; 111 112 ksft_print_msg( 113 "[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n", 114 getpid(), flags, size); 115 ret = call_clone3(flags, size, test_mode); 116 ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n", 117 getpid(), ret, expected); 118 if (ret != expected) { 119 ksft_print_msg( 120 "[%d] Result (%d) is different than expected (%d)\n", 121 getpid(), ret, expected); 122 return false; 123 } 124 125 return true; 126 } 127 128 typedef bool (*filter_function)(void); 129 typedef size_t (*size_function)(void); 130 131 static bool not_root(void) 132 { 133 if (getuid() != 0) { 134 ksft_print_msg("Not running as root\n"); 135 return true; 136 } 137 138 return false; 139 } 140 141 static bool no_timenamespace(void) 142 { 143 if (not_root()) 144 return true; 145 146 if (!access("/proc/self/ns/time", F_OK)) 147 return false; 148 149 ksft_print_msg("Time namespaces are not supported\n"); 150 return true; 151 } 152 153 static size_t page_size_plus_8(void) 154 { 155 return getpagesize() + 8; 156 } 157 158 struct test { 159 const char *name; 160 uint64_t flags; 161 size_t size; 162 size_function size_function; 163 int expected; 164 enum test_mode test_mode; 165 filter_function filter; 166 }; 167 168 static const struct test tests[] = { 169 { 170 .name = "simple clone3()", 171 .flags = 0, 172 .size = 0, 173 .expected = 0, 174 .test_mode = CLONE3_ARGS_NO_TEST, 175 }, 176 { 177 .name = "clone3() in a new PID_NS", 178 .flags = CLONE_NEWPID, 179 .size = 0, 180 .expected = 0, 181 .test_mode = CLONE3_ARGS_NO_TEST, 182 .filter = not_root, 183 }, 184 { 185 .name = "CLONE_ARGS_SIZE_VER0", 186 .flags = 0, 187 .size = CLONE_ARGS_SIZE_VER0, 188 .expected = 0, 189 .test_mode = CLONE3_ARGS_NO_TEST, 190 }, 191 { 192 .name = "CLONE_ARGS_SIZE_VER0 - 8", 193 .flags = 0, 194 .size = CLONE_ARGS_SIZE_VER0 - 8, 195 .expected = -EINVAL, 196 .test_mode = CLONE3_ARGS_NO_TEST, 197 }, 198 { 199 .name = "sizeof(struct clone_args) + 8", 200 .flags = 0, 201 .size = sizeof(struct __clone_args) + 8, 202 .expected = 0, 203 .test_mode = CLONE3_ARGS_NO_TEST, 204 }, 205 { 206 .name = "exit_signal with highest 32 bits non-zero", 207 .flags = 0, 208 .size = 0, 209 .expected = -EINVAL, 210 .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG, 211 }, 212 { 213 .name = "negative 32-bit exit_signal", 214 .flags = 0, 215 .size = 0, 216 .expected = -EINVAL, 217 .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG, 218 }, 219 { 220 .name = "exit_signal not fitting into CSIGNAL mask", 221 .flags = 0, 222 .size = 0, 223 .expected = -EINVAL, 224 .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG, 225 }, 226 { 227 .name = "NSIG < exit_signal < CSIG", 228 .flags = 0, 229 .size = 0, 230 .expected = -EINVAL, 231 .test_mode = CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG, 232 }, 233 { 234 .name = "Arguments sizeof(struct clone_args) + 8", 235 .flags = 0, 236 .size = sizeof(struct __clone_args) + 8, 237 .expected = 0, 238 .test_mode = CLONE3_ARGS_ALL_0, 239 }, 240 { 241 .name = "Arguments sizeof(struct clone_args) + 16", 242 .flags = 0, 243 .size = sizeof(struct __clone_args) + 16, 244 .expected = -E2BIG, 245 .test_mode = CLONE3_ARGS_ALL_0, 246 }, 247 { 248 .name = "Arguments sizeof(struct clone_arg) * 2", 249 .flags = 0, 250 .size = sizeof(struct __clone_args) + 16, 251 .expected = -E2BIG, 252 .test_mode = CLONE3_ARGS_ALL_0, 253 }, 254 { 255 .name = "Arguments > page size", 256 .flags = 0, 257 .size_function = page_size_plus_8, 258 .expected = -E2BIG, 259 .test_mode = CLONE3_ARGS_NO_TEST, 260 }, 261 { 262 .name = "CLONE_ARGS_SIZE_VER0 in a new PID NS", 263 .flags = CLONE_NEWPID, 264 .size = CLONE_ARGS_SIZE_VER0, 265 .expected = 0, 266 .test_mode = CLONE3_ARGS_NO_TEST, 267 .filter = not_root, 268 }, 269 { 270 .name = "CLONE_ARGS_SIZE_VER0 - 8 in a new PID NS", 271 .flags = CLONE_NEWPID, 272 .size = CLONE_ARGS_SIZE_VER0 - 8, 273 .expected = -EINVAL, 274 .test_mode = CLONE3_ARGS_NO_TEST, 275 }, 276 { 277 .name = "sizeof(struct clone_args) + 8 in a new PID NS", 278 .flags = CLONE_NEWPID, 279 .size = sizeof(struct __clone_args) + 8, 280 .expected = 0, 281 .test_mode = CLONE3_ARGS_NO_TEST, 282 .filter = not_root, 283 }, 284 { 285 .name = "Arguments > page size in a new PID NS", 286 .flags = CLONE_NEWPID, 287 .size_function = page_size_plus_8, 288 .expected = -E2BIG, 289 .test_mode = CLONE3_ARGS_NO_TEST, 290 }, 291 { 292 .name = "New time NS", 293 .flags = CLONE_NEWTIME, 294 .size = 0, 295 .expected = 0, 296 .test_mode = CLONE3_ARGS_NO_TEST, 297 .filter = no_timenamespace, 298 }, 299 { 300 .name = "exit signal (SIGCHLD) in flags", 301 .flags = SIGCHLD, 302 .size = 0, 303 .expected = -EINVAL, 304 .test_mode = CLONE3_ARGS_NO_TEST, 305 }, 306 }; 307 308 int main(int argc, char *argv[]) 309 { 310 size_t size; 311 int i; 312 313 ksft_print_header(); 314 ksft_set_plan(ARRAY_SIZE(tests)); 315 test_clone3_supported(); 316 317 for (i = 0; i < ARRAY_SIZE(tests); i++) { 318 if (tests[i].filter && tests[i].filter()) { 319 ksft_test_result_skip("%s\n", tests[i].name); 320 continue; 321 } 322 323 if (tests[i].size_function) 324 size = tests[i].size_function(); 325 else 326 size = tests[i].size; 327 328 ksft_print_msg("Running test '%s'\n", tests[i].name); 329 330 ksft_test_result(test_clone3(tests[i].flags, size, 331 tests[i].expected, 332 tests[i].test_mode), 333 "%s\n", tests[i].name); 334 } 335 336 ksft_finished(); 337 } 338