| @@ -0,0 +1,913 @@ |
| | 1 | #define _GNU_SOURCE |
| | 2 | #define __EXPORTED_HEADERS__ |
| | 3 | |
| | 4 | #include <errno.h> |
| | 5 | #include <inttypes.h> |
| | 6 | #include <limits.h> |
| | 7 | #include <linux/falloc.h> |
| | 8 | #include <linux/fcntl.h> |
| | 9 | #include <linux/memfd.h> |
| | 10 | #include <sched.h> |
| | 11 | #include <stdio.h> |
| | 12 | #include <stdlib.h> |
| | 13 | #include <signal.h> |
| | 14 | #include <string.h> |
| | 15 | #include <sys/mman.h> |
| | 16 | #include <sys/stat.h> |
| | 17 | #include <sys/syscall.h> |
| | 18 | #include <unistd.h> |
| | 19 | |
| | 20 | #define MFD_DEF_SIZE 8192 |
| | 21 | #define STACK_SIZE 65535 |
| | 22 | |
| | 23 | static int sys_memfd_create(const char *name, |
| | 24 | unsigned int flags) |
| | 25 | { |
| | 26 | return syscall(__NR_memfd_create, name, flags); |
| | 27 | } |
| | 28 | |
| | 29 | static int mfd_assert_new(const char *name, loff_t sz, unsigned int flags) |
| | 30 | { |
| | 31 | int r, fd; |
| | 32 | |
| | 33 | fd = sys_memfd_create(name, flags); |
| | 34 | if (fd < 0) { |
| | 35 | printf("memfd_create(\"%s\", %u) failed: %m\n", |
| | 36 | name, flags); |
| | 37 | abort(); |
| | 38 | } |
| | 39 | |
| | 40 | r = ftruncate(fd, sz); |
| | 41 | if (r < 0) { |
| | 42 | printf("ftruncate(%llu) failed: %m\n", (unsigned long long)sz); |
| | 43 | abort(); |
| | 44 | } |
| | 45 | |
| | 46 | return fd; |
| | 47 | } |
| | 48 | |
| | 49 | static void mfd_fail_new(const char *name, unsigned int flags) |
| | 50 | { |
| | 51 | int r; |
| | 52 | |
| | 53 | r = sys_memfd_create(name, flags); |
| | 54 | if (r >= 0) { |
| | 55 | printf("memfd_create(\"%s\", %u) succeeded, but failure expected\n", |
| | 56 | name, flags); |
| | 57 | close(r); |
| | 58 | abort(); |
| | 59 | } |
| | 60 | } |
| | 61 | |
| | 62 | static __u64 mfd_assert_get_seals(int fd) |
| | 63 | { |
| | 64 | long r; |
| | 65 | |
| | 66 | r = fcntl(fd, F_GET_SEALS); |
| | 67 | if (r < 0) { |
| | 68 | printf("GET_SEALS(%d) failed: %m\n", fd); |
| | 69 | abort(); |
| | 70 | } |
| | 71 | |
| | 72 | return r; |
| | 73 | } |
| | 74 | |
| | 75 | static void mfd_assert_has_seals(int fd, __u64 seals) |
| | 76 | { |
| | 77 | __u64 s; |
| | 78 | |
| | 79 | s = mfd_assert_get_seals(fd); |
| | 80 | if (s != seals) { |
| | 81 | printf("%llu != %llu = GET_SEALS(%d)\n", |
| | 82 | (unsigned long long)seals, (unsigned long long)s, fd); |
| | 83 | abort(); |
| | 84 | } |
| | 85 | } |
| | 86 | |
| | 87 | static void mfd_assert_add_seals(int fd, __u64 seals) |
| | 88 | { |
| | 89 | long r; |
| | 90 | __u64 s; |
| | 91 | |
| | 92 | s = mfd_assert_get_seals(fd); |
| | 93 | r = fcntl(fd, F_ADD_SEALS, seals); |
| | 94 | if (r < 0) { |
| | 95 | printf("ADD_SEALS(%d, %llu -> %llu) failed: %m\n", |
| | 96 | fd, (unsigned long long)s, (unsigned long long)seals); |
| | 97 | abort(); |
| | 98 | } |
| | 99 | } |
| | 100 | |
| | 101 | static void mfd_fail_add_seals(int fd, __u64 seals) |
| | 102 | { |
| | 103 | long r; |
| | 104 | __u64 s; |
| | 105 | |
| | 106 | r = fcntl(fd, F_GET_SEALS); |
| | 107 | if (r < 0) |
| | 108 | s = 0; |
| | 109 | else |
| | 110 | s = r; |
| | 111 | |
| | 112 | r = fcntl(fd, F_ADD_SEALS, seals); |
| | 113 | if (r >= 0) { |
| | 114 | printf("ADD_SEALS(%d, %llu -> %llu) didn't fail as expected\n", |
| | 115 | fd, (unsigned long long)s, (unsigned long long)seals); |
| | 116 | abort(); |
| | 117 | } |
| | 118 | } |
| | 119 | |
| | 120 | static void mfd_assert_size(int fd, size_t size) |
| | 121 | { |
| | 122 | struct stat st; |
| | 123 | int r; |
| | 124 | |
| | 125 | r = fstat(fd, &st); |
| | 126 | if (r < 0) { |
| | 127 | printf("fstat(%d) failed: %m\n", fd); |
| | 128 | abort(); |
| | 129 | } else if (st.st_size != size) { |
| | 130 | printf("wrong file size %lld, but expected %lld\n", |
| | 131 | (long long)st.st_size, (long long)size); |
| | 132 | abort(); |
| | 133 | } |
| | 134 | } |
| | 135 | |
| | 136 | static int mfd_assert_dup(int fd) |
| | 137 | { |
| | 138 | int r; |
| | 139 | |
| | 140 | r = dup(fd); |
| | 141 | if (r < 0) { |
| | 142 | printf("dup(%d) failed: %m\n", fd); |
| | 143 | abort(); |
| | 144 | } |
| | 145 | |
| | 146 | return r; |
| | 147 | } |
| | 148 | |
| | 149 | static void *mfd_assert_mmap_shared(int fd) |
| | 150 | { |
| | 151 | void *p; |
| | 152 | |
| | 153 | p = mmap(NULL, |
| | 154 | MFD_DEF_SIZE, |
| | 155 | PROT_READ | PROT_WRITE, |
| | 156 | MAP_SHARED, |
| | 157 | fd, |
| | 158 | 0); |
| | 159 | if (p == MAP_FAILED) { |
| | 160 | printf("mmap() failed: %m\n"); |
| | 161 | abort(); |
| | 162 | } |
| | 163 | |
| | 164 | return p; |
| | 165 | } |
| | 166 | |
| | 167 | static void *mfd_assert_mmap_private(int fd) |
| | 168 | { |
| | 169 | void *p; |
| | 170 | |
| | 171 | p = mmap(NULL, |
| | 172 | MFD_DEF_SIZE, |
| | 173 | PROT_READ, |
| | 174 | MAP_PRIVATE, |
| | 175 | fd, |
| | 176 | 0); |
| | 177 | if (p == MAP_FAILED) { |
| | 178 | printf("mmap() failed: %m\n"); |
| | 179 | abort(); |
| | 180 | } |
| | 181 | |
| | 182 | return p; |
| | 183 | } |
| | 184 | |
| | 185 | static int mfd_assert_open(int fd, int flags, mode_t mode) |
| | 186 | { |
| | 187 | char buf[512]; |
| | 188 | int r; |
| | 189 | |
| | 190 | sprintf(buf, "/proc/self/fd/%d", fd); |
| | 191 | r = open(buf, flags, mode); |
| | 192 | if (r < 0) { |
| | 193 | printf("open(%s) failed: %m\n", buf); |
| | 194 | abort(); |
| | 195 | } |
| | 196 | |
| | 197 | return r; |
| | 198 | } |
| | 199 | |
| | 200 | static void mfd_fail_open(int fd, int flags, mode_t mode) |
| | 201 | { |
| | 202 | char buf[512]; |
| | 203 | int r; |
| | 204 | |
| | 205 | sprintf(buf, "/proc/self/fd/%d", fd); |
| | 206 | r = open(buf, flags, mode); |
| | 207 | if (r >= 0) { |
| | 208 | printf("open(%s) didn't fail as expected\n"); |
| | 209 | abort(); |
| | 210 | } |
| | 211 | } |
| | 212 | |
| | 213 | static void mfd_assert_read(int fd) |
| | 214 | { |
| | 215 | char buf[16]; |
| | 216 | void *p; |
| | 217 | ssize_t l; |
| | 218 | |
| | 219 | l = read(fd, buf, sizeof(buf)); |
| | 220 | if (l != sizeof(buf)) { |
| | 221 | printf("read() failed: %m\n"); |
| | 222 | abort(); |
| | 223 | } |
| | 224 | |
| | 225 | /* verify PROT_READ *is* allowed */ |
| | 226 | p = mmap(NULL, |
| | 227 | MFD_DEF_SIZE, |
| | 228 | PROT_READ, |
| | 229 | MAP_PRIVATE, |
| | 230 | fd, |
| | 231 | 0); |
| | 232 | if (p == MAP_FAILED) { |
| | 233 | printf("mmap() failed: %m\n"); |
| | 234 | abort(); |
| | 235 | } |
| | 236 | munmap(p, MFD_DEF_SIZE); |
| | 237 | |
| | 238 | /* verify MAP_PRIVATE is *always* allowed (even writable) */ |
| | 239 | p = mmap(NULL, |
| | 240 | MFD_DEF_SIZE, |
| | 241 | PROT_READ | PROT_WRITE, |
| | 242 | MAP_PRIVATE, |
| | 243 | fd, |
| | 244 | 0); |
| | 245 | if (p == MAP_FAILED) { |
| | 246 | printf("mmap() failed: %m\n"); |
| | 247 | abort(); |
| | 248 | } |
| | 249 | munmap(p, MFD_DEF_SIZE); |
| | 250 | } |
| | 251 | |
| | 252 | static void mfd_assert_write(int fd) |
| | 253 | { |
| | 254 | ssize_t l; |
| | 255 | void *p; |
| | 256 | int r; |
| | 257 | |
| | 258 | /* verify write() succeeds */ |
| | 259 | l = write(fd, "\0\0\0\0", 4); |
| | 260 | if (l != 4) { |
| | 261 | printf("write() failed: %m\n"); |
| | 262 | abort(); |
| | 263 | } |
| | 264 | |
| | 265 | /* verify PROT_READ | PROT_WRITE is allowed */ |
| | 266 | p = mmap(NULL, |
| | 267 | MFD_DEF_SIZE, |
| | 268 | PROT_READ | PROT_WRITE, |
| | 269 | MAP_SHARED, |
| | 270 | fd, |
| | 271 | 0); |
| | 272 | if (p == MAP_FAILED) { |
| | 273 | printf("mmap() failed: %m\n"); |
| | 274 | abort(); |
| | 275 | } |
| | 276 | *(char *)p = 0; |
| | 277 | munmap(p, MFD_DEF_SIZE); |
| | 278 | |
| | 279 | /* verify PROT_WRITE is allowed */ |
| | 280 | p = mmap(NULL, |
| | 281 | MFD_DEF_SIZE, |
| | 282 | PROT_WRITE, |
| | 283 | MAP_SHARED, |
| | 284 | fd, |
| | 285 | 0); |
| | 286 | if (p == MAP_FAILED) { |
| | 287 | printf("mmap() failed: %m\n"); |
| | 288 | abort(); |
| | 289 | } |
| | 290 | *(char *)p = 0; |
| | 291 | munmap(p, MFD_DEF_SIZE); |
| | 292 | |
| | 293 | /* verify PROT_READ with MAP_SHARED is allowed and a following |
| | 294 | * mprotect(PROT_WRITE) allows writing */ |
| | 295 | p = mmap(NULL, |
| | 296 | MFD_DEF_SIZE, |
| | 297 | PROT_READ, |
| | 298 | MAP_SHARED, |
| | 299 | fd, |
| | 300 | 0); |
| | 301 | if (p == MAP_FAILED) { |
| | 302 | printf("mmap() failed: %m\n"); |
| | 303 | abort(); |
| | 304 | } |
| | 305 | |
| | 306 | r = mprotect(p, MFD_DEF_SIZE, PROT_READ | PROT_WRITE); |
| | 307 | if (r < 0) { |
| | 308 | printf("mprotect() failed: %m\n"); |
| | 309 | abort(); |
| | 310 | } |
| | 311 | |
| | 312 | *(char *)p = 0; |
| | 313 | munmap(p, MFD_DEF_SIZE); |
| | 314 | |
| | 315 | /* verify PUNCH_HOLE works */ |
| | 316 | r = fallocate(fd, |
| | 317 | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
| | 318 | 0, |
| | 319 | MFD_DEF_SIZE); |
| | 320 | if (r < 0) { |
| | 321 | printf("fallocate(PUNCH_HOLE) failed: %m\n"); |
| | 322 | abort(); |
| | 323 | } |
| | 324 | } |
| | 325 | |
| | 326 | static void mfd_fail_write(int fd) |
| | 327 | { |
| | 328 | ssize_t l; |
| | 329 | void *p; |
| | 330 | int r; |
| | 331 | |
| | 332 | /* verify write() fails */ |
| | 333 | l = write(fd, "data", 4); |
| | 334 | if (l != -EPERM) { |
| | 335 | printf("expected EPERM on write(), but got %d: %m\n", (int)l); |
| | 336 | abort(); |
| | 337 | } |
| | 338 | |
| | 339 | /* verify PROT_READ | PROT_WRITE is not allowed */ |
| | 340 | p = mmap(NULL, |
| | 341 | MFD_DEF_SIZE, |
| | 342 | PROT_READ | PROT_WRITE, |
| | 343 | MAP_SHARED, |
| | 344 | fd, |
| | 345 | 0); |
| | 346 | if (p != MAP_FAILED) { |
| | 347 | printf("mmap() didn't fail as expected\n"); |
| | 348 | abort(); |
| | 349 | } |
| | 350 | |
| | 351 | /* verify PROT_WRITE is not allowed */ |
| | 352 | p = mmap(NULL, |
| | 353 | MFD_DEF_SIZE, |
| | 354 | PROT_WRITE, |
| | 355 | MAP_SHARED, |
| | 356 | fd, |
| | 357 | 0); |
| | 358 | if (p != MAP_FAILED) { |
| | 359 | printf("mmap() didn't fail as expected\n"); |
| | 360 | abort(); |
| | 361 | } |
| | 362 | |
| | 363 | /* Verify PROT_READ with MAP_SHARED with a following mprotect is not |
| | 364 | * allowed. Note that for r/w the kernel already prevents the mmap. */ |
| | 365 | p = mmap(NULL, |
| | 366 | MFD_DEF_SIZE, |
| | 367 | PROT_READ, |
| | 368 | MAP_SHARED, |
| | 369 | fd, |
| | 370 | 0); |
| | 371 | if (p != MAP_FAILED) { |
| | 372 | r = mprotect(p, MFD_DEF_SIZE, PROT_READ | PROT_WRITE); |
| | 373 | if (r >= 0) { |
| | 374 | printf("mmap()+mprotect() didn't fail as expected\n"); |
| | 375 | abort(); |
| | 376 | } |
| | 377 | } |
| | 378 | |
| | 379 | /* verify PUNCH_HOLE fails */ |
| | 380 | r = fallocate(fd, |
| | 381 | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
| | 382 | 0, |
| | 383 | MFD_DEF_SIZE); |
| | 384 | if (r >= 0) { |
| | 385 | printf("fallocate(PUNCH_HOLE) didn't fail as expected\n"); |
| | 386 | abort(); |
| | 387 | } |
| | 388 | } |
| | 389 | |
| | 390 | static void mfd_assert_shrink(int fd) |
| | 391 | { |
| | 392 | int r, fd2; |
| | 393 | |
| | 394 | r = ftruncate(fd, MFD_DEF_SIZE / 2); |
| | 395 | if (r < 0) { |
| | 396 | printf("ftruncate(SHRINK) failed: %m\n"); |
| | 397 | abort(); |
| | 398 | } |
| | 399 | |
| | 400 | mfd_assert_size(fd, MFD_DEF_SIZE / 2); |
| | 401 | |
| | 402 | fd2 = mfd_assert_open(fd, |
| | 403 | O_RDWR | O_CREAT | O_TRUNC, |
| | 404 | S_IRUSR | S_IWUSR); |
| | 405 | close(fd2); |
| | 406 | |
| | 407 | mfd_assert_size(fd, 0); |
| | 408 | } |
| | 409 | |
| | 410 | static void mfd_fail_shrink(int fd) |
| | 411 | { |
| | 412 | int r; |
| | 413 | |
| | 414 | r = ftruncate(fd, MFD_DEF_SIZE / 2); |
| | 415 | if (r >= 0) { |
| | 416 | printf("ftruncate(SHRINK) didn't fail as expected\n"); |
| | 417 | abort(); |
| | 418 | } |
| | 419 | |
| | 420 | mfd_fail_open(fd, |
| | 421 | O_RDWR | O_CREAT | O_TRUNC, |
| | 422 | S_IRUSR | S_IWUSR); |
| | 423 | } |
| | 424 | |
| | 425 | static void mfd_assert_grow(int fd) |
| | 426 | { |
| | 427 | int r; |
| | 428 | |
| | 429 | r = ftruncate(fd, MFD_DEF_SIZE * 2); |
| | 430 | if (r < 0) { |
| | 431 | printf("ftruncate(GROW) failed: %m\n"); |
| | 432 | abort(); |
| | 433 | } |
| | 434 | |
| | 435 | mfd_assert_size(fd, MFD_DEF_SIZE * 2); |
| | 436 | |
| | 437 | r = fallocate(fd, |
| | 438 | 0, |
| | 439 | 0, |
| | 440 | MFD_DEF_SIZE * 4); |
| | 441 | if (r < 0) { |
| | 442 | printf("fallocate(ALLOC) failed: %m\n"); |
| | 443 | abort(); |
| | 444 | } |
| | 445 | |
| | 446 | mfd_assert_size(fd, MFD_DEF_SIZE * 4); |
| | 447 | } |
| | 448 | |
| | 449 | static void mfd_fail_grow(int fd) |
| | 450 | { |
| | 451 | int r; |
| | 452 | |
| | 453 | r = ftruncate(fd, MFD_DEF_SIZE * 2); |
| | 454 | if (r >= 0) { |
| | 455 | printf("ftruncate(GROW) didn't fail as expected\n"); |
| | 456 | abort(); |
| | 457 | } |
| | 458 | |
| | 459 | r = fallocate(fd, |
| | 460 | 0, |
| | 461 | 0, |
| | 462 | MFD_DEF_SIZE * 4); |
| | 463 | if (r >= 0) { |
| | 464 | printf("fallocate(ALLOC) didn't fail as expected\n"); |
| | 465 | abort(); |
| | 466 | } |
| | 467 | } |
| | 468 | |
| | 469 | static void mfd_assert_grow_write(int fd) |
| | 470 | { |
| | 471 | static char buf[MFD_DEF_SIZE * 8]; |
| | 472 | ssize_t l; |
| | 473 | |
| | 474 | l = pwrite(fd, buf, sizeof(buf), 0); |
| | 475 | if (l != sizeof(buf)) { |
| | 476 | printf("pwrite() failed: %m\n"); |
| | 477 | abort(); |
| | 478 | } |
| | 479 | |
| | 480 | mfd_assert_size(fd, MFD_DEF_SIZE * 8); |
| | 481 | } |
| | 482 | |
| | 483 | static void mfd_fail_grow_write(int fd) |
| | 484 | { |
| | 485 | static char buf[MFD_DEF_SIZE * 8]; |
| | 486 | ssize_t l; |
| | 487 | |
| | 488 | l = pwrite(fd, buf, sizeof(buf), 0); |
| | 489 | if (l == sizeof(buf)) { |
| | 490 | printf("pwrite() didn't fail as expected\n"); |
| | 491 | abort(); |
| | 492 | } |
| | 493 | } |
| | 494 | |
| | 495 | static int idle_thread_fn(void *arg) |
| | 496 | { |
| | 497 | sigset_t set; |
| | 498 | int sig; |
| | 499 | |
| | 500 | /* dummy waiter; SIGTERM terminates us anyway */ |
| | 501 | sigemptyset(&set); |
| | 502 | sigaddset(&set, SIGTERM); |
| | 503 | sigwait(&set, &sig); |
| | 504 | |
| | 505 | return 0; |
| | 506 | } |
| | 507 | |
| | 508 | static pid_t spawn_idle_thread(unsigned int flags) |
| | 509 | { |
| | 510 | uint8_t *stack; |
| | 511 | pid_t pid; |
| | 512 | |
| | 513 | stack = malloc(STACK_SIZE); |
| | 514 | if (!stack) { |
| | 515 | printf("malloc(STACK_SIZE) failed: %m\n"); |
| | 516 | abort(); |
| | 517 | } |
| | 518 | |
| | 519 | pid = clone(idle_thread_fn, |
| | 520 | stack + STACK_SIZE, |
| | 521 | SIGCHLD | flags, |
| | 522 | NULL); |
| | 523 | if (pid < 0) { |
| | 524 | printf("clone() failed: %m\n"); |
| | 525 | abort(); |
| | 526 | } |
| | 527 | |
| | 528 | return pid; |
| | 529 | } |
| | 530 | |
| | 531 | static void join_idle_thread(pid_t pid) |
| | 532 | { |
| | 533 | kill(pid, SIGTERM); |
| | 534 | waitpid(pid, NULL, 0); |
| | 535 | } |
| | 536 | |
| | 537 | /* |
| | 538 | * Test memfd_create() syscall |
| | 539 | * Verify syscall-argument validation, including name checks, flag validation |
| | 540 | * and more. |
| | 541 | */ |
| | 542 | static void test_create(void) |
| | 543 | { |
| | 544 | char buf[2048]; |
| | 545 | int fd; |
| | 546 | |
| | 547 | /* test NULL name */ |
| | 548 | mfd_fail_new(NULL, 0); |
| | 549 | |
| | 550 | /* test over-long name (not zero-terminated) */ |
| | 551 | memset(buf, 0xff, sizeof(buf)); |
| | 552 | mfd_fail_new(buf, 0); |
| | 553 | |
| | 554 | /* test over-long zero-terminated name */ |
| | 555 | memset(buf, 0xff, sizeof(buf)); |
| | 556 | buf[sizeof(buf) - 1] = 0; |
| | 557 | mfd_fail_new(buf, 0); |
| | 558 | |
| | 559 | /* verify "" is a valid name */ |
| | 560 | fd = mfd_assert_new("", 0, 0); |
| | 561 | close(fd); |
| | 562 | |
| | 563 | /* verify invalid O_* open flags */ |
| | 564 | mfd_fail_new("", 0x0100); |
| | 565 | mfd_fail_new("", ~MFD_CLOEXEC); |
| | 566 | mfd_fail_new("", ~MFD_ALLOW_SEALING); |
| | 567 | mfd_fail_new("", ~0); |
| | 568 | mfd_fail_new("", 0x80000000U); |
| | 569 | |
| | 570 | /* verify MFD_CLOEXEC is allowed */ |
| | 571 | fd = mfd_assert_new("", 0, MFD_CLOEXEC); |
| | 572 | close(fd); |
| | 573 | |
| | 574 | /* verify MFD_ALLOW_SEALING is allowed */ |
| | 575 | fd = mfd_assert_new("", 0, MFD_ALLOW_SEALING); |
| | 576 | close(fd); |
| | 577 | |
| | 578 | /* verify MFD_ALLOW_SEALING | MFD_CLOEXEC is allowed */ |
| | 579 | fd = mfd_assert_new("", 0, MFD_ALLOW_SEALING | MFD_CLOEXEC); |
| | 580 | close(fd); |
| | 581 | } |
| | 582 | |
| | 583 | /* |
| | 584 | * Test basic sealing |
| | 585 | * A very basic sealing test to see whether setting/retrieving seals works. |
| | 586 | */ |
| | 587 | static void test_basic(void) |
| | 588 | { |
| | 589 | int fd; |
| | 590 | |
| | 591 | fd = mfd_assert_new("kern_memfd_basic", |
| | 592 | MFD_DEF_SIZE, |
| | 593 | MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| | 594 | |
| | 595 | /* add basic seals */ |
| | 596 | mfd_assert_has_seals(fd, 0); |
| | 597 | mfd_assert_add_seals(fd, F_SEAL_SHRINK | |
| | 598 | F_SEAL_WRITE); |
| | 599 | mfd_assert_has_seals(fd, F_SEAL_SHRINK | |
| | 600 | F_SEAL_WRITE); |
| | 601 | |
| | 602 | /* add them again */ |
| | 603 | mfd_assert_add_seals(fd, F_SEAL_SHRINK | |
| | 604 | F_SEAL_WRITE); |
| | 605 | mfd_assert_has_seals(fd, F_SEAL_SHRINK | |
| | 606 | F_SEAL_WRITE); |
| | 607 | |
| | 608 | /* add more seals and seal against sealing */ |
| | 609 | mfd_assert_add_seals(fd, F_SEAL_GROW | F_SEAL_SEAL); |
| | 610 | mfd_assert_has_seals(fd, F_SEAL_SHRINK | |
| | 611 | F_SEAL_GROW | |
| | 612 | F_SEAL_WRITE | |
| | 613 | F_SEAL_SEAL); |
| | 614 | |
| | 615 | /* verify that sealing no longer works */ |
| | 616 | mfd_fail_add_seals(fd, F_SEAL_GROW); |
| | 617 | mfd_fail_add_seals(fd, 0); |
| | 618 | |
| | 619 | close(fd); |
| | 620 | |
| | 621 | /* verify sealing does not work without MFD_ALLOW_SEALING */ |
| | 622 | fd = mfd_assert_new("kern_memfd_basic", |
| | 623 | MFD_DEF_SIZE, |
| | 624 | MFD_CLOEXEC); |
| | 625 | mfd_assert_has_seals(fd, F_SEAL_SEAL); |
| | 626 | mfd_fail_add_seals(fd, F_SEAL_SHRINK | |
| | 627 | F_SEAL_GROW | |
| | 628 | F_SEAL_WRITE); |
| | 629 | mfd_assert_has_seals(fd, F_SEAL_SEAL); |
| | 630 | close(fd); |
| | 631 | } |
| | 632 | |
| | 633 | /* |
| | 634 | * Test SEAL_WRITE |
| | 635 | * Test whether SEAL_WRITE actually prevents modifications. |
| | 636 | */ |
| | 637 | static void test_seal_write(void) |
| | 638 | { |
| | 639 | int fd; |
| | 640 | |
| | 641 | fd = mfd_assert_new("kern_memfd_seal_write", |
| | 642 | MFD_DEF_SIZE, |
| | 643 | MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| | 644 | mfd_assert_has_seals(fd, 0); |
| | 645 | mfd_assert_add_seals(fd, F_SEAL_WRITE); |
| | 646 | mfd_assert_has_seals(fd, F_SEAL_WRITE); |
| | 647 | |
| | 648 | mfd_assert_read(fd); |
| | 649 | mfd_fail_write(fd); |
| | 650 | mfd_assert_shrink(fd); |
| | 651 | mfd_assert_grow(fd); |
| | 652 | mfd_fail_grow_write(fd); |
| | 653 | |
| | 654 | close(fd); |
| | 655 | } |
| | 656 | |
| | 657 | /* |
| | 658 | * Test SEAL_SHRINK |
| | 659 | * Test whether SEAL_SHRINK actually prevents shrinking |
| | 660 | */ |
| | 661 | static void test_seal_shrink(void) |
| | 662 | { |
| | 663 | int fd; |
| | 664 | |
| | 665 | fd = mfd_assert_new("kern_memfd_seal_shrink", |
| | 666 | MFD_DEF_SIZE, |
| | 667 | MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| | 668 | mfd_assert_has_seals(fd, 0); |
| | 669 | mfd_assert_add_seals(fd, F_SEAL_SHRINK); |
| | 670 | mfd_assert_has_seals(fd, F_SEAL_SHRINK); |
| | 671 | |
| | 672 | mfd_assert_read(fd); |
| | 673 | mfd_assert_write(fd); |
| | 674 | mfd_fail_shrink(fd); |
| | 675 | mfd_assert_grow(fd); |
| | 676 | mfd_assert_grow_write(fd); |
| | 677 | |
| | 678 | close(fd); |
| | 679 | } |
| | 680 | |
| | 681 | /* |
| | 682 | * Test SEAL_GROW |
| | 683 | * Test whether SEAL_GROW actually prevents growing |
| | 684 | */ |
| | 685 | static void test_seal_grow(void) |
| | 686 | { |
| | 687 | int fd; |
| | 688 | |
| | 689 | fd = mfd_assert_new("kern_memfd_seal_grow", |
| | 690 | MFD_DEF_SIZE, |
| | 691 | MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| | 692 | mfd_assert_has_seals(fd, 0); |
| | 693 | mfd_assert_add_seals(fd, F_SEAL_GROW); |
| | 694 | mfd_assert_has_seals(fd, F_SEAL_GROW); |
| | 695 | |
| | 696 | mfd_assert_read(fd); |
| | 697 | mfd_assert_write(fd); |
| | 698 | mfd_assert_shrink(fd); |
| | 699 | mfd_fail_grow(fd); |
| | 700 | mfd_fail_grow_write(fd); |
| | 701 | |
| | 702 | close(fd); |
| | 703 | } |
| | 704 | |
| | 705 | /* |
| | 706 | * Test SEAL_SHRINK | SEAL_GROW |
| | 707 | * Test whether SEAL_SHRINK | SEAL_GROW actually prevents resizing |
| | 708 | */ |
| | 709 | static void test_seal_resize(void) |
| | 710 | { |
| | 711 | int fd; |
| | 712 | |
| | 713 | fd = mfd_assert_new("kern_memfd_seal_resize", |
| | 714 | MFD_DEF_SIZE, |
| | 715 | MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| | 716 | mfd_assert_has_seals(fd, 0); |
| | 717 | mfd_assert_add_seals(fd, F_SEAL_SHRINK | F_SEAL_GROW); |
| | 718 | mfd_assert_has_seals(fd, F_SEAL_SHRINK | F_SEAL_GROW); |
| | 719 | |
| | 720 | mfd_assert_read(fd); |
| | 721 | mfd_assert_write(fd); |
| | 722 | mfd_fail_shrink(fd); |
| | 723 | mfd_fail_grow(fd); |
| | 724 | mfd_fail_grow_write(fd); |
| | 725 | |
| | 726 | close(fd); |
| | 727 | } |
| | 728 | |
| | 729 | /* |
| | 730 | * Test sharing via dup() |
| | 731 | * Test that seals are shared between dupped FDs and they're all equal. |
| | 732 | */ |
| | 733 | static void test_share_dup(void) |
| | 734 | { |
| | 735 | int fd, fd2; |
| | 736 | |
| | 737 | fd = mfd_assert_new("kern_memfd_share_dup", |
| | 738 | MFD_DEF_SIZE, |
| | 739 | MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| | 740 | mfd_assert_has_seals(fd, 0); |
| | 741 | |
| | 742 | fd2 = mfd_assert_dup(fd); |
| | 743 | mfd_assert_has_seals(fd2, 0); |
| | 744 | |
| | 745 | mfd_assert_add_seals(fd, F_SEAL_WRITE); |
| | 746 | mfd_assert_has_seals(fd, F_SEAL_WRITE); |
| | 747 | mfd_assert_has_seals(fd2, F_SEAL_WRITE); |
| | 748 | |
| | 749 | mfd_assert_add_seals(fd2, F_SEAL_SHRINK); |
| | 750 | mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK); |
| | 751 | mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK); |
| | 752 | |
| | 753 | mfd_assert_add_seals(fd, F_SEAL_SEAL); |
| | 754 | mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL); |
| | 755 | mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL); |
| | 756 | |
| | 757 | mfd_fail_add_seals(fd, F_SEAL_GROW); |
| | 758 | mfd_fail_add_seals(fd2, F_SEAL_GROW); |
| | 759 | mfd_fail_add_seals(fd, F_SEAL_SEAL); |
| | 760 | mfd_fail_add_seals(fd2, F_SEAL_SEAL); |
| | 761 | |
| | 762 | close(fd2); |
| | 763 | |
| | 764 | mfd_fail_add_seals(fd, F_SEAL_GROW); |
| | 765 | close(fd); |
| | 766 | } |
| | 767 | |
| | 768 | /* |
| | 769 | * Test sealing with active mmap()s |
| | 770 | * Modifying seals is only allowed if no other mmap() refs exist. |
| | 771 | */ |
| | 772 | static void test_share_mmap(void) |
| | 773 | { |
| | 774 | int fd; |
| | 775 | void *p; |
| | 776 | |
| | 777 | fd = mfd_assert_new("kern_memfd_share_mmap", |
| | 778 | MFD_DEF_SIZE, |
| | 779 | MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| | 780 | mfd_assert_has_seals(fd, 0); |
| | 781 | |
| | 782 | /* shared/writable ref prevents sealing WRITE, but allows others */ |
| | 783 | p = mfd_assert_mmap_shared(fd); |
| | 784 | mfd_fail_add_seals(fd, F_SEAL_WRITE); |
| | 785 | mfd_assert_has_seals(fd, 0); |
| | 786 | mfd_assert_add_seals(fd, F_SEAL_SHRINK); |
| | 787 | mfd_assert_has_seals(fd, F_SEAL_SHRINK); |
| | 788 | munmap(p, MFD_DEF_SIZE); |
| | 789 | |
| | 790 | /* readable ref allows sealing */ |
| | 791 | p = mfd_assert_mmap_private(fd); |
| | 792 | mfd_assert_add_seals(fd, F_SEAL_WRITE); |
| | 793 | mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK); |
| | 794 | munmap(p, MFD_DEF_SIZE); |
| | 795 | |
| | 796 | close(fd); |
| | 797 | } |
| | 798 | |
| | 799 | /* |
| | 800 | * Test sealing with open(/proc/self/fd/%d) |
| | 801 | * Via /proc we can get access to a separate file-context for the same memfd. |
| | 802 | * This is *not* like dup(), but like a real separate open(). Make sure the |
| | 803 | * semantics are as expected and we correctly check for RDONLY / WRONLY / RDWR. |
| | 804 | */ |
| | 805 | static void test_share_open(void) |
| | 806 | { |
| | 807 | int fd, fd2; |
| | 808 | |
| | 809 | fd = mfd_assert_new("kern_memfd_share_open", |
| | 810 | MFD_DEF_SIZE, |
| | 811 | MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| | 812 | mfd_assert_has_seals(fd, 0); |
| | 813 | |
| | 814 | fd2 = mfd_assert_open(fd, O_RDWR, 0); |
| | 815 | mfd_assert_add_seals(fd, F_SEAL_WRITE); |
| | 816 | mfd_assert_has_seals(fd, F_SEAL_WRITE); |
| | 817 | mfd_assert_has_seals(fd2, F_SEAL_WRITE); |
| | 818 | |
| | 819 | mfd_assert_add_seals(fd2, F_SEAL_SHRINK); |
| | 820 | mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK); |
| | 821 | mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK); |
| | 822 | |
| | 823 | close(fd); |
| | 824 | fd = mfd_assert_open(fd2, O_RDONLY, 0); |
| | 825 | |
| | 826 | mfd_fail_add_seals(fd, F_SEAL_SEAL); |
| | 827 | mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK); |
| | 828 | mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK); |
| | 829 | |
| | 830 | close(fd2); |
| | 831 | fd2 = mfd_assert_open(fd, O_RDWR, 0); |
| | 832 | |
| | 833 | mfd_assert_add_seals(fd2, F_SEAL_SEAL); |
| | 834 | mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL); |
| | 835 | mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL); |
| | 836 | |
| | 837 | close(fd2); |
| | 838 | close(fd); |
| | 839 | } |
| | 840 | |
| | 841 | /* |
| | 842 | * Test sharing via fork() |
| | 843 | * Test whether seal-modifications work as expected with forked childs. |
| | 844 | */ |
| | 845 | static void test_share_fork(void) |
| | 846 | { |
| | 847 | int fd; |
| | 848 | pid_t pid; |
| | 849 | |
| | 850 | fd = mfd_assert_new("kern_memfd_share_fork", |
| | 851 | MFD_DEF_SIZE, |
| | 852 | MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| | 853 | mfd_assert_has_seals(fd, 0); |
| | 854 | |
| | 855 | pid = spawn_idle_thread(0); |
| | 856 | mfd_assert_add_seals(fd, F_SEAL_SEAL); |
| | 857 | mfd_assert_has_seals(fd, F_SEAL_SEAL); |
| | 858 | |
| | 859 | mfd_fail_add_seals(fd, F_SEAL_WRITE); |
| | 860 | mfd_assert_has_seals(fd, F_SEAL_SEAL); |
| | 861 | |
| | 862 | join_idle_thread(pid); |
| | 863 | |
| | 864 | mfd_fail_add_seals(fd, F_SEAL_WRITE); |
| | 865 | mfd_assert_has_seals(fd, F_SEAL_SEAL); |
| | 866 | |
| | 867 | close(fd); |
| | 868 | } |
| | 869 | |
| | 870 | int main(int argc, char **argv) |
| | 871 | { |
| | 872 | pid_t pid; |
| | 873 | |
| | 874 | printf("memfd: CREATE\n"); |
| | 875 | test_create(); |
| | 876 | printf("memfd: BASIC\n"); |
| | 877 | test_basic(); |
| | 878 | |
| | 879 | printf("memfd: SEAL-WRITE\n"); |
| | 880 | test_seal_write(); |
| | 881 | printf("memfd: SEAL-SHRINK\n"); |
| | 882 | test_seal_shrink(); |
| | 883 | printf("memfd: SEAL-GROW\n"); |
| | 884 | test_seal_grow(); |
| | 885 | printf("memfd: SEAL-RESIZE\n"); |
| | 886 | test_seal_resize(); |
| | 887 | |
| | 888 | printf("memfd: SHARE-DUP\n"); |
| | 889 | test_share_dup(); |
| | 890 | printf("memfd: SHARE-MMAP\n"); |
| | 891 | test_share_mmap(); |
| | 892 | printf("memfd: SHARE-OPEN\n"); |
| | 893 | test_share_open(); |
| | 894 | printf("memfd: SHARE-FORK\n"); |
| | 895 | test_share_fork(); |
| | 896 | |
| | 897 | /* Run test-suite in a multi-threaded environment with a shared |
| | 898 | * file-table. */ |
| | 899 | pid = spawn_idle_thread(CLONE_FILES | CLONE_FS | CLONE_VM); |
| | 900 | printf("memfd: SHARE-DUP (shared file-table)\n"); |
| | 901 | test_share_dup(); |
| | 902 | printf("memfd: SHARE-MMAP (shared file-table)\n"); |
| | 903 | test_share_mmap(); |
| | 904 | printf("memfd: SHARE-OPEN (shared file-table)\n"); |
| | 905 | test_share_open(); |
| | 906 | printf("memfd: SHARE-FORK (shared file-table)\n"); |
| | 907 | test_share_fork(); |
| | 908 | join_idle_thread(pid); |
| | 909 | |
| | 910 | printf("memfd: DONE\n"); |
| | 911 | |
| | 912 | return 0; |
| | 913 | } |