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