src/test/test-fd-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <fcntl.h>
   4 #include <sys/eventfd.h>
   5 #include <unistd.h>
   6
   7 #include "alloc-util.h"
   8 #include "data-fd-util.h"
   9 #include "fd-util.h"
  10 #include "fileio.h"
  11 #include "macro.h"
  12 #include "memory-util.h"
  13 #include "missing_syscall.h"
  14 #include "mount-util.h"
  15 #include "path-util.h"
  16 #include "process-util.h"
  17 #include "random-util.h"
  18 #include "rlimit-util.h"
  19 #include "seccomp-util.h"
  20 #include "serialize.h"
  21 #include "string-util.h"
  22 #include "tests.h"
  23 #include "tmpfile-util.h"
  24
  25 TEST(close_many) {
  26         int fds[3];
  27         char name0[] = "/tmp/test-close-many.XXXXXX";
  28         char name1[] = "/tmp/test-close-many.XXXXXX";
  29         char name2[] = "/tmp/test-close-many.XXXXXX";
  30
  31         fds[0] = mkostemp_safe(name0);
  32         fds[1] = mkostemp_safe(name1);
  33         fds[2] = mkostemp_safe(name2);
  34
  35         close_many(fds, 2);
  36
  37         assert_se(fcntl(fds[0], F_GETFD) == -1);
  38         assert_se(fcntl(fds[1], F_GETFD) == -1);
  39         assert_se(fcntl(fds[2], F_GETFD) >= 0);
  40
  41         safe_close(fds[2]);
  42
  43         unlink(name0);
  44         unlink(name1);
  45         unlink(name2);
  46 }
  47
  48 TEST(close_nointr) {
  49         char name[] = "/tmp/test-test-close_nointr.XXXXXX";
  50         int fd;
  51
  52         fd = mkostemp_safe(name);
  53         assert_se(fd >= 0);
  54         assert_se(close_nointr(fd) >= 0);
  55         assert_se(close_nointr(fd) < 0);
  56
  57         unlink(name);
  58 }
  59
  60 TEST(same_fd) {
  61         _cleanup_close_pair_ int p[2] = { -1, -1 };
  62         _cleanup_close_ int a = -1, b = -1, c = -1;
  63
  64         assert_se(pipe2(p, O_CLOEXEC) >= 0);
  65         assert_se((a = fcntl(p[0], F_DUPFD, 3)) >= 0);
  66         assert_se((b = open("/dev/null", O_RDONLY|O_CLOEXEC)) >= 0);
  67         assert_se((c = fcntl(a, F_DUPFD, 3)) >= 0);
  68
  69         assert_se(same_fd(p[0], p[0]) > 0);
  70         assert_se(same_fd(p[1], p[1]) > 0);
  71         assert_se(same_fd(a, a) > 0);
  72         assert_se(same_fd(b, b) > 0);
  73
  74         assert_se(same_fd(a, p[0]) > 0);
  75         assert_se(same_fd(p[0], a) > 0);
  76         assert_se(same_fd(c, p[0]) > 0);
  77         assert_se(same_fd(p[0], c) > 0);
  78         assert_se(same_fd(a, c) > 0);
  79         assert_se(same_fd(c, a) > 0);
  80
  81         assert_se(same_fd(p[0], p[1]) == 0);
  82         assert_se(same_fd(p[1], p[0]) == 0);
  83         assert_se(same_fd(p[0], b) == 0);
  84         assert_se(same_fd(b, p[0]) == 0);
  85         assert_se(same_fd(p[1], a) == 0);
  86         assert_se(same_fd(a, p[1]) == 0);
  87         assert_se(same_fd(p[1], b) == 0);
  88         assert_se(same_fd(b, p[1]) == 0);
  89
  90         assert_se(same_fd(a, b) == 0);
  91         assert_se(same_fd(b, a) == 0);
  92 }
  93
  94 TEST(open_serialization_fd) {
  95         _cleanup_close_ int fd = -1;
  96
  97         fd = open_serialization_fd("test");
  98         assert_se(fd >= 0);
  99
 100         assert_se(write(fd, "test\n", 5) == 5);
 101 }
 102
 103 TEST(fd_move_above_stdio) {
 104         int original_stdin, new_fd;
 105
 106         original_stdin = fcntl(0, F_DUPFD, 3);
 107         assert_se(original_stdin >= 3);
 108         assert_se(close_nointr(0) != EBADF);
 109
 110         new_fd = open("/dev/null", O_RDONLY);
 111         assert_se(new_fd == 0);
 112
 113         new_fd = fd_move_above_stdio(new_fd);
 114         assert_se(new_fd >= 3);
 115
 116         assert_se(dup(original_stdin) == 0);
 117         assert_se(close_nointr(original_stdin) != EBADF);
 118         assert_se(close_nointr(new_fd) != EBADF);
 119 }
 120
 121 TEST(rearrange_stdio) {
 122         pid_t pid;
 123         int r;
 124
 125         r = safe_fork("rearrange", FORK_WAIT|FORK_LOG, &pid);
 126         assert_se(r >= 0);
 127
 128         if (r == 0) {
 129                 _cleanup_free_ char *path = NULL;
 130                 char buffer[10];
 131
 132                 /* Child */
 133
 134                 safe_close(STDERR_FILENO); /* Let's close an fd < 2, to make it more interesting */
 135
 136                 assert_se(rearrange_stdio(-1, -1, -1) >= 0);
 137
 138                 assert_se(fd_get_path(STDIN_FILENO, &path) >= 0);
 139                 assert_se(path_equal(path, "/dev/null"));
 140                 path = mfree(path);
 141
 142                 assert_se(fd_get_path(STDOUT_FILENO, &path) >= 0);
 143                 assert_se(path_equal(path, "/dev/null"));
 144                 path = mfree(path);
 145
 146                 assert_se(fd_get_path(STDOUT_FILENO, &path) >= 0);
 147                 assert_se(path_equal(path, "/dev/null"));
 148                 path = mfree(path);
 149
 150                 safe_close(STDIN_FILENO);
 151                 safe_close(STDOUT_FILENO);
 152                 safe_close(STDERR_FILENO);
 153
 154                 {
 155                         int pair[2];
 156                         assert_se(pipe(pair) >= 0);
 157                         assert_se(pair[0] == 0);
 158                         assert_se(pair[1] == 1);
 159                         assert_se(fd_move_above_stdio(0) == 3);
 160                 }
 161                 assert_se(open("/dev/full", O_WRONLY|O_CLOEXEC) == 0);
 162                 assert_se(acquire_data_fd("foobar", 6, 0) == 2);
 163
 164                 assert_se(rearrange_stdio(2, 0, 1) >= 0);
 165
 166                 assert_se(write(1, "x", 1) < 0 && errno == ENOSPC);
 167                 assert_se(write(2, "z", 1) == 1);
 168                 assert_se(read(3, buffer, sizeof(buffer)) == 1);
 169                 assert_se(buffer[0] == 'z');
 170                 assert_se(read(0, buffer, sizeof(buffer)) == 6);
 171                 assert_se(memcmp(buffer, "foobar", 6) == 0);
 172
 173                 assert_se(rearrange_stdio(-1, 1, 2) >= 0);
 174                 assert_se(write(1, "a", 1) < 0 && errno == ENOSPC);
 175                 assert_se(write(2, "y", 1) == 1);
 176                 assert_se(read(3, buffer, sizeof(buffer)) == 1);
 177                 assert_se(buffer[0] == 'y');
 178
 179                 assert_se(fd_get_path(0, &path) >= 0);
 180                 assert_se(path_equal(path, "/dev/null"));
 181                 path = mfree(path);
 182
 183                 _exit(EXIT_SUCCESS);
 184         }
 185 }
 186
 187 TEST(read_nr_open) {
 188         log_info("nr-open: %i", read_nr_open());
 189 }
 190
 191 static size_t validate_fds(
 192                 bool opened,
 193                 const int *fds,
 194                 size_t n_fds) {
 195
 196         size_t c = 0;
 197
 198         /* Validates that fds in the specified array are one of the following three:
 199          *
 200          *  1. < 0 (test is skipped) or
 201          *  2. opened (if 'opened' param is true) or
 202          *  3. closed (if 'opened' param is false)
 203          */
 204
 205         for (size_t i = 0; i < n_fds; i++) {
 206                 if (fds[i] < 0)
 207                         continue;
 208
 209                 if (opened)
 210                         assert_se(fcntl(fds[i], F_GETFD) >= 0);
 211                 else
 212                         assert_se(fcntl(fds[i], F_GETFD) < 0 && errno == EBADF);
 213
 214                 c++;
 215         }
 216
 217         return c; /* Return number of fds >= 0 in the array */
 218 }
 219
 220 static void test_close_all_fds_inner(void) {
 221         _cleanup_free_ int *fds = NULL, *keep = NULL;
 222         size_t n_fds, n_keep;
 223         int max_fd;
 224
 225         log_info("/* %s */", __func__);
 226
 227         rlimit_nofile_bump(-1);
 228
 229         max_fd = get_max_fd();
 230         assert_se(max_fd > 10);
 231
 232         if (max_fd > 7000) {
 233                 /* If the worst fallback is activated we need to iterate through all possible fds, hence,
 234                  * let's lower the limit a small bit, so that we don't run for too long. Yes, this undoes the
 235                  * rlimit_nofile_bump() call above partially. */
 236
 237                 (void) setrlimit_closest(RLIMIT_NOFILE, &(struct rlimit) { 7000, 7000 });
 238                 max_fd = 7000;
 239         }
 240
 241         /* Try to use 5000 fds, but when we can't bump the rlimit to make that happen use the whole limit minus 10 */
 242         n_fds = MIN(((size_t) max_fd & ~1U) - 10U, 5000U);
 243         assert_se((n_fds & 1U) == 0U); /* make sure even number of fds */
 244
 245         /* Allocate the determined number of fds, always two at a time */
 246         assert_se(fds = new(int, n_fds));
 247         for (size_t i = 0; i < n_fds; i += 2)
 248                 assert_se(pipe2(fds + i, O_CLOEXEC) >= 0);
 249
 250         /* Validate this worked */
 251         assert_se(validate_fds(true, fds, n_fds) == n_fds);
 252
 253         /* Randomized number of fds to keep, but at most every second */
 254         n_keep = (random_u64() % (n_fds / 2));
 255
 256         /* Now randomly select a number of fds from the array above to keep */
 257         assert_se(keep = new(int, n_keep));
 258         for (size_t k = 0; k < n_keep; k++) {
 259                 for (;;) {
 260                         size_t p;
 261
 262                         p = random_u64() % n_fds;
 263                         if (fds[p] >= 0) {
 264                                 keep[k] = TAKE_FD(fds[p]);
 265                                 break;
 266                         }
 267                 }
 268         }
 269
 270         /* Check that all fds from both arrays are still open, and test how many in each are >= 0 */
 271         assert_se(validate_fds(true, fds, n_fds) == n_fds - n_keep);
 272         assert_se(validate_fds(true, keep, n_keep) == n_keep);
 273
 274         /* Close logging fd first, so that we don't confuse it by closing its fd */
 275         log_close();
 276         log_set_open_when_needed(true);
 277
 278         /* Close all but the ones to keep */
 279         assert_se(close_all_fds(keep, n_keep) >= 0);
 280
 281         assert_se(validate_fds(false, fds, n_fds) == n_fds - n_keep);
 282         assert_se(validate_fds(true, keep, n_keep) == n_keep);
 283
 284         /* Close everything else too! */
 285         assert_se(close_all_fds(NULL, 0) >= 0);
 286
 287         assert_se(validate_fds(false, fds, n_fds) == n_fds - n_keep);
 288         assert_se(validate_fds(false, keep, n_keep) == n_keep);
 289
 290         log_set_open_when_needed(false);
 291         log_open();
 292 }
 293
 294 static int seccomp_prohibit_close_range(void) {
 295 #if HAVE_SECCOMP && defined(__SNR_close_range)
 296         _cleanup_(seccomp_releasep) scmp_filter_ctx seccomp = NULL;
 297         int r;
 298
 299         r = seccomp_init_for_arch(&seccomp, SCMP_ARCH_NATIVE, SCMP_ACT_ALLOW);
 300         if (r < 0)
 301                 return log_warning_errno(r, "Failed to acquire seccomp context, ignoring: %m");
 302
 303         r = seccomp_rule_add_exact(
 304                         seccomp,
 305                         SCMP_ACT_ERRNO(EPERM),
 306                         SCMP_SYS(close_range),
 307                         0);
 308         if (r < 0)
 309                 return log_warning_errno(r, "Failed to add close_range() rule, ignoring: %m");
 310
 311         r = seccomp_load(seccomp);
 312         if (r < 0)
 313                 return log_warning_errno(r, "Failed to apply close_range() restrictions, ignoring: %m");
 314
 315         return 0;
 316 #else
 317         return log_warning_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Seccomp support or close_range() syscall definition not available.");
 318 #endif
 319 }
 320
 321 TEST(close_all_fds) {
 322         int r;
 323
 324         /* Runs the test four times. Once as is. Once with close_range() syscall blocked via seccomp, once
 325          * with /proc/ overmounted, and once with the combination of both. This should trigger all fallbacks
 326          * in the close_range_all() function. */
 327
 328         r = safe_fork("(caf-plain)", FORK_CLOSE_ALL_FDS|FORK_DEATHSIG|FORK_LOG|FORK_WAIT, NULL);
 329         if (r == 0) {
 330                 test_close_all_fds_inner();
 331                 _exit(EXIT_SUCCESS);
 332         }
 333         assert_se(r >= 0);
 334
 335         if (geteuid() != 0)
 336                 return (void) log_tests_skipped("Lacking privileges for test with close_range() blocked and /proc/ overmounted");
 337
 338         r = safe_fork("(caf-noproc)", FORK_CLOSE_ALL_FDS|FORK_DEATHSIG|FORK_LOG|FORK_WAIT|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE, NULL);
 339         if (r == 0) {
 340                 r = mount_nofollow_verbose(LOG_WARNING, "tmpfs", "/proc", "tmpfs", 0, NULL);
 341                 if (r < 0)
 342                         log_notice("Overmounting /proc/ didn't work, skipping close_all_fds() with masked /proc/.");
 343                 else
 344                         test_close_all_fds_inner();
 345                 _exit(EXIT_SUCCESS);
 346         }
 347         assert_se(r >= 0);
 348
 349         if (!is_seccomp_available())
 350                 return (void) log_tests_skipped("Seccomp not available");
 351
 352         r = safe_fork("(caf-seccomp)", FORK_CLOSE_ALL_FDS|FORK_DEATHSIG|FORK_LOG|FORK_WAIT, NULL);
 353         if (r == 0) {
 354                 r = seccomp_prohibit_close_range();
 355                 if (r < 0)
 356                         log_notice("Applying seccomp filter didn't work, skipping close_all_fds() test with masked close_range().");
 357                 else
 358                         test_close_all_fds_inner();
 359
 360                 _exit(EXIT_SUCCESS);
 361         }
 362         assert_se(r >= 0);
 363
 364         r = safe_fork("(caf-scnp)", FORK_CLOSE_ALL_FDS|FORK_DEATHSIG|FORK_LOG|FORK_WAIT|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE, NULL);
 365         if (r == 0) {
 366                 r = seccomp_prohibit_close_range();
 367                 if (r < 0)
 368                         log_notice("Applying seccomp filter didn't work, skipping close_all_fds() test with masked close_range().");
 369                 else {
 370                         r = mount_nofollow_verbose(LOG_WARNING, "tmpfs", "/proc", "tmpfs", 0, NULL);
 371                         if (r < 0)
 372                                 log_notice("Overmounting /proc/ didn't work, skipping close_all_fds() with masked /proc/.");
 373                         else
 374                                 test_close_all_fds_inner();
 375                 }
 376
 377                 test_close_all_fds_inner();
 378                 _exit(EXIT_SUCCESS);
 379         }
 380         assert_se(r >= 0);
 381 }
 382
 383 TEST(format_proc_fd_path) {
 384         assert_se(streq_ptr(FORMAT_PROC_FD_PATH(0), "/proc/self/fd/0"));
 385         assert_se(streq_ptr(FORMAT_PROC_FD_PATH(1), "/proc/self/fd/1"));
 386         assert_se(streq_ptr(FORMAT_PROC_FD_PATH(2), "/proc/self/fd/2"));
 387         assert_se(streq_ptr(FORMAT_PROC_FD_PATH(3), "/proc/self/fd/3"));
 388         assert_se(streq_ptr(FORMAT_PROC_FD_PATH(2147483647), "/proc/self/fd/2147483647"));
 389 }
 390
 391 TEST(fd_reopen) {
 392         _cleanup_close_ int fd1 = -1, fd2 = -1;
 393         struct stat st1, st2;
 394         int fl;
 395
 396         /* Test this with a directory */
 397         fd1 = open("/proc", O_DIRECTORY|O_PATH|O_CLOEXEC);
 398         assert_se(fd1 >= 0);
 399
 400         assert_se(fstat(fd1, &st1) >= 0);
 401         assert_se(S_ISDIR(st1.st_mode));
 402
 403         fl = fcntl(fd1, F_GETFL);
 404         assert_se(fl >= 0);
 405         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 406         assert_se(FLAGS_SET(fl, O_PATH));
 407
 408         fd2 = fd_reopen(fd1, O_RDONLY|O_DIRECTORY|O_CLOEXEC);  /* drop the O_PATH */
 409         assert_se(fd2 >= 0);
 410
 411         assert_se(fstat(fd2, &st2) >= 0);
 412         assert_se(S_ISDIR(st2.st_mode));
 413         assert_se(st1.st_ino == st2.st_ino);
 414         assert_se(st1.st_rdev == st2.st_rdev);
 415
 416         fl = fcntl(fd2, F_GETFL);
 417         assert_se(fl >= 0);
 418         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 419         assert_se(!FLAGS_SET(fl, O_PATH));
 420
 421         safe_close(fd1);
 422
 423         fd1 = fd_reopen(fd2, O_DIRECTORY|O_PATH|O_CLOEXEC);  /* reacquire the O_PATH */
 424         assert_se(fd1 >= 0);
 425
 426         assert_se(fstat(fd1, &st1) >= 0);
 427         assert_se(S_ISDIR(st1.st_mode));
 428         assert_se(st1.st_ino == st2.st_ino);
 429         assert_se(st1.st_rdev == st2.st_rdev);
 430
 431         fl = fcntl(fd1, F_GETFL);
 432         assert_se(fl >= 0);
 433         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 434         assert_se(FLAGS_SET(fl, O_PATH));
 435
 436         safe_close(fd1);
 437
 438         /* And now, test this with a file. */
 439         fd1 = open("/proc/version", O_PATH|O_CLOEXEC);
 440         assert_se(fd1 >= 0);
 441
 442         assert_se(fstat(fd1, &st1) >= 0);
 443         assert_se(S_ISREG(st1.st_mode));
 444
 445         fl = fcntl(fd1, F_GETFL);
 446         assert_se(fl >= 0);
 447         assert_se(!FLAGS_SET(fl, O_DIRECTORY));
 448         assert_se(FLAGS_SET(fl, O_PATH));
 449
 450         assert_se(fd_reopen(fd1, O_RDONLY|O_DIRECTORY|O_CLOEXEC) == -ENOTDIR);
 451         fd2 = fd_reopen(fd1, O_RDONLY|O_CLOEXEC);  /* drop the O_PATH */
 452         assert_se(fd2 >= 0);
 453
 454         assert_se(fstat(fd2, &st2) >= 0);
 455         assert_se(S_ISREG(st2.st_mode));
 456         assert_se(st1.st_ino == st2.st_ino);
 457         assert_se(st1.st_rdev == st2.st_rdev);
 458
 459         fl = fcntl(fd2, F_GETFL);
 460         assert_se(fl >= 0);
 461         assert_se(!FLAGS_SET(fl, O_DIRECTORY));
 462         assert_se(!FLAGS_SET(fl, O_PATH));
 463
 464         safe_close(fd1);
 465
 466         assert_se(fd_reopen(fd2, O_DIRECTORY|O_PATH|O_CLOEXEC) == -ENOTDIR);
 467         fd1 = fd_reopen(fd2, O_PATH|O_CLOEXEC);  /* reacquire the O_PATH */
 468         assert_se(fd1 >= 0);
 469
 470         assert_se(fstat(fd1, &st1) >= 0);
 471         assert_se(S_ISREG(st1.st_mode));
 472         assert_se(st1.st_ino == st2.st_ino);
 473         assert_se(st1.st_rdev == st2.st_rdev);
 474
 475         fl = fcntl(fd1, F_GETFL);
 476         assert_se(fl >= 0);
 477         assert_se(!FLAGS_SET(fl, O_DIRECTORY));
 478         assert_se(FLAGS_SET(fl, O_PATH));
 479
 480         /* Also check the right error is generated if the fd is already closed */
 481         safe_close(fd1);
 482         assert_se(fd_reopen(fd1, O_RDONLY|O_CLOEXEC) == -EBADF);
 483         fd1 = -1;
 484 }
 485
 486 TEST(fd_reopen_condition) {
 487         _cleanup_close_ int fd1 = -1, fd3 = -1;
 488         int fd2, fl;
 489
 490         /* Open without O_PATH */
 491         fd1 = open("/usr/", O_RDONLY|O_DIRECTORY|O_CLOEXEC);
 492         assert_se(fd1 >= 0);
 493
 494         fl = fcntl(fd1, F_GETFL);
 495         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 496         assert_se(!FLAGS_SET(fl, O_PATH));
 497
 498         fd2 = fd_reopen_condition(fd1, O_DIRECTORY, O_DIRECTORY|O_PATH, &fd3);
 499         assert_se(fd2 == fd1);
 500         assert_se(fd3 < 0);
 501
 502         /* Switch on O_PATH */
 503         fd2 = fd_reopen_condition(fd1, O_DIRECTORY|O_PATH, O_DIRECTORY|O_PATH, &fd3);
 504         assert_se(fd2 != fd1);
 505         assert_se(fd3 == fd2);
 506
 507         fl = fcntl(fd2, F_GETFL);
 508         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 509         assert_se(FLAGS_SET(fl, O_PATH));
 510
 511         close_and_replace(fd1, fd3);
 512
 513         fd2 = fd_reopen_condition(fd1, O_DIRECTORY|O_PATH, O_DIRECTORY|O_PATH, &fd3);
 514         assert_se(fd2 == fd1);
 515         assert_se(fd3 < 0);
 516
 517         /* Switch off O_PATH again */
 518         fd2 = fd_reopen_condition(fd1, O_DIRECTORY, O_DIRECTORY|O_PATH, &fd3);
 519         assert_se(fd2 != fd1);
 520         assert_se(fd3 == fd2);
 521
 522         fl = fcntl(fd2, F_GETFL);
 523         assert_se(FLAGS_SET(fl, O_DIRECTORY));
 524         assert_se(!FLAGS_SET(fl, O_PATH));
 525
 526         close_and_replace(fd1, fd3);
 527
 528         fd2 = fd_reopen_condition(fd1, O_DIRECTORY, O_DIRECTORY|O_PATH, &fd3);
 529         assert_se(fd2 == fd1);
 530         assert_se(fd3 < 0);
 531 }
 532
 533 TEST(take_fd) {
 534         _cleanup_close_ int fd1 = -1, fd2 = -1;
 535         int array[2] = { -1, -1 }, i = 0;
 536
 537         assert_se(fd1 == -1);
 538         assert_se(fd2 == -1);
 539
 540         fd1 = eventfd(0, EFD_CLOEXEC);
 541         assert_se(fd1 >= 0);
 542
 543         fd2 = TAKE_FD(fd1);
 544         assert_se(fd1 == -1);
 545         assert_se(fd2 >= 0);
 546
 547         assert_se(array[0] == -1);
 548         assert_se(array[1] == -1);
 549
 550         array[0] = TAKE_FD(fd2);
 551         assert_se(fd1 == -1);
 552         assert_se(fd2 == -1);
 553         assert_se(array[0] >= 0);
 554         assert_se(array[1] == -1);
 555
 556         array[1] = TAKE_FD(array[i]);
 557         assert_se(array[0] == -1);
 558         assert_se(array[1] >= 0);
 559
 560         i = 1 - i;
 561         array[0] = TAKE_FD(*(array + i));
 562         assert_se(array[0] >= 0);
 563         assert_se(array[1] == -1);
 564
 565         i = 1 - i;
 566         fd1 = TAKE_FD(array[i]);
 567         assert_se(fd1 >= 0);
 568         assert_se(array[0] == -1);
 569         assert_se(array[1] == -1);
 570 }
 571
 572 DEFINE_TEST_MAIN(LOG_DEBUG);