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6b20880b22
It ensures a continuous range of file descriptor and avoid hitting the RLIMIT_NOFILE. Checked on x86_64-linux-gnu.
144 lines
3.6 KiB
C
144 lines
3.6 KiB
C
/* Smoke test for the closefrom.
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Copyright (C) 2021 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <fcntl.h>
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#include <sys/resource.h>
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#include <unistd.h>
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#include <support/check.h>
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#include <support/descriptors.h>
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#include <support/xunistd.h>
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#include <support/support.h>
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#include <array_length.h>
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#define NFDS 100
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static int
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closefrom_test (void)
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{
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struct support_descriptors *descrs = support_descriptors_list ();
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int lowfd = support_open_dev_null_range (NFDS, O_RDONLY, 0600);
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const int maximum_fd = lowfd + NFDS - 1;
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const int half_fd = lowfd + NFDS / 2;
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const int gap = lowfd + NFDS / 4;
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/* Close half of the descriptors and check result. */
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closefrom (half_fd);
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for (int i = half_fd; i <= maximum_fd; i++)
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{
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TEST_COMPARE (fcntl (i, F_GETFL), -1);
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TEST_COMPARE (errno, EBADF);
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}
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for (int i = lowfd; i < half_fd; i++)
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TEST_VERIFY (fcntl (i, F_GETFL) > -1);
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/* Create some gaps, close up to a threshold, and check result. */
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xclose (lowfd + 35);
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xclose (lowfd + 38);
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xclose (lowfd + 42);
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xclose (lowfd + 46);
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/* Close half of the descriptors and check result. */
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closefrom (gap);
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for (int i = gap + 1; i < maximum_fd; i++)
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{
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TEST_COMPARE (fcntl (i, F_GETFL), -1);
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TEST_COMPARE (errno, EBADF);
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}
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for (int i = lowfd; i < gap; i++)
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TEST_VERIFY (fcntl (i, F_GETFL) > -1);
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/* Close the remmaining but the last one. */
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closefrom (lowfd + 1);
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for (int i = lowfd + 1; i <= maximum_fd; i++)
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{
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TEST_COMPARE (fcntl (i, F_GETFL), -1);
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TEST_COMPARE (errno, EBADF);
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}
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TEST_VERIFY (fcntl (lowfd, F_GETFL) > -1);
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/* Close the last one. */
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closefrom (lowfd);
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TEST_COMPARE (fcntl (lowfd, F_GETFL), -1);
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TEST_COMPARE (errno, EBADF);
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/* Double check by check the /proc. */
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support_descriptors_check (descrs);
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support_descriptors_free (descrs);
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return 0;
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}
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/* Check if closefrom works even when no new file descriptors can be
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created. */
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static int
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closefrom_test_file_desc_limit (void)
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{
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int max_fd = NFDS;
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{
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struct rlimit rl;
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if (getrlimit (RLIMIT_NOFILE, &rl) == -1)
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FAIL_EXIT1 ("getrlimit (RLIMIT_NOFILE): %m");
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max_fd = (rl.rlim_cur < max_fd ? rl.rlim_cur : max_fd);
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rl.rlim_cur = max_fd;
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if (setrlimit (RLIMIT_NOFILE, &rl) == 1)
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FAIL_EXIT1 ("setrlimit (RLIMIT_NOFILE): %m");
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}
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/* Exhauste the file descriptor limit. */
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int lowfd = xopen ("/dev/null", O_RDONLY, 0600);
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for (;;)
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{
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int fd = open ("/dev/null", O_RDONLY, 0600);
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if (fd == -1)
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{
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if (errno != EMFILE)
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FAIL_EXIT1 ("open: %m");
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break;
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}
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TEST_VERIFY_EXIT (fd < max_fd);
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}
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closefrom (lowfd);
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for (int i = lowfd; i < NFDS; i++)
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{
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TEST_COMPARE (fcntl (i, F_GETFL), -1);
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TEST_COMPARE (errno, EBADF);
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}
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return 0;
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}
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static int
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do_test (void)
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{
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closefrom_test ();
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closefrom_test_file_desc_limit ();
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return 0;
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}
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#include <support/test-driver.c>
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