1  /* Test sysconf with an empty chroot.
       2     Copyright (C) 2017-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <stdio.h>
      20  #include <stdlib.h>
      21  #include <support/check.h>
      22  #include <support/namespace.h>
      23  #include <support/support.h>
      24  #include <support/temp_file.h>
      25  #include <support/test-driver.h>
      26  #include <support/xunistd.h>
      27  #include <unistd.h>
      28  
      29  /* Check for an SMP system in a forked process, so that the parent
      30     process does not cache the value.  */
      31  static void
      32  is_smp_callback (void *closure)
      33  {
      34    bool *result = closure;
      35  
      36    long cpus = sysconf (_SC_NPROCESSORS_ONLN);
      37    TEST_VERIFY_EXIT (cpus > 0);
      38    *result = cpus != 1;
      39  }
      40  
      41  static bool
      42  is_smp (void)
      43  {
      44    bool *result = support_shared_allocate (sizeof (*result));
      45    support_isolate_in_subprocess (is_smp_callback, result);
      46    bool result_copy = *result;
      47    support_shared_free (result);
      48    return result_copy;
      49  }
      50  
      51  static char *path_chroot;
      52  
      53  /* Prepare an empty directory, to be used as a chroot.  */
      54  static void
      55  prepare (int argc, char **argv)
      56  {
      57    path_chroot = xasprintf ("%s/tst-resolv-res_init-XXXXXX", test_dir);
      58    if (mkdtemp (path_chroot) == NULL)
      59      FAIL_EXIT1 ("mkdtemp (\"%s\"): %m", path_chroot);
      60    add_temp_file (path_chroot);
      61  }
      62  
      63  /* The actual test.  Run it in a subprocess, so that the test harness
      64     can remove the temporary directory in --direct mode.  */
      65  static void
      66  chroot_callback (void *closure)
      67  {
      68    xchroot (path_chroot);
      69    long cpus = sysconf (_SC_NPROCESSORS_ONLN);
      70    printf ("info: sysconf (_SC_NPROCESSORS_ONLN) in chroot: %ld\n", cpus);
      71    TEST_VERIFY (cpus > 0);
      72    TEST_VERIFY (cpus != 1);
      73    _exit (0);
      74  }
      75  
      76  static int
      77  do_test (void)
      78  {
      79    if (!is_smp ())
      80      {
      81        printf ("warning: test not supported on uniprocessor system\n");
      82        return EXIT_UNSUPPORTED;
      83      }
      84  
      85    support_become_root ();
      86    if (!support_can_chroot ())
      87      return EXIT_UNSUPPORTED;
      88  
      89    support_isolate_in_subprocess (chroot_callback, NULL);
      90  
      91    return 0;
      92  }
      93  
      94  #define PREPARE prepare
      95  #include <support/test-driver.c>