posix/tst-sysconf-empty-chroot.c

   1 /* Test sysconf with an empty chroot.
   2    Copyright (C) 2017-2022 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>