1  /* Test the mlock2 function.
       2     Copyright (C) 2017-2023 Free Software Foundation, Inc.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <errno.h>
      19  #include <stdio.h>
      20  #include <support/check.h>
      21  #include <support/xunistd.h>
      22  #include <sys/mman.h>
      23  
      24  /* Allocate a page using mmap.  */
      25  static void *
      26  get_page (void)
      27  {
      28    return xmmap (NULL, 1, PROT_READ | PROT_WRITE,
      29                  MAP_ANONYMOUS | MAP_PRIVATE, -1);
      30  }
      31  
      32  static int
      33  do_test (void)
      34  {
      35    /* Current kernels have a small reserve of locked memory, so this
      36       test does not need any privileges to run.  */
      37  
      38    void *page = get_page ();
      39    if (mlock (page, 1) != 0)
      40      FAIL_EXIT1 ("mlock: %m\n");
      41    xmunmap (page, 1);
      42  
      43    page = get_page ();
      44    if (mlock2 (page, 1, 0) != 0)
      45      /* Should be implemented using mlock if necessary.  */
      46      FAIL_EXIT1 ("mlock2 (0): %m\n");
      47    xmunmap (page, 1);
      48  
      49    page = get_page ();
      50    int ret = mlock2 (page, 1, MLOCK_ONFAULT);
      51    if (ret != 0)
      52      {
      53        TEST_VERIFY (ret == -1);
      54        if (errno != EINVAL)
      55          /* EINVAL means the system does not support the mlock2 system
      56             call.  */
      57          FAIL_EXIT1 ("mlock2 (0): %m\n");
      58        else
      59          puts ("warning: mlock2 system call not supported");
      60      }
      61    xmunmap (page, 1);
      62  
      63    return 0;
      64  }
      65  
      66  #include <support/test-driver.c>