sysdeps/unix/sysv/linux/tst-mlock2.c

   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>