posix/tst-mmap-offset.c

   1 /* BZ #18877 mmap offset test.
   2
   3    Copyright (C) 2015-2016 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <sys/mman.h>
  25
  26 static int
  27 printmsg (int rc, const char *msg)
  28 {
  29   printf ("%s failed: %m\n", msg);
  30   return rc;
  31 }
  32
  33 /* Check if negative offsets are handled correctly by mmap.  */
  34 static int
  35 do_test (void)
  36 {
  37   const int prot = PROT_READ | PROT_WRITE;
  38   const int flags = MAP_SHARED;
  39   const unsigned long length = 0x10000;
  40   const unsigned long offset = 0xace00000;
  41   const unsigned long size = offset + length;
  42   void *addr;
  43   int fd;
  44   char fname[] = "tst-mmap-offset-XXXXXX";
  45
  46   fd = mkstemp64 (fname);
  47   if (fd < 0)
  48     return printmsg (1, "mkstemp");
  49
  50   if (unlink (fname))
  51     return printmsg (1, "unlink");
  52
  53   if (ftruncate64 (fd, size))
  54     return printmsg (0, "ftruncate64");
  55
  56   addr = mmap (NULL, length, prot, flags, fd, offset);
  57   if (MAP_FAILED == addr)
  58     return printmsg (1, "mmap");
  59
  60   /* This memcpy is likely to SIGBUS if mmap has messed up with offset.  */
  61   memcpy (addr, fname, sizeof (fname));
  62
  63   return 0;
  64 }
  65
  66 #define TEST_FUNCTION do_test ()
  67 #include "../test-skeleton.c"