posix/tst-mmap.c

   1 #include <assert.h>
   2 #include <errno.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6 #include <sys/mman.h>
   7
   8
   9 int
  10 main (void)
  11 {
  12   int result = 0;
  13   FILE *fp;
  14   size_t c;
  15   char buf[1000];
  16   int fd;
  17   unsigned char *ptr;
  18   size_t ps = sysconf (_SC_PAGESIZE);
  19   void *mem;
  20
  21   /* Create a file and put some data in it.  */
  22   fp = tmpfile ();
  23   if (fp == NULL)
  24     {
  25       printf ("Cannot create temporary file: %m\n");
  26       return 1;
  27     }
  28   fd = fileno (fp);
  29
  30   for (c = 0; c < sizeof (buf); ++c)
  31     buf[c] = '0' + (c % 10);
  32
  33   for (c = 0; c < (ps * 4) / sizeof (buf); ++c)
  34     if (fwrite (buf, 1, sizeof (buf), fp) != sizeof (buf))
  35       {
  36         printf ("`fwrite' failed: %m\n");
  37         return 1;
  38       }
  39   fflush (fp);
  40   assert (ps + 1000 < c * sizeof (buf));
  41
  42   /* First try something which is not allowed: map at an offset which is
  43      not modulo the pagesize.  */
  44   ptr = mmap (NULL, 1000, PROT_READ, MAP_SHARED, fd, ps - 1);
  45   if (ptr != MAP_FAILED)
  46     {
  47       puts ("mapping at offset with mod pagesize != 0 succeeded!");
  48       result = 1;
  49     }
  50   else if (errno != EINVAL && errno != ENOSYS)
  51     {
  52       puts ("wrong error value for mapping at offset with mod pagesize != 0: %m (should be EINVAL)");
  53       result = 1;
  54     }
  55
  56   /* Try the same for mmap64.  */
  57   ptr = mmap64 (NULL, 1000, PROT_READ, MAP_SHARED, fd, ps - 1);
  58   if (ptr != MAP_FAILED)
  59     {
  60       puts ("mapping at offset with mod pagesize != 0 succeeded!");
  61       result = 1;
  62     }
  63   else if (errno != EINVAL && errno != ENOSYS)
  64     {
  65       puts ("wrong error value for mapping at offset with mod pagesize != 0: %m (should be EINVAL)");
  66       result = 1;
  67     }
  68
  69   /* And the same for private mapping.  */
  70   ptr = mmap (NULL, 1000, PROT_READ, MAP_PRIVATE, fd, ps - 1);
  71   if (ptr != MAP_FAILED)
  72     {
  73       puts ("mapping at offset with mod pagesize != 0 succeeded!");
  74       result = 1;
  75     }
  76   else if (errno != EINVAL && errno != ENOSYS)
  77     {
  78       puts ("wrong error value for mapping at offset with mod pagesize != 0: %m (should be EINVAL)");
  79       result = 1;
  80     }
  81
  82   /* Try the same for mmap64.  */
  83   ptr = mmap64 (NULL, 1000, PROT_READ, MAP_PRIVATE, fd, ps - 1);
  84   if (ptr != MAP_FAILED)
  85     {
  86       puts ("mapping at offset with mod pagesize != 0 succeeded!");
  87       result = 1;
  88     }
  89   else if (errno != EINVAL && errno != ENOSYS)
  90     {
  91       puts ("wrong error value for mapping at offset with mod pagesize != 0: %m (should be EINVAL)");
  92       result = 1;
  93     }
  94
  95   /* Get a valid address.  */
  96   mem = malloc (2 * ps);
  97   if (mem != NULL)
  98     {
  99       /* Now we map at an address which is not mod pagesize.  */
 100       ptr = mmap (mem + 1, 1000, PROT_READ, MAP_SHARED | MAP_FIXED, fd, ps);
 101       if (ptr != MAP_FAILED)
 102         {
 103           puts ("mapping at address with mod pagesize != 0 succeeded!");
 104           result = 1;
 105         }
 106       else  if (errno != EINVAL && errno != ENOSYS)
 107         {
 108           puts ("wrong error value for mapping at address with mod pagesize != 0: %m (should be EINVAL)");
 109           result = 1;
 110         }
 111
 112       /* Try the same for mmap64.  */
 113       ptr = mmap64 (mem + 1, 1000, PROT_READ, MAP_SHARED | MAP_FIXED, fd, ps);
 114       if (ptr != MAP_FAILED)
 115         {
 116           puts ("mapping at address with mod pagesize != 0 succeeded!");
 117           result = 1;
 118         }
 119       else  if (errno != EINVAL && errno != ENOSYS)
 120         {
 121           puts ("wrong error value for mapping at address with mod pagesize != 0: %m (should be EINVAL)");
 122           result = 1;
 123         }
 124
 125       /* And again for MAP_PRIVATE.  */
 126       ptr = mmap (mem + 1, 1000, PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, ps);
 127       if (ptr != MAP_FAILED)
 128         {
 129           puts ("mapping at address with mod pagesize != 0 succeeded!");
 130           result = 1;
 131         }
 132       else  if (errno != EINVAL && errno != ENOSYS)
 133         {
 134           puts ("wrong error value for mapping at address with mod pagesize != 0: %m (should be EINVAL)");
 135           result = 1;
 136         }
 137
 138       /* Try the same for mmap64.  */
 139       ptr = mmap64 (mem + 1, 1000, PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, ps);
 140       if (ptr != MAP_FAILED)
 141         {
 142           puts ("mapping at address with mod pagesize != 0 succeeded!");
 143           result = 1;
 144         }
 145       else  if (errno != EINVAL && errno != ENOSYS)
 146         {
 147           puts ("wrong error value for mapping at address with mod pagesize != 0: %m (should be EINVAL)");
 148           result = 1;
 149         }
 150
 151       free (mem);
 152     }
 153
 154   /* Now map the memory and see whether the content of the mapped area
 155      is correct.  */
 156   ptr = mmap (NULL, 1000, PROT_READ, MAP_SHARED, fd, ps);
 157   if (ptr == MAP_FAILED)
 158     {
 159       if (errno != ENOSYS)
 160         {
 161           printf ("cannot mmap file: %m\n");
 162           result = 1;
 163         }
 164     }
 165   else
 166     {
 167       for (c = ps; c < ps + 1000; ++c)
 168         if (ptr[c - ps] != '0' + (c % 10))
 169           {
 170             printf ("wrong data mapped at offset %zd\n", c);
 171             result = 1;
 172           }
 173     }
 174
 175   /* And for mmap64. */
 176   ptr = mmap64 (NULL, 1000, PROT_READ, MAP_SHARED, fd, ps);
 177   if (ptr == MAP_FAILED)
 178     {
 179       if (errno != ENOSYS)
 180         {
 181           printf ("cannot mmap file: %m\n");
 182           result = 1;
 183         }
 184     }
 185   else
 186     {
 187       for (c = ps; c < ps + 1000; ++c)
 188         if (ptr[c - ps] != '0' + (c % 10))
 189           {
 190             printf ("wrong data mapped at offset %zd\n", c);
 191             result = 1;
 192           }
 193     }
 194
 195   /* That's it.  */
 196   return result;
 197 }