libio/tst-mmap-offend.c

   1 /* Test case for bug with mmap stdio read past end of file.  */
   2
   3 #include <stdio.h>
   4 #include <error.h>
   5 #include <errno.h>
   6
   7 static void do_prepare (void);
   8 #define PREPARE(argc, argv) do_prepare ()
   9 static int do_test (void);
  10 #define TEST_FUNCTION do_test ()
  11 #include <test-skeleton.c>
  12
  13 static char *temp_file;
  14
  15 static const char text1[] = "hello\n";
  16
  17 static void
  18 do_prepare (void)
  19 {
  20   int temp_fd = create_temp_file ("tst-mmap-offend.", &temp_file);
  21   if (temp_fd == -1)
  22     error (1, errno, "cannot create temporary file");
  23   else
  24     {
  25       ssize_t cc = write (temp_fd, text1, sizeof text1 - 1);
  26       if (cc != sizeof text1 - 1)
  27         error (1, errno, "cannot write to temporary file");
  28     }
  29   close (temp_fd);
  30 }
  31
  32 static int
  33 do_test (void)
  34 {
  35   unsigned char buffer[8192];
  36   int result = 0;
  37   FILE *f = fopen (temp_file, "rm");
  38   size_t cc;
  39
  40   if (f == NULL)
  41     {
  42       perror (temp_file);
  43       return 1;
  44     }
  45
  46   cc = fread (buffer, 1, sizeof (buffer), f);
  47   printf ("fread %zu: \"%.*s\"\n", cc, (int) cc, buffer);
  48   if (cc != sizeof text1 - 1)
  49     {
  50       perror ("fread");
  51       result = 1;
  52     }
  53
  54   if (fseek (f, 2048, SEEK_SET) != 0)
  55     {
  56       perror ("fseek off end");
  57       result = 1;
  58     }
  59
  60   if (fread (buffer, 1, sizeof (buffer), f) != 0
  61       || ferror (f) || !feof (f))
  62     {
  63       printf ("after fread error %d eof %d\n",
  64               ferror (f), feof (f));
  65       result = 1;
  66     }
  67
  68   printf ("ftell %ld\n", ftell (f));
  69
  70   if (fseek (f, 0, SEEK_SET) != 0)
  71     {
  72       perror ("fseek rewind");
  73       result = 1;
  74     }
  75
  76   cc = fread (buffer, 1, sizeof (buffer), f);
  77   printf ("fread after rewind %zu: \"%.*s\"\n", cc, (int) cc, buffer);
  78   if (cc != sizeof text1 - 1)
  79     {
  80       perror ("fread after rewind");
  81       result = 1;
  82     }
  83
  84   fclose (f);
  85   return result;
  86 }