tests/sigsegv1.c

   1 /* Test that the handler is called, with the right fault address.
   2    Copyright (C) 2002-2006, 2008  Bruno Haible <bruno@clisp.org>
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program 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
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  17
  18 #ifndef _MSC_VER
  19 # include <config.h>
  20 #endif
  21
  22 #include "sigsegv.h"
  23 #include <stdio.h>
  24
  25 #if HAVE_SIGSEGV_RECOVERY
  26
  27 #include "mmaputil.h"
  28 #include <stdlib.h>
  29
  30 unsigned long page;
  31
  32 volatile int handler_called = 0;
  33
  34 int
  35 handler (void *fault_address, int serious)
  36 {
  37   handler_called++;
  38   if (handler_called > 10)
  39     abort ();
  40   if (fault_address != (void *)(page + 0x678))
  41     abort ();
  42   if (mprotect ((void *) page, 0x4000, PROT_READ_WRITE) == 0)
  43     return 1;
  44   return 0;
  45 }
  46
  47 void
  48 crasher (unsigned long p)
  49 {
  50   *(volatile int *) (p + 0x678) = 42;
  51 }
  52
  53 int
  54 main ()
  55 {
  56   void *p;
  57
  58   /* Preparations.  */
  59 #if !HAVE_MMAP_ANON && !HAVE_MMAP_ANONYMOUS && HAVE_MMAP_DEVZERO
  60   zero_fd = open ("/dev/zero", O_RDONLY, 0644);
  61 #endif
  62
  63   /* Setup some mmaped memory.  */
  64   p = mmap_zeromap ((void *) 0x12340000, 0x4000);
  65   if (p == (void *)(-1))
  66     {
  67       fprintf (stderr, "mmap_zeromap failed.\n");
  68       exit (2);
  69     }
  70   page = (unsigned long) p;
  71
  72   /* Make it read-only.  */
  73   if (mprotect ((void *) page, 0x4000, PROT_READ) < 0)
  74     {
  75       fprintf (stderr, "mprotect failed.\n");
  76       exit (2);
  77     }
  78   /* Test whether it's possible to make it read-write after it was read-only.
  79      This is not possible on Cygwin.  */
  80   if (mprotect ((void *) page, 0x4000, PROT_READ_WRITE) < 0
  81       || mprotect ((void *) page, 0x4000, PROT_READ) < 0)
  82     {
  83       fprintf (stderr, "mprotect failed.\n");
  84       exit (2);
  85     }
  86
  87   /* Install the SIGSEGV handler.  */
  88   sigsegv_install_handler (&handler);
  89
  90   /* The first write access should invoke the handler and then complete.  */
  91   crasher (page);
  92   /* The second write access should not invoke the handler.  */
  93   crasher (page);
  94
  95   /* Check that the handler was called only once.  */
  96   if (handler_called != 1)
  97     exit (1);
  98   /* Test passed!  */
  99   printf ("Test passed.\n");
 100   return 0;
 101 }
 102
 103 #else
 104
 105 int
 106 main ()
 107 {
 108   return 77;
 109 }
 110
 111 #endif