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/* Test that the handler is called, with the right fault address.
Copyright (C) 2002-2023 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Bruno Haible. */
#include <config.h>
/* Specification. */
#include "sigsegv.h"
#include <stdint.h>
#include <stdio.h>
#if HAVE_SIGSEGV_RECOVERY
# include "mmap-anon-util.h"
# include <stdlib.h>
# if SIGSEGV_FAULT_ADDRESS_ALIGNMENT > 1UL
# include <unistd.h>
# define SIGSEGV_FAULT_ADDRESS_ROUNDOFF_BITS (getpagesize () - 1)
# else
# define SIGSEGV_FAULT_ADDRESS_ROUNDOFF_BITS 0
# endif
uintptr_t page;
volatile int handler_called = 0;
static int
handler (void *fault_address, int serious)
{
handler_called++;
if (handler_called > 10)
abort ();
if (fault_address
!= (void *)((page + 0x678) & ~SIGSEGV_FAULT_ADDRESS_ROUNDOFF_BITS))
abort ();
if (mprotect ((void *) page, 0x4000, PROT_READ_WRITE) == 0)
return 1;
return 0;
}
static void
crasher (uintptr_t p)
{
*(volatile int *) (p + 0x678) = 42;
}
int
main ()
{
int prot_unwritable;
void *p;
/* Preparations. */
# if !HAVE_MAP_ANONYMOUS
zero_fd = open ("/dev/zero", O_RDONLY, 0644);
# endif
# if defined __linux__ && defined __sparc__
/* On Linux 2.6.26/SPARC64, PROT_READ has the same effect as
PROT_READ | PROT_WRITE. */
prot_unwritable = PROT_NONE;
# else
prot_unwritable = PROT_READ;
# endif
/* Setup some mmaped memory. */
p = mmap_zeromap ((void *) 0x12340000, 0x4000);
if (p == (void *)(-1))
{
fprintf (stderr, "mmap_zeromap failed.\n");
exit (2);
}
page = (uintptr_t) p;
/* Make it read-only. */
if (mprotect ((void *) page, 0x4000, prot_unwritable) < 0)
{
fprintf (stderr, "mprotect failed.\n");
exit (2);
}
/* Test whether it's possible to make it read-write after it was read-only.
This is not possible on Cygwin. */
if (mprotect ((void *) page, 0x4000, PROT_READ_WRITE) < 0
|| mprotect ((void *) page, 0x4000, prot_unwritable) < 0)
{
fprintf (stderr, "mprotect failed.\n");
exit (2);
}
/* Install the SIGSEGV handler. */
sigsegv_install_handler (&handler);
/* The first write access should invoke the handler and then complete. */
crasher (page);
/* The second write access should not invoke the handler. */
crasher (page);
/* Check that the handler was called only once. */
if (handler_called != 1)
exit (1);
/* Test passed! */
printf ("Test passed.\n");
return 0;
}
#else
int
main ()
{
return 77;
}
#endif
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