glibc/posix/tst-mmap-offset.c

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/* BZ #18877 mmap offset test.
Copyright (C) 2015-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
static int
printmsg (int rc, const char *msg)
{
printf ("%s failed: %m\n", msg);
return rc;
}
/* Check if negative offsets are handled correctly by mmap. */
static int
do_test (void)
{
const int prot = PROT_READ | PROT_WRITE;
const int flags = MAP_SHARED;
const unsigned long length = 0x10000;
const unsigned long offset = 0xace00000;
const unsigned long size = offset + length;
void *addr;
int fd;
char fname[] = "tst-mmap-offset-XXXXXX";
fd = mkstemp64 (fname);
if (fd < 0)
return printmsg (1, "mkstemp");
if (unlink (fname))
return printmsg (1, "unlink");
if (ftruncate64 (fd, size))
return printmsg (0, "ftruncate64");
addr = mmap (NULL, length, prot, flags, fd, offset);
if (MAP_FAILED == addr)
return printmsg (1, "mmap");
/* This memcpy is likely to SIGBUS if mmap has messed up with offset. */
memcpy (addr, fname, sizeof (fname));
return 0;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"