1/*
2 * Copyright (c) 2015-2016 Dmitry V. Levin <ldv@altlinux.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "tests.h"
29#include <string.h>
30#include <sys/mman.h>
31
32void *
33tail_alloc(const size_t size)
34{
35	const size_t page_size = get_page_size();
36	const size_t len = (size + page_size - 1) & -page_size;
37	const size_t alloc_size = len + 6 * page_size;
38
39	void *p = mmap(NULL, alloc_size, PROT_READ | PROT_WRITE,
40		       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
41	if (MAP_FAILED == p)
42		perror_msg_and_fail("mmap(%zu)", alloc_size);
43
44	void *start_work = p + 3 * page_size;
45	void *tail_guard = start_work + len;
46
47	if (munmap(p, page_size) ||
48	    munmap(p + 2 * page_size, page_size) ||
49	    munmap(tail_guard, page_size) ||
50	    munmap(tail_guard + 2 * page_size, page_size))
51		perror_msg_and_fail("munmap");
52
53	memset(start_work, 0xff, len);
54	return tail_guard - size;
55}
56
57void *
58tail_memdup(const void *p, const size_t size)
59{
60	void *dest = tail_alloc(size);
61	memcpy(dest, p, size);
62	return dest;
63}
64