1/*
2 * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23
24#ifndef NO_SYSCALL_LEGACY
25
26#define _NONSTD_SOURCE
27#include <sys/cdefs.h>
28
29#include <sys/types.h>
30#include <sys/mman.h>
31#include <mach/vm_param.h>
32
33/*
34 * Stub function to account for the differences in standard compliance
35 * while maintaining binary backward compatibility.
36 *
37 * This is only the legacy behavior.
38 */
39extern int __munmap(void *, size_t);
40
41int
42munmap(void *addr, size_t len)
43{
44	size_t	offset;
45
46	if (len == 0) {
47		/*
48		 * Standard compliance now requires the system to return EINVAL
49		 * for munmap(addr, 0).  Return success now to maintain
50		 * backwards compatibility.
51		 */
52		return 0;
53	}
54	/*
55	 * Page-align "addr" since the system now requires it
56	 * for standards compliance.
57	 * Update "len" to reflect the adjustment and still cover the same area.
58	 */
59	offset = ((uintptr_t) addr) & PAGE_MASK;
60	addr = (void *) (((uintptr_t) addr) & ~PAGE_MASK);
61	len += offset;
62	return __munmap(addr, len);
63}
64
65#endif /* NO_SYSCALL_LEGACY */
66