xref: /xnu-8796.121.2/libsyscall/wrappers/legacy/munmap.c (revision c54f35ca767986246321eb901baf8f5ff7923f6a)
1*c54f35caSApple OSS Distributions /*
2*c54f35caSApple OSS Distributions  * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
3*c54f35caSApple OSS Distributions  *
4*c54f35caSApple OSS Distributions  * @APPLE_LICENSE_HEADER_START@
5*c54f35caSApple OSS Distributions  *
6*c54f35caSApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*c54f35caSApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*c54f35caSApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*c54f35caSApple OSS Distributions  * compliance with the License. Please obtain a copy of the License at
10*c54f35caSApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this
11*c54f35caSApple OSS Distributions  * file.
12*c54f35caSApple OSS Distributions  *
13*c54f35caSApple OSS Distributions  * The Original Code and all software distributed under the License are
14*c54f35caSApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15*c54f35caSApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16*c54f35caSApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17*c54f35caSApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18*c54f35caSApple OSS Distributions  * Please see the License for the specific language governing rights and
19*c54f35caSApple OSS Distributions  * limitations under the License.
20*c54f35caSApple OSS Distributions  *
21*c54f35caSApple OSS Distributions  * @APPLE_LICENSE_HEADER_END@
22*c54f35caSApple OSS Distributions  */
23*c54f35caSApple OSS Distributions 
24*c54f35caSApple OSS Distributions #ifndef NO_SYSCALL_LEGACY
25*c54f35caSApple OSS Distributions 
26*c54f35caSApple OSS Distributions #define _NONSTD_SOURCE
27*c54f35caSApple OSS Distributions #include <sys/cdefs.h>
28*c54f35caSApple OSS Distributions 
29*c54f35caSApple OSS Distributions #include <sys/types.h>
30*c54f35caSApple OSS Distributions #include <sys/mman.h>
31*c54f35caSApple OSS Distributions #include <mach/vm_param.h>
32*c54f35caSApple OSS Distributions #include <mach/mach_init.h>
33*c54f35caSApple OSS Distributions #include "stack_logging_internal.h"
34*c54f35caSApple OSS Distributions 
35*c54f35caSApple OSS Distributions /*
36*c54f35caSApple OSS Distributions  * Stub function to account for the differences in standard compliance
37*c54f35caSApple OSS Distributions  * while maintaining binary backward compatibility.
38*c54f35caSApple OSS Distributions  *
39*c54f35caSApple OSS Distributions  * This is only the legacy behavior.
40*c54f35caSApple OSS Distributions  */
41*c54f35caSApple OSS Distributions extern int __munmap(void *, size_t);
42*c54f35caSApple OSS Distributions 
43*c54f35caSApple OSS Distributions int
munmap(void * addr,size_t len)44*c54f35caSApple OSS Distributions munmap(void *addr, size_t len)
45*c54f35caSApple OSS Distributions {
46*c54f35caSApple OSS Distributions 	size_t  offset;
47*c54f35caSApple OSS Distributions 
48*c54f35caSApple OSS Distributions 	if (len == 0) {
49*c54f35caSApple OSS Distributions 		/*
50*c54f35caSApple OSS Distributions 		 * Standard compliance now requires the system to return EINVAL
51*c54f35caSApple OSS Distributions 		 * for munmap(addr, 0).  Return success now to maintain
52*c54f35caSApple OSS Distributions 		 * backwards compatibility.
53*c54f35caSApple OSS Distributions 		 */
54*c54f35caSApple OSS Distributions 		return 0;
55*c54f35caSApple OSS Distributions 	}
56*c54f35caSApple OSS Distributions 	/*
57*c54f35caSApple OSS Distributions 	 * Page-align "addr" since the system now requires it
58*c54f35caSApple OSS Distributions 	 * for standards compliance.
59*c54f35caSApple OSS Distributions 	 * Update "len" to reflect the adjustment and still cover the same area.
60*c54f35caSApple OSS Distributions 	 */
61*c54f35caSApple OSS Distributions 	offset = ((uintptr_t) addr) & PAGE_MASK;
62*c54f35caSApple OSS Distributions 	addr = (void *) (((uintptr_t) addr) & ~PAGE_MASK);
63*c54f35caSApple OSS Distributions 	len += offset;
64*c54f35caSApple OSS Distributions 
65*c54f35caSApple OSS Distributions 	if (__syscall_logger) {
66*c54f35caSApple OSS Distributions 		__syscall_logger(stack_logging_type_vm_deallocate, (uintptr_t)mach_task_self(), (uintptr_t)addr, len, 0, 0);
67*c54f35caSApple OSS Distributions 	}
68*c54f35caSApple OSS Distributions 
69*c54f35caSApple OSS Distributions 	int result = __munmap(addr, len);
70*c54f35caSApple OSS Distributions 
71*c54f35caSApple OSS Distributions 	return result;
72*c54f35caSApple OSS Distributions }
73*c54f35caSApple OSS Distributions #endif /* NO_SYSCALL_LEGACY */
74