1/*
2 * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_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. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * @OSF_COPYRIGHT@
30 */
31/*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
49 * School of Computer Science
50 * Carnegie Mellon University
51 * Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56/*
57 */
58/*
59 * File: mach/vm_prot.h
60 * Author: Avadis Tevanian, Jr., Michael Wayne Young
61 *
62 * Virtual memory protection definitions.
63 *
64 */
65
66#ifndef _MACH_VM_PROT_H_
67#define _MACH_VM_PROT_H_
68
69/*
70 * Types defined:
71 *
72 * vm_prot_t VM protection values.
73 */
74
75typedef int vm_prot_t;
76
77/*
78 * Protection values, defined as bits within the vm_prot_t type
79 */
80
81#define VM_PROT_NONE ((vm_prot_t) 0x00)
82
83#define VM_PROT_READ ((vm_prot_t) 0x01) /* read permission */
84#define VM_PROT_WRITE ((vm_prot_t) 0x02) /* write permission */
85#define VM_PROT_EXECUTE ((vm_prot_t) 0x04) /* execute permission */
86
87/*
88 * The default protection for newly-created virtual memory
89 */
90
91#define VM_PROT_DEFAULT (VM_PROT_READ|VM_PROT_WRITE)
92
93/*
94 * The maximum privileges possible, for parameter checking.
95 */
96
97#define VM_PROT_ALL (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)
98
99/*
100 * An invalid protection value.
101 * Used only by memory_object_lock_request to indicate no change
102 * to page locks. Using -1 here is a bad idea because it
103 * looks like VM_PROT_ALL and then some.
104 */
105
106#define VM_PROT_NO_CHANGE ((vm_prot_t) 0x08)
107
108/*
109 * When a caller finds that he cannot obtain write permission on a
110 * mapped entry, the following flag can be used. The entry will
111 * be made "needs copy" effectively copying the object (using COW),
112 * and write permission will be added to the maximum protections
113 * for the associated entry.
114 */
115
116#define VM_PROT_COPY ((vm_prot_t) 0x10)
117
118
119/*
120 * Another invalid protection value.
121 * Used only by memory_object_data_request upon an object
122 * which has specified a copy_call copy strategy. It is used
123 * when the kernel wants a page belonging to a copy of the
124 * object, and is only asking the object as a result of
125 * following a shadow chain. This solves the race between pages
126 * being pushed up by the memory manager and the kernel
127 * walking down the shadow chain.
128 */
129
130#define VM_PROT_WANTS_COPY ((vm_prot_t) 0x10)
131
132#ifdef PRIVATE
133/*
134 * The caller wants this memory region treated as if it had a valid
135 * code signature.
136 */
137
138#define VM_PROT_TRUSTED ((vm_prot_t) 0x20)
139#endif /* PRIVATE */
140
141/*
142 * Another invalid protection value.
143 * Indicates that the other protection bits are to be applied as a mask
144 * against the actual protection bits of the map entry.
145 */
146#define VM_PROT_IS_MASK ((vm_prot_t) 0x40)
147
148/*
149 * Another invalid protection value to support execute-only protection.
150 * VM_PROT_STRIP_READ is a special marker that tells mprotect to not
151 * set VM_PROT_READ. We have to do it this way because existing code
152 * expects the system to set VM_PROT_READ if VM_PROT_EXECUTE is set.
153 * VM_PROT_EXECUTE_ONLY is just a convenience value to indicate that
154 * the memory should be executable and explicitly not readable. It will
155 * be ignored on platforms that do not support this type of protection.
156 */
157#define VM_PROT_STRIP_READ ((vm_prot_t) 0x80)
158#define VM_PROT_EXECUTE_ONLY (VM_PROT_EXECUTE|VM_PROT_STRIP_READ)
159
160#endif /* _MACH_VM_PROT_H_ */
161