osfmk/mach/vm_prot.h

   1 /*
   2  * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
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   6  * This file contains Original Code and/or Modifications of Original Code
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   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,
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  23  * Please see the License for the specific language governing rights and
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  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
  75 typedef 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
 133 #endif  /* _MACH_VM_PROT_H_ */