xref: /xnu-11215.1.10/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision 8d741a5de7ff4191bf97d57b9f54c2f6d4a15585)
1*8d741a5dSApple OSS Distributions /*
2*8d741a5dSApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*8d741a5dSApple OSS Distributions  *
4*8d741a5dSApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*8d741a5dSApple OSS Distributions  *
6*8d741a5dSApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*8d741a5dSApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*8d741a5dSApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*8d741a5dSApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*8d741a5dSApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*8d741a5dSApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*8d741a5dSApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*8d741a5dSApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*8d741a5dSApple OSS Distributions  *
15*8d741a5dSApple OSS Distributions  * Please obtain a copy of the License at
16*8d741a5dSApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*8d741a5dSApple OSS Distributions  *
18*8d741a5dSApple OSS Distributions  * The Original Code and all software distributed under the License are
19*8d741a5dSApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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21*8d741a5dSApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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23*8d741a5dSApple OSS Distributions  * Please see the License for the specific language governing rights and
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26*8d741a5dSApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*8d741a5dSApple OSS Distributions  */
28*8d741a5dSApple OSS Distributions 
29*8d741a5dSApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*8d741a5dSApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*8d741a5dSApple OSS Distributions 
32*8d741a5dSApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*8d741a5dSApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*8d741a5dSApple OSS Distributions 
35*8d741a5dSApple OSS Distributions /*!
36*8d741a5dSApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*8d741a5dSApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*8d741a5dSApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*8d741a5dSApple OSS Distributions  */
40*8d741a5dSApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*8d741a5dSApple OSS Distributions {
42*8d741a5dSApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*8d741a5dSApple OSS Distributions 
44*8d741a5dSApple OSS Distributions protected:
45*8d741a5dSApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*8d741a5dSApple OSS Distributions 
47*8d741a5dSApple OSS Distributions 	vm_offset_t    _buffer;
48*8d741a5dSApple OSS Distributions 	vm_size_t      _size;
49*8d741a5dSApple OSS Distributions 
50*8d741a5dSApple OSS Distributions public:
51*8d741a5dSApple OSS Distributions 
52*8d741a5dSApple OSS Distributions 	/* @function withSize
53*8d741a5dSApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*8d741a5dSApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*8d741a5dSApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*8d741a5dSApple OSS Distributions 	 *          virtual memory region.
57*8d741a5dSApple OSS Distributions 	 */
58*8d741a5dSApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*8d741a5dSApple OSS Distributions 
60*8d741a5dSApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*8d741a5dSApple OSS Distributions 
62*8d741a5dSApple OSS Distributions private:
63*8d741a5dSApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*8d741a5dSApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*8d741a5dSApple OSS Distributions 	    IOOptionBits       options,
66*8d741a5dSApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*8d741a5dSApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*8d741a5dSApple OSS Distributions };
69*8d741a5dSApple OSS Distributions 
70*8d741a5dSApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
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