xref: /xnu-10002.41.9/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision 699cd48037512bf4380799317ca44ca453c82f57)
1*699cd480SApple OSS Distributions /*
2*699cd480SApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*699cd480SApple OSS Distributions  *
4*699cd480SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*699cd480SApple OSS Distributions  *
6*699cd480SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*699cd480SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*699cd480SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
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10*699cd480SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*699cd480SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
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15*699cd480SApple OSS Distributions  * Please obtain a copy of the License at
16*699cd480SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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19*699cd480SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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28*699cd480SApple OSS Distributions 
29*699cd480SApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*699cd480SApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*699cd480SApple OSS Distributions 
32*699cd480SApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*699cd480SApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*699cd480SApple OSS Distributions 
35*699cd480SApple OSS Distributions /*!
36*699cd480SApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*699cd480SApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*699cd480SApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*699cd480SApple OSS Distributions  */
40*699cd480SApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*699cd480SApple OSS Distributions {
42*699cd480SApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*699cd480SApple OSS Distributions 
44*699cd480SApple OSS Distributions protected:
45*699cd480SApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*699cd480SApple OSS Distributions 
47*699cd480SApple OSS Distributions 	vm_offset_t    _buffer;
48*699cd480SApple OSS Distributions 	vm_size_t      _size;
49*699cd480SApple OSS Distributions 
50*699cd480SApple OSS Distributions public:
51*699cd480SApple OSS Distributions 
52*699cd480SApple OSS Distributions 	/* @function withSize
53*699cd480SApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*699cd480SApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*699cd480SApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*699cd480SApple OSS Distributions 	 *          virtual memory region.
57*699cd480SApple OSS Distributions 	 */
58*699cd480SApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*699cd480SApple OSS Distributions 
60*699cd480SApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*699cd480SApple OSS Distributions 
62*699cd480SApple OSS Distributions private:
63*699cd480SApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*699cd480SApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*699cd480SApple OSS Distributions 	    IOOptionBits       options,
66*699cd480SApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*699cd480SApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*699cd480SApple OSS Distributions };
69*699cd480SApple OSS Distributions 
70*699cd480SApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
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