xref: /xnu-10002.61.3/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision 0f4c859e951fba394238ab619495c4e1d54d0f34)
1*0f4c859eSApple OSS Distributions /*
2*0f4c859eSApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*0f4c859eSApple OSS Distributions  *
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6*0f4c859eSApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*0f4c859eSApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*0f4c859eSApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*0f4c859eSApple OSS Distributions  * compliance with the License. The rights granted to you under the License
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11*0f4c859eSApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
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27*0f4c859eSApple OSS Distributions  */
28*0f4c859eSApple OSS Distributions 
29*0f4c859eSApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*0f4c859eSApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*0f4c859eSApple OSS Distributions 
32*0f4c859eSApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*0f4c859eSApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*0f4c859eSApple OSS Distributions 
35*0f4c859eSApple OSS Distributions /*!
36*0f4c859eSApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*0f4c859eSApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*0f4c859eSApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*0f4c859eSApple OSS Distributions  */
40*0f4c859eSApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*0f4c859eSApple OSS Distributions {
42*0f4c859eSApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*0f4c859eSApple OSS Distributions 
44*0f4c859eSApple OSS Distributions protected:
45*0f4c859eSApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*0f4c859eSApple OSS Distributions 
47*0f4c859eSApple OSS Distributions 	vm_offset_t    _buffer;
48*0f4c859eSApple OSS Distributions 	vm_size_t      _size;
49*0f4c859eSApple OSS Distributions 
50*0f4c859eSApple OSS Distributions public:
51*0f4c859eSApple OSS Distributions 
52*0f4c859eSApple OSS Distributions 	/* @function withSize
53*0f4c859eSApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*0f4c859eSApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*0f4c859eSApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*0f4c859eSApple OSS Distributions 	 *          virtual memory region.
57*0f4c859eSApple OSS Distributions 	 */
58*0f4c859eSApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*0f4c859eSApple OSS Distributions 
60*0f4c859eSApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*0f4c859eSApple OSS Distributions 
62*0f4c859eSApple OSS Distributions private:
63*0f4c859eSApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*0f4c859eSApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*0f4c859eSApple OSS Distributions 	    IOOptionBits       options,
66*0f4c859eSApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*0f4c859eSApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*0f4c859eSApple OSS Distributions };
69*0f4c859eSApple OSS Distributions 
70*0f4c859eSApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
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