xref: /xnu-12377.81.4/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision 043036a2b3718f7f0be807e2870f8f47d3fa0796)
1*043036a2SApple OSS Distributions /*
2*043036a2SApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*043036a2SApple OSS Distributions  *
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6*043036a2SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*043036a2SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*043036a2SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
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27*043036a2SApple OSS Distributions  */
28*043036a2SApple OSS Distributions 
29*043036a2SApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*043036a2SApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*043036a2SApple OSS Distributions 
32*043036a2SApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*043036a2SApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*043036a2SApple OSS Distributions 
35*043036a2SApple OSS Distributions /*!
36*043036a2SApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*043036a2SApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*043036a2SApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*043036a2SApple OSS Distributions  */
40*043036a2SApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*043036a2SApple OSS Distributions {
42*043036a2SApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*043036a2SApple OSS Distributions 
44*043036a2SApple OSS Distributions protected:
45*043036a2SApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*043036a2SApple OSS Distributions 
47*043036a2SApple OSS Distributions 	vm_offset_t    _buffer;
48*043036a2SApple OSS Distributions 	vm_size_t      _size;
49*043036a2SApple OSS Distributions 
50*043036a2SApple OSS Distributions public:
51*043036a2SApple OSS Distributions 
52*043036a2SApple OSS Distributions 	/* @function withSize
53*043036a2SApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*043036a2SApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*043036a2SApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*043036a2SApple OSS Distributions 	 *          virtual memory region.
57*043036a2SApple OSS Distributions 	 */
58*043036a2SApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*043036a2SApple OSS Distributions 
60*043036a2SApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*043036a2SApple OSS Distributions 
62*043036a2SApple OSS Distributions private:
63*043036a2SApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*043036a2SApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*043036a2SApple OSS Distributions 	    IOOptionBits       options,
66*043036a2SApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*043036a2SApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*043036a2SApple OSS Distributions };
69*043036a2SApple OSS Distributions 
70*043036a2SApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
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