xref: /xnu-8796.121.2/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision c54f35ca767986246321eb901baf8f5ff7923f6a) !
1*c54f35caSApple OSS Distributions /*
2*c54f35caSApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*c54f35caSApple OSS Distributions  *
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5*c54f35caSApple OSS Distributions  *
6*c54f35caSApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*c54f35caSApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*c54f35caSApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*c54f35caSApple OSS Distributions  * compliance with the License. The rights granted to you under the License
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11*c54f35caSApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
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15*c54f35caSApple OSS Distributions  * Please obtain a copy of the License at
16*c54f35caSApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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18*c54f35caSApple OSS Distributions  * The Original Code and all software distributed under the License are
19*c54f35caSApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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27*c54f35caSApple OSS Distributions  */
28*c54f35caSApple OSS Distributions 
29*c54f35caSApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*c54f35caSApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*c54f35caSApple OSS Distributions 
32*c54f35caSApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*c54f35caSApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*c54f35caSApple OSS Distributions 
35*c54f35caSApple OSS Distributions /*!
36*c54f35caSApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*c54f35caSApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*c54f35caSApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*c54f35caSApple OSS Distributions  */
40*c54f35caSApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*c54f35caSApple OSS Distributions {
42*c54f35caSApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*c54f35caSApple OSS Distributions 
44*c54f35caSApple OSS Distributions protected:
45*c54f35caSApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*c54f35caSApple OSS Distributions 
47*c54f35caSApple OSS Distributions 	vm_offset_t    _buffer;
48*c54f35caSApple OSS Distributions 	vm_size_t      _size;
49*c54f35caSApple OSS Distributions 
50*c54f35caSApple OSS Distributions public:
51*c54f35caSApple OSS Distributions 
52*c54f35caSApple OSS Distributions 	/* @function withSize
53*c54f35caSApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*c54f35caSApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*c54f35caSApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*c54f35caSApple OSS Distributions 	 *          virtual memory region.
57*c54f35caSApple OSS Distributions 	 */
58*c54f35caSApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*c54f35caSApple OSS Distributions 
60*c54f35caSApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*c54f35caSApple OSS Distributions 
62*c54f35caSApple OSS Distributions private:
63*c54f35caSApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*c54f35caSApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*c54f35caSApple OSS Distributions 	    IOOptionBits       options,
66*c54f35caSApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*c54f35caSApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*c54f35caSApple OSS Distributions };
69*c54f35caSApple OSS Distributions 
70*c54f35caSApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
71