xref: /xnu-12377.41.6/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision bbb1b6f9e71b8cdde6e5cd6f4841f207dee3d828)
1*bbb1b6f9SApple OSS Distributions /*
2*bbb1b6f9SApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*bbb1b6f9SApple OSS Distributions  *
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5*bbb1b6f9SApple OSS Distributions  *
6*bbb1b6f9SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*bbb1b6f9SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*bbb1b6f9SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*bbb1b6f9SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*bbb1b6f9SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*bbb1b6f9SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*bbb1b6f9SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
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15*bbb1b6f9SApple OSS Distributions  * Please obtain a copy of the License at
16*bbb1b6f9SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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18*bbb1b6f9SApple OSS Distributions  * The Original Code and all software distributed under the License are
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27*bbb1b6f9SApple OSS Distributions  */
28*bbb1b6f9SApple OSS Distributions 
29*bbb1b6f9SApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*bbb1b6f9SApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*bbb1b6f9SApple OSS Distributions 
32*bbb1b6f9SApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*bbb1b6f9SApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*bbb1b6f9SApple OSS Distributions 
35*bbb1b6f9SApple OSS Distributions /*!
36*bbb1b6f9SApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*bbb1b6f9SApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*bbb1b6f9SApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*bbb1b6f9SApple OSS Distributions  */
40*bbb1b6f9SApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*bbb1b6f9SApple OSS Distributions {
42*bbb1b6f9SApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*bbb1b6f9SApple OSS Distributions 
44*bbb1b6f9SApple OSS Distributions protected:
45*bbb1b6f9SApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*bbb1b6f9SApple OSS Distributions 
47*bbb1b6f9SApple OSS Distributions 	vm_offset_t    _buffer;
48*bbb1b6f9SApple OSS Distributions 	vm_size_t      _size;
49*bbb1b6f9SApple OSS Distributions 
50*bbb1b6f9SApple OSS Distributions public:
51*bbb1b6f9SApple OSS Distributions 
52*bbb1b6f9SApple OSS Distributions 	/* @function withSize
53*bbb1b6f9SApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*bbb1b6f9SApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*bbb1b6f9SApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*bbb1b6f9SApple OSS Distributions 	 *          virtual memory region.
57*bbb1b6f9SApple OSS Distributions 	 */
58*bbb1b6f9SApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*bbb1b6f9SApple OSS Distributions 
60*bbb1b6f9SApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*bbb1b6f9SApple OSS Distributions 
62*bbb1b6f9SApple OSS Distributions private:
63*bbb1b6f9SApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*bbb1b6f9SApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*bbb1b6f9SApple OSS Distributions 	    IOOptionBits       options,
66*bbb1b6f9SApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*bbb1b6f9SApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*bbb1b6f9SApple OSS Distributions };
69*bbb1b6f9SApple OSS Distributions 
70*bbb1b6f9SApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
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