xref: /xnu-10063.121.3/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision 2c2f96dc2b9a4408a43d3150ae9c105355ca3daa)
1*2c2f96dcSApple OSS Distributions /*
2*2c2f96dcSApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*2c2f96dcSApple OSS Distributions  *
4*2c2f96dcSApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*2c2f96dcSApple OSS Distributions  *
6*2c2f96dcSApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*2c2f96dcSApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*2c2f96dcSApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*2c2f96dcSApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*2c2f96dcSApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*2c2f96dcSApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*2c2f96dcSApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
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14*2c2f96dcSApple OSS Distributions  *
15*2c2f96dcSApple OSS Distributions  * Please obtain a copy of the License at
16*2c2f96dcSApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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18*2c2f96dcSApple OSS Distributions  * The Original Code and all software distributed under the License are
19*2c2f96dcSApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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27*2c2f96dcSApple OSS Distributions  */
28*2c2f96dcSApple OSS Distributions 
29*2c2f96dcSApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*2c2f96dcSApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*2c2f96dcSApple OSS Distributions 
32*2c2f96dcSApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*2c2f96dcSApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*2c2f96dcSApple OSS Distributions 
35*2c2f96dcSApple OSS Distributions /*!
36*2c2f96dcSApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*2c2f96dcSApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*2c2f96dcSApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*2c2f96dcSApple OSS Distributions  */
40*2c2f96dcSApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*2c2f96dcSApple OSS Distributions {
42*2c2f96dcSApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*2c2f96dcSApple OSS Distributions 
44*2c2f96dcSApple OSS Distributions protected:
45*2c2f96dcSApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*2c2f96dcSApple OSS Distributions 
47*2c2f96dcSApple OSS Distributions 	vm_offset_t    _buffer;
48*2c2f96dcSApple OSS Distributions 	vm_size_t      _size;
49*2c2f96dcSApple OSS Distributions 
50*2c2f96dcSApple OSS Distributions public:
51*2c2f96dcSApple OSS Distributions 
52*2c2f96dcSApple OSS Distributions 	/* @function withSize
53*2c2f96dcSApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*2c2f96dcSApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*2c2f96dcSApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*2c2f96dcSApple OSS Distributions 	 *          virtual memory region.
57*2c2f96dcSApple OSS Distributions 	 */
58*2c2f96dcSApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*2c2f96dcSApple OSS Distributions 
60*2c2f96dcSApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*2c2f96dcSApple OSS Distributions 
62*2c2f96dcSApple OSS Distributions private:
63*2c2f96dcSApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*2c2f96dcSApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*2c2f96dcSApple OSS Distributions 	    IOOptionBits       options,
66*2c2f96dcSApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*2c2f96dcSApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*2c2f96dcSApple OSS Distributions };
69*2c2f96dcSApple OSS Distributions 
70*2c2f96dcSApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
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