xref: /xnu-10063.101.15/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision 94d3b452840153a99b38a3a9659680b2a006908e)
1*94d3b452SApple OSS Distributions /*
2*94d3b452SApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*94d3b452SApple OSS Distributions  *
4*94d3b452SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*94d3b452SApple OSS Distributions  *
6*94d3b452SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*94d3b452SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*94d3b452SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*94d3b452SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*94d3b452SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*94d3b452SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*94d3b452SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
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14*94d3b452SApple OSS Distributions  *
15*94d3b452SApple OSS Distributions  * Please obtain a copy of the License at
16*94d3b452SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*94d3b452SApple OSS Distributions  *
18*94d3b452SApple OSS Distributions  * The Original Code and all software distributed under the License are
19*94d3b452SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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26*94d3b452SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*94d3b452SApple OSS Distributions  */
28*94d3b452SApple OSS Distributions 
29*94d3b452SApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*94d3b452SApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*94d3b452SApple OSS Distributions 
32*94d3b452SApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*94d3b452SApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*94d3b452SApple OSS Distributions 
35*94d3b452SApple OSS Distributions /*!
36*94d3b452SApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*94d3b452SApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*94d3b452SApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*94d3b452SApple OSS Distributions  */
40*94d3b452SApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*94d3b452SApple OSS Distributions {
42*94d3b452SApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*94d3b452SApple OSS Distributions 
44*94d3b452SApple OSS Distributions protected:
45*94d3b452SApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*94d3b452SApple OSS Distributions 
47*94d3b452SApple OSS Distributions 	vm_offset_t    _buffer;
48*94d3b452SApple OSS Distributions 	vm_size_t      _size;
49*94d3b452SApple OSS Distributions 
50*94d3b452SApple OSS Distributions public:
51*94d3b452SApple OSS Distributions 
52*94d3b452SApple OSS Distributions 	/* @function withSize
53*94d3b452SApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*94d3b452SApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*94d3b452SApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*94d3b452SApple OSS Distributions 	 *          virtual memory region.
57*94d3b452SApple OSS Distributions 	 */
58*94d3b452SApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*94d3b452SApple OSS Distributions 
60*94d3b452SApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*94d3b452SApple OSS Distributions 
62*94d3b452SApple OSS Distributions private:
63*94d3b452SApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*94d3b452SApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*94d3b452SApple OSS Distributions 	    IOOptionBits       options,
66*94d3b452SApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*94d3b452SApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*94d3b452SApple OSS Distributions };
69*94d3b452SApple OSS Distributions 
70*94d3b452SApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
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