xref: /xnu-8019.80.24/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision a325d9c4a84054e40bbe985afedcb50ab80993ea)
1*a325d9c4SApple OSS Distributions /*
2*a325d9c4SApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*a325d9c4SApple OSS Distributions  *
4*a325d9c4SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*a325d9c4SApple OSS Distributions  *
6*a325d9c4SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*a325d9c4SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*a325d9c4SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*a325d9c4SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*a325d9c4SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*a325d9c4SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
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14*a325d9c4SApple OSS Distributions  *
15*a325d9c4SApple OSS Distributions  * Please obtain a copy of the License at
16*a325d9c4SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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18*a325d9c4SApple OSS Distributions  * The Original Code and all software distributed under the License are
19*a325d9c4SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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27*a325d9c4SApple OSS Distributions  */
28*a325d9c4SApple OSS Distributions 
29*a325d9c4SApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*a325d9c4SApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*a325d9c4SApple OSS Distributions 
32*a325d9c4SApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*a325d9c4SApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*a325d9c4SApple OSS Distributions 
35*a325d9c4SApple OSS Distributions /*!
36*a325d9c4SApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*a325d9c4SApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*a325d9c4SApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*a325d9c4SApple OSS Distributions  */
40*a325d9c4SApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*a325d9c4SApple OSS Distributions {
42*a325d9c4SApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*a325d9c4SApple OSS Distributions 
44*a325d9c4SApple OSS Distributions protected:
45*a325d9c4SApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*a325d9c4SApple OSS Distributions 
47*a325d9c4SApple OSS Distributions 	vm_offset_t    _buffer;
48*a325d9c4SApple OSS Distributions 	vm_size_t      _size;
49*a325d9c4SApple OSS Distributions 
50*a325d9c4SApple OSS Distributions public:
51*a325d9c4SApple OSS Distributions 
52*a325d9c4SApple OSS Distributions 	/* @function withSize
53*a325d9c4SApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*a325d9c4SApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*a325d9c4SApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*a325d9c4SApple OSS Distributions 	 *          virtual memory region.
57*a325d9c4SApple OSS Distributions 	 */
58*a325d9c4SApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*a325d9c4SApple OSS Distributions 
60*a325d9c4SApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*a325d9c4SApple OSS Distributions 
62*a325d9c4SApple OSS Distributions private:
63*a325d9c4SApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*a325d9c4SApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*a325d9c4SApple OSS Distributions 	    IOOptionBits       options,
66*a325d9c4SApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*a325d9c4SApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*a325d9c4SApple OSS Distributions };
69*a325d9c4SApple OSS Distributions 
70*a325d9c4SApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
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