xref: /xnu-10063.141.1/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision d8b80295118ef25ac3a784134bcf95cd8e88109f)
1*d8b80295SApple OSS Distributions /*
2*d8b80295SApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*d8b80295SApple OSS Distributions  *
4*d8b80295SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*d8b80295SApple OSS Distributions  *
6*d8b80295SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*d8b80295SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*d8b80295SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*d8b80295SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*d8b80295SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*d8b80295SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*d8b80295SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
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14*d8b80295SApple OSS Distributions  *
15*d8b80295SApple OSS Distributions  * Please obtain a copy of the License at
16*d8b80295SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*d8b80295SApple OSS Distributions  *
18*d8b80295SApple OSS Distributions  * The Original Code and all software distributed under the License are
19*d8b80295SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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21*d8b80295SApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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23*d8b80295SApple OSS Distributions  * Please see the License for the specific language governing rights and
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26*d8b80295SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*d8b80295SApple OSS Distributions  */
28*d8b80295SApple OSS Distributions 
29*d8b80295SApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*d8b80295SApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*d8b80295SApple OSS Distributions 
32*d8b80295SApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*d8b80295SApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*d8b80295SApple OSS Distributions 
35*d8b80295SApple OSS Distributions /*!
36*d8b80295SApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*d8b80295SApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*d8b80295SApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*d8b80295SApple OSS Distributions  */
40*d8b80295SApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*d8b80295SApple OSS Distributions {
42*d8b80295SApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*d8b80295SApple OSS Distributions 
44*d8b80295SApple OSS Distributions protected:
45*d8b80295SApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*d8b80295SApple OSS Distributions 
47*d8b80295SApple OSS Distributions 	vm_offset_t    _buffer;
48*d8b80295SApple OSS Distributions 	vm_size_t      _size;
49*d8b80295SApple OSS Distributions 
50*d8b80295SApple OSS Distributions public:
51*d8b80295SApple OSS Distributions 
52*d8b80295SApple OSS Distributions 	/* @function withSize
53*d8b80295SApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*d8b80295SApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*d8b80295SApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*d8b80295SApple OSS Distributions 	 *          virtual memory region.
57*d8b80295SApple OSS Distributions 	 */
58*d8b80295SApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*d8b80295SApple OSS Distributions 
60*d8b80295SApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*d8b80295SApple OSS Distributions 
62*d8b80295SApple OSS Distributions private:
63*d8b80295SApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*d8b80295SApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*d8b80295SApple OSS Distributions 	    IOOptionBits       options,
66*d8b80295SApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*d8b80295SApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*d8b80295SApple OSS Distributions };
69*d8b80295SApple OSS Distributions 
70*d8b80295SApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
71