xref: /xnu-8020.101.4/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision e7776783b89a353188416a9a346c6cdb4928faad)
1*e7776783SApple OSS Distributions /*
2*e7776783SApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
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28*e7776783SApple OSS Distributions 
29*e7776783SApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*e7776783SApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*e7776783SApple OSS Distributions 
32*e7776783SApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*e7776783SApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*e7776783SApple OSS Distributions 
35*e7776783SApple OSS Distributions /*!
36*e7776783SApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*e7776783SApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*e7776783SApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*e7776783SApple OSS Distributions  */
40*e7776783SApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*e7776783SApple OSS Distributions {
42*e7776783SApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*e7776783SApple OSS Distributions 
44*e7776783SApple OSS Distributions protected:
45*e7776783SApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*e7776783SApple OSS Distributions 
47*e7776783SApple OSS Distributions 	vm_offset_t    _buffer;
48*e7776783SApple OSS Distributions 	vm_size_t      _size;
49*e7776783SApple OSS Distributions 
50*e7776783SApple OSS Distributions public:
51*e7776783SApple OSS Distributions 
52*e7776783SApple OSS Distributions 	/* @function withSize
53*e7776783SApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*e7776783SApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*e7776783SApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*e7776783SApple OSS Distributions 	 *          virtual memory region.
57*e7776783SApple OSS Distributions 	 */
58*e7776783SApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*e7776783SApple OSS Distributions 
60*e7776783SApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*e7776783SApple OSS Distributions 
62*e7776783SApple OSS Distributions private:
63*e7776783SApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*e7776783SApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*e7776783SApple OSS Distributions 	    IOOptionBits       options,
66*e7776783SApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*e7776783SApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*e7776783SApple OSS Distributions };
69*e7776783SApple OSS Distributions 
70*e7776783SApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
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