xref: /xnu-8796.141.3/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision 1b191cb58250d0705d8a51287127505aa4bc0789) !
1*1b191cb5SApple OSS Distributions /*
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28*1b191cb5SApple OSS Distributions 
29*1b191cb5SApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*1b191cb5SApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*1b191cb5SApple OSS Distributions 
32*1b191cb5SApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*1b191cb5SApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*1b191cb5SApple OSS Distributions 
35*1b191cb5SApple OSS Distributions /*!
36*1b191cb5SApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*1b191cb5SApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*1b191cb5SApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*1b191cb5SApple OSS Distributions  */
40*1b191cb5SApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*1b191cb5SApple OSS Distributions {
42*1b191cb5SApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*1b191cb5SApple OSS Distributions 
44*1b191cb5SApple OSS Distributions protected:
45*1b191cb5SApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*1b191cb5SApple OSS Distributions 
47*1b191cb5SApple OSS Distributions 	vm_offset_t    _buffer;
48*1b191cb5SApple OSS Distributions 	vm_size_t      _size;
49*1b191cb5SApple OSS Distributions 
50*1b191cb5SApple OSS Distributions public:
51*1b191cb5SApple OSS Distributions 
52*1b191cb5SApple OSS Distributions 	/* @function withSize
53*1b191cb5SApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*1b191cb5SApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*1b191cb5SApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*1b191cb5SApple OSS Distributions 	 *          virtual memory region.
57*1b191cb5SApple OSS Distributions 	 */
58*1b191cb5SApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*1b191cb5SApple OSS Distributions 
60*1b191cb5SApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*1b191cb5SApple OSS Distributions 
62*1b191cb5SApple OSS Distributions private:
63*1b191cb5SApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*1b191cb5SApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*1b191cb5SApple OSS Distributions 	    IOOptionBits       options,
66*1b191cb5SApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*1b191cb5SApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*1b191cb5SApple OSS Distributions };
69*1b191cb5SApple OSS Distributions 
70*1b191cb5SApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
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