/*
* Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
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#ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
#define _IOGUARDPAGEMEMORYDESCRIPTOR_H
#include <IOKit/IOMemoryDescriptor.h>
#include <libkern/c++/OSPtr.h>
/*!
* @class IOGuardPageMemoryDescriptor
* @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
* IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
*/
class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
{
OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
protected:
virtual void free() APPLE_KEXT_OVERRIDE;
vm_offset_t _buffer;
vm_size_t _size;
public:
/* @function withSize
* @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
* @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
* @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
* virtual memory region.
*/
static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
virtual bool initWithSize(vm_size_t size);
private:
virtual IOReturn doMap(vm_map_t addressMap,
IOVirtualAddress * atAddress,
IOOptionBits options,
IOByteCount sourceOffset = 0,
IOByteCount length = 0 ) APPLE_KEXT_OVERRIDE;
};
#endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */