1 /* 2 * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 29 #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H 30 #define _IOGUARDPAGEMEMORYDESCRIPTOR_H 31 32 #include <IOKit/IOMemoryDescriptor.h> 33 #include <libkern/c++/OSPtr.h> 34 35 /*! 36 * @class IOGuardPageMemoryDescriptor 37 * @abstract Provides a memory descriptor that allows for variable size guard regions. Use with 38 * IOMultiMemoryDescriptor to surround other memory descriptors with guard pages. 39 */ 40 class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor 41 { 42 OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor); 43 44 protected: 45 virtual void free() APPLE_KEXT_OVERRIDE; 46 47 vm_offset_t _buffer; 48 vm_size_t _size; 49 50 public: 51 52 /* @function withSize 53 * @discussion Create a IOGuardPageMemoryDescriptor with the specified size. 54 * @param Size of the guard region. This will be rounded up to the nearest multiple of page size. 55 * @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated 56 * virtual memory region. 57 */ 58 static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size); 59 60 virtual bool initWithSize(vm_size_t size); 61 62 private: 63 virtual IOReturn doMap(vm_map_t addressMap, 64 IOVirtualAddress * atAddress, 65 IOOptionBits options, 66 IOByteCount sourceOffset = 0, 67 IOByteCount length = 0 ) APPLE_KEXT_OVERRIDE; 68 }; 69 70 #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */ 71