xref: /xnu-8792.41.9/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision 5c2921b07a2480ab43ec66f5b9e41cb872bc554f)
1*5c2921b0SApple OSS Distributions /*
2*5c2921b0SApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*5c2921b0SApple OSS Distributions  *
4*5c2921b0SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*5c2921b0SApple OSS Distributions  *
6*5c2921b0SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*5c2921b0SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*5c2921b0SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*5c2921b0SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*5c2921b0SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*5c2921b0SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*5c2921b0SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*5c2921b0SApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*5c2921b0SApple OSS Distributions  *
15*5c2921b0SApple OSS Distributions  * Please obtain a copy of the License at
16*5c2921b0SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*5c2921b0SApple OSS Distributions  *
18*5c2921b0SApple OSS Distributions  * The Original Code and all software distributed under the License are
19*5c2921b0SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*5c2921b0SApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*5c2921b0SApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*5c2921b0SApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*5c2921b0SApple OSS Distributions  * Please see the License for the specific language governing rights and
24*5c2921b0SApple OSS Distributions  * limitations under the License.
25*5c2921b0SApple OSS Distributions  *
26*5c2921b0SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*5c2921b0SApple OSS Distributions  */
28*5c2921b0SApple OSS Distributions 
29*5c2921b0SApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*5c2921b0SApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*5c2921b0SApple OSS Distributions 
32*5c2921b0SApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*5c2921b0SApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*5c2921b0SApple OSS Distributions 
35*5c2921b0SApple OSS Distributions /*!
36*5c2921b0SApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*5c2921b0SApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*5c2921b0SApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*5c2921b0SApple OSS Distributions  */
40*5c2921b0SApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*5c2921b0SApple OSS Distributions {
42*5c2921b0SApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*5c2921b0SApple OSS Distributions 
44*5c2921b0SApple OSS Distributions protected:
45*5c2921b0SApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*5c2921b0SApple OSS Distributions 
47*5c2921b0SApple OSS Distributions 	vm_offset_t    _buffer;
48*5c2921b0SApple OSS Distributions 	vm_size_t      _size;
49*5c2921b0SApple OSS Distributions 
50*5c2921b0SApple OSS Distributions public:
51*5c2921b0SApple OSS Distributions 
52*5c2921b0SApple OSS Distributions 	/* @function withSize
53*5c2921b0SApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*5c2921b0SApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*5c2921b0SApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*5c2921b0SApple OSS Distributions 	 *          virtual memory region.
57*5c2921b0SApple OSS Distributions 	 */
58*5c2921b0SApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*5c2921b0SApple OSS Distributions 
60*5c2921b0SApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*5c2921b0SApple OSS Distributions 
62*5c2921b0SApple OSS Distributions private:
63*5c2921b0SApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*5c2921b0SApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*5c2921b0SApple OSS Distributions 	    IOOptionBits       options,
66*5c2921b0SApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*5c2921b0SApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*5c2921b0SApple OSS Distributions };
69*5c2921b0SApple OSS Distributions 
70*5c2921b0SApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
71