xref: /xnu-11417.121.6/iokit/IOKit/IOGuardPageMemoryDescriptor.h (revision a1e26a70f38d1d7daa7b49b258e2f8538ad81650)
1*a1e26a70SApple OSS Distributions /*
2*a1e26a70SApple OSS Distributions  * Copyright (c) 1998-2020 Apple Computer, Inc. All rights reserved.
3*a1e26a70SApple OSS Distributions  *
4*a1e26a70SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*a1e26a70SApple OSS Distributions  *
6*a1e26a70SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*a1e26a70SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*a1e26a70SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*a1e26a70SApple OSS Distributions  * compliance with the License. The rights granted to you under the License
10*a1e26a70SApple OSS Distributions  * may not be used to create, or enable the creation or redistribution of,
11*a1e26a70SApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
12*a1e26a70SApple OSS Distributions  * circumvent, violate, or enable the circumvention or violation of, any
13*a1e26a70SApple OSS Distributions  * terms of an Apple operating system software license agreement.
14*a1e26a70SApple OSS Distributions  *
15*a1e26a70SApple OSS Distributions  * Please obtain a copy of the License at
16*a1e26a70SApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*a1e26a70SApple OSS Distributions  *
18*a1e26a70SApple OSS Distributions  * The Original Code and all software distributed under the License are
19*a1e26a70SApple OSS Distributions  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*a1e26a70SApple OSS Distributions  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*a1e26a70SApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*a1e26a70SApple OSS Distributions  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*a1e26a70SApple OSS Distributions  * Please see the License for the specific language governing rights and
24*a1e26a70SApple OSS Distributions  * limitations under the License.
25*a1e26a70SApple OSS Distributions  *
26*a1e26a70SApple OSS Distributions  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*a1e26a70SApple OSS Distributions  */
28*a1e26a70SApple OSS Distributions 
29*a1e26a70SApple OSS Distributions #ifndef _IOGUARDPAGEMEMORYDESCRIPTOR_H
30*a1e26a70SApple OSS Distributions #define _IOGUARDPAGEMEMORYDESCRIPTOR_H
31*a1e26a70SApple OSS Distributions 
32*a1e26a70SApple OSS Distributions #include <IOKit/IOMemoryDescriptor.h>
33*a1e26a70SApple OSS Distributions #include <libkern/c++/OSPtr.h>
34*a1e26a70SApple OSS Distributions 
35*a1e26a70SApple OSS Distributions /*!
36*a1e26a70SApple OSS Distributions  *   @class IOGuardPageMemoryDescriptor
37*a1e26a70SApple OSS Distributions  *   @abstract Provides a memory descriptor that allows for variable size guard regions. Use with
38*a1e26a70SApple OSS Distributions  *             IOMultiMemoryDescriptor to surround other memory descriptors with guard pages.
39*a1e26a70SApple OSS Distributions  */
40*a1e26a70SApple OSS Distributions class IOGuardPageMemoryDescriptor : public IOGeneralMemoryDescriptor
41*a1e26a70SApple OSS Distributions {
42*a1e26a70SApple OSS Distributions 	OSDeclareDefaultStructors(IOGuardPageMemoryDescriptor);
43*a1e26a70SApple OSS Distributions 
44*a1e26a70SApple OSS Distributions protected:
45*a1e26a70SApple OSS Distributions 	virtual void free() APPLE_KEXT_OVERRIDE;
46*a1e26a70SApple OSS Distributions 
47*a1e26a70SApple OSS Distributions 	vm_offset_t    _buffer;
48*a1e26a70SApple OSS Distributions 	vm_size_t      _size;
49*a1e26a70SApple OSS Distributions 
50*a1e26a70SApple OSS Distributions public:
51*a1e26a70SApple OSS Distributions 
52*a1e26a70SApple OSS Distributions 	/* @function withSize
53*a1e26a70SApple OSS Distributions 	 *  @discussion Create a IOGuardPageMemoryDescriptor with the specified size.
54*a1e26a70SApple OSS Distributions 	 *  @param Size of the guard region. This will be rounded up to the nearest multiple of page size.
55*a1e26a70SApple OSS Distributions 	 *  @return IOGuardPageMemoryDescriptor instance to be released by the caller, which will free the allocated
56*a1e26a70SApple OSS Distributions 	 *          virtual memory region.
57*a1e26a70SApple OSS Distributions 	 */
58*a1e26a70SApple OSS Distributions 	static OSPtr<IOGuardPageMemoryDescriptor> withSize(vm_size_t size);
59*a1e26a70SApple OSS Distributions 
60*a1e26a70SApple OSS Distributions 	virtual bool initWithSize(vm_size_t size);
61*a1e26a70SApple OSS Distributions 
62*a1e26a70SApple OSS Distributions private:
63*a1e26a70SApple OSS Distributions 	virtual IOReturn doMap(vm_map_t           addressMap,
64*a1e26a70SApple OSS Distributions 	    IOVirtualAddress * atAddress,
65*a1e26a70SApple OSS Distributions 	    IOOptionBits       options,
66*a1e26a70SApple OSS Distributions 	    IOByteCount        sourceOffset = 0,
67*a1e26a70SApple OSS Distributions 	    IOByteCount        length = 0 ) APPLE_KEXT_OVERRIDE;
68*a1e26a70SApple OSS Distributions };
69*a1e26a70SApple OSS Distributions 
70*a1e26a70SApple OSS Distributions #endif /* !_IOGUARDPAGEMEMORYDESCRIPTOR_H */
71