1 /*
2  * Copyright (c) 1998-2000 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,
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23  * Please see the License for the specific language governing rights and
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27  */
28 #define IOKIT_ENABLE_SHARED_PTR
29 #include <IOKit/IOGuardPageMemoryDescriptor.h>
30 #include <IOKit/IOMemoryDescriptor.h>
31 #include <IOKit/IOLib.h>
32 #include <vm/vm_kern_xnu.h>
33 #include <mach/mach_vm.h>
34 
35 #define super IOGeneralMemoryDescriptor
36 
37 OSDefineMetaClassAndStructorsWithZone(IOGuardPageMemoryDescriptor, IOGeneralMemoryDescriptor, ZC_ZFREE_CLEARMEM);
38 
39 OSSharedPtr<IOGuardPageMemoryDescriptor>
40 IOGuardPageMemoryDescriptor::withSize(vm_size_t size)
41 {
42 	OSSharedPtr<IOGuardPageMemoryDescriptor> me = OSMakeShared<IOGuardPageMemoryDescriptor>();
43 
44 	if (me && !me->initWithSize(size)) {
45 		me.reset();
46 	}
47 	return me;
48 }
49 
50 bool
51 IOGuardPageMemoryDescriptor::initWithSize(vm_size_t size)
52 {
53 	mach_vm_address_t address;
54 	kern_return_t kr;
55 	IOOptionBits  iomdOptions = kIOMemoryTypeVirtual64 | kIOMemoryAsReference | kIODirectionOutIn;
56 
57 	size = round_page(size);
58 
59 	_ranges.v64 = IOMallocType(IOAddressRange);
60 	if (!_ranges.v64) {
61 		return false;
62 	}
63 
64 	kr = mach_vm_allocate_kernel(kernel_map, &address, size,
65 	    VM_MAP_KERNEL_FLAGS_ANYWHERE(.vm_tag = VM_KERN_MEMORY_IOKIT));
66 	if (kr != KERN_SUCCESS) {
67 		return false;
68 	}
69 
70 
71 	_ranges.v64->address = address;
72 	_ranges.v64->length  = size;
73 
74 	if (!super::initWithOptions(_ranges.v64, 1, 0, kernel_task, iomdOptions, NULL)) {
75 		return false;
76 	}
77 
78 	_size = size;
79 	_buffer = (vm_offset_t)address;
80 
81 	return true;
82 }
83 
84 void
85 IOGuardPageMemoryDescriptor::free()
86 {
87 	if (_buffer) {
88 		vm_deallocate(kernel_map, _buffer, _size);
89 		_buffer = 0;
90 	}
91 
92 	if (_ranges.v64) {
93 		IOFreeType(_ranges.v64, IOAddressRange);
94 	}
95 
96 	super::free();
97 }
98 
99 IOReturn
100 IOGuardPageMemoryDescriptor::doMap(vm_map_t           addressMap,
101     IOVirtualAddress * atAddress,
102     IOOptionBits       options,
103     IOByteCount        sourceOffset,
104     IOByteCount        length)
105 {
106 	IOReturn ret = super::doMap(addressMap, atAddress, options, sourceOffset, length);
107 	if (ret == kIOReturnSuccess) {
108 		IOMemoryMap *     mapping = (IOMemoryMap *) *atAddress;
109 		vm_map_t          map     = mapping->fAddressMap;
110 		mach_vm_size_t    length  = mapping->fLength;
111 		mach_vm_address_t address = mapping->fAddress;
112 		kern_return_t kr = mach_vm_protect(map, address, length, true, VM_PROT_NONE);
113 		if (kr != KERN_SUCCESS) {
114 			doUnmap(map, (IOVirtualAddress) mapping, 0);
115 			return kIOReturnError;
116 		}
117 	}
118 	return ret;
119 }
120