xref: /xnu-10063.141.1/iokit/Kernel/IOGuardPageMemoryDescriptor.cpp (revision d8b80295118ef25ac3a784134bcf95cd8e88109f)
1 /*
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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.h>
33 #include <mach/mach_vm.h>
34 
35 #define super IOGeneralMemoryDescriptor
36 
37 OSDefineMetaClassAndStructorsWithZone(IOGuardPageMemoryDescriptor, IOGeneralMemoryDescriptor, ZC_ZFREE_CLEARMEM);
38 
39 OSSharedPtr<IOGuardPageMemoryDescriptor>
withSize(vm_size_t size)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
initWithSize(vm_size_t size)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, VM_FLAGS_ANYWHERE, VM_KERN_MEMORY_IOKIT);
65 	if (kr != KERN_SUCCESS) {
66 		return false;
67 	}
68 
69 
70 	_ranges.v64->address = address;
71 	_ranges.v64->length  = size;
72 
73 	if (!super::initWithOptions(_ranges.v64, 1, 0, kernel_task, iomdOptions, NULL)) {
74 		return false;
75 	}
76 
77 	_size = size;
78 	_buffer = (vm_offset_t)address;
79 
80 	return true;
81 }
82 
83 void
free()84 IOGuardPageMemoryDescriptor::free()
85 {
86 	if (_buffer) {
87 		vm_deallocate(kernel_map, _buffer, _size);
88 		_buffer = 0;
89 	}
90 
91 	if (_ranges.v64) {
92 		IOFreeType(_ranges.v64, IOAddressRange);
93 	}
94 
95 	super::free();
96 }
97 
98 IOReturn
doMap(vm_map_t addressMap,IOVirtualAddress * atAddress,IOOptionBits options,IOByteCount sourceOffset,IOByteCount length)99 IOGuardPageMemoryDescriptor::doMap(vm_map_t           addressMap,
100     IOVirtualAddress * atAddress,
101     IOOptionBits       options,
102     IOByteCount        sourceOffset,
103     IOByteCount        length)
104 {
105 	IOReturn ret = super::doMap(addressMap, atAddress, options, sourceOffset, length);
106 	if (ret == kIOReturnSuccess) {
107 		IOMemoryMap *     mapping = (IOMemoryMap *) *atAddress;
108 		vm_map_t          map     = mapping->fAddressMap;
109 		mach_vm_size_t    length  = mapping->fLength;
110 		mach_vm_address_t address = mapping->fAddress;
111 		kern_return_t kr = mach_vm_protect(map, address, length, true, VM_PROT_NONE);
112 		if (kr != KERN_SUCCESS) {
113 			doUnmap(map, (IOVirtualAddress) mapping, 0);
114 			return kIOReturnError;
115 		}
116 	}
117 	return ret;
118 }
119