1 /*
2 * Copyright (C) 2010 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "config.h"
27 #include "SharedMemory.h"
28
29 #include "ArgumentDecoder.h"
30 #include "ArgumentEncoder.h"
31 #include "Arguments.h"
32 #include "MachPort.h"
33 #include <mach/mach_port.h>
34 #include <mach/mach_vm.h>
35 #include <mach/vm_map.h>
36 #include <wtf/RefPtr.h>
37
38 namespace WebKit {
39
Handle()40 SharedMemory::Handle::Handle()
41 : m_port(MACH_PORT_NULL)
42 , m_size(0)
43 {
44 }
45
~Handle()46 SharedMemory::Handle::~Handle()
47 {
48 if (m_port)
49 mach_port_deallocate(mach_task_self(), m_port);
50 }
51
isNull() const52 bool SharedMemory::Handle::isNull() const
53 {
54 return !m_port;
55 }
56
encode(CoreIPC::ArgumentEncoder * encoder) const57 void SharedMemory::Handle::encode(CoreIPC::ArgumentEncoder* encoder) const
58 {
59 encoder->encodeUInt64(m_size);
60 encoder->encode(CoreIPC::MachPort(m_port, MACH_MSG_TYPE_MOVE_SEND));
61 m_port = MACH_PORT_NULL;
62 }
63
decode(CoreIPC::ArgumentDecoder * decoder,Handle & handle)64 bool SharedMemory::Handle::decode(CoreIPC::ArgumentDecoder* decoder, Handle& handle)
65 {
66 ASSERT(!handle.m_port);
67 ASSERT(!handle.m_size);
68
69 uint64_t size;
70 if (!decoder->decodeUInt64(size))
71 return false;
72
73 CoreIPC::MachPort machPort;
74 if (!decoder->decode(CoreIPC::Out(machPort)))
75 return false;
76
77 handle.m_size = size;
78 handle.m_port = machPort.port();
79 return true;
80 }
81
toPointer(mach_vm_address_t address)82 static inline void* toPointer(mach_vm_address_t address)
83 {
84 return reinterpret_cast<void*>(static_cast<uintptr_t>(address));
85 }
86
toVMAddress(void * pointer)87 static inline mach_vm_address_t toVMAddress(void* pointer)
88 {
89 return static_cast<mach_vm_address_t>(reinterpret_cast<uintptr_t>(pointer));
90 }
91
create(size_t size)92 PassRefPtr<SharedMemory> SharedMemory::create(size_t size)
93 {
94 ASSERT(size);
95
96 mach_vm_address_t address;
97 kern_return_t kr = mach_vm_allocate(mach_task_self(), &address, round_page(size), VM_FLAGS_ANYWHERE);
98 if (kr != KERN_SUCCESS)
99 return 0;
100
101 // Create a Mach port that represents the shared memory.
102 mach_port_t port;
103 memory_object_size_t memoryObjectSize = round_page(size);
104 kr = mach_make_memory_entry_64(mach_task_self(), &memoryObjectSize, address, VM_PROT_DEFAULT, &port, MACH_PORT_NULL);
105
106 if (kr != KERN_SUCCESS) {
107 mach_vm_deallocate(mach_task_self(), address, round_page(size));
108 return 0;
109 }
110
111 ASSERT(memoryObjectSize >= round_page(size));
112
113 RefPtr<SharedMemory> sharedMemory(adoptRef(new SharedMemory));
114 sharedMemory->m_size = size;
115 sharedMemory->m_data = toPointer(address);
116 sharedMemory->m_port = port;
117
118 return sharedMemory.release();
119 }
120
machProtection(SharedMemory::Protection protection)121 static inline vm_prot_t machProtection(SharedMemory::Protection protection)
122 {
123 switch (protection) {
124 case SharedMemory::ReadOnly:
125 return VM_PROT_READ;
126 case SharedMemory::ReadWrite:
127 return VM_PROT_READ | VM_PROT_WRITE;
128 }
129
130 ASSERT_NOT_REACHED();
131 return VM_PROT_NONE;
132 }
133
create(const Handle & handle,Protection protection)134 PassRefPtr<SharedMemory> SharedMemory::create(const Handle& handle, Protection protection)
135 {
136 if (handle.isNull())
137 return 0;
138
139 // Map the memory.
140 vm_prot_t vmProtection = machProtection(protection);
141 mach_vm_address_t mappedAddress = 0;
142 kern_return_t kr = mach_vm_map(mach_task_self(), &mappedAddress, handle.m_size, 0, VM_FLAGS_ANYWHERE, handle.m_port, 0, false, vmProtection, vmProtection, VM_INHERIT_NONE);
143 if (kr != KERN_SUCCESS)
144 return 0;
145
146 RefPtr<SharedMemory> sharedMemory(adoptRef(new SharedMemory));
147 sharedMemory->m_size = handle.m_size;
148 sharedMemory->m_data = toPointer(mappedAddress);
149 sharedMemory->m_port = MACH_PORT_NULL;
150
151 return sharedMemory.release();
152 }
153
~SharedMemory()154 SharedMemory::~SharedMemory()
155 {
156 if (m_data) {
157 kern_return_t kr = mach_vm_deallocate(mach_task_self(), toVMAddress(m_data), round_page(m_size));
158 ASSERT_UNUSED(kr, kr == KERN_SUCCESS);
159 }
160
161 if (m_port) {
162 kern_return_t kr = mach_port_deallocate(mach_task_self(), m_port);
163 ASSERT_UNUSED(kr, kr == KERN_SUCCESS);
164 }
165 }
166
createHandle(Handle & handle,Protection protection)167 bool SharedMemory::createHandle(Handle& handle, Protection protection)
168 {
169 ASSERT(!handle.m_port);
170 ASSERT(!handle.m_size);
171
172 mach_vm_address_t address = toVMAddress(m_data);
173 memory_object_size_t size = round_page(m_size);
174
175 mach_port_t port;
176
177 if (protection == ReadWrite && m_port) {
178 // Just re-use the port we have.
179 port = m_port;
180 if (mach_port_mod_refs(mach_task_self(), port, MACH_PORT_RIGHT_SEND, 1) != KERN_SUCCESS)
181 return false;
182 } else {
183 // Create a mach port that represents the shared memory.
184 kern_return_t kr = mach_make_memory_entry_64(mach_task_self(), &size, address, machProtection(protection), &port, MACH_PORT_NULL);
185 if (kr != KERN_SUCCESS)
186 return false;
187
188 ASSERT(size >= round_page(m_size));
189 }
190
191 handle.m_port = port;
192 handle.m_size = size;
193
194 return true;
195 }
196
systemPageSize()197 unsigned SharedMemory::systemPageSize()
198 {
199 return vm_page_size;
200 }
201
202 } // namespace WebKit
203