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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 // The allocator shim is only enabled in Release Static builds. | |
6 // This #if is needed as gyp can't have different compile | |
7 // targets between Debug and Release. | |
8 // TODO(wfh): Remove this once gyp is dead. | |
9 #if defined(ALLOCATOR_SHIM) | |
10 | |
11 #include <limits.h> | 5 #include <limits.h> |
12 #include <malloc.h> | 6 #include <malloc.h> |
13 #include <new.h> | 7 #include <new.h> |
14 #include <windows.h> | 8 #include <windows.h> |
15 #include <stddef.h> | 9 #include <stddef.h> |
16 | 10 |
17 #include "allocator_shim_win.h" | |
18 | |
19 // This shim make it possible to perform additional checks on allocations | 11 // This shim make it possible to perform additional checks on allocations |
20 // before passing them to the Heap functions. | 12 // before passing them to the Heap functions. |
21 | 13 |
22 // Override heap functions to perform additional checks: | 14 // Heap functions are stripped from libcmt.lib using the prep_libc.py |
| 15 // for each object file stripped, we re-implement them here to allow us to |
| 16 // perform additional checks: |
23 // 1. Enforcing the maximum size that can be allocated to 2Gb. | 17 // 1. Enforcing the maximum size that can be allocated to 2Gb. |
24 // 2. Calling new_handler if malloc fails | 18 // 2. Calling new_handler if malloc fails. |
25 | 19 |
26 // See definitions of original functions in ucrt\corecrt_malloc.h in SDK | 20 extern "C" { |
27 // include directory. | 21 // We set this to 1 because part of the CRT uses a check of _crtheap != 0 |
| 22 // to test whether the CRT has been initialized. Once we've ripped out |
| 23 // the allocators from libcmt, we need to provide this definition so that |
| 24 // the rest of the CRT is still usable. |
| 25 // heapinit.c |
| 26 void* _crtheap = reinterpret_cast<void*>(1); |
| 27 } |
28 | 28 |
29 namespace base { | 29 namespace base { |
30 namespace allocator { | 30 namespace allocator { |
31 bool g_is_win_shim_layer_initialized = false; | 31 bool g_is_win_shim_layer_initialized = false; |
32 } // namespace allocator | 32 } // namespace allocator |
33 } // namespace base | 33 } // namespace base |
34 | 34 |
35 namespace { | 35 namespace { |
36 | 36 |
37 const size_t kWindowsPageSize = 4096; | 37 const size_t kWindowsPageSize = 4096; |
38 const size_t kMaxWindowsAllocation = INT_MAX - kWindowsPageSize; | 38 const size_t kMaxWindowsAllocation = INT_MAX - kWindowsPageSize; |
39 int new_mode = 0; | 39 int new_mode = 0; |
40 | 40 |
41 inline HANDLE get_heap_handle() { | 41 // VS2013 crt uses the process heap as its heap, so we do the same here. |
42 return reinterpret_cast<HANDLE>(_get_heap_handle()); | 42 // See heapinit.c in VS CRT sources. |
| 43 bool win_heap_init() { |
| 44 // Set the _crtheap global here. THis allows us to offload most of the |
| 45 // memory management to the CRT, except the functions we need to shim. |
| 46 _crtheap = GetProcessHeap(); |
| 47 if (_crtheap == NULL) |
| 48 return false; |
| 49 |
| 50 ULONG enable_lfh = 2; |
| 51 // NOTE: Setting LFH may fail. Vista already has it enabled. |
| 52 // And under the debugger, it won't use LFH. So we |
| 53 // ignore any errors. |
| 54 HeapSetInformation(_crtheap, HeapCompatibilityInformation, &enable_lfh, |
| 55 sizeof(enable_lfh)); |
| 56 |
| 57 return true; |
43 } | 58 } |
44 | 59 |
45 void* win_heap_malloc(size_t size) { | 60 void* win_heap_malloc(size_t size) { |
46 if (size < kMaxWindowsAllocation) | 61 if (size < kMaxWindowsAllocation) |
47 return HeapAlloc(get_heap_handle(), 0, size); | 62 return HeapAlloc(_crtheap, 0, size); |
48 return nullptr; | 63 return NULL; |
49 } | 64 } |
50 | 65 |
51 void win_heap_free(void* size) { | 66 void win_heap_free(void* size) { |
52 HeapFree(get_heap_handle(), 0, size); | 67 HeapFree(_crtheap, 0, size); |
53 } | 68 } |
54 | 69 |
55 void* win_heap_realloc(void* ptr, size_t size) { | 70 void* win_heap_realloc(void* ptr, size_t size) { |
56 if (!ptr) | 71 if (!ptr) |
57 return win_heap_malloc(size); | 72 return win_heap_malloc(size); |
58 if (!size) { | 73 if (!size) { |
59 win_heap_free(ptr); | 74 win_heap_free(ptr); |
60 return nullptr; | 75 return NULL; |
61 } | 76 } |
62 if (size < kMaxWindowsAllocation) | 77 if (size < kMaxWindowsAllocation) |
63 return HeapReAlloc(get_heap_handle(), 0, ptr, size); | 78 return HeapReAlloc(_crtheap, 0, ptr, size); |
64 return nullptr; | 79 return NULL; |
| 80 } |
| 81 |
| 82 void win_heap_term() { |
| 83 _crtheap = NULL; |
65 } | 84 } |
66 | 85 |
67 // Call the new handler, if one has been set. | 86 // Call the new handler, if one has been set. |
68 // Returns true on successfully calling the handler, false otherwise. | 87 // Returns true on successfully calling the handler, false otherwise. |
69 inline bool call_new_handler(bool nothrow, size_t size) { | 88 inline bool call_new_handler(bool nothrow, size_t size) { |
70 // Get the current new handler. | 89 // Get the current new handler. |
71 _PNH nh = _query_new_handler(); | 90 _PNH nh = _query_new_handler(); |
72 #if defined(_HAS_EXCEPTIONS) && !_HAS_EXCEPTIONS | 91 #if defined(_HAS_EXCEPTIONS) && !_HAS_EXCEPTIONS |
73 if (!nh) | 92 if (!nh) |
74 return false; | 93 return false; |
75 // Since exceptions are disabled, we don't really know if new_handler | 94 // Since exceptions are disabled, we don't really know if new_handler |
76 // failed. Assume it will abort if it fails. | 95 // failed. Assume it will abort if it fails. |
77 return nh(size) ? true : false; | 96 return nh(size); |
78 #else | 97 #else |
79 #error "Exceptions in allocator shim are not supported!" | 98 #error "Exceptions in allocator shim are not supported!" |
80 #endif // defined(_HAS_EXCEPTIONS) && !_HAS_EXCEPTIONS | 99 #endif // defined(_HAS_EXCEPTIONS) && !_HAS_EXCEPTIONS |
| 100 return false; |
| 101 } |
| 102 |
| 103 // Implement a C++ style allocation, which always calls the new_handler |
| 104 // on failure. |
| 105 inline void* generic_cpp_alloc(size_t size, bool nothrow) { |
| 106 void* ptr; |
| 107 for (;;) { |
| 108 ptr = malloc(size); |
| 109 if (ptr) |
| 110 return ptr; |
| 111 if (!call_new_handler(nothrow, size)) |
| 112 break; |
| 113 } |
| 114 return ptr; |
81 } | 115 } |
82 | 116 |
83 } // namespace | 117 } // namespace |
84 | 118 |
85 extern "C" { | 119 // new.cpp |
| 120 void* operator new(size_t size) { |
| 121 return generic_cpp_alloc(size, false); |
| 122 } |
86 | 123 |
87 // Symbol to allow weak linkage to win_heap_malloc from memory_win.cc. | 124 // delete.cpp |
88 void* (*malloc_unchecked)(size_t) = &win_heap_malloc; | 125 void operator delete(void* p) throw() { |
| 126 free(p); |
| 127 } |
| 128 |
| 129 // new2.cpp |
| 130 void* operator new[](size_t size) { |
| 131 return generic_cpp_alloc(size, false); |
| 132 } |
| 133 |
| 134 // delete2.cpp |
| 135 void operator delete[](void* p) throw() { |
| 136 free(p); |
| 137 } |
| 138 |
| 139 // newopnt.cpp |
| 140 void* operator new(size_t size, const std::nothrow_t& nt) { |
| 141 return generic_cpp_alloc(size, true); |
| 142 } |
| 143 |
| 144 // newaopnt.cpp |
| 145 void* operator new[](size_t size, const std::nothrow_t& nt) { |
| 146 return generic_cpp_alloc(size, true); |
| 147 } |
89 | 148 |
90 // This function behaves similarly to MSVC's _set_new_mode. | 149 // This function behaves similarly to MSVC's _set_new_mode. |
91 // If flag is 0 (default), calls to malloc will behave normally. | 150 // If flag is 0 (default), calls to malloc will behave normally. |
92 // If flag is 1, calls to malloc will behave like calls to new, | 151 // If flag is 1, calls to malloc will behave like calls to new, |
93 // and the std_new_handler will be invoked on failure. | 152 // and the std_new_handler will be invoked on failure. |
94 // Returns the previous mode. | 153 // Returns the previous mode. |
95 // | 154 // new_mode.cpp |
96 // Replaces _set_new_mode in ucrt\heap\new_mode.cpp | 155 int _set_new_mode(int flag) throw() { |
97 int _set_new_mode(int flag) { | |
98 // The MS CRT calls this function early on in startup, so this serves as a low | |
99 // overhead proof that the allocator shim is in place for this process. | |
100 base::allocator::g_is_win_shim_layer_initialized = true; | |
101 int old_mode = new_mode; | 156 int old_mode = new_mode; |
102 new_mode = flag; | 157 new_mode = flag; |
103 return old_mode; | 158 return old_mode; |
104 } | 159 } |
105 | 160 |
106 // Replaces _query_new_mode in ucrt\heap\new_mode.cpp | 161 // new_mode.cpp |
107 int _query_new_mode() { | 162 int _query_new_mode() { |
108 return new_mode; | 163 return new_mode; |
109 } | 164 } |
110 | 165 |
111 // Replaces malloc in ucrt\heap\malloc.cpp | 166 extern "C" { |
112 __declspec(restrict) void* malloc(size_t size) { | 167 // malloc.c |
| 168 void* malloc(size_t size) { |
113 void* ptr; | 169 void* ptr; |
114 for (;;) { | 170 for (;;) { |
115 ptr = win_heap_malloc(size); | 171 ptr = win_heap_malloc(size); |
116 if (ptr) | 172 if (ptr) |
117 return ptr; | 173 return ptr; |
118 | 174 |
119 if (!new_mode || !call_new_handler(true, size)) | 175 if (!new_mode || !call_new_handler(true, size)) |
120 break; | 176 break; |
121 } | 177 } |
122 return ptr; | 178 return ptr; |
123 } | 179 } |
124 | 180 |
125 // Replaces free in ucrt\heap\free.cpp | 181 // Symbol to allow weak linkage to win_heap_malloc from memory_win.cc. |
| 182 void* (*malloc_unchecked)(size_t) = &win_heap_malloc; |
| 183 |
| 184 // free.c |
126 void free(void* p) { | 185 void free(void* p) { |
127 win_heap_free(p); | 186 win_heap_free(p); |
128 return; | 187 return; |
129 } | 188 } |
130 | 189 |
131 // Replaces realloc in ucrt\heap\realloc.cpp | 190 // realloc.c |
132 __declspec(restrict) void* realloc(void* ptr, size_t size) { | 191 void* realloc(void* ptr, size_t size) { |
133 // Webkit is brittle for allocators that return NULL for malloc(0). The | 192 // Webkit is brittle for allocators that return NULL for malloc(0). The |
134 // realloc(0, 0) code path does not guarantee a non-NULL return, so be sure | 193 // realloc(0, 0) code path does not guarantee a non-NULL return, so be sure |
135 // to call malloc for this case. | 194 // to call malloc for this case. |
136 if (!ptr) | 195 if (!ptr) |
137 return malloc(size); | 196 return malloc(size); |
138 | 197 |
139 void* new_ptr; | 198 void* new_ptr; |
140 for (;;) { | 199 for (;;) { |
141 new_ptr = win_heap_realloc(ptr, size); | 200 new_ptr = win_heap_realloc(ptr, size); |
142 | 201 |
143 // Subtle warning: NULL return does not alwas indicate out-of-memory. If | 202 // Subtle warning: NULL return does not alwas indicate out-of-memory. If |
144 // the requested new size is zero, realloc should free the ptr and return | 203 // the requested new size is zero, realloc should free the ptr and return |
145 // NULL. | 204 // NULL. |
146 if (new_ptr || !size) | 205 if (new_ptr || !size) |
147 return new_ptr; | 206 return new_ptr; |
148 if (!new_mode || !call_new_handler(true, size)) | 207 if (!new_mode || !call_new_handler(true, size)) |
149 break; | 208 break; |
150 } | 209 } |
151 return new_ptr; | 210 return new_ptr; |
152 } | 211 } |
153 | 212 |
154 // Replaces calloc in ucrt\heap\calloc.cpp | 213 // heapinit.c |
155 __declspec(restrict) void* calloc(size_t n, size_t elem_size) { | 214 intptr_t _get_heap_handle() { |
| 215 return reinterpret_cast<intptr_t>(_crtheap); |
| 216 } |
| 217 |
| 218 // heapinit.c |
| 219 int _heap_init() { |
| 220 base::allocator::g_is_win_shim_layer_initialized = true; |
| 221 return win_heap_init() ? 1 : 0; |
| 222 } |
| 223 |
| 224 // heapinit.c |
| 225 void _heap_term() { |
| 226 win_heap_term(); |
| 227 } |
| 228 |
| 229 // calloc.c |
| 230 void* calloc(size_t n, size_t elem_size) { |
156 // Overflow check. | 231 // Overflow check. |
157 const size_t size = n * elem_size; | 232 const size_t size = n * elem_size; |
158 if (elem_size != 0 && size / elem_size != n) | 233 if (elem_size != 0 && size / elem_size != n) |
159 return nullptr; | 234 return NULL; |
160 | 235 |
161 void* result = malloc(size); | 236 void* result = malloc(size); |
162 if (result) { | 237 if (result != NULL) { |
163 memset(result, 0, size); | 238 memset(result, 0, size); |
164 } | 239 } |
165 return result; | 240 return result; |
166 } | 241 } |
167 | 242 |
| 243 // recalloc.c |
| 244 void* _recalloc(void* p, size_t n, size_t elem_size) { |
| 245 if (!p) |
| 246 return calloc(n, elem_size); |
| 247 |
| 248 // This API is a bit odd. |
| 249 // Note: recalloc only guarantees zeroed memory when p is NULL. |
| 250 // Generally, calls to malloc() have padding. So a request |
| 251 // to malloc N bytes actually malloc's N+x bytes. Later, if |
| 252 // that buffer is passed to recalloc, we don't know what N |
| 253 // was anymore. We only know what N+x is. As such, there is |
| 254 // no way to know what to zero out. |
| 255 const size_t size = n * elem_size; |
| 256 if (elem_size != 0 && size / elem_size != n) |
| 257 return NULL; |
| 258 return realloc(p, size); |
| 259 } |
| 260 |
| 261 // calloc_impl.c |
| 262 void* _calloc_impl(size_t n, size_t size) { |
| 263 return calloc(n, size); |
| 264 } |
| 265 |
| 266 #ifndef NDEBUG |
| 267 #undef malloc |
| 268 #undef free |
| 269 #undef calloc |
| 270 |
| 271 static int error_handler(int reportType) { |
| 272 switch (reportType) { |
| 273 case 0: // _CRT_WARN |
| 274 __debugbreak(); |
| 275 return 0; |
| 276 |
| 277 case 1: // _CRT_ERROR |
| 278 __debugbreak(); |
| 279 return 0; |
| 280 |
| 281 case 2: // _CRT_ASSERT |
| 282 __debugbreak(); |
| 283 return 0; |
| 284 } |
| 285 char* p = NULL; |
| 286 *p = '\0'; |
| 287 return 0; |
| 288 } |
| 289 |
| 290 int _CrtDbgReport(int reportType, |
| 291 const char*, |
| 292 int, |
| 293 const char*, |
| 294 const char*, |
| 295 ...) { |
| 296 return error_handler(reportType); |
| 297 } |
| 298 |
| 299 int _CrtDbgReportW(int reportType, |
| 300 const wchar_t*, |
| 301 int, |
| 302 const wchar_t*, |
| 303 const wchar_t*, |
| 304 ...) { |
| 305 return error_handler(reportType); |
| 306 } |
| 307 |
| 308 int _CrtSetReportMode(int, int) { |
| 309 return 0; |
| 310 } |
| 311 |
| 312 void* _malloc_dbg(size_t size, int, const char*, int) { |
| 313 return malloc(size); |
| 314 } |
| 315 |
| 316 void* _realloc_dbg(void* ptr, size_t size, int, const char*, int) { |
| 317 return realloc(ptr, size); |
| 318 } |
| 319 |
| 320 void _free_dbg(void* ptr, int) { |
| 321 free(ptr); |
| 322 } |
| 323 |
| 324 void* _calloc_dbg(size_t n, size_t size, int, const char*, int) { |
| 325 return calloc(n, size); |
| 326 } |
| 327 #endif // NDEBUG |
| 328 |
168 } // extern C | 329 } // extern C |
169 | |
170 #endif // defined(ALLOCATOR_SHIM) | |
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