1 /* 2 * Copyright (C) 2008 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. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #ifndef ExecutableAllocator_h 27 #define ExecutableAllocator_h 28 #include <stddef.h> // for ptrdiff_t 29 #include <limits> 30 #include <wtf/Assertions.h> 31 #include <wtf/PageAllocation.h> 32 #include <wtf/PassRefPtr.h> 33 #include <wtf/RefCounted.h> 34 #include <wtf/UnusedParam.h> 35 #include <wtf/Vector.h> 36 37 #if OS(IOS) 38 #include <libkern/OSCacheControl.h> 39 #include <sys/mman.h> 40 #endif 41 42 #if OS(SYMBIAN) 43 #include <e32std.h> 44 #endif 45 46 #if CPU(MIPS) && OS(LINUX) 47 #include <sys/cachectl.h> 48 #endif 49 50 #if CPU(SH4) && OS(LINUX) 51 #include <asm/cachectl.h> 52 #include <asm/unistd.h> 53 #include <sys/syscall.h> 54 #include <unistd.h> 55 #endif 56 57 #if OS(WINCE) 58 // From pkfuncs.h (private header file from the Platform Builder) 59 #define CACHE_SYNC_ALL 0x07F 60 extern "C" __declspec(dllimport) void CacheRangeFlush(LPVOID pAddr, DWORD dwLength, DWORD dwFlags); 61 #endif 62 63 #if PLATFORM(BREWMP) 64 #include <AEEIMemCache1.h> 65 #include <AEEMemCache1.bid> 66 #include <wtf/brew/RefPtrBrew.h> 67 #endif 68 69 #define JIT_ALLOCATOR_PAGE_SIZE (ExecutableAllocator::pageSize) 70 #define JIT_ALLOCATOR_LARGE_ALLOC_SIZE (ExecutableAllocator::pageSize * 4) 71 72 #if ENABLE(ASSEMBLER_WX_EXCLUSIVE) 73 #define PROTECTION_FLAGS_RW (PROT_READ | PROT_WRITE) 74 #define PROTECTION_FLAGS_RX (PROT_READ | PROT_EXEC) 75 #define EXECUTABLE_POOL_WRITABLE false 76 #else 77 #define EXECUTABLE_POOL_WRITABLE true 78 #endif 79 80 namespace JSC { 81 82 inline size_t roundUpAllocationSize(size_t request, size_t granularity) 83 { 84 if ((std::numeric_limits<size_t>::max() - granularity) <= request) 85 CRASH(); // Allocation is too large 86 87 // Round up to next page boundary 88 size_t size = request + (granularity - 1); 89 size = size & ~(granularity - 1); 90 ASSERT(size >= request); 91 return size; 92 } 93 94 } 95 96 #if ENABLE(JIT) && ENABLE(ASSEMBLER) 97 98 namespace JSC { 99 100 class ExecutablePool : public RefCounted<ExecutablePool> { 101 public: 102 #if ENABLE(EXECUTABLE_ALLOCATOR_DEMAND) 103 typedef PageAllocation Allocation; 104 #else 105 class Allocation { 106 public: 107 Allocation(void* base, size_t size) 108 : m_base(base) 109 , m_size(size) 110 { 111 } 112 void* base() { return m_base; } 113 size_t size() { return m_size; } 114 bool operator!() const { return !m_base; } 115 116 private: 117 void* m_base; 118 size_t m_size; 119 }; 120 #endif 121 typedef Vector<Allocation, 2> AllocationList; 122 123 static PassRefPtr<ExecutablePool> create(size_t n) 124 { 125 return adoptRef(new ExecutablePool(n)); 126 } 127 128 void* alloc(size_t n) 129 { 130 ASSERT(m_freePtr <= m_end); 131 132 // Round 'n' up to a multiple of word size; if all allocations are of 133 // word sized quantities, then all subsequent allocations will be aligned. 134 n = roundUpAllocationSize(n, sizeof(void*)); 135 136 if (static_cast<ptrdiff_t>(n) < (m_end - m_freePtr)) { 137 void* result = m_freePtr; 138 m_freePtr += n; 139 return result; 140 } 141 142 // Insufficient space to allocate in the existing pool 143 // so we need allocate into a new pool 144 return poolAllocate(n); 145 } 146 147 void tryShrink(void* allocation, size_t oldSize, size_t newSize) 148 { 149 if (static_cast<char*>(allocation) + oldSize != m_freePtr) 150 return; 151 m_freePtr = static_cast<char*>(allocation) + roundUpAllocationSize(newSize, sizeof(void*)); 152 } 153 154 ~ExecutablePool() 155 { 156 AllocationList::iterator end = m_pools.end(); 157 for (AllocationList::iterator ptr = m_pools.begin(); ptr != end; ++ptr) 158 ExecutablePool::systemRelease(*ptr); 159 } 160 161 size_t available() const { return (m_pools.size() > 1) ? 0 : m_end - m_freePtr; } 162 163 private: 164 static Allocation systemAlloc(size_t n); 165 static void systemRelease(Allocation& alloc); 166 167 ExecutablePool(size_t n); 168 169 void* poolAllocate(size_t n); 170 171 char* m_freePtr; 172 char* m_end; 173 AllocationList m_pools; 174 }; 175 176 class ExecutableAllocator { 177 enum ProtectionSetting { Writable, Executable }; 178 179 public: 180 static size_t pageSize; 181 ExecutableAllocator() 182 { 183 if (!pageSize) 184 intializePageSize(); 185 if (isValid()) 186 m_smallAllocationPool = ExecutablePool::create(JIT_ALLOCATOR_LARGE_ALLOC_SIZE); 187 #if !ENABLE(INTERPRETER) 188 else 189 CRASH(); 190 #endif 191 } 192 193 bool isValid() const; 194 195 static bool underMemoryPressure(); 196 197 PassRefPtr<ExecutablePool> poolForSize(size_t n) 198 { 199 // Try to fit in the existing small allocator 200 ASSERT(m_smallAllocationPool); 201 if (n < m_smallAllocationPool->available()) 202 return m_smallAllocationPool; 203 204 // If the request is large, we just provide a unshared allocator 205 if (n > JIT_ALLOCATOR_LARGE_ALLOC_SIZE) 206 return ExecutablePool::create(n); 207 208 // Create a new allocator 209 RefPtr<ExecutablePool> pool = ExecutablePool::create(JIT_ALLOCATOR_LARGE_ALLOC_SIZE); 210 211 // If the new allocator will result in more free space than in 212 // the current small allocator, then we will use it instead 213 if ((pool->available() - n) > m_smallAllocationPool->available()) 214 m_smallAllocationPool = pool; 215 return pool.release(); 216 } 217 218 #if ENABLE(ASSEMBLER_WX_EXCLUSIVE) 219 static void makeWritable(void* start, size_t size) 220 { 221 reprotectRegion(start, size, Writable); 222 } 223 224 static void makeExecutable(void* start, size_t size) 225 { 226 reprotectRegion(start, size, Executable); 227 } 228 #else 229 static void makeWritable(void*, size_t) {} 230 static void makeExecutable(void*, size_t) {} 231 #endif 232 233 234 #if CPU(X86) || CPU(X86_64) 235 static void cacheFlush(void*, size_t) 236 { 237 } 238 #elif CPU(MIPS) 239 static void cacheFlush(void* code, size_t size) 240 { 241 #if GCC_VERSION_AT_LEAST(4, 3, 0) 242 #if WTF_MIPS_ISA_REV(2) && !GCC_VERSION_AT_LEAST(4, 4, 3) 243 int lineSize; 244 asm("rdhwr %0, $1" : "=r" (lineSize)); 245 // 246 // Modify "start" and "end" to avoid GCC 4.3.0-4.4.2 bug in 247 // mips_expand_synci_loop that may execute synci one more time. 248 // "start" points to the fisrt byte of the cache line. 249 // "end" points to the last byte of the line before the last cache line. 250 // Because size is always a multiple of 4, this is safe to set 251 // "end" to the last byte. 252 // 253 intptr_t start = reinterpret_cast<intptr_t>(code) & (-lineSize); 254 intptr_t end = ((reinterpret_cast<intptr_t>(code) + size - 1) & (-lineSize)) - 1; 255 __builtin___clear_cache(reinterpret_cast<char*>(start), reinterpret_cast<char*>(end)); 256 #else 257 intptr_t end = reinterpret_cast<intptr_t>(code) + size; 258 __builtin___clear_cache(reinterpret_cast<char*>(code), reinterpret_cast<char*>(end)); 259 #endif 260 #else 261 _flush_cache(reinterpret_cast<char*>(code), size, BCACHE); 262 #endif 263 } 264 #elif CPU(ARM_THUMB2) && OS(IOS) 265 static void cacheFlush(void* code, size_t size) 266 { 267 sys_cache_control(kCacheFunctionPrepareForExecution, code, size); 268 } 269 #elif CPU(ARM_THUMB2) && OS(LINUX) 270 static void cacheFlush(void* code, size_t size) 271 { 272 asm volatile ( 273 "push {r7}\n" 274 "mov r0, %0\n" 275 "mov r1, %1\n" 276 "movw r7, #0x2\n" 277 "movt r7, #0xf\n" 278 "movs r2, #0x0\n" 279 "svc 0x0\n" 280 "pop {r7}\n" 281 : 282 : "r" (code), "r" (reinterpret_cast<char*>(code) + size) 283 : "r0", "r1", "r2"); 284 } 285 #elif OS(SYMBIAN) 286 static void cacheFlush(void* code, size_t size) 287 { 288 User::IMB_Range(code, static_cast<char*>(code) + size); 289 } 290 #elif CPU(ARM_TRADITIONAL) && OS(LINUX) && COMPILER(RVCT) 291 static __asm void cacheFlush(void* code, size_t size); 292 #elif CPU(ARM_TRADITIONAL) && OS(LINUX) && COMPILER(GCC) 293 static void cacheFlush(void* code, size_t size) 294 { 295 asm volatile ( 296 "push {r7}\n" 297 "mov r0, %0\n" 298 "mov r1, %1\n" 299 "mov r7, #0xf0000\n" 300 "add r7, r7, #0x2\n" 301 "mov r2, #0x0\n" 302 "svc 0x0\n" 303 "pop {r7}\n" 304 : 305 : "r" (code), "r" (reinterpret_cast<char*>(code) + size) 306 : "r0", "r1", "r2"); 307 } 308 #elif OS(WINCE) 309 static void cacheFlush(void* code, size_t size) 310 { 311 CacheRangeFlush(code, size, CACHE_SYNC_ALL); 312 } 313 #elif PLATFORM(BREWMP) 314 static void cacheFlush(void* code, size_t size) 315 { 316 RefPtr<IMemCache1> memCache = createRefPtrInstance<IMemCache1>(AEECLSID_MemCache1); 317 IMemCache1_ClearCache(memCache.get(), reinterpret_cast<uint32>(code), size, MEMSPACE_CACHE_FLUSH, MEMSPACE_DATACACHE); 318 IMemCache1_ClearCache(memCache.get(), reinterpret_cast<uint32>(code), size, MEMSPACE_CACHE_INVALIDATE, MEMSPACE_INSTCACHE); 319 } 320 #elif CPU(SH4) && OS(LINUX) 321 static void cacheFlush(void* code, size_t size) 322 { 323 #ifdef CACHEFLUSH_D_L2 324 syscall(__NR_cacheflush, reinterpret_cast<unsigned>(code), size, CACHEFLUSH_D_WB | CACHEFLUSH_I | CACHEFLUSH_D_L2); 325 #else 326 syscall(__NR_cacheflush, reinterpret_cast<unsigned>(code), size, CACHEFLUSH_D_WB | CACHEFLUSH_I); 327 #endif 328 } 329 #else 330 #error "The cacheFlush support is missing on this platform." 331 #endif 332 static size_t committedByteCount(); 333 334 private: 335 336 #if ENABLE(ASSEMBLER_WX_EXCLUSIVE) 337 static void reprotectRegion(void*, size_t, ProtectionSetting); 338 #endif 339 340 RefPtr<ExecutablePool> m_smallAllocationPool; 341 static void intializePageSize(); 342 }; 343 344 inline ExecutablePool::ExecutablePool(size_t n) 345 { 346 size_t allocSize = roundUpAllocationSize(n, JIT_ALLOCATOR_PAGE_SIZE); 347 Allocation mem = systemAlloc(allocSize); 348 m_pools.append(mem); 349 m_freePtr = static_cast<char*>(mem.base()); 350 if (!m_freePtr) 351 CRASH(); // Failed to allocate 352 m_end = m_freePtr + allocSize; 353 } 354 355 inline void* ExecutablePool::poolAllocate(size_t n) 356 { 357 size_t allocSize = roundUpAllocationSize(n, JIT_ALLOCATOR_PAGE_SIZE); 358 359 Allocation result = systemAlloc(allocSize); 360 if (!result.base()) 361 CRASH(); // Failed to allocate 362 363 ASSERT(m_end >= m_freePtr); 364 if ((allocSize - n) > static_cast<size_t>(m_end - m_freePtr)) { 365 // Replace allocation pool 366 m_freePtr = static_cast<char*>(result.base()) + n; 367 m_end = static_cast<char*>(result.base()) + allocSize; 368 } 369 370 m_pools.append(result); 371 return result.base(); 372 } 373 374 } 375 376 #endif // ENABLE(JIT) && ENABLE(ASSEMBLER) 377 378 #endif // !defined(ExecutableAllocator) 379
