1 //===-- tsan_rtl_thread.cc ------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file is a part of ThreadSanitizer (TSan), a race detector. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_common/sanitizer_placement_new.h" 15 #include "tsan_rtl.h" 16 #include "tsan_mman.h" 17 #include "tsan_platform.h" 18 #include "tsan_report.h" 19 #include "tsan_sync.h" 20 21 namespace __tsan { 22 23 // ThreadContext implementation. 24 25 ThreadContext::ThreadContext(int tid) 26 : ThreadContextBase(tid) 27 , thr() 28 , sync() 29 , epoch0() 30 , epoch1() { 31 } 32 33 #ifndef SANITIZER_GO 34 ThreadContext::~ThreadContext() { 35 } 36 #endif 37 38 void ThreadContext::OnDead() { 39 CHECK_EQ(sync.size(), 0); 40 } 41 42 void ThreadContext::OnJoined(void *arg) { 43 ThreadState *caller_thr = static_cast<ThreadState *>(arg); 44 AcquireImpl(caller_thr, 0, &sync); 45 sync.Reset(&caller_thr->clock_cache); 46 } 47 48 struct OnCreatedArgs { 49 ThreadState *thr; 50 uptr pc; 51 }; 52 53 void ThreadContext::OnCreated(void *arg) { 54 thr = 0; 55 if (tid == 0) 56 return; 57 OnCreatedArgs *args = static_cast<OnCreatedArgs *>(arg); 58 if (!args->thr) // GCD workers don't have a parent thread. 59 return; 60 args->thr->fast_state.IncrementEpoch(); 61 // Can't increment epoch w/o writing to the trace as well. 62 TraceAddEvent(args->thr, args->thr->fast_state, EventTypeMop, 0); 63 ReleaseImpl(args->thr, 0, &sync); 64 creation_stack_id = CurrentStackId(args->thr, args->pc); 65 if (reuse_count == 0) 66 StatInc(args->thr, StatThreadMaxTid); 67 } 68 69 void ThreadContext::OnReset() { 70 CHECK_EQ(sync.size(), 0); 71 FlushUnneededShadowMemory(GetThreadTrace(tid), TraceSize() * sizeof(Event)); 72 //!!! FlushUnneededShadowMemory(GetThreadTraceHeader(tid), sizeof(Trace)); 73 } 74 75 void ThreadContext::OnDetached(void *arg) { 76 ThreadState *thr1 = static_cast<ThreadState*>(arg); 77 sync.Reset(&thr1->clock_cache); 78 } 79 80 struct OnStartedArgs { 81 ThreadState *thr; 82 uptr stk_addr; 83 uptr stk_size; 84 uptr tls_addr; 85 uptr tls_size; 86 }; 87 88 void ThreadContext::OnStarted(void *arg) { 89 OnStartedArgs *args = static_cast<OnStartedArgs*>(arg); 90 thr = args->thr; 91 // RoundUp so that one trace part does not contain events 92 // from different threads. 93 epoch0 = RoundUp(epoch1 + 1, kTracePartSize); 94 epoch1 = (u64)-1; 95 new(thr) ThreadState(ctx, tid, unique_id, epoch0, reuse_count, 96 args->stk_addr, args->stk_size, args->tls_addr, args->tls_size); 97 #ifndef SANITIZER_GO 98 thr->shadow_stack = &ThreadTrace(thr->tid)->shadow_stack[0]; 99 thr->shadow_stack_pos = thr->shadow_stack; 100 thr->shadow_stack_end = thr->shadow_stack + kShadowStackSize; 101 #else 102 // Setup dynamic shadow stack. 103 const int kInitStackSize = 8; 104 thr->shadow_stack = (uptr*)internal_alloc(MBlockShadowStack, 105 kInitStackSize * sizeof(uptr)); 106 thr->shadow_stack_pos = thr->shadow_stack; 107 thr->shadow_stack_end = thr->shadow_stack + kInitStackSize; 108 #endif 109 #ifndef SANITIZER_GO 110 AllocatorThreadStart(thr); 111 #endif 112 if (common_flags()->detect_deadlocks) { 113 thr->dd_pt = ctx->dd->CreatePhysicalThread(); 114 thr->dd_lt = ctx->dd->CreateLogicalThread(unique_id); 115 } 116 thr->fast_state.SetHistorySize(flags()->history_size); 117 // Commit switch to the new part of the trace. 118 // TraceAddEvent will reset stack0/mset0 in the new part for us. 119 TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0); 120 121 thr->fast_synch_epoch = epoch0; 122 AcquireImpl(thr, 0, &sync); 123 StatInc(thr, StatSyncAcquire); 124 sync.Reset(&thr->clock_cache); 125 thr->is_inited = true; 126 DPrintf("#%d: ThreadStart epoch=%zu stk_addr=%zx stk_size=%zx " 127 "tls_addr=%zx tls_size=%zx\n", 128 tid, (uptr)epoch0, args->stk_addr, args->stk_size, 129 args->tls_addr, args->tls_size); 130 } 131 132 void ThreadContext::OnFinished() { 133 if (!detached) { 134 thr->fast_state.IncrementEpoch(); 135 // Can't increment epoch w/o writing to the trace as well. 136 TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0); 137 ReleaseImpl(thr, 0, &sync); 138 } 139 epoch1 = thr->fast_state.epoch(); 140 141 if (common_flags()->detect_deadlocks) { 142 ctx->dd->DestroyPhysicalThread(thr->dd_pt); 143 ctx->dd->DestroyLogicalThread(thr->dd_lt); 144 } 145 ctx->clock_alloc.FlushCache(&thr->clock_cache); 146 ctx->metamap.OnThreadIdle(thr); 147 #ifndef SANITIZER_GO 148 AllocatorThreadFinish(thr); 149 #endif 150 thr->~ThreadState(); 151 #if TSAN_COLLECT_STATS 152 StatAggregate(ctx->stat, thr->stat); 153 #endif 154 thr = 0; 155 } 156 157 #ifndef SANITIZER_GO 158 struct ThreadLeak { 159 ThreadContext *tctx; 160 int count; 161 }; 162 163 static void MaybeReportThreadLeak(ThreadContextBase *tctx_base, void *arg) { 164 Vector<ThreadLeak> &leaks = *(Vector<ThreadLeak>*)arg; 165 ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base); 166 if (tctx->detached || tctx->status != ThreadStatusFinished) 167 return; 168 for (uptr i = 0; i < leaks.Size(); i++) { 169 if (leaks[i].tctx->creation_stack_id == tctx->creation_stack_id) { 170 leaks[i].count++; 171 return; 172 } 173 } 174 ThreadLeak leak = {tctx, 1}; 175 leaks.PushBack(leak); 176 } 177 #endif 178 179 #ifndef SANITIZER_GO 180 static void ReportIgnoresEnabled(ThreadContext *tctx, IgnoreSet *set) { 181 if (tctx->tid == 0) { 182 Printf("ThreadSanitizer: main thread finished with ignores enabled\n"); 183 } else { 184 Printf("ThreadSanitizer: thread T%d %s finished with ignores enabled," 185 " created at:\n", tctx->tid, tctx->name); 186 PrintStack(SymbolizeStackId(tctx->creation_stack_id)); 187 } 188 Printf(" One of the following ignores was not ended" 189 " (in order of probability)\n"); 190 for (uptr i = 0; i < set->Size(); i++) { 191 Printf(" Ignore was enabled at:\n"); 192 PrintStack(SymbolizeStackId(set->At(i))); 193 } 194 Die(); 195 } 196 197 static void ThreadCheckIgnore(ThreadState *thr) { 198 if (ctx->after_multithreaded_fork) 199 return; 200 if (thr->ignore_reads_and_writes) 201 ReportIgnoresEnabled(thr->tctx, &thr->mop_ignore_set); 202 if (thr->ignore_sync) 203 ReportIgnoresEnabled(thr->tctx, &thr->sync_ignore_set); 204 } 205 #else 206 static void ThreadCheckIgnore(ThreadState *thr) {} 207 #endif 208 209 void ThreadFinalize(ThreadState *thr) { 210 ThreadCheckIgnore(thr); 211 #ifndef SANITIZER_GO 212 if (!flags()->report_thread_leaks) 213 return; 214 ThreadRegistryLock l(ctx->thread_registry); 215 Vector<ThreadLeak> leaks(MBlockScopedBuf); 216 ctx->thread_registry->RunCallbackForEachThreadLocked( 217 MaybeReportThreadLeak, &leaks); 218 for (uptr i = 0; i < leaks.Size(); i++) { 219 ScopedReport rep(ReportTypeThreadLeak); 220 rep.AddThread(leaks[i].tctx, true); 221 rep.SetCount(leaks[i].count); 222 OutputReport(thr, rep); 223 } 224 #endif 225 } 226 227 int ThreadCount(ThreadState *thr) { 228 uptr result; 229 ctx->thread_registry->GetNumberOfThreads(0, 0, &result); 230 return (int)result; 231 } 232 233 int ThreadCreate(ThreadState *thr, uptr pc, uptr uid, bool detached) { 234 StatInc(thr, StatThreadCreate); 235 OnCreatedArgs args = { thr, pc }; 236 u32 parent_tid = thr ? thr->tid : kInvalidTid; // No parent for GCD workers. 237 int tid = 238 ctx->thread_registry->CreateThread(uid, detached, parent_tid, &args); 239 DPrintf("#%d: ThreadCreate tid=%d uid=%zu\n", parent_tid, tid, uid); 240 StatSet(thr, StatThreadMaxAlive, ctx->thread_registry->GetMaxAliveThreads()); 241 return tid; 242 } 243 244 void ThreadStart(ThreadState *thr, int tid, uptr os_id) { 245 uptr stk_addr = 0; 246 uptr stk_size = 0; 247 uptr tls_addr = 0; 248 uptr tls_size = 0; 249 #ifndef SANITIZER_GO 250 GetThreadStackAndTls(tid == 0, &stk_addr, &stk_size, &tls_addr, &tls_size); 251 252 if (tid) { 253 if (stk_addr && stk_size) 254 MemoryRangeImitateWrite(thr, /*pc=*/ 1, stk_addr, stk_size); 255 256 if (tls_addr && tls_size) { 257 // Check that the thr object is in tls; 258 const uptr thr_beg = (uptr)thr; 259 const uptr thr_end = (uptr)thr + sizeof(*thr); 260 CHECK_GE(thr_beg, tls_addr); 261 CHECK_LE(thr_beg, tls_addr + tls_size); 262 CHECK_GE(thr_end, tls_addr); 263 CHECK_LE(thr_end, tls_addr + tls_size); 264 // Since the thr object is huge, skip it. 265 MemoryRangeImitateWrite(thr, /*pc=*/ 2, tls_addr, thr_beg - tls_addr); 266 MemoryRangeImitateWrite(thr, /*pc=*/ 2, 267 thr_end, tls_addr + tls_size - thr_end); 268 } 269 } 270 #endif 271 272 ThreadRegistry *tr = ctx->thread_registry; 273 OnStartedArgs args = { thr, stk_addr, stk_size, tls_addr, tls_size }; 274 tr->StartThread(tid, os_id, &args); 275 276 tr->Lock(); 277 thr->tctx = (ThreadContext*)tr->GetThreadLocked(tid); 278 tr->Unlock(); 279 280 #ifndef SANITIZER_GO 281 if (ctx->after_multithreaded_fork) { 282 thr->ignore_interceptors++; 283 ThreadIgnoreBegin(thr, 0); 284 ThreadIgnoreSyncBegin(thr, 0); 285 } 286 #endif 287 } 288 289 void ThreadFinish(ThreadState *thr) { 290 ThreadCheckIgnore(thr); 291 StatInc(thr, StatThreadFinish); 292 if (thr->stk_addr && thr->stk_size) 293 DontNeedShadowFor(thr->stk_addr, thr->stk_size); 294 if (thr->tls_addr && thr->tls_size) 295 DontNeedShadowFor(thr->tls_addr, thr->tls_size); 296 thr->is_dead = true; 297 ctx->thread_registry->FinishThread(thr->tid); 298 } 299 300 static bool FindThreadByUid(ThreadContextBase *tctx, void *arg) { 301 uptr uid = (uptr)arg; 302 if (tctx->user_id == uid && tctx->status != ThreadStatusInvalid) { 303 tctx->user_id = 0; 304 return true; 305 } 306 return false; 307 } 308 309 int ThreadTid(ThreadState *thr, uptr pc, uptr uid) { 310 int res = ctx->thread_registry->FindThread(FindThreadByUid, (void*)uid); 311 DPrintf("#%d: ThreadTid uid=%zu tid=%d\n", thr->tid, uid, res); 312 return res; 313 } 314 315 void ThreadJoin(ThreadState *thr, uptr pc, int tid) { 316 CHECK_GT(tid, 0); 317 CHECK_LT(tid, kMaxTid); 318 DPrintf("#%d: ThreadJoin tid=%d\n", thr->tid, tid); 319 ctx->thread_registry->JoinThread(tid, thr); 320 } 321 322 void ThreadDetach(ThreadState *thr, uptr pc, int tid) { 323 CHECK_GT(tid, 0); 324 CHECK_LT(tid, kMaxTid); 325 ctx->thread_registry->DetachThread(tid, thr); 326 } 327 328 void ThreadSetName(ThreadState *thr, const char *name) { 329 ctx->thread_registry->SetThreadName(thr->tid, name); 330 } 331 332 void MemoryAccessRange(ThreadState *thr, uptr pc, uptr addr, 333 uptr size, bool is_write) { 334 if (size == 0) 335 return; 336 337 u64 *shadow_mem = (u64*)MemToShadow(addr); 338 DPrintf2("#%d: MemoryAccessRange: @%p %p size=%d is_write=%d\n", 339 thr->tid, (void*)pc, (void*)addr, 340 (int)size, is_write); 341 342 #if SANITIZER_DEBUG 343 if (!IsAppMem(addr)) { 344 Printf("Access to non app mem %zx\n", addr); 345 DCHECK(IsAppMem(addr)); 346 } 347 if (!IsAppMem(addr + size - 1)) { 348 Printf("Access to non app mem %zx\n", addr + size - 1); 349 DCHECK(IsAppMem(addr + size - 1)); 350 } 351 if (!IsShadowMem((uptr)shadow_mem)) { 352 Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr); 353 DCHECK(IsShadowMem((uptr)shadow_mem)); 354 } 355 if (!IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1))) { 356 Printf("Bad shadow addr %p (%zx)\n", 357 shadow_mem + size * kShadowCnt / 8 - 1, addr + size - 1); 358 DCHECK(IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1))); 359 } 360 #endif 361 362 StatInc(thr, StatMopRange); 363 364 if (*shadow_mem == kShadowRodata) { 365 // Access to .rodata section, no races here. 366 // Measurements show that it can be 10-20% of all memory accesses. 367 StatInc(thr, StatMopRangeRodata); 368 return; 369 } 370 371 FastState fast_state = thr->fast_state; 372 if (fast_state.GetIgnoreBit()) 373 return; 374 375 fast_state.IncrementEpoch(); 376 thr->fast_state = fast_state; 377 TraceAddEvent(thr, fast_state, EventTypeMop, pc); 378 379 bool unaligned = (addr % kShadowCell) != 0; 380 381 // Handle unaligned beginning, if any. 382 for (; addr % kShadowCell && size; addr++, size--) { 383 int const kAccessSizeLog = 0; 384 Shadow cur(fast_state); 385 cur.SetWrite(is_write); 386 cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog); 387 MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false, 388 shadow_mem, cur); 389 } 390 if (unaligned) 391 shadow_mem += kShadowCnt; 392 // Handle middle part, if any. 393 for (; size >= kShadowCell; addr += kShadowCell, size -= kShadowCell) { 394 int const kAccessSizeLog = 3; 395 Shadow cur(fast_state); 396 cur.SetWrite(is_write); 397 cur.SetAddr0AndSizeLog(0, kAccessSizeLog); 398 MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false, 399 shadow_mem, cur); 400 shadow_mem += kShadowCnt; 401 } 402 // Handle ending, if any. 403 for (; size; addr++, size--) { 404 int const kAccessSizeLog = 0; 405 Shadow cur(fast_state); 406 cur.SetWrite(is_write); 407 cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog); 408 MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false, 409 shadow_mem, cur); 410 } 411 } 412 413 } // namespace __tsan 414
