libsanitizer/tsan/tsan_rtl_mutex.cpp

   1 //===-- tsan_rtl_mutex.cpp ------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is a part of ThreadSanitizer (TSan), a race detector.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include <sanitizer_common/sanitizer_deadlock_detector_interface.h>
  14 #include <sanitizer_common/sanitizer_stackdepot.h>
  15
  16 #include "tsan_rtl.h"
  17 #include "tsan_flags.h"
  18 #include "tsan_sync.h"
  19 #include "tsan_report.h"
  20 #include "tsan_symbolize.h"
  21 #include "tsan_platform.h"
  22
  23 namespace __tsan {
  24
  25 void ReportDeadlock(ThreadState *thr, uptr pc, DDReport *r);
  26
  27 struct Callback : DDCallback {
  28   ThreadState *thr;
  29   uptr pc;
  30
  31   Callback(ThreadState *thr, uptr pc)
  32       : thr(thr)
  33       , pc(pc) {
  34     DDCallback::pt = thr->proc()->dd_pt;
  35     DDCallback::lt = thr->dd_lt;
  36   }
  37
  38   u32 Unwind() override { return CurrentStackId(thr, pc); }
  39   int UniqueTid() override { return thr->unique_id; }
  40 };
  41
  42 void DDMutexInit(ThreadState *thr, uptr pc, SyncVar *s) {
  43   Callback cb(thr, pc);
  44   ctx->dd->MutexInit(&cb, &s->dd);
  45   s->dd.ctx = s->GetId();
  46 }
  47
  48 static void ReportMutexMisuse(ThreadState *thr, uptr pc, ReportType typ,
  49     uptr addr, u64 mid) {
  50   // In Go, these misuses are either impossible, or detected by std lib,
  51   // or false positives (e.g. unlock in a different thread).
  52   if (SANITIZER_GO)
  53     return;
  54   ThreadRegistryLock l(ctx->thread_registry);
  55   ScopedReport rep(typ);
  56   rep.AddMutex(mid);
  57   VarSizeStackTrace trace;
  58   ObtainCurrentStack(thr, pc, &trace);
  59   rep.AddStack(trace, true);
  60   rep.AddLocation(addr, 1);
  61   OutputReport(thr, rep);
  62 }
  63
  64 void MutexCreate(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
  65   DPrintf("#%d: MutexCreate %zx flagz=0x%x\n", thr->tid, addr, flagz);
  66   StatInc(thr, StatMutexCreate);
  67   if (!(flagz & MutexFlagLinkerInit) && IsAppMem(addr)) {
  68     CHECK(!thr->is_freeing);
  69     thr->is_freeing = true;
  70     MemoryWrite(thr, pc, addr, kSizeLog1);
  71     thr->is_freeing = false;
  72   }
  73   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
  74   s->SetFlags(flagz & MutexCreationFlagMask);
  75   if (!SANITIZER_GO && s->creation_stack_id == 0)
  76     s->creation_stack_id = CurrentStackId(thr, pc);
  77   s->mtx.Unlock();
  78 }
  79
  80 void MutexDestroy(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
  81   DPrintf("#%d: MutexDestroy %zx\n", thr->tid, addr);
  82   StatInc(thr, StatMutexDestroy);
  83   SyncVar *s = ctx->metamap.GetIfExistsAndLock(addr, true);
  84   if (s == 0)
  85     return;
  86   if ((flagz & MutexFlagLinkerInit)
  87       || s->IsFlagSet(MutexFlagLinkerInit)
  88       || ((flagz & MutexFlagNotStatic) && !s->IsFlagSet(MutexFlagNotStatic))) {
  89     // Destroy is no-op for linker-initialized mutexes.
  90     s->mtx.Unlock();
  91     return;
  92   }
  93   if (common_flags()->detect_deadlocks) {
  94     Callback cb(thr, pc);
  95     ctx->dd->MutexDestroy(&cb, &s->dd);
  96     ctx->dd->MutexInit(&cb, &s->dd);
  97   }
  98   bool unlock_locked = false;
  99   if (flags()->report_destroy_locked
 100       && s->owner_tid != SyncVar::kInvalidTid
 101       && !s->IsFlagSet(MutexFlagBroken)) {
 102     s->SetFlags(MutexFlagBroken);
 103     unlock_locked = true;
 104   }
 105   u64 mid = s->GetId();
 106   u64 last_lock = s->last_lock;
 107   if (!unlock_locked)
 108     s->Reset(thr->proc());  // must not reset it before the report is printed
 109   s->mtx.Unlock();
 110   if (unlock_locked) {
 111     ThreadRegistryLock l(ctx->thread_registry);
 112     ScopedReport rep(ReportTypeMutexDestroyLocked);
 113     rep.AddMutex(mid);
 114     VarSizeStackTrace trace;
 115     ObtainCurrentStack(thr, pc, &trace);
 116     rep.AddStack(trace, true);
 117     FastState last(last_lock);
 118     RestoreStack(last.tid(), last.epoch(), &trace, 0);
 119     rep.AddStack(trace, true);
 120     rep.AddLocation(addr, 1);
 121     OutputReport(thr, rep);
 122
 123     SyncVar *s = ctx->metamap.GetIfExistsAndLock(addr, true);
 124     if (s != 0) {
 125       s->Reset(thr->proc());
 126       s->mtx.Unlock();
 127     }
 128   }
 129   thr->mset.Remove(mid);
 130   // Imitate a memory write to catch unlock-destroy races.
 131   // Do this outside of sync mutex, because it can report a race which locks
 132   // sync mutexes.
 133   if (IsAppMem(addr)) {
 134     CHECK(!thr->is_freeing);
 135     thr->is_freeing = true;
 136     MemoryWrite(thr, pc, addr, kSizeLog1);
 137     thr->is_freeing = false;
 138   }
 139   // s will be destroyed and freed in MetaMap::FreeBlock.
 140 }
 141
 142 void MutexPreLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
 143   DPrintf("#%d: MutexPreLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
 144   if (!(flagz & MutexFlagTryLock) && common_flags()->detect_deadlocks) {
 145     SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, false);
 146     s->UpdateFlags(flagz);
 147     if (s->owner_tid != thr->tid) {
 148       Callback cb(thr, pc);
 149       ctx->dd->MutexBeforeLock(&cb, &s->dd, true);
 150       s->mtx.ReadUnlock();
 151       ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
 152     } else {
 153       s->mtx.ReadUnlock();
 154     }
 155   }
 156 }
 157
 158 void MutexPostLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz, int rec) {
 159   DPrintf("#%d: MutexPostLock %zx flag=0x%x rec=%d\n",
 160       thr->tid, addr, flagz, rec);
 161   if (flagz & MutexFlagRecursiveLock)
 162     CHECK_GT(rec, 0);
 163   else
 164     rec = 1;
 165   if (IsAppMem(addr))
 166     MemoryReadAtomic(thr, pc, addr, kSizeLog1);
 167   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
 168   s->UpdateFlags(flagz);
 169   thr->fast_state.IncrementEpoch();
 170   TraceAddEvent(thr, thr->fast_state, EventTypeLock, s->GetId());
 171   bool report_double_lock = false;
 172   if (s->owner_tid == SyncVar::kInvalidTid) {
 173     CHECK_EQ(s->recursion, 0);
 174     s->owner_tid = thr->tid;
 175     s->last_lock = thr->fast_state.raw();
 176   } else if (s->owner_tid == thr->tid) {
 177     CHECK_GT(s->recursion, 0);
 178   } else if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
 179     s->SetFlags(MutexFlagBroken);
 180     report_double_lock = true;
 181   }
 182   const bool first = s->recursion == 0;
 183   s->recursion += rec;
 184   if (first) {
 185     StatInc(thr, StatMutexLock);
 186     AcquireImpl(thr, pc, &s->clock);
 187     AcquireImpl(thr, pc, &s->read_clock);
 188   } else if (!s->IsFlagSet(MutexFlagWriteReentrant)) {
 189     StatInc(thr, StatMutexRecLock);
 190   }
 191   thr->mset.Add(s->GetId(), true, thr->fast_state.epoch());
 192   bool pre_lock = false;
 193   if (first && common_flags()->detect_deadlocks) {
 194     pre_lock = (flagz & MutexFlagDoPreLockOnPostLock) &&
 195         !(flagz & MutexFlagTryLock);
 196     Callback cb(thr, pc);
 197     if (pre_lock)
 198       ctx->dd->MutexBeforeLock(&cb, &s->dd, true);
 199     ctx->dd->MutexAfterLock(&cb, &s->dd, true, flagz & MutexFlagTryLock);
 200   }
 201   u64 mid = s->GetId();
 202   s->mtx.Unlock();
 203   // Can't touch s after this point.
 204   s = 0;
 205   if (report_double_lock)
 206     ReportMutexMisuse(thr, pc, ReportTypeMutexDoubleLock, addr, mid);
 207   if (first && pre_lock && common_flags()->detect_deadlocks) {
 208     Callback cb(thr, pc);
 209     ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
 210   }
 211 }
 212
 213 int MutexUnlock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
 214   DPrintf("#%d: MutexUnlock %zx flagz=0x%x\n", thr->tid, addr, flagz);
 215   if (IsAppMem(addr))
 216     MemoryReadAtomic(thr, pc, addr, kSizeLog1);
 217   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
 218   thr->fast_state.IncrementEpoch();
 219   TraceAddEvent(thr, thr->fast_state, EventTypeUnlock, s->GetId());
 220   int rec = 0;
 221   bool report_bad_unlock = false;
 222   if (!SANITIZER_GO && (s->recursion == 0 || s->owner_tid != thr->tid)) {
 223     if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
 224       s->SetFlags(MutexFlagBroken);
 225       report_bad_unlock = true;
 226     }
 227   } else {
 228     rec = (flagz & MutexFlagRecursiveUnlock) ? s->recursion : 1;
 229     s->recursion -= rec;
 230     if (s->recursion == 0) {
 231       StatInc(thr, StatMutexUnlock);
 232       s->owner_tid = SyncVar::kInvalidTid;
 233       ReleaseStoreImpl(thr, pc, &s->clock);
 234     } else {
 235       StatInc(thr, StatMutexRecUnlock);
 236     }
 237   }
 238   thr->mset.Del(s->GetId(), true);
 239   if (common_flags()->detect_deadlocks && s->recursion == 0 &&
 240       !report_bad_unlock) {
 241     Callback cb(thr, pc);
 242     ctx->dd->MutexBeforeUnlock(&cb, &s->dd, true);
 243   }
 244   u64 mid = s->GetId();
 245   s->mtx.Unlock();
 246   // Can't touch s after this point.
 247   if (report_bad_unlock)
 248     ReportMutexMisuse(thr, pc, ReportTypeMutexBadUnlock, addr, mid);
 249   if (common_flags()->detect_deadlocks && !report_bad_unlock) {
 250     Callback cb(thr, pc);
 251     ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
 252   }
 253   return rec;
 254 }
 255
 256 void MutexPreReadLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
 257   DPrintf("#%d: MutexPreReadLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
 258   if (!(flagz & MutexFlagTryLock) && common_flags()->detect_deadlocks) {
 259     SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, false);
 260     s->UpdateFlags(flagz);
 261     Callback cb(thr, pc);
 262     ctx->dd->MutexBeforeLock(&cb, &s->dd, false);
 263     s->mtx.ReadUnlock();
 264     ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
 265   }
 266 }
 267
 268 void MutexPostReadLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
 269   DPrintf("#%d: MutexPostReadLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
 270   StatInc(thr, StatMutexReadLock);
 271   if (IsAppMem(addr))
 272     MemoryReadAtomic(thr, pc, addr, kSizeLog1);
 273   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, false);
 274   s->UpdateFlags(flagz);
 275   thr->fast_state.IncrementEpoch();
 276   TraceAddEvent(thr, thr->fast_state, EventTypeRLock, s->GetId());
 277   bool report_bad_lock = false;
 278   if (s->owner_tid != SyncVar::kInvalidTid) {
 279     if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
 280       s->SetFlags(MutexFlagBroken);
 281       report_bad_lock = true;
 282     }
 283   }
 284   AcquireImpl(thr, pc, &s->clock);
 285   s->last_lock = thr->fast_state.raw();
 286   thr->mset.Add(s->GetId(), false, thr->fast_state.epoch());
 287   bool pre_lock = false;
 288   if (common_flags()->detect_deadlocks) {
 289     pre_lock = (flagz & MutexFlagDoPreLockOnPostLock) &&
 290         !(flagz & MutexFlagTryLock);
 291     Callback cb(thr, pc);
 292     if (pre_lock)
 293       ctx->dd->MutexBeforeLock(&cb, &s->dd, false);
 294     ctx->dd->MutexAfterLock(&cb, &s->dd, false, flagz & MutexFlagTryLock);
 295   }
 296   u64 mid = s->GetId();
 297   s->mtx.ReadUnlock();
 298   // Can't touch s after this point.
 299   s = 0;
 300   if (report_bad_lock)
 301     ReportMutexMisuse(thr, pc, ReportTypeMutexBadReadLock, addr, mid);
 302   if (pre_lock  && common_flags()->detect_deadlocks) {
 303     Callback cb(thr, pc);
 304     ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
 305   }
 306 }
 307
 308 void MutexReadUnlock(ThreadState *thr, uptr pc, uptr addr) {
 309   DPrintf("#%d: MutexReadUnlock %zx\n", thr->tid, addr);
 310   StatInc(thr, StatMutexReadUnlock);
 311   if (IsAppMem(addr))
 312     MemoryReadAtomic(thr, pc, addr, kSizeLog1);
 313   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
 314   thr->fast_state.IncrementEpoch();
 315   TraceAddEvent(thr, thr->fast_state, EventTypeRUnlock, s->GetId());
 316   bool report_bad_unlock = false;
 317   if (s->owner_tid != SyncVar::kInvalidTid) {
 318     if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
 319       s->SetFlags(MutexFlagBroken);
 320       report_bad_unlock = true;
 321     }
 322   }
 323   ReleaseImpl(thr, pc, &s->read_clock);
 324   if (common_flags()->detect_deadlocks && s->recursion == 0) {
 325     Callback cb(thr, pc);
 326     ctx->dd->MutexBeforeUnlock(&cb, &s->dd, false);
 327   }
 328   u64 mid = s->GetId();
 329   s->mtx.Unlock();
 330   // Can't touch s after this point.
 331   thr->mset.Del(mid, false);
 332   if (report_bad_unlock)
 333     ReportMutexMisuse(thr, pc, ReportTypeMutexBadReadUnlock, addr, mid);
 334   if (common_flags()->detect_deadlocks) {
 335     Callback cb(thr, pc);
 336     ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
 337   }
 338 }
 339
 340 void MutexReadOrWriteUnlock(ThreadState *thr, uptr pc, uptr addr) {
 341   DPrintf("#%d: MutexReadOrWriteUnlock %zx\n", thr->tid, addr);
 342   if (IsAppMem(addr))
 343     MemoryReadAtomic(thr, pc, addr, kSizeLog1);
 344   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
 345   bool write = true;
 346   bool report_bad_unlock = false;
 347   if (s->owner_tid == SyncVar::kInvalidTid) {
 348     // Seems to be read unlock.
 349     write = false;
 350     StatInc(thr, StatMutexReadUnlock);
 351     thr->fast_state.IncrementEpoch();
 352     TraceAddEvent(thr, thr->fast_state, EventTypeRUnlock, s->GetId());
 353     ReleaseImpl(thr, pc, &s->read_clock);
 354   } else if (s->owner_tid == thr->tid) {
 355     // Seems to be write unlock.
 356     thr->fast_state.IncrementEpoch();
 357     TraceAddEvent(thr, thr->fast_state, EventTypeUnlock, s->GetId());
 358     CHECK_GT(s->recursion, 0);
 359     s->recursion--;
 360     if (s->recursion == 0) {
 361       StatInc(thr, StatMutexUnlock);
 362       s->owner_tid = SyncVar::kInvalidTid;
 363       ReleaseStoreImpl(thr, pc, &s->clock);
 364     } else {
 365       StatInc(thr, StatMutexRecUnlock);
 366     }
 367   } else if (!s->IsFlagSet(MutexFlagBroken)) {
 368     s->SetFlags(MutexFlagBroken);
 369     report_bad_unlock = true;
 370   }
 371   thr->mset.Del(s->GetId(), write);
 372   if (common_flags()->detect_deadlocks && s->recursion == 0) {
 373     Callback cb(thr, pc);
 374     ctx->dd->MutexBeforeUnlock(&cb, &s->dd, write);
 375   }
 376   u64 mid = s->GetId();
 377   s->mtx.Unlock();
 378   // Can't touch s after this point.
 379   if (report_bad_unlock)
 380     ReportMutexMisuse(thr, pc, ReportTypeMutexBadUnlock, addr, mid);
 381   if (common_flags()->detect_deadlocks) {
 382     Callback cb(thr, pc);
 383     ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
 384   }
 385 }
 386
 387 void MutexRepair(ThreadState *thr, uptr pc, uptr addr) {
 388   DPrintf("#%d: MutexRepair %zx\n", thr->tid, addr);
 389   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
 390   s->owner_tid = SyncVar::kInvalidTid;
 391   s->recursion = 0;
 392   s->mtx.Unlock();
 393 }
 394
 395 void MutexInvalidAccess(ThreadState *thr, uptr pc, uptr addr) {
 396   DPrintf("#%d: MutexInvalidAccess %zx\n", thr->tid, addr);
 397   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
 398   u64 mid = s->GetId();
 399   s->mtx.Unlock();
 400   ReportMutexMisuse(thr, pc, ReportTypeMutexInvalidAccess, addr, mid);
 401 }
 402
 403 void Acquire(ThreadState *thr, uptr pc, uptr addr) {
 404   DPrintf("#%d: Acquire %zx\n", thr->tid, addr);
 405   if (thr->ignore_sync)
 406     return;
 407   SyncVar *s = ctx->metamap.GetIfExistsAndLock(addr, false);
 408   if (!s)
 409     return;
 410   AcquireImpl(thr, pc, &s->clock);
 411   s->mtx.ReadUnlock();
 412 }
 413
 414 static void UpdateClockCallback(ThreadContextBase *tctx_base, void *arg) {
 415   ThreadState *thr = reinterpret_cast<ThreadState*>(arg);
 416   ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base);
 417   u64 epoch = tctx->epoch1;
 418   if (tctx->status == ThreadStatusRunning)
 419     epoch = tctx->thr->fast_state.epoch();
 420   thr->clock.set(&thr->proc()->clock_cache, tctx->tid, epoch);
 421 }
 422
 423 void AcquireGlobal(ThreadState *thr, uptr pc) {
 424   DPrintf("#%d: AcquireGlobal\n", thr->tid);
 425   if (thr->ignore_sync)
 426     return;
 427   ThreadRegistryLock l(ctx->thread_registry);
 428   ctx->thread_registry->RunCallbackForEachThreadLocked(
 429       UpdateClockCallback, thr);
 430 }
 431
 432 void Release(ThreadState *thr, uptr pc, uptr addr) {
 433   DPrintf("#%d: Release %zx\n", thr->tid, addr);
 434   if (thr->ignore_sync)
 435     return;
 436   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
 437   thr->fast_state.IncrementEpoch();
 438   // Can't increment epoch w/o writing to the trace as well.
 439   TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
 440   ReleaseImpl(thr, pc, &s->clock);
 441   s->mtx.Unlock();
 442 }
 443
 444 void ReleaseStore(ThreadState *thr, uptr pc, uptr addr) {
 445   DPrintf("#%d: ReleaseStore %zx\n", thr->tid, addr);
 446   if (thr->ignore_sync)
 447     return;
 448   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
 449   thr->fast_state.IncrementEpoch();
 450   // Can't increment epoch w/o writing to the trace as well.
 451   TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
 452   ReleaseStoreImpl(thr, pc, &s->clock);
 453   s->mtx.Unlock();
 454 }
 455
 456 #if !SANITIZER_GO
 457 static void UpdateSleepClockCallback(ThreadContextBase *tctx_base, void *arg) {
 458   ThreadState *thr = reinterpret_cast<ThreadState*>(arg);
 459   ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base);
 460   u64 epoch = tctx->epoch1;
 461   if (tctx->status == ThreadStatusRunning)
 462     epoch = tctx->thr->fast_state.epoch();
 463   thr->last_sleep_clock.set(&thr->proc()->clock_cache, tctx->tid, epoch);
 464 }
 465
 466 void AfterSleep(ThreadState *thr, uptr pc) {
 467   DPrintf("#%d: AfterSleep %zx\n", thr->tid);
 468   if (thr->ignore_sync)
 469     return;
 470   thr->last_sleep_stack_id = CurrentStackId(thr, pc);
 471   ThreadRegistryLock l(ctx->thread_registry);
 472   ctx->thread_registry->RunCallbackForEachThreadLocked(
 473       UpdateSleepClockCallback, thr);
 474 }
 475 #endif
 476
 477 void AcquireImpl(ThreadState *thr, uptr pc, SyncClock *c) {
 478   if (thr->ignore_sync)
 479     return;
 480   thr->clock.set(thr->fast_state.epoch());
 481   thr->clock.acquire(&thr->proc()->clock_cache, c);
 482   StatInc(thr, StatSyncAcquire);
 483 }
 484
 485 void ReleaseImpl(ThreadState *thr, uptr pc, SyncClock *c) {
 486   if (thr->ignore_sync)
 487     return;
 488   thr->clock.set(thr->fast_state.epoch());
 489   thr->fast_synch_epoch = thr->fast_state.epoch();
 490   thr->clock.release(&thr->proc()->clock_cache, c);
 491   StatInc(thr, StatSyncRelease);
 492 }
 493
 494 void ReleaseStoreImpl(ThreadState *thr, uptr pc, SyncClock *c) {
 495   if (thr->ignore_sync)
 496     return;
 497   thr->clock.set(thr->fast_state.epoch());
 498   thr->fast_synch_epoch = thr->fast_state.epoch();
 499   thr->clock.ReleaseStore(&thr->proc()->clock_cache, c);
 500   StatInc(thr, StatSyncRelease);
 501 }
 502
 503 void AcquireReleaseImpl(ThreadState *thr, uptr pc, SyncClock *c) {
 504   if (thr->ignore_sync)
 505     return;
 506   thr->clock.set(thr->fast_state.epoch());
 507   thr->fast_synch_epoch = thr->fast_state.epoch();
 508   thr->clock.acq_rel(&thr->proc()->clock_cache, c);
 509   StatInc(thr, StatSyncAcquire);
 510   StatInc(thr, StatSyncRelease);
 511 }
 512
 513 void ReportDeadlock(ThreadState *thr, uptr pc, DDReport *r) {
 514   if (r == 0)
 515     return;
 516   ThreadRegistryLock l(ctx->thread_registry);
 517   ScopedReport rep(ReportTypeDeadlock);
 518   for (int i = 0; i < r->n; i++) {
 519     rep.AddMutex(r->loop[i].mtx_ctx0);
 520     rep.AddUniqueTid((int)r->loop[i].thr_ctx);
 521     rep.AddThread((int)r->loop[i].thr_ctx);
 522   }
 523   uptr dummy_pc = 0x42;
 524   for (int i = 0; i < r->n; i++) {
 525     for (int j = 0; j < (flags()->second_deadlock_stack ? 2 : 1); j++) {
 526       u32 stk = r->loop[i].stk[j];
 527       if (stk && stk != 0xffffffff) {
 528         rep.AddStack(StackDepotGet(stk), true);
 529       } else {
 530         // Sometimes we fail to extract the stack trace (FIXME: investigate),
 531         // but we should still produce some stack trace in the report.
 532         rep.AddStack(StackTrace(&dummy_pc, 1), true);
 533       }
 534     }
 535   }
 536   OutputReport(thr, rep);
 537 }
 538
 539 }  // namespace __tsan