libsanitizer/tsan/tsan_interface_ann.cpp

   1 //===-- tsan_interface_ann.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 #include "sanitizer_common/sanitizer_libc.h"
  13 #include "sanitizer_common/sanitizer_internal_defs.h"
  14 #include "sanitizer_common/sanitizer_placement_new.h"
  15 #include "sanitizer_common/sanitizer_stacktrace.h"
  16 #include "sanitizer_common/sanitizer_vector.h"
  17 #include "tsan_interface_ann.h"
  18 #include "tsan_mutex.h"
  19 #include "tsan_report.h"
  20 #include "tsan_rtl.h"
  21 #include "tsan_mman.h"
  22 #include "tsan_flags.h"
  23 #include "tsan_platform.h"
  24
  25 #define CALLERPC ((uptr)__builtin_return_address(0))
  26
  27 using namespace __tsan;
  28
  29 namespace __tsan {
  30
  31 class ScopedAnnotation {
  32  public:
  33   ScopedAnnotation(ThreadState *thr, const char *aname, uptr pc)
  34       : thr_(thr) {
  35     FuncEntry(thr_, pc);
  36     DPrintf("#%d: annotation %s()\n", thr_->tid, aname);
  37   }
  38
  39   ~ScopedAnnotation() {
  40     FuncExit(thr_);
  41     CheckNoLocks(thr_);
  42   }
  43  private:
  44   ThreadState *const thr_;
  45 };
  46
  47 #define SCOPED_ANNOTATION_RET(typ, ret) \
  48     if (!flags()->enable_annotations) \
  49       return ret; \
  50     ThreadState *thr = cur_thread(); \
  51     const uptr caller_pc = (uptr)__builtin_return_address(0); \
  52     StatInc(thr, StatAnnotation); \
  53     StatInc(thr, Stat##typ); \
  54     ScopedAnnotation sa(thr, __func__, caller_pc); \
  55     const uptr pc = StackTrace::GetCurrentPc(); \
  56     (void)pc; \
  57 /**/
  58
  59 #define SCOPED_ANNOTATION(typ) SCOPED_ANNOTATION_RET(typ, )
  60
  61 static const int kMaxDescLen = 128;
  62
  63 struct ExpectRace {
  64   ExpectRace *next;
  65   ExpectRace *prev;
  66   atomic_uintptr_t hitcount;
  67   atomic_uintptr_t addcount;
  68   uptr addr;
  69   uptr size;
  70   char *file;
  71   int line;
  72   char desc[kMaxDescLen];
  73 };
  74
  75 struct DynamicAnnContext {
  76   Mutex mtx;
  77   ExpectRace expect;
  78   ExpectRace benign;
  79
  80   DynamicAnnContext()
  81     : mtx(MutexTypeAnnotations, StatMtxAnnotations) {
  82   }
  83 };
  84
  85 static DynamicAnnContext *dyn_ann_ctx;
  86 static char dyn_ann_ctx_placeholder[sizeof(DynamicAnnContext)] ALIGNED(64);
  87
  88 static void AddExpectRace(ExpectRace *list,
  89     char *f, int l, uptr addr, uptr size, char *desc) {
  90   ExpectRace *race = list->next;
  91   for (; race != list; race = race->next) {
  92     if (race->addr == addr && race->size == size) {
  93       atomic_store_relaxed(&race->addcount,
  94           atomic_load_relaxed(&race->addcount) + 1);
  95       return;
  96     }
  97   }
  98   race = (ExpectRace*)internal_alloc(MBlockExpectRace, sizeof(ExpectRace));
  99   race->addr = addr;
 100   race->size = size;
 101   race->file = f;
 102   race->line = l;
 103   race->desc[0] = 0;
 104   atomic_store_relaxed(&race->hitcount, 0);
 105   atomic_store_relaxed(&race->addcount, 1);
 106   if (desc) {
 107     int i = 0;
 108     for (; i < kMaxDescLen - 1 && desc[i]; i++)
 109       race->desc[i] = desc[i];
 110     race->desc[i] = 0;
 111   }
 112   race->prev = list;
 113   race->next = list->next;
 114   race->next->prev = race;
 115   list->next = race;
 116 }
 117
 118 static ExpectRace *FindRace(ExpectRace *list, uptr addr, uptr size) {
 119   for (ExpectRace *race = list->next; race != list; race = race->next) {
 120     uptr maxbegin = max(race->addr, addr);
 121     uptr minend = min(race->addr + race->size, addr + size);
 122     if (maxbegin < minend)
 123       return race;
 124   }
 125   return 0;
 126 }
 127
 128 static bool CheckContains(ExpectRace *list, uptr addr, uptr size) {
 129   ExpectRace *race = FindRace(list, addr, size);
 130   if (race == 0)
 131     return false;
 132   DPrintf("Hit expected/benign race: %s addr=%zx:%d %s:%d\n",
 133       race->desc, race->addr, (int)race->size, race->file, race->line);
 134   atomic_fetch_add(&race->hitcount, 1, memory_order_relaxed);
 135   return true;
 136 }
 137
 138 static void InitList(ExpectRace *list) {
 139   list->next = list;
 140   list->prev = list;
 141 }
 142
 143 void InitializeDynamicAnnotations() {
 144   dyn_ann_ctx = new(dyn_ann_ctx_placeholder) DynamicAnnContext;
 145   InitList(&dyn_ann_ctx->expect);
 146   InitList(&dyn_ann_ctx->benign);
 147 }
 148
 149 bool IsExpectedReport(uptr addr, uptr size) {
 150   ReadLock lock(&dyn_ann_ctx->mtx);
 151   if (CheckContains(&dyn_ann_ctx->expect, addr, size))
 152     return true;
 153   if (CheckContains(&dyn_ann_ctx->benign, addr, size))
 154     return true;
 155   return false;
 156 }
 157
 158 static void CollectMatchedBenignRaces(Vector<ExpectRace> *matched,
 159     int *unique_count, int *hit_count, atomic_uintptr_t ExpectRace::*counter) {
 160   ExpectRace *list = &dyn_ann_ctx->benign;
 161   for (ExpectRace *race = list->next; race != list; race = race->next) {
 162     (*unique_count)++;
 163     const uptr cnt = atomic_load_relaxed(&(race->*counter));
 164     if (cnt == 0)
 165       continue;
 166     *hit_count += cnt;
 167     uptr i = 0;
 168     for (; i < matched->Size(); i++) {
 169       ExpectRace *race0 = &(*matched)[i];
 170       if (race->line == race0->line
 171           && internal_strcmp(race->file, race0->file) == 0
 172           && internal_strcmp(race->desc, race0->desc) == 0) {
 173         atomic_fetch_add(&(race0->*counter), cnt, memory_order_relaxed);
 174         break;
 175       }
 176     }
 177     if (i == matched->Size())
 178       matched->PushBack(*race);
 179   }
 180 }
 181
 182 void PrintMatchedBenignRaces() {
 183   Lock lock(&dyn_ann_ctx->mtx);
 184   int unique_count = 0;
 185   int hit_count = 0;
 186   int add_count = 0;
 187   Vector<ExpectRace> hit_matched;
 188   CollectMatchedBenignRaces(&hit_matched, &unique_count, &hit_count,
 189       &ExpectRace::hitcount);
 190   Vector<ExpectRace> add_matched;
 191   CollectMatchedBenignRaces(&add_matched, &unique_count, &add_count,
 192       &ExpectRace::addcount);
 193   if (hit_matched.Size()) {
 194     Printf("ThreadSanitizer: Matched %d \"benign\" races (pid=%d):\n",
 195         hit_count, (int)internal_getpid());
 196     for (uptr i = 0; i < hit_matched.Size(); i++) {
 197       Printf("%d %s:%d %s\n",
 198           atomic_load_relaxed(&hit_matched[i].hitcount),
 199           hit_matched[i].file, hit_matched[i].line, hit_matched[i].desc);
 200     }
 201   }
 202   if (hit_matched.Size()) {
 203     Printf("ThreadSanitizer: Annotated %d \"benign\" races, %d unique"
 204            " (pid=%d):\n",
 205         add_count, unique_count, (int)internal_getpid());
 206     for (uptr i = 0; i < add_matched.Size(); i++) {
 207       Printf("%d %s:%d %s\n",
 208           atomic_load_relaxed(&add_matched[i].addcount),
 209           add_matched[i].file, add_matched[i].line, add_matched[i].desc);
 210     }
 211   }
 212 }
 213
 214 static void ReportMissedExpectedRace(ExpectRace *race) {
 215   Printf("==================\n");
 216   Printf("WARNING: ThreadSanitizer: missed expected data race\n");
 217   Printf("  %s addr=%zx %s:%d\n",
 218       race->desc, race->addr, race->file, race->line);
 219   Printf("==================\n");
 220 }
 221 }  // namespace __tsan
 222
 223 using namespace __tsan;
 224
 225 extern "C" {
 226 void INTERFACE_ATTRIBUTE AnnotateHappensBefore(char *f, int l, uptr addr) {
 227   SCOPED_ANNOTATION(AnnotateHappensBefore);
 228   Release(thr, pc, addr);
 229 }
 230
 231 void INTERFACE_ATTRIBUTE AnnotateHappensAfter(char *f, int l, uptr addr) {
 232   SCOPED_ANNOTATION(AnnotateHappensAfter);
 233   Acquire(thr, pc, addr);
 234 }
 235
 236 void INTERFACE_ATTRIBUTE AnnotateCondVarSignal(char *f, int l, uptr cv) {
 237   SCOPED_ANNOTATION(AnnotateCondVarSignal);
 238 }
 239
 240 void INTERFACE_ATTRIBUTE AnnotateCondVarSignalAll(char *f, int l, uptr cv) {
 241   SCOPED_ANNOTATION(AnnotateCondVarSignalAll);
 242 }
 243
 244 void INTERFACE_ATTRIBUTE AnnotateMutexIsNotPHB(char *f, int l, uptr mu) {
 245   SCOPED_ANNOTATION(AnnotateMutexIsNotPHB);
 246 }
 247
 248 void INTERFACE_ATTRIBUTE AnnotateCondVarWait(char *f, int l, uptr cv,
 249                                              uptr lock) {
 250   SCOPED_ANNOTATION(AnnotateCondVarWait);
 251 }
 252
 253 void INTERFACE_ATTRIBUTE AnnotateRWLockCreate(char *f, int l, uptr m) {
 254   SCOPED_ANNOTATION(AnnotateRWLockCreate);
 255   MutexCreate(thr, pc, m, MutexFlagWriteReentrant);
 256 }
 257
 258 void INTERFACE_ATTRIBUTE AnnotateRWLockCreateStatic(char *f, int l, uptr m) {
 259   SCOPED_ANNOTATION(AnnotateRWLockCreateStatic);
 260   MutexCreate(thr, pc, m, MutexFlagWriteReentrant | MutexFlagLinkerInit);
 261 }
 262
 263 void INTERFACE_ATTRIBUTE AnnotateRWLockDestroy(char *f, int l, uptr m) {
 264   SCOPED_ANNOTATION(AnnotateRWLockDestroy);
 265   MutexDestroy(thr, pc, m);
 266 }
 267
 268 void INTERFACE_ATTRIBUTE AnnotateRWLockAcquired(char *f, int l, uptr m,
 269                                                 uptr is_w) {
 270   SCOPED_ANNOTATION(AnnotateRWLockAcquired);
 271   if (is_w)
 272     MutexPostLock(thr, pc, m, MutexFlagDoPreLockOnPostLock);
 273   else
 274     MutexPostReadLock(thr, pc, m, MutexFlagDoPreLockOnPostLock);
 275 }
 276
 277 void INTERFACE_ATTRIBUTE AnnotateRWLockReleased(char *f, int l, uptr m,
 278                                                 uptr is_w) {
 279   SCOPED_ANNOTATION(AnnotateRWLockReleased);
 280   if (is_w)
 281     MutexUnlock(thr, pc, m);
 282   else
 283     MutexReadUnlock(thr, pc, m);
 284 }
 285
 286 void INTERFACE_ATTRIBUTE AnnotateTraceMemory(char *f, int l, uptr mem) {
 287   SCOPED_ANNOTATION(AnnotateTraceMemory);
 288 }
 289
 290 void INTERFACE_ATTRIBUTE AnnotateFlushState(char *f, int l) {
 291   SCOPED_ANNOTATION(AnnotateFlushState);
 292 }
 293
 294 void INTERFACE_ATTRIBUTE AnnotateNewMemory(char *f, int l, uptr mem,
 295                                            uptr size) {
 296   SCOPED_ANNOTATION(AnnotateNewMemory);
 297 }
 298
 299 void INTERFACE_ATTRIBUTE AnnotateNoOp(char *f, int l, uptr mem) {
 300   SCOPED_ANNOTATION(AnnotateNoOp);
 301 }
 302
 303 void INTERFACE_ATTRIBUTE AnnotateFlushExpectedRaces(char *f, int l) {
 304   SCOPED_ANNOTATION(AnnotateFlushExpectedRaces);
 305   Lock lock(&dyn_ann_ctx->mtx);
 306   while (dyn_ann_ctx->expect.next != &dyn_ann_ctx->expect) {
 307     ExpectRace *race = dyn_ann_ctx->expect.next;
 308     if (atomic_load_relaxed(&race->hitcount) == 0) {
 309       ctx->nmissed_expected++;
 310       ReportMissedExpectedRace(race);
 311     }
 312     race->prev->next = race->next;
 313     race->next->prev = race->prev;
 314     internal_free(race);
 315   }
 316 }
 317
 318 void INTERFACE_ATTRIBUTE AnnotateEnableRaceDetection(
 319     char *f, int l, int enable) {
 320   SCOPED_ANNOTATION(AnnotateEnableRaceDetection);
 321   // FIXME: Reconsider this functionality later. It may be irrelevant.
 322 }
 323
 324 void INTERFACE_ATTRIBUTE AnnotateMutexIsUsedAsCondVar(
 325     char *f, int l, uptr mu) {
 326   SCOPED_ANNOTATION(AnnotateMutexIsUsedAsCondVar);
 327 }
 328
 329 void INTERFACE_ATTRIBUTE AnnotatePCQGet(
 330     char *f, int l, uptr pcq) {
 331   SCOPED_ANNOTATION(AnnotatePCQGet);
 332 }
 333
 334 void INTERFACE_ATTRIBUTE AnnotatePCQPut(
 335     char *f, int l, uptr pcq) {
 336   SCOPED_ANNOTATION(AnnotatePCQPut);
 337 }
 338
 339 void INTERFACE_ATTRIBUTE AnnotatePCQDestroy(
 340     char *f, int l, uptr pcq) {
 341   SCOPED_ANNOTATION(AnnotatePCQDestroy);
 342 }
 343
 344 void INTERFACE_ATTRIBUTE AnnotatePCQCreate(
 345     char *f, int l, uptr pcq) {
 346   SCOPED_ANNOTATION(AnnotatePCQCreate);
 347 }
 348
 349 void INTERFACE_ATTRIBUTE AnnotateExpectRace(
 350     char *f, int l, uptr mem, char *desc) {
 351   SCOPED_ANNOTATION(AnnotateExpectRace);
 352   Lock lock(&dyn_ann_ctx->mtx);
 353   AddExpectRace(&dyn_ann_ctx->expect,
 354                 f, l, mem, 1, desc);
 355   DPrintf("Add expected race: %s addr=%zx %s:%d\n", desc, mem, f, l);
 356 }
 357
 358 static void BenignRaceImpl(
 359     char *f, int l, uptr mem, uptr size, char *desc) {
 360   Lock lock(&dyn_ann_ctx->mtx);
 361   AddExpectRace(&dyn_ann_ctx->benign,
 362                 f, l, mem, size, desc);
 363   DPrintf("Add benign race: %s addr=%zx %s:%d\n", desc, mem, f, l);
 364 }
 365
 366 // FIXME: Turn it off later. WTF is benign race?1?? Go talk to Hans Boehm.
 367 void INTERFACE_ATTRIBUTE AnnotateBenignRaceSized(
 368     char *f, int l, uptr mem, uptr size, char *desc) {
 369   SCOPED_ANNOTATION(AnnotateBenignRaceSized);
 370   BenignRaceImpl(f, l, mem, size, desc);
 371 }
 372
 373 void INTERFACE_ATTRIBUTE AnnotateBenignRace(
 374     char *f, int l, uptr mem, char *desc) {
 375   SCOPED_ANNOTATION(AnnotateBenignRace);
 376   BenignRaceImpl(f, l, mem, 1, desc);
 377 }
 378
 379 void INTERFACE_ATTRIBUTE AnnotateIgnoreReadsBegin(char *f, int l) {
 380   SCOPED_ANNOTATION(AnnotateIgnoreReadsBegin);
 381   ThreadIgnoreBegin(thr, pc);
 382 }
 383
 384 void INTERFACE_ATTRIBUTE AnnotateIgnoreReadsEnd(char *f, int l) {
 385   SCOPED_ANNOTATION(AnnotateIgnoreReadsEnd);
 386   ThreadIgnoreEnd(thr, pc);
 387 }
 388
 389 void INTERFACE_ATTRIBUTE AnnotateIgnoreWritesBegin(char *f, int l) {
 390   SCOPED_ANNOTATION(AnnotateIgnoreWritesBegin);
 391   ThreadIgnoreBegin(thr, pc);
 392 }
 393
 394 void INTERFACE_ATTRIBUTE AnnotateIgnoreWritesEnd(char *f, int l) {
 395   SCOPED_ANNOTATION(AnnotateIgnoreWritesEnd);
 396   ThreadIgnoreEnd(thr, pc);
 397 }
 398
 399 void INTERFACE_ATTRIBUTE AnnotateIgnoreSyncBegin(char *f, int l) {
 400   SCOPED_ANNOTATION(AnnotateIgnoreSyncBegin);
 401   ThreadIgnoreSyncBegin(thr, pc);
 402 }
 403
 404 void INTERFACE_ATTRIBUTE AnnotateIgnoreSyncEnd(char *f, int l) {
 405   SCOPED_ANNOTATION(AnnotateIgnoreSyncEnd);
 406   ThreadIgnoreSyncEnd(thr, pc);
 407 }
 408
 409 void INTERFACE_ATTRIBUTE AnnotatePublishMemoryRange(
 410     char *f, int l, uptr addr, uptr size) {
 411   SCOPED_ANNOTATION(AnnotatePublishMemoryRange);
 412 }
 413
 414 void INTERFACE_ATTRIBUTE AnnotateUnpublishMemoryRange(
 415     char *f, int l, uptr addr, uptr size) {
 416   SCOPED_ANNOTATION(AnnotateUnpublishMemoryRange);
 417 }
 418
 419 void INTERFACE_ATTRIBUTE AnnotateThreadName(
 420     char *f, int l, char *name) {
 421   SCOPED_ANNOTATION(AnnotateThreadName);
 422   ThreadSetName(thr, name);
 423 }
 424
 425 // We deliberately omit the implementation of WTFAnnotateHappensBefore() and
 426 // WTFAnnotateHappensAfter(). Those are being used by Webkit to annotate
 427 // atomic operations, which should be handled by ThreadSanitizer correctly.
 428 void INTERFACE_ATTRIBUTE WTFAnnotateHappensBefore(char *f, int l, uptr addr) {
 429   SCOPED_ANNOTATION(AnnotateHappensBefore);
 430 }
 431
 432 void INTERFACE_ATTRIBUTE WTFAnnotateHappensAfter(char *f, int l, uptr addr) {
 433   SCOPED_ANNOTATION(AnnotateHappensAfter);
 434 }
 435
 436 void INTERFACE_ATTRIBUTE WTFAnnotateBenignRaceSized(
 437     char *f, int l, uptr mem, uptr sz, char *desc) {
 438   SCOPED_ANNOTATION(AnnotateBenignRaceSized);
 439   BenignRaceImpl(f, l, mem, sz, desc);
 440 }
 441
 442 int INTERFACE_ATTRIBUTE RunningOnValgrind() {
 443   return flags()->running_on_valgrind;
 444 }
 445
 446 double __attribute__((weak)) INTERFACE_ATTRIBUTE ValgrindSlowdown(void) {
 447   return 10.0;
 448 }
 449
 450 const char INTERFACE_ATTRIBUTE* ThreadSanitizerQuery(const char *query) {
 451   if (internal_strcmp(query, "pure_happens_before") == 0)
 452     return "1";
 453   else
 454     return "0";
 455 }
 456
 457 void INTERFACE_ATTRIBUTE
 458 AnnotateMemoryIsInitialized(char *f, int l, uptr mem, uptr sz) {}
 459 void INTERFACE_ATTRIBUTE
 460 AnnotateMemoryIsUninitialized(char *f, int l, uptr mem, uptr sz) {}
 461
 462 // Note: the parameter is called flagz, because flags is already taken
 463 // by the global function that returns flags.
 464 INTERFACE_ATTRIBUTE
 465 void __tsan_mutex_create(void *m, unsigned flagz) {
 466   SCOPED_ANNOTATION(__tsan_mutex_create);
 467   MutexCreate(thr, pc, (uptr)m, flagz & MutexCreationFlagMask);
 468 }
 469
 470 INTERFACE_ATTRIBUTE
 471 void __tsan_mutex_destroy(void *m, unsigned flagz) {
 472   SCOPED_ANNOTATION(__tsan_mutex_destroy);
 473   MutexDestroy(thr, pc, (uptr)m, flagz);
 474 }
 475
 476 INTERFACE_ATTRIBUTE
 477 void __tsan_mutex_pre_lock(void *m, unsigned flagz) {
 478   SCOPED_ANNOTATION(__tsan_mutex_pre_lock);
 479   if (!(flagz & MutexFlagTryLock)) {
 480     if (flagz & MutexFlagReadLock)
 481       MutexPreReadLock(thr, pc, (uptr)m);
 482     else
 483       MutexPreLock(thr, pc, (uptr)m);
 484   }
 485   ThreadIgnoreBegin(thr, pc, /*save_stack=*/false);
 486   ThreadIgnoreSyncBegin(thr, pc, /*save_stack=*/false);
 487 }
 488
 489 INTERFACE_ATTRIBUTE
 490 void __tsan_mutex_post_lock(void *m, unsigned flagz, int rec) {
 491   SCOPED_ANNOTATION(__tsan_mutex_post_lock);
 492   ThreadIgnoreSyncEnd(thr, pc);
 493   ThreadIgnoreEnd(thr, pc);
 494   if (!(flagz & MutexFlagTryLockFailed)) {
 495     if (flagz & MutexFlagReadLock)
 496       MutexPostReadLock(thr, pc, (uptr)m, flagz);
 497     else
 498       MutexPostLock(thr, pc, (uptr)m, flagz, rec);
 499   }
 500 }
 501
 502 INTERFACE_ATTRIBUTE
 503 int __tsan_mutex_pre_unlock(void *m, unsigned flagz) {
 504   SCOPED_ANNOTATION_RET(__tsan_mutex_pre_unlock, 0);
 505   int ret = 0;
 506   if (flagz & MutexFlagReadLock) {
 507     CHECK(!(flagz & MutexFlagRecursiveUnlock));
 508     MutexReadUnlock(thr, pc, (uptr)m);
 509   } else {
 510     ret = MutexUnlock(thr, pc, (uptr)m, flagz);
 511   }
 512   ThreadIgnoreBegin(thr, pc, /*save_stack=*/false);
 513   ThreadIgnoreSyncBegin(thr, pc, /*save_stack=*/false);
 514   return ret;
 515 }
 516
 517 INTERFACE_ATTRIBUTE
 518 void __tsan_mutex_post_unlock(void *m, unsigned flagz) {
 519   SCOPED_ANNOTATION(__tsan_mutex_post_unlock);
 520   ThreadIgnoreSyncEnd(thr, pc);
 521   ThreadIgnoreEnd(thr, pc);
 522 }
 523
 524 INTERFACE_ATTRIBUTE
 525 void __tsan_mutex_pre_signal(void *addr, unsigned flagz) {
 526   SCOPED_ANNOTATION(__tsan_mutex_pre_signal);
 527   ThreadIgnoreBegin(thr, pc, /*save_stack=*/false);
 528   ThreadIgnoreSyncBegin(thr, pc, /*save_stack=*/false);
 529 }
 530
 531 INTERFACE_ATTRIBUTE
 532 void __tsan_mutex_post_signal(void *addr, unsigned flagz) {
 533   SCOPED_ANNOTATION(__tsan_mutex_post_signal);
 534   ThreadIgnoreSyncEnd(thr, pc);
 535   ThreadIgnoreEnd(thr, pc);
 536 }
 537
 538 INTERFACE_ATTRIBUTE
 539 void __tsan_mutex_pre_divert(void *addr, unsigned flagz) {
 540   SCOPED_ANNOTATION(__tsan_mutex_pre_divert);
 541   // Exit from ignore region started in __tsan_mutex_pre_lock/unlock/signal.
 542   ThreadIgnoreSyncEnd(thr, pc);
 543   ThreadIgnoreEnd(thr, pc);
 544 }
 545
 546 INTERFACE_ATTRIBUTE
 547 void __tsan_mutex_post_divert(void *addr, unsigned flagz) {
 548   SCOPED_ANNOTATION(__tsan_mutex_post_divert);
 549   ThreadIgnoreBegin(thr, pc, /*save_stack=*/false);
 550   ThreadIgnoreSyncBegin(thr, pc, /*save_stack=*/false);
 551 }
 552 }  // extern "C"