libsanitizer/tsan/tsan_rtl_report.cc

   1 //===-- tsan_rtl_report.cc ------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of ThreadSanitizer (TSan), a race detector.
   9 //
  10 //===----------------------------------------------------------------------===//
  11
  12 #include "sanitizer_common/sanitizer_libc.h"
  13 #include "sanitizer_common/sanitizer_placement_new.h"
  14 #include "sanitizer_common/sanitizer_stackdepot.h"
  15 #include "sanitizer_common/sanitizer_common.h"
  16 #include "sanitizer_common/sanitizer_stacktrace.h"
  17 #include "tsan_platform.h"
  18 #include "tsan_rtl.h"
  19 #include "tsan_suppressions.h"
  20 #include "tsan_symbolize.h"
  21 #include "tsan_report.h"
  22 #include "tsan_sync.h"
  23 #include "tsan_mman.h"
  24 #include "tsan_flags.h"
  25 #include "tsan_fd.h"
  26
  27 namespace __tsan {
  28
  29 using namespace __sanitizer;  // NOLINT
  30
  31 static ReportStack *SymbolizeStack(StackTrace trace);
  32
  33 void TsanCheckFailed(const char *file, int line, const char *cond,
  34                      u64 v1, u64 v2) {
  35   // There is high probability that interceptors will check-fail as well,
  36   // on the other hand there is no sense in processing interceptors
  37   // since we are going to die soon.
  38   ScopedIgnoreInterceptors ignore;
  39   Printf("FATAL: ThreadSanitizer CHECK failed: "
  40          "%s:%d \"%s\" (0x%zx, 0x%zx)\n",
  41          file, line, cond, (uptr)v1, (uptr)v2);
  42   PrintCurrentStackSlow(StackTrace::GetCurrentPc());
  43   Die();
  44 }
  45
  46 // Can be overriden by an application/test to intercept reports.
  47 #ifdef TSAN_EXTERNAL_HOOKS
  48 bool OnReport(const ReportDesc *rep, bool suppressed);
  49 #else
  50 SANITIZER_INTERFACE_ATTRIBUTE
  51 bool WEAK OnReport(const ReportDesc *rep, bool suppressed) {
  52   (void)rep;
  53   return suppressed;
  54 }
  55 #endif
  56
  57 static void StackStripMain(ReportStack *stack) {
  58   ReportStack *last_frame = 0;
  59   ReportStack *last_frame2 = 0;
  60   for (ReportStack *ent = stack; ent; ent = ent->next) {
  61     last_frame2 = last_frame;
  62     last_frame = ent;
  63   }
  64
  65   if (last_frame2 == 0)
  66     return;
  67   const char *last = last_frame->info.function;
  68 #ifndef TSAN_GO
  69   const char *last2 = last_frame2->info.function;
  70   // Strip frame above 'main'
  71   if (last2 && 0 == internal_strcmp(last2, "main")) {
  72     last_frame2->next = 0;
  73   // Strip our internal thread start routine.
  74   } else if (last && 0 == internal_strcmp(last, "__tsan_thread_start_func")) {
  75     last_frame2->next = 0;
  76   // Strip global ctors init.
  77   } else if (last && 0 == internal_strcmp(last, "__do_global_ctors_aux")) {
  78     last_frame2->next = 0;
  79   // If both are 0, then we probably just failed to symbolize.
  80   } else if (last || last2) {
  81     // Ensure that we recovered stack completely. Trimmed stack
  82     // can actually happen if we do not instrument some code,
  83     // so it's only a debug print. However we must try hard to not miss it
  84     // due to our fault.
  85     DPrintf("Bottom stack frame of stack %zx is missed\n", stack->pc);
  86   }
  87 #else
  88   // The last frame always point into runtime (gosched0, goexit0, runtime.main).
  89   last_frame2->next = 0;
  90   (void)last;
  91 #endif
  92 }
  93
  94 ReportStack *SymbolizeStackId(u32 stack_id) {
  95   if (stack_id == 0)
  96     return 0;
  97   StackTrace stack = StackDepotGet(stack_id);
  98   if (stack.trace == nullptr)
  99     return nullptr;
 100   return SymbolizeStack(stack);
 101 }
 102
 103 static ReportStack *SymbolizeStack(StackTrace trace) {
 104   if (trace.size == 0)
 105     return 0;
 106   ReportStack *stack = 0;
 107   for (uptr si = 0; si < trace.size; si++) {
 108     const uptr pc = trace.trace[si];
 109 #ifndef TSAN_GO
 110     // We obtain the return address, that is, address of the next instruction,
 111     // so offset it by 1 byte.
 112     const uptr pc1 = StackTrace::GetPreviousInstructionPc(pc);
 113 #else
 114     // FIXME(dvyukov): Go sometimes uses address of a function as top pc.
 115     uptr pc1 = pc;
 116     if (si != trace.size - 1)
 117       pc1 -= 1;
 118 #endif
 119     ReportStack *ent = SymbolizeCode(pc1);
 120     CHECK_NE(ent, 0);
 121     ReportStack *last = ent;
 122     while (last->next) {
 123       last->info.address = pc;  // restore original pc for report
 124       last = last->next;
 125     }
 126     last->info.address = pc;  // restore original pc for report
 127     last->next = stack;
 128     stack = ent;
 129   }
 130   StackStripMain(stack);
 131   return stack;
 132 }
 133
 134 ScopedReport::ScopedReport(ReportType typ) {
 135   ctx->thread_registry->CheckLocked();
 136   void *mem = internal_alloc(MBlockReport, sizeof(ReportDesc));
 137   rep_ = new(mem) ReportDesc;
 138   rep_->typ = typ;
 139   ctx->report_mtx.Lock();
 140   CommonSanitizerReportMutex.Lock();
 141 }
 142
 143 ScopedReport::~ScopedReport() {
 144   CommonSanitizerReportMutex.Unlock();
 145   ctx->report_mtx.Unlock();
 146   DestroyAndFree(rep_);
 147 }
 148
 149 void ScopedReport::AddStack(StackTrace stack, bool suppressable) {
 150   ReportStack **rs = rep_->stacks.PushBack();
 151   *rs = SymbolizeStack(stack);
 152   (*rs)->suppressable = suppressable;
 153 }
 154
 155 void ScopedReport::AddMemoryAccess(uptr addr, Shadow s, StackTrace stack,
 156                                    const MutexSet *mset) {
 157   void *mem = internal_alloc(MBlockReportMop, sizeof(ReportMop));
 158   ReportMop *mop = new(mem) ReportMop;
 159   rep_->mops.PushBack(mop);
 160   mop->tid = s.tid();
 161   mop->addr = addr + s.addr0();
 162   mop->size = s.size();
 163   mop->write = s.IsWrite();
 164   mop->atomic = s.IsAtomic();
 165   mop->stack = SymbolizeStack(stack);
 166   if (mop->stack)
 167     mop->stack->suppressable = true;
 168   for (uptr i = 0; i < mset->Size(); i++) {
 169     MutexSet::Desc d = mset->Get(i);
 170     u64 mid = this->AddMutex(d.id);
 171     ReportMopMutex mtx = {mid, d.write};
 172     mop->mset.PushBack(mtx);
 173   }
 174 }
 175
 176 void ScopedReport::AddUniqueTid(int unique_tid) {
 177   rep_->unique_tids.PushBack(unique_tid);
 178 }
 179
 180 void ScopedReport::AddThread(const ThreadContext *tctx, bool suppressable) {
 181   for (uptr i = 0; i < rep_->threads.Size(); i++) {
 182     if ((u32)rep_->threads[i]->id == tctx->tid)
 183       return;
 184   }
 185   void *mem = internal_alloc(MBlockReportThread, sizeof(ReportThread));
 186   ReportThread *rt = new(mem) ReportThread();
 187   rep_->threads.PushBack(rt);
 188   rt->id = tctx->tid;
 189   rt->pid = tctx->os_id;
 190   rt->running = (tctx->status == ThreadStatusRunning);
 191   rt->name = internal_strdup(tctx->name);
 192   rt->parent_tid = tctx->parent_tid;
 193   rt->stack = 0;
 194   rt->stack = SymbolizeStackId(tctx->creation_stack_id);
 195   if (rt->stack)
 196     rt->stack->suppressable = suppressable;
 197 }
 198
 199 #ifndef TSAN_GO
 200 static ThreadContext *FindThreadByUidLocked(int unique_id) {
 201   ctx->thread_registry->CheckLocked();
 202   for (unsigned i = 0; i < kMaxTid; i++) {
 203     ThreadContext *tctx = static_cast<ThreadContext*>(
 204         ctx->thread_registry->GetThreadLocked(i));
 205     if (tctx && tctx->unique_id == (u32)unique_id) {
 206       return tctx;
 207     }
 208   }
 209   return 0;
 210 }
 211
 212 static ThreadContext *FindThreadByTidLocked(int tid) {
 213   ctx->thread_registry->CheckLocked();
 214   return static_cast<ThreadContext*>(
 215       ctx->thread_registry->GetThreadLocked(tid));
 216 }
 217
 218 static bool IsInStackOrTls(ThreadContextBase *tctx_base, void *arg) {
 219   uptr addr = (uptr)arg;
 220   ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base);
 221   if (tctx->status != ThreadStatusRunning)
 222     return false;
 223   ThreadState *thr = tctx->thr;
 224   CHECK(thr);
 225   return ((addr >= thr->stk_addr && addr < thr->stk_addr + thr->stk_size) ||
 226           (addr >= thr->tls_addr && addr < thr->tls_addr + thr->tls_size));
 227 }
 228
 229 ThreadContext *IsThreadStackOrTls(uptr addr, bool *is_stack) {
 230   ctx->thread_registry->CheckLocked();
 231   ThreadContext *tctx = static_cast<ThreadContext*>(
 232       ctx->thread_registry->FindThreadContextLocked(IsInStackOrTls,
 233                                                     (void*)addr));
 234   if (!tctx)
 235     return 0;
 236   ThreadState *thr = tctx->thr;
 237   CHECK(thr);
 238   *is_stack = (addr >= thr->stk_addr && addr < thr->stk_addr + thr->stk_size);
 239   return tctx;
 240 }
 241 #endif
 242
 243 void ScopedReport::AddThread(int unique_tid, bool suppressable) {
 244 #ifndef TSAN_GO
 245   if (const ThreadContext *tctx = FindThreadByUidLocked(unique_tid))
 246     AddThread(tctx, suppressable);
 247 #endif
 248 }
 249
 250 void ScopedReport::AddMutex(const SyncVar *s) {
 251   for (uptr i = 0; i < rep_->mutexes.Size(); i++) {
 252     if (rep_->mutexes[i]->id == s->uid)
 253       return;
 254   }
 255   void *mem = internal_alloc(MBlockReportMutex, sizeof(ReportMutex));
 256   ReportMutex *rm = new(mem) ReportMutex();
 257   rep_->mutexes.PushBack(rm);
 258   rm->id = s->uid;
 259   rm->addr = s->addr;
 260   rm->destroyed = false;
 261   rm->stack = SymbolizeStackId(s->creation_stack_id);
 262 }
 263
 264 u64 ScopedReport::AddMutex(u64 id) {
 265   u64 uid = 0;
 266   u64 mid = id;
 267   uptr addr = SyncVar::SplitId(id, &uid);
 268   SyncVar *s = ctx->metamap.GetIfExistsAndLock(addr);
 269   // Check that the mutex is still alive.
 270   // Another mutex can be created at the same address,
 271   // so check uid as well.
 272   if (s && s->CheckId(uid)) {
 273     mid = s->uid;
 274     AddMutex(s);
 275   } else {
 276     AddDeadMutex(id);
 277   }
 278   if (s)
 279     s->mtx.Unlock();
 280   return mid;
 281 }
 282
 283 void ScopedReport::AddDeadMutex(u64 id) {
 284   for (uptr i = 0; i < rep_->mutexes.Size(); i++) {
 285     if (rep_->mutexes[i]->id == id)
 286       return;
 287   }
 288   void *mem = internal_alloc(MBlockReportMutex, sizeof(ReportMutex));
 289   ReportMutex *rm = new(mem) ReportMutex();
 290   rep_->mutexes.PushBack(rm);
 291   rm->id = id;
 292   rm->addr = 0;
 293   rm->destroyed = true;
 294   rm->stack = 0;
 295 }
 296
 297 void ScopedReport::AddLocation(uptr addr, uptr size) {
 298   if (addr == 0)
 299     return;
 300 #ifndef TSAN_GO
 301   int fd = -1;
 302   int creat_tid = -1;
 303   u32 creat_stack = 0;
 304   if (FdLocation(addr, &fd, &creat_tid, &creat_stack)) {
 305     ReportLocation *loc = ReportLocation::New(ReportLocationFD);
 306     loc->fd = fd;
 307     loc->tid = creat_tid;
 308     loc->stack = SymbolizeStackId(creat_stack);
 309     rep_->locs.PushBack(loc);
 310     ThreadContext *tctx = FindThreadByUidLocked(creat_tid);
 311     if (tctx)
 312       AddThread(tctx);
 313     return;
 314   }
 315   MBlock *b = 0;
 316   Allocator *a = allocator();
 317   if (a->PointerIsMine((void*)addr)) {
 318     void *block_begin = a->GetBlockBegin((void*)addr);
 319     if (block_begin)
 320       b = ctx->metamap.GetBlock((uptr)block_begin);
 321   }
 322   if (b != 0) {
 323     ThreadContext *tctx = FindThreadByTidLocked(b->tid);
 324     ReportLocation *loc = ReportLocation::New(ReportLocationHeap);
 325     loc->heap_chunk_start = (uptr)allocator()->GetBlockBegin((void *)addr);
 326     loc->heap_chunk_size = b->siz;
 327     loc->tid = tctx ? tctx->tid : b->tid;
 328     loc->stack = SymbolizeStackId(b->stk);
 329     rep_->locs.PushBack(loc);
 330     if (tctx)
 331       AddThread(tctx);
 332     return;
 333   }
 334   bool is_stack = false;
 335   if (ThreadContext *tctx = IsThreadStackOrTls(addr, &is_stack)) {
 336     ReportLocation *loc =
 337         ReportLocation::New(is_stack ? ReportLocationStack : ReportLocationTLS);
 338     loc->tid = tctx->tid;
 339     rep_->locs.PushBack(loc);
 340     AddThread(tctx);
 341   }
 342   if (ReportLocation *loc = SymbolizeData(addr)) {
 343     loc->suppressable = true;
 344     rep_->locs.PushBack(loc);
 345     return;
 346   }
 347 #endif
 348 }
 349
 350 #ifndef TSAN_GO
 351 void ScopedReport::AddSleep(u32 stack_id) {
 352   rep_->sleep = SymbolizeStackId(stack_id);
 353 }
 354 #endif
 355
 356 void ScopedReport::SetCount(int count) {
 357   rep_->count = count;
 358 }
 359
 360 const ReportDesc *ScopedReport::GetReport() const {
 361   return rep_;
 362 }
 363
 364 void RestoreStack(int tid, const u64 epoch, VarSizeStackTrace *stk,
 365                   MutexSet *mset) {
 366   // This function restores stack trace and mutex set for the thread/epoch.
 367   // It does so by getting stack trace and mutex set at the beginning of
 368   // trace part, and then replaying the trace till the given epoch.
 369   ctx->thread_registry->CheckLocked();
 370   ThreadContext *tctx = static_cast<ThreadContext*>(
 371       ctx->thread_registry->GetThreadLocked(tid));
 372   if (tctx == 0)
 373     return;
 374   if (tctx->status != ThreadStatusRunning
 375       && tctx->status != ThreadStatusFinished
 376       && tctx->status != ThreadStatusDead)
 377     return;
 378   Trace* trace = ThreadTrace(tctx->tid);
 379   Lock l(&trace->mtx);
 380   const int partidx = (epoch / kTracePartSize) % TraceParts();
 381   TraceHeader* hdr = &trace->headers[partidx];
 382   if (epoch < hdr->epoch0)
 383     return;
 384   const u64 epoch0 = RoundDown(epoch, TraceSize());
 385   const u64 eend = epoch % TraceSize();
 386   const u64 ebegin = RoundDown(eend, kTracePartSize);
 387   DPrintf("#%d: RestoreStack epoch=%zu ebegin=%zu eend=%zu partidx=%d\n",
 388           tid, (uptr)epoch, (uptr)ebegin, (uptr)eend, partidx);
 389   InternalScopedBuffer<uptr> stack(kShadowStackSize);
 390   for (uptr i = 0; i < hdr->stack0.size; i++) {
 391     stack[i] = hdr->stack0.trace[i];
 392     DPrintf2("  #%02lu: pc=%zx\n", i, stack[i]);
 393   }
 394   if (mset)
 395     *mset = hdr->mset0;
 396   uptr pos = hdr->stack0.size;
 397   Event *events = (Event*)GetThreadTrace(tid);
 398   for (uptr i = ebegin; i <= eend; i++) {
 399     Event ev = events[i];
 400     EventType typ = (EventType)(ev >> 61);
 401     uptr pc = (uptr)(ev & ((1ull << 61) - 1));
 402     DPrintf2("  %zu typ=%d pc=%zx\n", i, typ, pc);
 403     if (typ == EventTypeMop) {
 404       stack[pos] = pc;
 405     } else if (typ == EventTypeFuncEnter) {
 406       stack[pos++] = pc;
 407     } else if (typ == EventTypeFuncExit) {
 408       if (pos > 0)
 409         pos--;
 410     }
 411     if (mset) {
 412       if (typ == EventTypeLock) {
 413         mset->Add(pc, true, epoch0 + i);
 414       } else if (typ == EventTypeUnlock) {
 415         mset->Del(pc, true);
 416       } else if (typ == EventTypeRLock) {
 417         mset->Add(pc, false, epoch0 + i);
 418       } else if (typ == EventTypeRUnlock) {
 419         mset->Del(pc, false);
 420       }
 421     }
 422     for (uptr j = 0; j <= pos; j++)
 423       DPrintf2("      #%zu: %zx\n", j, stack[j]);
 424   }
 425   if (pos == 0 && stack[0] == 0)
 426     return;
 427   pos++;
 428   stk->Init(stack.data(), pos);
 429 }
 430
 431 static bool HandleRacyStacks(ThreadState *thr, VarSizeStackTrace traces[2],
 432                              uptr addr_min, uptr addr_max) {
 433   bool equal_stack = false;
 434   RacyStacks hash;
 435   if (flags()->suppress_equal_stacks) {
 436     hash.hash[0] = md5_hash(traces[0].trace, traces[0].size * sizeof(uptr));
 437     hash.hash[1] = md5_hash(traces[1].trace, traces[1].size * sizeof(uptr));
 438     for (uptr i = 0; i < ctx->racy_stacks.Size(); i++) {
 439       if (hash == ctx->racy_stacks[i]) {
 440         DPrintf("ThreadSanitizer: suppressing report as doubled (stack)\n");
 441         equal_stack = true;
 442         break;
 443       }
 444     }
 445   }
 446   bool equal_address = false;
 447   RacyAddress ra0 = {addr_min, addr_max};
 448   if (flags()->suppress_equal_addresses) {
 449     for (uptr i = 0; i < ctx->racy_addresses.Size(); i++) {
 450       RacyAddress ra2 = ctx->racy_addresses[i];
 451       uptr maxbeg = max(ra0.addr_min, ra2.addr_min);
 452       uptr minend = min(ra0.addr_max, ra2.addr_max);
 453       if (maxbeg < minend) {
 454         DPrintf("ThreadSanitizer: suppressing report as doubled (addr)\n");
 455         equal_address = true;
 456         break;
 457       }
 458     }
 459   }
 460   if (equal_stack || equal_address) {
 461     if (!equal_stack)
 462       ctx->racy_stacks.PushBack(hash);
 463     if (!equal_address)
 464       ctx->racy_addresses.PushBack(ra0);
 465     return true;
 466   }
 467   return false;
 468 }
 469
 470 static void AddRacyStacks(ThreadState *thr, VarSizeStackTrace traces[2],
 471                           uptr addr_min, uptr addr_max) {
 472   if (flags()->suppress_equal_stacks) {
 473     RacyStacks hash;
 474     hash.hash[0] = md5_hash(traces[0].trace, traces[0].size * sizeof(uptr));
 475     hash.hash[1] = md5_hash(traces[1].trace, traces[1].size * sizeof(uptr));
 476     ctx->racy_stacks.PushBack(hash);
 477   }
 478   if (flags()->suppress_equal_addresses) {
 479     RacyAddress ra0 = {addr_min, addr_max};
 480     ctx->racy_addresses.PushBack(ra0);
 481   }
 482 }
 483
 484 bool OutputReport(ThreadState *thr, const ScopedReport &srep) {
 485   atomic_store(&ctx->last_symbolize_time_ns, NanoTime(), memory_order_relaxed);
 486   const ReportDesc *rep = srep.GetReport();
 487   Suppression *supp = 0;
 488   uptr suppress_pc = 0;
 489   for (uptr i = 0; suppress_pc == 0 && i < rep->mops.Size(); i++)
 490     suppress_pc = IsSuppressed(rep->typ, rep->mops[i]->stack, &supp);
 491   for (uptr i = 0; suppress_pc == 0 && i < rep->stacks.Size(); i++)
 492     suppress_pc = IsSuppressed(rep->typ, rep->stacks[i], &supp);
 493   for (uptr i = 0; suppress_pc == 0 && i < rep->threads.Size(); i++)
 494     suppress_pc = IsSuppressed(rep->typ, rep->threads[i]->stack, &supp);
 495   for (uptr i = 0; suppress_pc == 0 && i < rep->locs.Size(); i++)
 496     suppress_pc = IsSuppressed(rep->typ, rep->locs[i], &supp);
 497   if (suppress_pc != 0) {
 498     FiredSuppression s = {srep.GetReport()->typ, suppress_pc, supp};
 499     ctx->fired_suppressions.push_back(s);
 500   }
 501   {
 502     bool old_is_freeing = thr->is_freeing;
 503     thr->is_freeing = false;
 504     bool suppressed = OnReport(rep, suppress_pc != 0);
 505     thr->is_freeing = old_is_freeing;
 506     if (suppressed)
 507       return false;
 508   }
 509   PrintReport(rep);
 510   ctx->nreported++;
 511   if (flags()->halt_on_error)
 512     internal__exit(flags()->exitcode);
 513   return true;
 514 }
 515
 516 bool IsFiredSuppression(Context *ctx, const ScopedReport &srep,
 517                         StackTrace trace) {
 518   for (uptr k = 0; k < ctx->fired_suppressions.size(); k++) {
 519     if (ctx->fired_suppressions[k].type != srep.GetReport()->typ)
 520       continue;
 521     for (uptr j = 0; j < trace.size; j++) {
 522       FiredSuppression *s = &ctx->fired_suppressions[k];
 523       if (trace.trace[j] == s->pc) {
 524         if (s->supp)
 525           s->supp->hit_count++;
 526         return true;
 527       }
 528     }
 529   }
 530   return false;
 531 }
 532
 533 static bool IsFiredSuppression(Context *ctx,
 534                                const ScopedReport &srep,
 535                                uptr addr) {
 536   for (uptr k = 0; k < ctx->fired_suppressions.size(); k++) {
 537     if (ctx->fired_suppressions[k].type != srep.GetReport()->typ)
 538       continue;
 539     FiredSuppression *s = &ctx->fired_suppressions[k];
 540     if (addr == s->pc) {
 541       if (s->supp)
 542         s->supp->hit_count++;
 543       return true;
 544     }
 545   }
 546   return false;
 547 }
 548
 549 bool FrameIsInternal(const ReportStack *frame) {
 550   if (frame == 0)
 551     return false;
 552   const char *file = frame->info.file;
 553   return file != 0 &&
 554          (internal_strstr(file, "tsan_interceptors.cc") ||
 555           internal_strstr(file, "sanitizer_common_interceptors.inc") ||
 556           internal_strstr(file, "tsan_interface_"));
 557 }
 558
 559 static bool RaceBetweenAtomicAndFree(ThreadState *thr) {
 560   Shadow s0(thr->racy_state[0]);
 561   Shadow s1(thr->racy_state[1]);
 562   CHECK(!(s0.IsAtomic() && s1.IsAtomic()));
 563   if (!s0.IsAtomic() && !s1.IsAtomic())
 564     return true;
 565   if (s0.IsAtomic() && s1.IsFreed())
 566     return true;
 567   if (s1.IsAtomic() && thr->is_freeing)
 568     return true;
 569   return false;
 570 }
 571
 572 void ReportRace(ThreadState *thr) {
 573   CheckNoLocks(thr);
 574
 575   // Symbolizer makes lots of intercepted calls. If we try to process them,
 576   // at best it will cause deadlocks on internal mutexes.
 577   ScopedIgnoreInterceptors ignore;
 578
 579   if (!flags()->report_bugs)
 580     return;
 581   if (!flags()->report_atomic_races && !RaceBetweenAtomicAndFree(thr))
 582     return;
 583
 584   bool freed = false;
 585   {
 586     Shadow s(thr->racy_state[1]);
 587     freed = s.GetFreedAndReset();
 588     thr->racy_state[1] = s.raw();
 589   }
 590
 591   uptr addr = ShadowToMem((uptr)thr->racy_shadow_addr);
 592   uptr addr_min = 0;
 593   uptr addr_max = 0;
 594   {
 595     uptr a0 = addr + Shadow(thr->racy_state[0]).addr0();
 596     uptr a1 = addr + Shadow(thr->racy_state[1]).addr0();
 597     uptr e0 = a0 + Shadow(thr->racy_state[0]).size();
 598     uptr e1 = a1 + Shadow(thr->racy_state[1]).size();
 599     addr_min = min(a0, a1);
 600     addr_max = max(e0, e1);
 601     if (IsExpectedReport(addr_min, addr_max - addr_min))
 602       return;
 603   }
 604
 605   ThreadRegistryLock l0(ctx->thread_registry);
 606
 607   ReportType typ = ReportTypeRace;
 608   if (thr->is_vptr_access && freed)
 609     typ = ReportTypeVptrUseAfterFree;
 610   else if (thr->is_vptr_access)
 611     typ = ReportTypeVptrRace;
 612   else if (freed)
 613     typ = ReportTypeUseAfterFree;
 614   ScopedReport rep(typ);
 615   if (IsFiredSuppression(ctx, rep, addr))
 616     return;
 617   const uptr kMop = 2;
 618   VarSizeStackTrace traces[kMop];
 619   const uptr toppc = TraceTopPC(thr);
 620   ObtainCurrentStack(thr, toppc, &traces[0]);
 621   if (IsFiredSuppression(ctx, rep, traces[0]))
 622     return;
 623   InternalScopedBuffer<MutexSet> mset2(1);
 624   new(mset2.data()) MutexSet();
 625   Shadow s2(thr->racy_state[1]);
 626   RestoreStack(s2.tid(), s2.epoch(), &traces[1], mset2.data());
 627   if (IsFiredSuppression(ctx, rep, traces[1]))
 628     return;
 629
 630   if (HandleRacyStacks(thr, traces, addr_min, addr_max))
 631     return;
 632
 633   for (uptr i = 0; i < kMop; i++) {
 634     Shadow s(thr->racy_state[i]);
 635     rep.AddMemoryAccess(addr, s, traces[i],
 636                         i == 0 ? &thr->mset : mset2.data());
 637   }
 638
 639   for (uptr i = 0; i < kMop; i++) {
 640     FastState s(thr->racy_state[i]);
 641     ThreadContext *tctx = static_cast<ThreadContext*>(
 642         ctx->thread_registry->GetThreadLocked(s.tid()));
 643     if (s.epoch() < tctx->epoch0 || s.epoch() > tctx->epoch1)
 644       continue;
 645     rep.AddThread(tctx);
 646   }
 647
 648   rep.AddLocation(addr_min, addr_max - addr_min);
 649
 650 #ifndef TSAN_GO
 651   {  // NOLINT
 652     Shadow s(thr->racy_state[1]);
 653     if (s.epoch() <= thr->last_sleep_clock.get(s.tid()))
 654       rep.AddSleep(thr->last_sleep_stack_id);
 655   }
 656 #endif
 657
 658   if (!OutputReport(thr, rep))
 659     return;
 660
 661   AddRacyStacks(thr, traces, addr_min, addr_max);
 662 }
 663
 664 void PrintCurrentStack(ThreadState *thr, uptr pc) {
 665   VarSizeStackTrace trace;
 666   ObtainCurrentStack(thr, pc, &trace);
 667   PrintStack(SymbolizeStack(trace));
 668 }
 669
 670 void PrintCurrentStackSlow(uptr pc) {
 671 #ifndef TSAN_GO
 672   BufferedStackTrace *ptrace =
 673       new(internal_alloc(MBlockStackTrace, sizeof(BufferedStackTrace)))
 674           BufferedStackTrace();
 675   ptrace->Unwind(kStackTraceMax, pc, 0, 0, 0, 0, false);
 676   for (uptr i = 0; i < ptrace->size / 2; i++) {
 677     uptr tmp = ptrace->trace_buffer[i];
 678     ptrace->trace_buffer[i] = ptrace->trace_buffer[ptrace->size - i - 1];
 679     ptrace->trace_buffer[ptrace->size - i - 1] = tmp;
 680   }
 681   PrintStack(SymbolizeStack(*ptrace));
 682 #endif
 683 }
 684
 685 }  // namespace __tsan
 686
 687 using namespace __tsan;
 688
 689 extern "C" {
 690 SANITIZER_INTERFACE_ATTRIBUTE
 691 void __sanitizer_print_stack_trace() {
 692   PrintCurrentStackSlow(StackTrace::GetCurrentPc());
 693 }
 694 }  // extern "C"