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(SymbolizedStack *frames) {
  58   SymbolizedStack *last_frame = nullptr;
  59   SymbolizedStack *last_frame2 = nullptr;
  60   for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
  61     last_frame2 = last_frame;
  62     last_frame = cur;
  63   }
  64
  65   if (last_frame2 == 0)
  66     return;
  67 #ifndef SANITIZER_GO
  68   const char *last = last_frame->info.function;
  69   const char *last2 = last_frame2->info.function;
  70   // Strip frame above 'main'
  71   if (last2 && 0 == internal_strcmp(last2, "main")) {
  72     last_frame->ClearAll();
  73     last_frame2->next = nullptr;
  74   // Strip our internal thread start routine.
  75   } else if (last && 0 == internal_strcmp(last, "__tsan_thread_start_func")) {
  76     last_frame->ClearAll();
  77     last_frame2->next = nullptr;
  78   // Strip global ctors init.
  79   } else if (last && 0 == internal_strcmp(last, "__do_global_ctors_aux")) {
  80     last_frame->ClearAll();
  81     last_frame2->next = nullptr;
  82   // If both are 0, then we probably just failed to symbolize.
  83   } else if (last || last2) {
  84     // Ensure that we recovered stack completely. Trimmed stack
  85     // can actually happen if we do not instrument some code,
  86     // so it's only a debug print. However we must try hard to not miss it
  87     // due to our fault.
  88     DPrintf("Bottom stack frame is missed\n");
  89   }
  90 #else
  91   // The last frame always point into runtime (gosched0, goexit0, runtime.main).
  92   last_frame->ClearAll();
  93   last_frame2->next = nullptr;
  94 #endif
  95 }
  96
  97 ReportStack *SymbolizeStackId(u32 stack_id) {
  98   if (stack_id == 0)
  99     return 0;
 100   StackTrace stack = StackDepotGet(stack_id);
 101   if (stack.trace == nullptr)
 102     return nullptr;
 103   return SymbolizeStack(stack);
 104 }
 105
 106 static ReportStack *SymbolizeStack(StackTrace trace) {
 107   if (trace.size == 0)
 108     return 0;
 109   SymbolizedStack *top = nullptr;
 110   for (uptr si = 0; si < trace.size; si++) {
 111     const uptr pc = trace.trace[si];
 112     uptr pc1 = pc;
 113     // We obtain the return address, but we're interested in the previous
 114     // instruction.
 115     if ((pc & kExternalPCBit) == 0)
 116       pc1 = StackTrace::GetPreviousInstructionPc(pc);
 117     SymbolizedStack *ent = SymbolizeCode(pc1);
 118     CHECK_NE(ent, 0);
 119     SymbolizedStack *last = ent;
 120     while (last->next) {
 121       last->info.address = pc;  // restore original pc for report
 122       last = last->next;
 123     }
 124     last->info.address = pc;  // restore original pc for report
 125     last->next = top;
 126     top = ent;
 127   }
 128   StackStripMain(top);
 129
 130   ReportStack *stack = ReportStack::New();
 131   stack->frames = top;
 132   return stack;
 133 }
 134
 135 ScopedReport::ScopedReport(ReportType typ) {
 136   ctx->thread_registry->CheckLocked();
 137   void *mem = internal_alloc(MBlockReport, sizeof(ReportDesc));
 138   rep_ = new(mem) ReportDesc;
 139   rep_->typ = typ;
 140   ctx->report_mtx.Lock();
 141   CommonSanitizerReportMutex.Lock();
 142 }
 143
 144 ScopedReport::~ScopedReport() {
 145   CommonSanitizerReportMutex.Unlock();
 146   ctx->report_mtx.Unlock();
 147   DestroyAndFree(rep_);
 148 }
 149
 150 void ScopedReport::AddStack(StackTrace stack, bool suppressable) {
 151   ReportStack **rs = rep_->stacks.PushBack();
 152   *rs = SymbolizeStack(stack);
 153   (*rs)->suppressable = suppressable;
 154 }
 155
 156 void ScopedReport::AddMemoryAccess(uptr addr, Shadow s, StackTrace stack,
 157                                    const MutexSet *mset) {
 158   void *mem = internal_alloc(MBlockReportMop, sizeof(ReportMop));
 159   ReportMop *mop = new(mem) ReportMop;
 160   rep_->mops.PushBack(mop);
 161   mop->tid = s.tid();
 162   mop->addr = addr + s.addr0();
 163   mop->size = s.size();
 164   mop->write = s.IsWrite();
 165   mop->atomic = s.IsAtomic();
 166   mop->stack = SymbolizeStack(stack);
 167   if (mop->stack)
 168     mop->stack->suppressable = true;
 169   for (uptr i = 0; i < mset->Size(); i++) {
 170     MutexSet::Desc d = mset->Get(i);
 171     u64 mid = this->AddMutex(d.id);
 172     ReportMopMutex mtx = {mid, d.write};
 173     mop->mset.PushBack(mtx);
 174   }
 175 }
 176
 177 void ScopedReport::AddUniqueTid(int unique_tid) {
 178   rep_->unique_tids.PushBack(unique_tid);
 179 }
 180
 181 void ScopedReport::AddThread(const ThreadContext *tctx, bool suppressable) {
 182   for (uptr i = 0; i < rep_->threads.Size(); i++) {
 183     if ((u32)rep_->threads[i]->id == tctx->tid)
 184       return;
 185   }
 186   void *mem = internal_alloc(MBlockReportThread, sizeof(ReportThread));
 187   ReportThread *rt = new(mem) ReportThread();
 188   rep_->threads.PushBack(rt);
 189   rt->id = tctx->tid;
 190   rt->pid = tctx->os_id;
 191   rt->running = (tctx->status == ThreadStatusRunning);
 192   rt->name = internal_strdup(tctx->name);
 193   rt->parent_tid = tctx->parent_tid;
 194   rt->stack = 0;
 195   rt->stack = SymbolizeStackId(tctx->creation_stack_id);
 196   if (rt->stack)
 197     rt->stack->suppressable = suppressable;
 198 }
 199
 200 #ifndef SANITIZER_GO
 201 static ThreadContext *FindThreadByUidLocked(int unique_id) {
 202   ctx->thread_registry->CheckLocked();
 203   for (unsigned i = 0; i < kMaxTid; i++) {
 204     ThreadContext *tctx = static_cast<ThreadContext*>(
 205         ctx->thread_registry->GetThreadLocked(i));
 206     if (tctx && tctx->unique_id == (u32)unique_id) {
 207       return tctx;
 208     }
 209   }
 210   return 0;
 211 }
 212
 213 static ThreadContext *FindThreadByTidLocked(int tid) {
 214   ctx->thread_registry->CheckLocked();
 215   return static_cast<ThreadContext*>(
 216       ctx->thread_registry->GetThreadLocked(tid));
 217 }
 218
 219 static bool IsInStackOrTls(ThreadContextBase *tctx_base, void *arg) {
 220   uptr addr = (uptr)arg;
 221   ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base);
 222   if (tctx->status != ThreadStatusRunning)
 223     return false;
 224   ThreadState *thr = tctx->thr;
 225   CHECK(thr);
 226   return ((addr >= thr->stk_addr && addr < thr->stk_addr + thr->stk_size) ||
 227           (addr >= thr->tls_addr && addr < thr->tls_addr + thr->tls_size));
 228 }
 229
 230 ThreadContext *IsThreadStackOrTls(uptr addr, bool *is_stack) {
 231   ctx->thread_registry->CheckLocked();
 232   ThreadContext *tctx = static_cast<ThreadContext*>(
 233       ctx->thread_registry->FindThreadContextLocked(IsInStackOrTls,
 234                                                     (void*)addr));
 235   if (!tctx)
 236     return 0;
 237   ThreadState *thr = tctx->thr;
 238   CHECK(thr);
 239   *is_stack = (addr >= thr->stk_addr && addr < thr->stk_addr + thr->stk_size);
 240   return tctx;
 241 }
 242 #endif
 243
 244 void ScopedReport::AddThread(int unique_tid, bool suppressable) {
 245 #ifndef SANITIZER_GO
 246   if (const ThreadContext *tctx = FindThreadByUidLocked(unique_tid))
 247     AddThread(tctx, suppressable);
 248 #endif
 249 }
 250
 251 void ScopedReport::AddMutex(const SyncVar *s) {
 252   for (uptr i = 0; i < rep_->mutexes.Size(); i++) {
 253     if (rep_->mutexes[i]->id == s->uid)
 254       return;
 255   }
 256   void *mem = internal_alloc(MBlockReportMutex, sizeof(ReportMutex));
 257   ReportMutex *rm = new(mem) ReportMutex();
 258   rep_->mutexes.PushBack(rm);
 259   rm->id = s->uid;
 260   rm->addr = s->addr;
 261   rm->destroyed = false;
 262   rm->stack = SymbolizeStackId(s->creation_stack_id);
 263 }
 264
 265 u64 ScopedReport::AddMutex(u64 id) {
 266   u64 uid = 0;
 267   u64 mid = id;
 268   uptr addr = SyncVar::SplitId(id, &uid);
 269   SyncVar *s = ctx->metamap.GetIfExistsAndLock(addr);
 270   // Check that the mutex is still alive.
 271   // Another mutex can be created at the same address,
 272   // so check uid as well.
 273   if (s && s->CheckId(uid)) {
 274     mid = s->uid;
 275     AddMutex(s);
 276   } else {
 277     AddDeadMutex(id);
 278   }
 279   if (s)
 280     s->mtx.Unlock();
 281   return mid;
 282 }
 283
 284 void ScopedReport::AddDeadMutex(u64 id) {
 285   for (uptr i = 0; i < rep_->mutexes.Size(); i++) {
 286     if (rep_->mutexes[i]->id == id)
 287       return;
 288   }
 289   void *mem = internal_alloc(MBlockReportMutex, sizeof(ReportMutex));
 290   ReportMutex *rm = new(mem) ReportMutex();
 291   rep_->mutexes.PushBack(rm);
 292   rm->id = id;
 293   rm->addr = 0;
 294   rm->destroyed = true;
 295   rm->stack = 0;
 296 }
 297
 298 void ScopedReport::AddLocation(uptr addr, uptr size) {
 299   if (addr == 0)
 300     return;
 301 #ifndef SANITIZER_GO
 302   int fd = -1;
 303   int creat_tid = -1;
 304   u32 creat_stack = 0;
 305   if (FdLocation(addr, &fd, &creat_tid, &creat_stack)) {
 306     ReportLocation *loc = ReportLocation::New(ReportLocationFD);
 307     loc->fd = fd;
 308     loc->tid = creat_tid;
 309     loc->stack = SymbolizeStackId(creat_stack);
 310     rep_->locs.PushBack(loc);
 311     ThreadContext *tctx = FindThreadByUidLocked(creat_tid);
 312     if (tctx)
 313       AddThread(tctx);
 314     return;
 315   }
 316   MBlock *b = 0;
 317   Allocator *a = allocator();
 318   if (a->PointerIsMine((void*)addr)) {
 319     void *block_begin = a->GetBlockBegin((void*)addr);
 320     if (block_begin)
 321       b = ctx->metamap.GetBlock((uptr)block_begin);
 322   }
 323   if (b != 0) {
 324     ThreadContext *tctx = FindThreadByTidLocked(b->tid);
 325     ReportLocation *loc = ReportLocation::New(ReportLocationHeap);
 326     loc->heap_chunk_start = (uptr)allocator()->GetBlockBegin((void *)addr);
 327     loc->heap_chunk_size = b->siz;
 328     loc->tid = tctx ? tctx->tid : b->tid;
 329     loc->stack = SymbolizeStackId(b->stk);
 330     rep_->locs.PushBack(loc);
 331     if (tctx)
 332       AddThread(tctx);
 333     return;
 334   }
 335   bool is_stack = false;
 336   if (ThreadContext *tctx = IsThreadStackOrTls(addr, &is_stack)) {
 337     ReportLocation *loc =
 338         ReportLocation::New(is_stack ? ReportLocationStack : ReportLocationTLS);
 339     loc->tid = tctx->tid;
 340     rep_->locs.PushBack(loc);
 341     AddThread(tctx);
 342   }
 343   if (ReportLocation *loc = SymbolizeData(addr)) {
 344     loc->suppressable = true;
 345     rep_->locs.PushBack(loc);
 346     return;
 347   }
 348 #endif
 349 }
 350
 351 #ifndef SANITIZER_GO
 352 void ScopedReport::AddSleep(u32 stack_id) {
 353   rep_->sleep = SymbolizeStackId(stack_id);
 354 }
 355 #endif
 356
 357 void ScopedReport::SetCount(int count) {
 358   rep_->count = count;
 359 }
 360
 361 const ReportDesc *ScopedReport::GetReport() const {
 362   return rep_;
 363 }
 364
 365 void RestoreStack(int tid, const u64 epoch, VarSizeStackTrace *stk,
 366                   MutexSet *mset) {
 367   // This function restores stack trace and mutex set for the thread/epoch.
 368   // It does so by getting stack trace and mutex set at the beginning of
 369   // trace part, and then replaying the trace till the given epoch.
 370   Trace* trace = ThreadTrace(tid);
 371   ReadLock l(&trace->mtx);
 372   const int partidx = (epoch / kTracePartSize) % TraceParts();
 373   TraceHeader* hdr = &trace->headers[partidx];
 374   if (epoch < hdr->epoch0 || epoch >= hdr->epoch0 + kTracePartSize)
 375     return;
 376   CHECK_EQ(RoundDown(epoch, kTracePartSize), hdr->epoch0);
 377   const u64 epoch0 = RoundDown(epoch, TraceSize());
 378   const u64 eend = epoch % TraceSize();
 379   const u64 ebegin = RoundDown(eend, kTracePartSize);
 380   DPrintf("#%d: RestoreStack epoch=%zu ebegin=%zu eend=%zu partidx=%d\n",
 381           tid, (uptr)epoch, (uptr)ebegin, (uptr)eend, partidx);
 382   Vector<uptr> stack(MBlockReportStack);
 383   stack.Resize(hdr->stack0.size + 64);
 384   for (uptr i = 0; i < hdr->stack0.size; i++) {
 385     stack[i] = hdr->stack0.trace[i];
 386     DPrintf2("  #%02zu: pc=%zx\n", i, stack[i]);
 387   }
 388   if (mset)
 389     *mset = hdr->mset0;
 390   uptr pos = hdr->stack0.size;
 391   Event *events = (Event*)GetThreadTrace(tid);
 392   for (uptr i = ebegin; i <= eend; i++) {
 393     Event ev = events[i];
 394     EventType typ = (EventType)(ev >> 61);
 395     uptr pc = (uptr)(ev & ((1ull << 61) - 1));
 396     DPrintf2("  %zu typ=%d pc=%zx\n", i, typ, pc);
 397     if (typ == EventTypeMop) {
 398       stack[pos] = pc;
 399     } else if (typ == EventTypeFuncEnter) {
 400       if (stack.Size() < pos + 2)
 401         stack.Resize(pos + 2);
 402       stack[pos++] = pc;
 403     } else if (typ == EventTypeFuncExit) {
 404       if (pos > 0)
 405         pos--;
 406     }
 407     if (mset) {
 408       if (typ == EventTypeLock) {
 409         mset->Add(pc, true, epoch0 + i);
 410       } else if (typ == EventTypeUnlock) {
 411         mset->Del(pc, true);
 412       } else if (typ == EventTypeRLock) {
 413         mset->Add(pc, false, epoch0 + i);
 414       } else if (typ == EventTypeRUnlock) {
 415         mset->Del(pc, false);
 416       }
 417     }
 418     for (uptr j = 0; j <= pos; j++)
 419       DPrintf2("      #%zu: %zx\n", j, stack[j]);
 420   }
 421   if (pos == 0 && stack[0] == 0)
 422     return;
 423   pos++;
 424   stk->Init(&stack[0], pos);
 425 }
 426
 427 static bool HandleRacyStacks(ThreadState *thr, VarSizeStackTrace traces[2],
 428                              uptr addr_min, uptr addr_max) {
 429   bool equal_stack = false;
 430   RacyStacks hash;
 431   bool equal_address = false;
 432   RacyAddress ra0 = {addr_min, addr_max};
 433   {
 434     ReadLock lock(&ctx->racy_mtx);
 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           VPrintf(2,
 441               "ThreadSanitizer: suppressing report as doubled (stack)\n");
 442           equal_stack = true;
 443           break;
 444         }
 445       }
 446     }
 447     if (flags()->suppress_equal_addresses) {
 448       for (uptr i = 0; i < ctx->racy_addresses.Size(); i++) {
 449         RacyAddress ra2 = ctx->racy_addresses[i];
 450         uptr maxbeg = max(ra0.addr_min, ra2.addr_min);
 451         uptr minend = min(ra0.addr_max, ra2.addr_max);
 452         if (maxbeg < minend) {
 453           VPrintf(2, "ThreadSanitizer: suppressing report as doubled (addr)\n");
 454           equal_address = true;
 455           break;
 456         }
 457       }
 458     }
 459   }
 460   if (!equal_stack && !equal_address)
 461     return false;
 462   if (!equal_stack) {
 463     Lock lock(&ctx->racy_mtx);
 464     ctx->racy_stacks.PushBack(hash);
 465   }
 466   if (!equal_address) {
 467     Lock lock(&ctx->racy_mtx);
 468     ctx->racy_addresses.PushBack(ra0);
 469   }
 470   return true;
 471 }
 472
 473 static void AddRacyStacks(ThreadState *thr, VarSizeStackTrace traces[2],
 474                           uptr addr_min, uptr addr_max) {
 475   Lock lock(&ctx->racy_mtx);
 476   if (flags()->suppress_equal_stacks) {
 477     RacyStacks hash;
 478     hash.hash[0] = md5_hash(traces[0].trace, traces[0].size * sizeof(uptr));
 479     hash.hash[1] = md5_hash(traces[1].trace, traces[1].size * sizeof(uptr));
 480     ctx->racy_stacks.PushBack(hash);
 481   }
 482   if (flags()->suppress_equal_addresses) {
 483     RacyAddress ra0 = {addr_min, addr_max};
 484     ctx->racy_addresses.PushBack(ra0);
 485   }
 486 }
 487
 488 bool OutputReport(ThreadState *thr, const ScopedReport &srep) {
 489   if (!flags()->report_bugs)
 490     return false;
 491   atomic_store_relaxed(&ctx->last_symbolize_time_ns, NanoTime());
 492   const ReportDesc *rep = srep.GetReport();
 493   Suppression *supp = 0;
 494   uptr pc_or_addr = 0;
 495   for (uptr i = 0; pc_or_addr == 0 && i < rep->mops.Size(); i++)
 496     pc_or_addr = IsSuppressed(rep->typ, rep->mops[i]->stack, &supp);
 497   for (uptr i = 0; pc_or_addr == 0 && i < rep->stacks.Size(); i++)
 498     pc_or_addr = IsSuppressed(rep->typ, rep->stacks[i], &supp);
 499   for (uptr i = 0; pc_or_addr == 0 && i < rep->threads.Size(); i++)
 500     pc_or_addr = IsSuppressed(rep->typ, rep->threads[i]->stack, &supp);
 501   for (uptr i = 0; pc_or_addr == 0 && i < rep->locs.Size(); i++)
 502     pc_or_addr = IsSuppressed(rep->typ, rep->locs[i], &supp);
 503   if (pc_or_addr != 0) {
 504     Lock lock(&ctx->fired_suppressions_mtx);
 505     FiredSuppression s = {srep.GetReport()->typ, pc_or_addr, supp};
 506     ctx->fired_suppressions.push_back(s);
 507   }
 508   {
 509     bool old_is_freeing = thr->is_freeing;
 510     thr->is_freeing = false;
 511     bool suppressed = OnReport(rep, pc_or_addr != 0);
 512     thr->is_freeing = old_is_freeing;
 513     if (suppressed)
 514       return false;
 515   }
 516   PrintReport(rep);
 517   ctx->nreported++;
 518   if (flags()->halt_on_error)
 519     Die();
 520   return true;
 521 }
 522
 523 bool IsFiredSuppression(Context *ctx, ReportType type, StackTrace trace) {
 524   ReadLock lock(&ctx->fired_suppressions_mtx);
 525   for (uptr k = 0; k < ctx->fired_suppressions.size(); k++) {
 526     if (ctx->fired_suppressions[k].type != type)
 527       continue;
 528     for (uptr j = 0; j < trace.size; j++) {
 529       FiredSuppression *s = &ctx->fired_suppressions[k];
 530       if (trace.trace[j] == s->pc_or_addr) {
 531         if (s->supp)
 532           atomic_fetch_add(&s->supp->hit_count, 1, memory_order_relaxed);
 533         return true;
 534       }
 535     }
 536   }
 537   return false;
 538 }
 539
 540 static bool IsFiredSuppression(Context *ctx, ReportType type, uptr addr) {
 541   ReadLock lock(&ctx->fired_suppressions_mtx);
 542   for (uptr k = 0; k < ctx->fired_suppressions.size(); k++) {
 543     if (ctx->fired_suppressions[k].type != type)
 544       continue;
 545     FiredSuppression *s = &ctx->fired_suppressions[k];
 546     if (addr == s->pc_or_addr) {
 547       if (s->supp)
 548         atomic_fetch_add(&s->supp->hit_count, 1, memory_order_relaxed);
 549       return true;
 550     }
 551   }
 552   return false;
 553 }
 554
 555 static bool RaceBetweenAtomicAndFree(ThreadState *thr) {
 556   Shadow s0(thr->racy_state[0]);
 557   Shadow s1(thr->racy_state[1]);
 558   CHECK(!(s0.IsAtomic() && s1.IsAtomic()));
 559   if (!s0.IsAtomic() && !s1.IsAtomic())
 560     return true;
 561   if (s0.IsAtomic() && s1.IsFreed())
 562     return true;
 563   if (s1.IsAtomic() && thr->is_freeing)
 564     return true;
 565   return false;
 566 }
 567
 568 void ReportRace(ThreadState *thr) {
 569   CheckNoLocks(thr);
 570
 571   // Symbolizer makes lots of intercepted calls. If we try to process them,
 572   // at best it will cause deadlocks on internal mutexes.
 573   ScopedIgnoreInterceptors ignore;
 574
 575   if (!flags()->report_bugs)
 576     return;
 577   if (!flags()->report_atomic_races && !RaceBetweenAtomicAndFree(thr))
 578     return;
 579
 580   bool freed = false;
 581   {
 582     Shadow s(thr->racy_state[1]);
 583     freed = s.GetFreedAndReset();
 584     thr->racy_state[1] = s.raw();
 585   }
 586
 587   uptr addr = ShadowToMem((uptr)thr->racy_shadow_addr);
 588   uptr addr_min = 0;
 589   uptr addr_max = 0;
 590   {
 591     uptr a0 = addr + Shadow(thr->racy_state[0]).addr0();
 592     uptr a1 = addr + Shadow(thr->racy_state[1]).addr0();
 593     uptr e0 = a0 + Shadow(thr->racy_state[0]).size();
 594     uptr e1 = a1 + Shadow(thr->racy_state[1]).size();
 595     addr_min = min(a0, a1);
 596     addr_max = max(e0, e1);
 597     if (IsExpectedReport(addr_min, addr_max - addr_min))
 598       return;
 599   }
 600
 601   ReportType typ = ReportTypeRace;
 602   if (thr->is_vptr_access && freed)
 603     typ = ReportTypeVptrUseAfterFree;
 604   else if (thr->is_vptr_access)
 605     typ = ReportTypeVptrRace;
 606   else if (freed)
 607     typ = ReportTypeUseAfterFree;
 608
 609   if (IsFiredSuppression(ctx, typ, addr))
 610     return;
 611
 612   const uptr kMop = 2;
 613   VarSizeStackTrace traces[kMop];
 614   const uptr toppc = TraceTopPC(thr);
 615   ObtainCurrentStack(thr, toppc, &traces[0]);
 616   if (IsFiredSuppression(ctx, typ, traces[0]))
 617     return;
 618
 619   // MutexSet is too large to live on stack.
 620   Vector<u64> mset_buffer(MBlockScopedBuf);
 621   mset_buffer.Resize(sizeof(MutexSet) / sizeof(u64) + 1);
 622   MutexSet *mset2 = new(&mset_buffer[0]) MutexSet();
 623
 624   Shadow s2(thr->racy_state[1]);
 625   RestoreStack(s2.tid(), s2.epoch(), &traces[1], mset2);
 626   if (IsFiredSuppression(ctx, typ, traces[1]))
 627     return;
 628
 629   if (HandleRacyStacks(thr, traces, addr_min, addr_max))
 630     return;
 631
 632   ThreadRegistryLock l0(ctx->thread_registry);
 633   ScopedReport rep(typ);
 634   for (uptr i = 0; i < kMop; i++) {
 635     Shadow s(thr->racy_state[i]);
 636     rep.AddMemoryAccess(addr, s, traces[i], i == 0 ? &thr->mset : mset2);
 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 SANITIZER_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 SANITIZER_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"