libsanitizer/tsan/tsan_rtl.cc

   1 //===-- tsan_rtl.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 // Main file (entry points) for the TSan run-time.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_common/sanitizer_atomic.h"
  14 #include "sanitizer_common/sanitizer_common.h"
  15 #include "sanitizer_common/sanitizer_file.h"
  16 #include "sanitizer_common/sanitizer_libc.h"
  17 #include "sanitizer_common/sanitizer_stackdepot.h"
  18 #include "sanitizer_common/sanitizer_placement_new.h"
  19 #include "sanitizer_common/sanitizer_symbolizer.h"
  20 #include "tsan_defs.h"
  21 #include "tsan_platform.h"
  22 #include "tsan_rtl.h"
  23 #include "tsan_mman.h"
  24 #include "tsan_suppressions.h"
  25 #include "tsan_symbolize.h"
  26 #include "ubsan/ubsan_init.h"
  27
  28 #ifdef __SSE3__
  29 // <emmintrin.h> transitively includes <stdlib.h>,
  30 // and it's prohibited to include std headers into tsan runtime.
  31 // So we do this dirty trick.
  32 #define _MM_MALLOC_H_INCLUDED
  33 #define __MM_MALLOC_H
  34 #include <emmintrin.h>
  35 typedef __m128i m128;
  36 #endif
  37
  38 volatile int __tsan_resumed = 0;
  39
  40 extern "C" void __tsan_resume() {
  41   __tsan_resumed = 1;
  42 }
  43
  44 namespace __tsan {
  45
  46 #if !SANITIZER_GO && !SANITIZER_MAC
  47 __attribute__((tls_model("initial-exec")))
  48 THREADLOCAL char cur_thread_placeholder[sizeof(ThreadState)] ALIGNED(64);
  49 #endif
  50 static char ctx_placeholder[sizeof(Context)] ALIGNED(64);
  51 Context *ctx;
  52
  53 // Can be overriden by a front-end.
  54 #ifdef TSAN_EXTERNAL_HOOKS
  55 bool OnFinalize(bool failed);
  56 void OnInitialize();
  57 #else
  58 SANITIZER_WEAK_CXX_DEFAULT_IMPL
  59 bool OnFinalize(bool failed) {
  60   return failed;
  61 }
  62 SANITIZER_WEAK_CXX_DEFAULT_IMPL
  63 void OnInitialize() {}
  64 #endif
  65
  66 static char thread_registry_placeholder[sizeof(ThreadRegistry)];
  67
  68 static ThreadContextBase *CreateThreadContext(u32 tid) {
  69   // Map thread trace when context is created.
  70   char name[50];
  71   internal_snprintf(name, sizeof(name), "trace %u", tid);
  72   MapThreadTrace(GetThreadTrace(tid), TraceSize() * sizeof(Event), name);
  73   const uptr hdr = GetThreadTraceHeader(tid);
  74   internal_snprintf(name, sizeof(name), "trace header %u", tid);
  75   MapThreadTrace(hdr, sizeof(Trace), name);
  76   new((void*)hdr) Trace();
  77   // We are going to use only a small part of the trace with the default
  78   // value of history_size. However, the constructor writes to the whole trace.
  79   // Unmap the unused part.
  80   uptr hdr_end = hdr + sizeof(Trace);
  81   hdr_end -= sizeof(TraceHeader) * (kTraceParts - TraceParts());
  82   hdr_end = RoundUp(hdr_end, GetPageSizeCached());
  83   if (hdr_end < hdr + sizeof(Trace))
  84     UnmapOrDie((void*)hdr_end, hdr + sizeof(Trace) - hdr_end);
  85   void *mem = internal_alloc(MBlockThreadContex, sizeof(ThreadContext));
  86   return new(mem) ThreadContext(tid);
  87 }
  88
  89 #if !SANITIZER_GO
  90 static const u32 kThreadQuarantineSize = 16;
  91 #else
  92 static const u32 kThreadQuarantineSize = 64;
  93 #endif
  94
  95 Context::Context()
  96   : initialized()
  97   , report_mtx(MutexTypeReport, StatMtxReport)
  98   , nreported()
  99   , nmissed_expected()
 100   , thread_registry(new(thread_registry_placeholder) ThreadRegistry(
 101       CreateThreadContext, kMaxTid, kThreadQuarantineSize, kMaxTidReuse))
 102   , racy_mtx(MutexTypeRacy, StatMtxRacy)
 103   , racy_stacks()
 104   , racy_addresses()
 105   , fired_suppressions_mtx(MutexTypeFired, StatMtxFired)
 106   , clock_alloc("clock allocator") {
 107   fired_suppressions.reserve(8);
 108 }
 109
 110 // The objects are allocated in TLS, so one may rely on zero-initialization.
 111 ThreadState::ThreadState(Context *ctx, int tid, int unique_id, u64 epoch,
 112                          unsigned reuse_count,
 113                          uptr stk_addr, uptr stk_size,
 114                          uptr tls_addr, uptr tls_size)
 115   : fast_state(tid, epoch)
 116   // Do not touch these, rely on zero initialization,
 117   // they may be accessed before the ctor.
 118   // , ignore_reads_and_writes()
 119   // , ignore_interceptors()
 120   , clock(tid, reuse_count)
 121 #if !SANITIZER_GO
 122   , jmp_bufs()
 123 #endif
 124   , tid(tid)
 125   , unique_id(unique_id)
 126   , stk_addr(stk_addr)
 127   , stk_size(stk_size)
 128   , tls_addr(tls_addr)
 129   , tls_size(tls_size)
 130 #if !SANITIZER_GO
 131   , last_sleep_clock(tid)
 132 #endif
 133 {
 134 }
 135
 136 #if !SANITIZER_GO
 137 static void MemoryProfiler(Context *ctx, fd_t fd, int i) {
 138   uptr n_threads;
 139   uptr n_running_threads;
 140   ctx->thread_registry->GetNumberOfThreads(&n_threads, &n_running_threads);
 141   InternalMmapVector<char> buf(4096);
 142   WriteMemoryProfile(buf.data(), buf.size(), n_threads, n_running_threads);
 143   WriteToFile(fd, buf.data(), internal_strlen(buf.data()));
 144 }
 145
 146 static void BackgroundThread(void *arg) {
 147   // This is a non-initialized non-user thread, nothing to see here.
 148   // We don't use ScopedIgnoreInterceptors, because we want ignores to be
 149   // enabled even when the thread function exits (e.g. during pthread thread
 150   // shutdown code).
 151   cur_thread()->ignore_interceptors++;
 152   const u64 kMs2Ns = 1000 * 1000;
 153
 154   fd_t mprof_fd = kInvalidFd;
 155   if (flags()->profile_memory && flags()->profile_memory[0]) {
 156     if (internal_strcmp(flags()->profile_memory, "stdout") == 0) {
 157       mprof_fd = 1;
 158     } else if (internal_strcmp(flags()->profile_memory, "stderr") == 0) {
 159       mprof_fd = 2;
 160     } else {
 161       InternalScopedString filename(kMaxPathLength);
 162       filename.append("%s.%d", flags()->profile_memory, (int)internal_getpid());
 163       fd_t fd = OpenFile(filename.data(), WrOnly);
 164       if (fd == kInvalidFd) {
 165         Printf("ThreadSanitizer: failed to open memory profile file '%s'\n",
 166             &filename[0]);
 167       } else {
 168         mprof_fd = fd;
 169       }
 170     }
 171   }
 172
 173   u64 last_flush = NanoTime();
 174   uptr last_rss = 0;
 175   for (int i = 0;
 176       atomic_load(&ctx->stop_background_thread, memory_order_relaxed) == 0;
 177       i++) {
 178     SleepForMillis(100);
 179     u64 now = NanoTime();
 180
 181     // Flush memory if requested.
 182     if (flags()->flush_memory_ms > 0) {
 183       if (last_flush + flags()->flush_memory_ms * kMs2Ns < now) {
 184         VPrintf(1, "ThreadSanitizer: periodic memory flush\n");
 185         FlushShadowMemory();
 186         last_flush = NanoTime();
 187       }
 188     }
 189     // GetRSS can be expensive on huge programs, so don't do it every 100ms.
 190     if (flags()->memory_limit_mb > 0) {
 191       uptr rss = GetRSS();
 192       uptr limit = uptr(flags()->memory_limit_mb) << 20;
 193       VPrintf(1, "ThreadSanitizer: memory flush check"
 194                  " RSS=%llu LAST=%llu LIMIT=%llu\n",
 195               (u64)rss >> 20, (u64)last_rss >> 20, (u64)limit >> 20);
 196       if (2 * rss > limit + last_rss) {
 197         VPrintf(1, "ThreadSanitizer: flushing memory due to RSS\n");
 198         FlushShadowMemory();
 199         rss = GetRSS();
 200         VPrintf(1, "ThreadSanitizer: memory flushed RSS=%llu\n", (u64)rss>>20);
 201       }
 202       last_rss = rss;
 203     }
 204
 205     // Write memory profile if requested.
 206     if (mprof_fd != kInvalidFd)
 207       MemoryProfiler(ctx, mprof_fd, i);
 208
 209     // Flush symbolizer cache if requested.
 210     if (flags()->flush_symbolizer_ms > 0) {
 211       u64 last = atomic_load(&ctx->last_symbolize_time_ns,
 212                              memory_order_relaxed);
 213       if (last != 0 && last + flags()->flush_symbolizer_ms * kMs2Ns < now) {
 214         Lock l(&ctx->report_mtx);
 215         ScopedErrorReportLock l2;
 216         SymbolizeFlush();
 217         atomic_store(&ctx->last_symbolize_time_ns, 0, memory_order_relaxed);
 218       }
 219     }
 220   }
 221 }
 222
 223 static void StartBackgroundThread() {
 224   ctx->background_thread = internal_start_thread(&BackgroundThread, 0);
 225 }
 226
 227 #ifndef __mips__
 228 static void StopBackgroundThread() {
 229   atomic_store(&ctx->stop_background_thread, 1, memory_order_relaxed);
 230   internal_join_thread(ctx->background_thread);
 231   ctx->background_thread = 0;
 232 }
 233 #endif
 234 #endif
 235
 236 void DontNeedShadowFor(uptr addr, uptr size) {
 237   ReleaseMemoryPagesToOS(MemToShadow(addr), MemToShadow(addr + size));
 238 }
 239
 240 void MapShadow(uptr addr, uptr size) {
 241   // Global data is not 64K aligned, but there are no adjacent mappings,
 242   // so we can get away with unaligned mapping.
 243   // CHECK_EQ(addr, addr & ~((64 << 10) - 1));  // windows wants 64K alignment
 244   const uptr kPageSize = GetPageSizeCached();
 245   uptr shadow_begin = RoundDownTo((uptr)MemToShadow(addr), kPageSize);
 246   uptr shadow_end = RoundUpTo((uptr)MemToShadow(addr + size), kPageSize);
 247   if (!MmapFixedNoReserve(shadow_begin, shadow_end - shadow_begin, "shadow"))
 248     Die();
 249
 250   // Meta shadow is 2:1, so tread carefully.
 251   static bool data_mapped = false;
 252   static uptr mapped_meta_end = 0;
 253   uptr meta_begin = (uptr)MemToMeta(addr);
 254   uptr meta_end = (uptr)MemToMeta(addr + size);
 255   meta_begin = RoundDownTo(meta_begin, 64 << 10);
 256   meta_end = RoundUpTo(meta_end, 64 << 10);
 257   if (!data_mapped) {
 258     // First call maps data+bss.
 259     data_mapped = true;
 260     if (!MmapFixedNoReserve(meta_begin, meta_end - meta_begin, "meta shadow"))
 261       Die();
 262   } else {
 263     // Mapping continous heap.
 264     // Windows wants 64K alignment.
 265     meta_begin = RoundDownTo(meta_begin, 64 << 10);
 266     meta_end = RoundUpTo(meta_end, 64 << 10);
 267     if (meta_end <= mapped_meta_end)
 268       return;
 269     if (meta_begin < mapped_meta_end)
 270       meta_begin = mapped_meta_end;
 271     if (!MmapFixedNoReserve(meta_begin, meta_end - meta_begin, "meta shadow"))
 272       Die();
 273     mapped_meta_end = meta_end;
 274   }
 275   VPrintf(2, "mapped meta shadow for (%p-%p) at (%p-%p)\n",
 276       addr, addr+size, meta_begin, meta_end);
 277 }
 278
 279 void MapThreadTrace(uptr addr, uptr size, const char *name) {
 280   DPrintf("#0: Mapping trace at %p-%p(0x%zx)\n", addr, addr + size, size);
 281   CHECK_GE(addr, TraceMemBeg());
 282   CHECK_LE(addr + size, TraceMemEnd());
 283   CHECK_EQ(addr, addr & ~((64 << 10) - 1));  // windows wants 64K alignment
 284   if (!MmapFixedNoReserve(addr, size, name)) {
 285     Printf("FATAL: ThreadSanitizer can not mmap thread trace (%p/%p)\n",
 286         addr, size);
 287     Die();
 288   }
 289 }
 290
 291 static void CheckShadowMapping() {
 292   uptr beg, end;
 293   for (int i = 0; GetUserRegion(i, &beg, &end); i++) {
 294     // Skip cases for empty regions (heap definition for architectures that
 295     // do not use 64-bit allocator).
 296     if (beg == end)
 297       continue;
 298     VPrintf(3, "checking shadow region %p-%p\n", beg, end);
 299     uptr prev = 0;
 300     for (uptr p0 = beg; p0 <= end; p0 += (end - beg) / 4) {
 301       for (int x = -(int)kShadowCell; x <= (int)kShadowCell; x += kShadowCell) {
 302         const uptr p = RoundDown(p0 + x, kShadowCell);
 303         if (p < beg || p >= end)
 304           continue;
 305         const uptr s = MemToShadow(p);
 306         const uptr m = (uptr)MemToMeta(p);
 307         VPrintf(3, "  checking pointer %p: shadow=%p meta=%p\n", p, s, m);
 308         CHECK(IsAppMem(p));
 309         CHECK(IsShadowMem(s));
 310         CHECK_EQ(p, ShadowToMem(s));
 311         CHECK(IsMetaMem(m));
 312         if (prev) {
 313           // Ensure that shadow and meta mappings are linear within a single
 314           // user range. Lots of code that processes memory ranges assumes it.
 315           const uptr prev_s = MemToShadow(prev);
 316           const uptr prev_m = (uptr)MemToMeta(prev);
 317           CHECK_EQ(s - prev_s, (p - prev) * kShadowMultiplier);
 318           CHECK_EQ((m - prev_m) / kMetaShadowSize,
 319                    (p - prev) / kMetaShadowCell);
 320         }
 321         prev = p;
 322       }
 323     }
 324   }
 325 }
 326
 327 #if !SANITIZER_GO
 328 static void OnStackUnwind(const SignalContext &sig, const void *,
 329                           BufferedStackTrace *stack) {
 330   uptr top = 0;
 331   uptr bottom = 0;
 332   bool fast = common_flags()->fast_unwind_on_fatal;
 333   if (fast) GetThreadStackTopAndBottom(false, &top, &bottom);
 334   stack->Unwind(kStackTraceMax, sig.pc, sig.bp, sig.context, top, bottom, fast);
 335 }
 336
 337 static void TsanOnDeadlySignal(int signo, void *siginfo, void *context) {
 338   HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
 339 }
 340 #endif
 341
 342 void Initialize(ThreadState *thr) {
 343   // Thread safe because done before all threads exist.
 344   static bool is_initialized = false;
 345   if (is_initialized)
 346     return;
 347   is_initialized = true;
 348   // We are not ready to handle interceptors yet.
 349   ScopedIgnoreInterceptors ignore;
 350   SanitizerToolName = "ThreadSanitizer";
 351   // Install tool-specific callbacks in sanitizer_common.
 352   SetCheckFailedCallback(TsanCheckFailed);
 353
 354   ctx = new(ctx_placeholder) Context;
 355   const char *options = GetEnv(SANITIZER_GO ? "GORACE" : "TSAN_OPTIONS");
 356   CacheBinaryName();
 357   CheckASLR();
 358   InitializeFlags(&ctx->flags, options);
 359   AvoidCVE_2016_2143();
 360   InitializePlatformEarly();
 361 #if !SANITIZER_GO
 362   // Re-exec ourselves if we need to set additional env or command line args.
 363   MaybeReexec();
 364
 365   InitializeAllocator();
 366   ReplaceSystemMalloc();
 367 #endif
 368   if (common_flags()->detect_deadlocks)
 369     ctx->dd = DDetector::Create(flags());
 370   Processor *proc = ProcCreate();
 371   ProcWire(proc, thr);
 372   InitializeInterceptors();
 373   CheckShadowMapping();
 374   InitializePlatform();
 375   InitializeMutex();
 376   InitializeDynamicAnnotations();
 377 #if !SANITIZER_GO
 378   InitializeShadowMemory();
 379   InitializeAllocatorLate();
 380   InstallDeadlySignalHandlers(TsanOnDeadlySignal);
 381 #endif
 382   // Setup correct file descriptor for error reports.
 383   __sanitizer_set_report_path(common_flags()->log_path);
 384   InitializeSuppressions();
 385 #if !SANITIZER_GO
 386   InitializeLibIgnore();
 387   Symbolizer::GetOrInit()->AddHooks(EnterSymbolizer, ExitSymbolizer);
 388 #endif
 389
 390   VPrintf(1, "***** Running under ThreadSanitizer v2 (pid %d) *****\n",
 391           (int)internal_getpid());
 392
 393   // Initialize thread 0.
 394   int tid = ThreadCreate(thr, 0, 0, true);
 395   CHECK_EQ(tid, 0);
 396   ThreadStart(thr, tid, GetTid(), /*workerthread*/ false);
 397 #if TSAN_CONTAINS_UBSAN
 398   __ubsan::InitAsPlugin();
 399 #endif
 400   ctx->initialized = true;
 401
 402 #if !SANITIZER_GO
 403   Symbolizer::LateInitialize();
 404 #endif
 405
 406   if (flags()->stop_on_start) {
 407     Printf("ThreadSanitizer is suspended at startup (pid %d)."
 408            " Call __tsan_resume().\n",
 409            (int)internal_getpid());
 410     while (__tsan_resumed == 0) {}
 411   }
 412
 413   OnInitialize();
 414 }
 415
 416 void MaybeSpawnBackgroundThread() {
 417   // On MIPS, TSan initialization is run before
 418   // __pthread_initialize_minimal_internal() is finished, so we can not spawn
 419   // new threads.
 420 #if !SANITIZER_GO && !defined(__mips__)
 421   static atomic_uint32_t bg_thread = {};
 422   if (atomic_load(&bg_thread, memory_order_relaxed) == 0 &&
 423       atomic_exchange(&bg_thread, 1, memory_order_relaxed) == 0) {
 424     StartBackgroundThread();
 425     SetSandboxingCallback(StopBackgroundThread);
 426   }
 427 #endif
 428 }
 429
 430
 431 int Finalize(ThreadState *thr) {
 432   bool failed = false;
 433
 434   if (common_flags()->print_module_map == 1) PrintModuleMap();
 435
 436   if (flags()->atexit_sleep_ms > 0 && ThreadCount(thr) > 1)
 437     SleepForMillis(flags()->atexit_sleep_ms);
 438
 439   // Wait for pending reports.
 440   ctx->report_mtx.Lock();
 441   { ScopedErrorReportLock l; }
 442   ctx->report_mtx.Unlock();
 443
 444 #if !SANITIZER_GO
 445   if (Verbosity()) AllocatorPrintStats();
 446 #endif
 447
 448   ThreadFinalize(thr);
 449
 450   if (ctx->nreported) {
 451     failed = true;
 452 #if !SANITIZER_GO
 453     Printf("ThreadSanitizer: reported %d warnings\n", ctx->nreported);
 454 #else
 455     Printf("Found %d data race(s)\n", ctx->nreported);
 456 #endif
 457   }
 458
 459   if (ctx->nmissed_expected) {
 460     failed = true;
 461     Printf("ThreadSanitizer: missed %d expected races\n",
 462         ctx->nmissed_expected);
 463   }
 464
 465   if (common_flags()->print_suppressions)
 466     PrintMatchedSuppressions();
 467 #if !SANITIZER_GO
 468   if (flags()->print_benign)
 469     PrintMatchedBenignRaces();
 470 #endif
 471
 472   failed = OnFinalize(failed);
 473
 474 #if TSAN_COLLECT_STATS
 475   StatAggregate(ctx->stat, thr->stat);
 476   StatOutput(ctx->stat);
 477 #endif
 478
 479   return failed ? common_flags()->exitcode : 0;
 480 }
 481
 482 #if !SANITIZER_GO
 483 void ForkBefore(ThreadState *thr, uptr pc) {
 484   ctx->thread_registry->Lock();
 485   ctx->report_mtx.Lock();
 486 }
 487
 488 void ForkParentAfter(ThreadState *thr, uptr pc) {
 489   ctx->report_mtx.Unlock();
 490   ctx->thread_registry->Unlock();
 491 }
 492
 493 void ForkChildAfter(ThreadState *thr, uptr pc) {
 494   ctx->report_mtx.Unlock();
 495   ctx->thread_registry->Unlock();
 496
 497   uptr nthread = 0;
 498   ctx->thread_registry->GetNumberOfThreads(0, 0, &nthread /* alive threads */);
 499   VPrintf(1, "ThreadSanitizer: forked new process with pid %d,"
 500       " parent had %d threads\n", (int)internal_getpid(), (int)nthread);
 501   if (nthread == 1) {
 502     StartBackgroundThread();
 503   } else {
 504     // We've just forked a multi-threaded process. We cannot reasonably function
 505     // after that (some mutexes may be locked before fork). So just enable
 506     // ignores for everything in the hope that we will exec soon.
 507     ctx->after_multithreaded_fork = true;
 508     thr->ignore_interceptors++;
 509     ThreadIgnoreBegin(thr, pc);
 510     ThreadIgnoreSyncBegin(thr, pc);
 511   }
 512 }
 513 #endif
 514
 515 #if SANITIZER_GO
 516 NOINLINE
 517 void GrowShadowStack(ThreadState *thr) {
 518   const int sz = thr->shadow_stack_end - thr->shadow_stack;
 519   const int newsz = 2 * sz;
 520   uptr *newstack = (uptr*)internal_alloc(MBlockShadowStack,
 521       newsz * sizeof(uptr));
 522   internal_memcpy(newstack, thr->shadow_stack, sz * sizeof(uptr));
 523   internal_free(thr->shadow_stack);
 524   thr->shadow_stack = newstack;
 525   thr->shadow_stack_pos = newstack + sz;
 526   thr->shadow_stack_end = newstack + newsz;
 527 }
 528 #endif
 529
 530 u32 CurrentStackId(ThreadState *thr, uptr pc) {
 531   if (!thr->is_inited)  // May happen during bootstrap.
 532     return 0;
 533   if (pc != 0) {
 534 #if !SANITIZER_GO
 535     DCHECK_LT(thr->shadow_stack_pos, thr->shadow_stack_end);
 536 #else
 537     if (thr->shadow_stack_pos == thr->shadow_stack_end)
 538       GrowShadowStack(thr);
 539 #endif
 540     thr->shadow_stack_pos[0] = pc;
 541     thr->shadow_stack_pos++;
 542   }
 543   u32 id = StackDepotPut(
 544       StackTrace(thr->shadow_stack, thr->shadow_stack_pos - thr->shadow_stack));
 545   if (pc != 0)
 546     thr->shadow_stack_pos--;
 547   return id;
 548 }
 549
 550 void TraceSwitch(ThreadState *thr) {
 551 #if !SANITIZER_GO
 552   if (ctx->after_multithreaded_fork)
 553     return;
 554 #endif
 555   thr->nomalloc++;
 556   Trace *thr_trace = ThreadTrace(thr->tid);
 557   Lock l(&thr_trace->mtx);
 558   unsigned trace = (thr->fast_state.epoch() / kTracePartSize) % TraceParts();
 559   TraceHeader *hdr = &thr_trace->headers[trace];
 560   hdr->epoch0 = thr->fast_state.epoch();
 561   ObtainCurrentStack(thr, 0, &hdr->stack0);
 562   hdr->mset0 = thr->mset;
 563   thr->nomalloc--;
 564 }
 565
 566 Trace *ThreadTrace(int tid) {
 567   return (Trace*)GetThreadTraceHeader(tid);
 568 }
 569
 570 uptr TraceTopPC(ThreadState *thr) {
 571   Event *events = (Event*)GetThreadTrace(thr->tid);
 572   uptr pc = events[thr->fast_state.GetTracePos()];
 573   return pc;
 574 }
 575
 576 uptr TraceSize() {
 577   return (uptr)(1ull << (kTracePartSizeBits + flags()->history_size + 1));
 578 }
 579
 580 uptr TraceParts() {
 581   return TraceSize() / kTracePartSize;
 582 }
 583
 584 #if !SANITIZER_GO
 585 extern "C" void __tsan_trace_switch() {
 586   TraceSwitch(cur_thread());
 587 }
 588
 589 extern "C" void __tsan_report_race() {
 590   ReportRace(cur_thread());
 591 }
 592 #endif
 593
 594 ALWAYS_INLINE
 595 Shadow LoadShadow(u64 *p) {
 596   u64 raw = atomic_load((atomic_uint64_t*)p, memory_order_relaxed);
 597   return Shadow(raw);
 598 }
 599
 600 ALWAYS_INLINE
 601 void StoreShadow(u64 *sp, u64 s) {
 602   atomic_store((atomic_uint64_t*)sp, s, memory_order_relaxed);
 603 }
 604
 605 ALWAYS_INLINE
 606 void StoreIfNotYetStored(u64 *sp, u64 *s) {
 607   StoreShadow(sp, *s);
 608   *s = 0;
 609 }
 610
 611 ALWAYS_INLINE
 612 void HandleRace(ThreadState *thr, u64 *shadow_mem,
 613                               Shadow cur, Shadow old) {
 614   thr->racy_state[0] = cur.raw();
 615   thr->racy_state[1] = old.raw();
 616   thr->racy_shadow_addr = shadow_mem;
 617 #if !SANITIZER_GO
 618   HACKY_CALL(__tsan_report_race);
 619 #else
 620   ReportRace(thr);
 621 #endif
 622 }
 623
 624 static inline bool HappensBefore(Shadow old, ThreadState *thr) {
 625   return thr->clock.get(old.TidWithIgnore()) >= old.epoch();
 626 }
 627
 628 ALWAYS_INLINE
 629 void MemoryAccessImpl1(ThreadState *thr, uptr addr,
 630     int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic,
 631     u64 *shadow_mem, Shadow cur) {
 632   StatInc(thr, StatMop);
 633   StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
 634   StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
 635
 636   // This potentially can live in an MMX/SSE scratch register.
 637   // The required intrinsics are:
 638   // __m128i _mm_move_epi64(__m128i*);
 639   // _mm_storel_epi64(u64*, __m128i);
 640   u64 store_word = cur.raw();
 641
 642   // scan all the shadow values and dispatch to 4 categories:
 643   // same, replace, candidate and race (see comments below).
 644   // we consider only 3 cases regarding access sizes:
 645   // equal, intersect and not intersect. initially I considered
 646   // larger and smaller as well, it allowed to replace some
 647   // 'candidates' with 'same' or 'replace', but I think
 648   // it's just not worth it (performance- and complexity-wise).
 649
 650   Shadow old(0);
 651
 652   // It release mode we manually unroll the loop,
 653   // because empirically gcc generates better code this way.
 654   // However, we can't afford unrolling in debug mode, because the function
 655   // consumes almost 4K of stack. Gtest gives only 4K of stack to death test
 656   // threads, which is not enough for the unrolled loop.
 657 #if SANITIZER_DEBUG
 658   for (int idx = 0; idx < 4; idx++) {
 659 #include "tsan_update_shadow_word_inl.h"
 660   }
 661 #else
 662   int idx = 0;
 663 #include "tsan_update_shadow_word_inl.h"
 664   idx = 1;
 665 #include "tsan_update_shadow_word_inl.h"
 666   idx = 2;
 667 #include "tsan_update_shadow_word_inl.h"
 668   idx = 3;
 669 #include "tsan_update_shadow_word_inl.h"
 670 #endif
 671
 672   // we did not find any races and had already stored
 673   // the current access info, so we are done
 674   if (LIKELY(store_word == 0))
 675     return;
 676   // choose a random candidate slot and replace it
 677   StoreShadow(shadow_mem + (cur.epoch() % kShadowCnt), store_word);
 678   StatInc(thr, StatShadowReplace);
 679   return;
 680  RACE:
 681   HandleRace(thr, shadow_mem, cur, old);
 682   return;
 683 }
 684
 685 void UnalignedMemoryAccess(ThreadState *thr, uptr pc, uptr addr,
 686     int size, bool kAccessIsWrite, bool kIsAtomic) {
 687   while (size) {
 688     int size1 = 1;
 689     int kAccessSizeLog = kSizeLog1;
 690     if (size >= 8 && (addr & ~7) == ((addr + 7) & ~7)) {
 691       size1 = 8;
 692       kAccessSizeLog = kSizeLog8;
 693     } else if (size >= 4 && (addr & ~7) == ((addr + 3) & ~7)) {
 694       size1 = 4;
 695       kAccessSizeLog = kSizeLog4;
 696     } else if (size >= 2 && (addr & ~7) == ((addr + 1) & ~7)) {
 697       size1 = 2;
 698       kAccessSizeLog = kSizeLog2;
 699     }
 700     MemoryAccess(thr, pc, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic);
 701     addr += size1;
 702     size -= size1;
 703   }
 704 }
 705
 706 ALWAYS_INLINE
 707 bool ContainsSameAccessSlow(u64 *s, u64 a, u64 sync_epoch, bool is_write) {
 708   Shadow cur(a);
 709   for (uptr i = 0; i < kShadowCnt; i++) {
 710     Shadow old(LoadShadow(&s[i]));
 711     if (Shadow::Addr0AndSizeAreEqual(cur, old) &&
 712         old.TidWithIgnore() == cur.TidWithIgnore() &&
 713         old.epoch() > sync_epoch &&
 714         old.IsAtomic() == cur.IsAtomic() &&
 715         old.IsRead() <= cur.IsRead())
 716       return true;
 717   }
 718   return false;
 719 }
 720
 721 #if defined(__SSE3__)
 722 #define SHUF(v0, v1, i0, i1, i2, i3) _mm_castps_si128(_mm_shuffle_ps( \
 723     _mm_castsi128_ps(v0), _mm_castsi128_ps(v1), \
 724     (i0)*1 + (i1)*4 + (i2)*16 + (i3)*64))
 725 ALWAYS_INLINE
 726 bool ContainsSameAccessFast(u64 *s, u64 a, u64 sync_epoch, bool is_write) {
 727   // This is an optimized version of ContainsSameAccessSlow.
 728   // load current access into access[0:63]
 729   const m128 access     = _mm_cvtsi64_si128(a);
 730   // duplicate high part of access in addr0:
 731   // addr0[0:31]        = access[32:63]
 732   // addr0[32:63]       = access[32:63]
 733   // addr0[64:95]       = access[32:63]
 734   // addr0[96:127]      = access[32:63]
 735   const m128 addr0      = SHUF(access, access, 1, 1, 1, 1);
 736   // load 4 shadow slots
 737   const m128 shadow0    = _mm_load_si128((__m128i*)s);
 738   const m128 shadow1    = _mm_load_si128((__m128i*)s + 1);
 739   // load high parts of 4 shadow slots into addr_vect:
 740   // addr_vect[0:31]    = shadow0[32:63]
 741   // addr_vect[32:63]   = shadow0[96:127]
 742   // addr_vect[64:95]   = shadow1[32:63]
 743   // addr_vect[96:127]  = shadow1[96:127]
 744   m128 addr_vect        = SHUF(shadow0, shadow1, 1, 3, 1, 3);
 745   if (!is_write) {
 746     // set IsRead bit in addr_vect
 747     const m128 rw_mask1 = _mm_cvtsi64_si128(1<<15);
 748     const m128 rw_mask  = SHUF(rw_mask1, rw_mask1, 0, 0, 0, 0);
 749     addr_vect           = _mm_or_si128(addr_vect, rw_mask);
 750   }
 751   // addr0 == addr_vect?
 752   const m128 addr_res   = _mm_cmpeq_epi32(addr0, addr_vect);
 753   // epoch1[0:63]       = sync_epoch
 754   const m128 epoch1     = _mm_cvtsi64_si128(sync_epoch);
 755   // epoch[0:31]        = sync_epoch[0:31]
 756   // epoch[32:63]       = sync_epoch[0:31]
 757   // epoch[64:95]       = sync_epoch[0:31]
 758   // epoch[96:127]      = sync_epoch[0:31]
 759   const m128 epoch      = SHUF(epoch1, epoch1, 0, 0, 0, 0);
 760   // load low parts of shadow cell epochs into epoch_vect:
 761   // epoch_vect[0:31]   = shadow0[0:31]
 762   // epoch_vect[32:63]  = shadow0[64:95]
 763   // epoch_vect[64:95]  = shadow1[0:31]
 764   // epoch_vect[96:127] = shadow1[64:95]
 765   const m128 epoch_vect = SHUF(shadow0, shadow1, 0, 2, 0, 2);
 766   // epoch_vect >= sync_epoch?
 767   const m128 epoch_res  = _mm_cmpgt_epi32(epoch_vect, epoch);
 768   // addr_res & epoch_res
 769   const m128 res        = _mm_and_si128(addr_res, epoch_res);
 770   // mask[0] = res[7]
 771   // mask[1] = res[15]
 772   // ...
 773   // mask[15] = res[127]
 774   const int mask        = _mm_movemask_epi8(res);
 775   return mask != 0;
 776 }
 777 #endif
 778
 779 ALWAYS_INLINE
 780 bool ContainsSameAccess(u64 *s, u64 a, u64 sync_epoch, bool is_write) {
 781 #if defined(__SSE3__)
 782   bool res = ContainsSameAccessFast(s, a, sync_epoch, is_write);
 783   // NOTE: this check can fail if the shadow is concurrently mutated
 784   // by other threads. But it still can be useful if you modify
 785   // ContainsSameAccessFast and want to ensure that it's not completely broken.
 786   // DCHECK_EQ(res, ContainsSameAccessSlow(s, a, sync_epoch, is_write));
 787   return res;
 788 #else
 789   return ContainsSameAccessSlow(s, a, sync_epoch, is_write);
 790 #endif
 791 }
 792
 793 ALWAYS_INLINE USED
 794 void MemoryAccess(ThreadState *thr, uptr pc, uptr addr,
 795     int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic) {
 796   u64 *shadow_mem = (u64*)MemToShadow(addr);
 797   DPrintf2("#%d: MemoryAccess: @%p %p size=%d"
 798       " is_write=%d shadow_mem=%p {%zx, %zx, %zx, %zx}\n",
 799       (int)thr->fast_state.tid(), (void*)pc, (void*)addr,
 800       (int)(1 << kAccessSizeLog), kAccessIsWrite, shadow_mem,
 801       (uptr)shadow_mem[0], (uptr)shadow_mem[1],
 802       (uptr)shadow_mem[2], (uptr)shadow_mem[3]);
 803 #if SANITIZER_DEBUG
 804   if (!IsAppMem(addr)) {
 805     Printf("Access to non app mem %zx\n", addr);
 806     DCHECK(IsAppMem(addr));
 807   }
 808   if (!IsShadowMem((uptr)shadow_mem)) {
 809     Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
 810     DCHECK(IsShadowMem((uptr)shadow_mem));
 811   }
 812 #endif
 813
 814   if (!SANITIZER_GO && *shadow_mem == kShadowRodata) {
 815     // Access to .rodata section, no races here.
 816     // Measurements show that it can be 10-20% of all memory accesses.
 817     StatInc(thr, StatMop);
 818     StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
 819     StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
 820     StatInc(thr, StatMopRodata);
 821     return;
 822   }
 823
 824   FastState fast_state = thr->fast_state;
 825   if (fast_state.GetIgnoreBit()) {
 826     StatInc(thr, StatMop);
 827     StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
 828     StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
 829     StatInc(thr, StatMopIgnored);
 830     return;
 831   }
 832
 833   Shadow cur(fast_state);
 834   cur.SetAddr0AndSizeLog(addr & 7, kAccessSizeLog);
 835   cur.SetWrite(kAccessIsWrite);
 836   cur.SetAtomic(kIsAtomic);
 837
 838   if (LIKELY(ContainsSameAccess(shadow_mem, cur.raw(),
 839       thr->fast_synch_epoch, kAccessIsWrite))) {
 840     StatInc(thr, StatMop);
 841     StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
 842     StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
 843     StatInc(thr, StatMopSame);
 844     return;
 845   }
 846
 847   if (kCollectHistory) {
 848     fast_state.IncrementEpoch();
 849     thr->fast_state = fast_state;
 850     TraceAddEvent(thr, fast_state, EventTypeMop, pc);
 851     cur.IncrementEpoch();
 852   }
 853
 854   MemoryAccessImpl1(thr, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic,
 855       shadow_mem, cur);
 856 }
 857
 858 // Called by MemoryAccessRange in tsan_rtl_thread.cc
 859 ALWAYS_INLINE USED
 860 void MemoryAccessImpl(ThreadState *thr, uptr addr,
 861     int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic,
 862     u64 *shadow_mem, Shadow cur) {
 863   if (LIKELY(ContainsSameAccess(shadow_mem, cur.raw(),
 864       thr->fast_synch_epoch, kAccessIsWrite))) {
 865     StatInc(thr, StatMop);
 866     StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
 867     StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
 868     StatInc(thr, StatMopSame);
 869     return;
 870   }
 871
 872   MemoryAccessImpl1(thr, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic,
 873       shadow_mem, cur);
 874 }
 875
 876 static void MemoryRangeSet(ThreadState *thr, uptr pc, uptr addr, uptr size,
 877                            u64 val) {
 878   (void)thr;
 879   (void)pc;
 880   if (size == 0)
 881     return;
 882   // FIXME: fix me.
 883   uptr offset = addr % kShadowCell;
 884   if (offset) {
 885     offset = kShadowCell - offset;
 886     if (size <= offset)
 887       return;
 888     addr += offset;
 889     size -= offset;
 890   }
 891   DCHECK_EQ(addr % 8, 0);
 892   // If a user passes some insane arguments (memset(0)),
 893   // let it just crash as usual.
 894   if (!IsAppMem(addr) || !IsAppMem(addr + size - 1))
 895     return;
 896   // Don't want to touch lots of shadow memory.
 897   // If a program maps 10MB stack, there is no need reset the whole range.
 898   size = (size + (kShadowCell - 1)) & ~(kShadowCell - 1);
 899   // UnmapOrDie/MmapFixedNoReserve does not work on Windows.
 900   if (SANITIZER_WINDOWS || size < common_flags()->clear_shadow_mmap_threshold) {
 901     u64 *p = (u64*)MemToShadow(addr);
 902     CHECK(IsShadowMem((uptr)p));
 903     CHECK(IsShadowMem((uptr)(p + size * kShadowCnt / kShadowCell - 1)));
 904     // FIXME: may overwrite a part outside the region
 905     for (uptr i = 0; i < size / kShadowCell * kShadowCnt;) {
 906       p[i++] = val;
 907       for (uptr j = 1; j < kShadowCnt; j++)
 908         p[i++] = 0;
 909     }
 910   } else {
 911     // The region is big, reset only beginning and end.
 912     const uptr kPageSize = GetPageSizeCached();
 913     u64 *begin = (u64*)MemToShadow(addr);
 914     u64 *end = begin + size / kShadowCell * kShadowCnt;
 915     u64 *p = begin;
 916     // Set at least first kPageSize/2 to page boundary.
 917     while ((p < begin + kPageSize / kShadowSize / 2) || ((uptr)p % kPageSize)) {
 918       *p++ = val;
 919       for (uptr j = 1; j < kShadowCnt; j++)
 920         *p++ = 0;
 921     }
 922     // Reset middle part.
 923     u64 *p1 = p;
 924     p = RoundDown(end, kPageSize);
 925     UnmapOrDie((void*)p1, (uptr)p - (uptr)p1);
 926     if (!MmapFixedNoReserve((uptr)p1, (uptr)p - (uptr)p1))
 927       Die();
 928     // Set the ending.
 929     while (p < end) {
 930       *p++ = val;
 931       for (uptr j = 1; j < kShadowCnt; j++)
 932         *p++ = 0;
 933     }
 934   }
 935 }
 936
 937 void MemoryResetRange(ThreadState *thr, uptr pc, uptr addr, uptr size) {
 938   MemoryRangeSet(thr, pc, addr, size, 0);
 939 }
 940
 941 void MemoryRangeFreed(ThreadState *thr, uptr pc, uptr addr, uptr size) {
 942   // Processing more than 1k (4k of shadow) is expensive,
 943   // can cause excessive memory consumption (user does not necessary touch
 944   // the whole range) and most likely unnecessary.
 945   if (size > 1024)
 946     size = 1024;
 947   CHECK_EQ(thr->is_freeing, false);
 948   thr->is_freeing = true;
 949   MemoryAccessRange(thr, pc, addr, size, true);
 950   thr->is_freeing = false;
 951   if (kCollectHistory) {
 952     thr->fast_state.IncrementEpoch();
 953     TraceAddEvent(thr, thr->fast_state, EventTypeMop, pc);
 954   }
 955   Shadow s(thr->fast_state);
 956   s.ClearIgnoreBit();
 957   s.MarkAsFreed();
 958   s.SetWrite(true);
 959   s.SetAddr0AndSizeLog(0, 3);
 960   MemoryRangeSet(thr, pc, addr, size, s.raw());
 961 }
 962
 963 void MemoryRangeImitateWrite(ThreadState *thr, uptr pc, uptr addr, uptr size) {
 964   if (kCollectHistory) {
 965     thr->fast_state.IncrementEpoch();
 966     TraceAddEvent(thr, thr->fast_state, EventTypeMop, pc);
 967   }
 968   Shadow s(thr->fast_state);
 969   s.ClearIgnoreBit();
 970   s.SetWrite(true);
 971   s.SetAddr0AndSizeLog(0, 3);
 972   MemoryRangeSet(thr, pc, addr, size, s.raw());
 973 }
 974
 975 ALWAYS_INLINE USED
 976 void FuncEntry(ThreadState *thr, uptr pc) {
 977   StatInc(thr, StatFuncEnter);
 978   DPrintf2("#%d: FuncEntry %p\n", (int)thr->fast_state.tid(), (void*)pc);
 979   if (kCollectHistory) {
 980     thr->fast_state.IncrementEpoch();
 981     TraceAddEvent(thr, thr->fast_state, EventTypeFuncEnter, pc);
 982   }
 983
 984   // Shadow stack maintenance can be replaced with
 985   // stack unwinding during trace switch (which presumably must be faster).
 986   DCHECK_GE(thr->shadow_stack_pos, thr->shadow_stack);
 987 #if !SANITIZER_GO
 988   DCHECK_LT(thr->shadow_stack_pos, thr->shadow_stack_end);
 989 #else
 990   if (thr->shadow_stack_pos == thr->shadow_stack_end)
 991     GrowShadowStack(thr);
 992 #endif
 993   thr->shadow_stack_pos[0] = pc;
 994   thr->shadow_stack_pos++;
 995 }
 996
 997 ALWAYS_INLINE USED
 998 void FuncExit(ThreadState *thr) {
 999   StatInc(thr, StatFuncExit);
1000   DPrintf2("#%d: FuncExit\n", (int)thr->fast_state.tid());
1001   if (kCollectHistory) {
1002     thr->fast_state.IncrementEpoch();
1003     TraceAddEvent(thr, thr->fast_state, EventTypeFuncExit, 0);
1004   }
1005
1006   DCHECK_GT(thr->shadow_stack_pos, thr->shadow_stack);
1007 #if !SANITIZER_GO
1008   DCHECK_LT(thr->shadow_stack_pos, thr->shadow_stack_end);
1009 #endif
1010   thr->shadow_stack_pos--;
1011 }
1012
1013 void ThreadIgnoreBegin(ThreadState *thr, uptr pc, bool save_stack) {
1014   DPrintf("#%d: ThreadIgnoreBegin\n", thr->tid);
1015   thr->ignore_reads_and_writes++;
1016   CHECK_GT(thr->ignore_reads_and_writes, 0);
1017   thr->fast_state.SetIgnoreBit();
1018 #if !SANITIZER_GO
1019   if (save_stack && !ctx->after_multithreaded_fork)
1020     thr->mop_ignore_set.Add(CurrentStackId(thr, pc));
1021 #endif
1022 }
1023
1024 void ThreadIgnoreEnd(ThreadState *thr, uptr pc) {
1025   DPrintf("#%d: ThreadIgnoreEnd\n", thr->tid);
1026   CHECK_GT(thr->ignore_reads_and_writes, 0);
1027   thr->ignore_reads_and_writes--;
1028   if (thr->ignore_reads_and_writes == 0) {
1029     thr->fast_state.ClearIgnoreBit();
1030 #if !SANITIZER_GO
1031     thr->mop_ignore_set.Reset();
1032 #endif
1033   }
1034 }
1035
1036 #if !SANITIZER_GO
1037 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
1038 uptr __tsan_testonly_shadow_stack_current_size() {
1039   ThreadState *thr = cur_thread();
1040   return thr->shadow_stack_pos - thr->shadow_stack;
1041 }
1042 #endif
1043
1044 void ThreadIgnoreSyncBegin(ThreadState *thr, uptr pc, bool save_stack) {
1045   DPrintf("#%d: ThreadIgnoreSyncBegin\n", thr->tid);
1046   thr->ignore_sync++;
1047   CHECK_GT(thr->ignore_sync, 0);
1048 #if !SANITIZER_GO
1049   if (save_stack && !ctx->after_multithreaded_fork)
1050     thr->sync_ignore_set.Add(CurrentStackId(thr, pc));
1051 #endif
1052 }
1053
1054 void ThreadIgnoreSyncEnd(ThreadState *thr, uptr pc) {
1055   DPrintf("#%d: ThreadIgnoreSyncEnd\n", thr->tid);
1056   CHECK_GT(thr->ignore_sync, 0);
1057   thr->ignore_sync--;
1058 #if !SANITIZER_GO
1059   if (thr->ignore_sync == 0)
1060     thr->sync_ignore_set.Reset();
1061 #endif
1062 }
1063
1064 bool MD5Hash::operator==(const MD5Hash &other) const {
1065   return hash[0] == other.hash[0] && hash[1] == other.hash[1];
1066 }
1067
1068 #if SANITIZER_DEBUG
1069 void build_consistency_debug() {}
1070 #else
1071 void build_consistency_release() {}
1072 #endif
1073
1074 #if TSAN_COLLECT_STATS
1075 void build_consistency_stats() {}
1076 #else
1077 void build_consistency_nostats() {}
1078 #endif
1079
1080 }  // namespace __tsan
1081
1082 #if !SANITIZER_GO
1083 // Must be included in this file to make sure everything is inlined.
1084 #include "tsan_interface_inl.h"
1085 #endif