src/llvm/projects/compiler-rt/lib/tsan/rtl/tsan_rtl.cc

   1 //===-- tsan_rtl.cc -------------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file is a part of ThreadSanitizer (TSan), a race detector.
  11 //
  12 // Main file (entry points) for the TSan run-time.
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_common/sanitizer_atomic.h"
  16 #include "sanitizer_common/sanitizer_common.h"
  17 #include "sanitizer_common/sanitizer_libc.h"
  18 #include "sanitizer_common/sanitizer_stackdepot.h"
  19 #include "sanitizer_common/sanitizer_placement_new.h"
  20 #include "sanitizer_common/sanitizer_symbolizer.h"
  21 #include "tsan_defs.h"
  22 #include "tsan_platform.h"
  23 #include "tsan_rtl.h"
  24 #include "tsan_mman.h"
  25 #include "tsan_suppressions.h"
  26
  27 volatile int __tsan_resumed = 0;
  28
  29 extern "C" void __tsan_resume() {
  30   __tsan_resumed = 1;
  31 }
  32
  33 namespace __tsan {
  34
  35 #ifndef TSAN_GO
  36 THREADLOCAL char cur_thread_placeholder[sizeof(ThreadState)] ALIGNED(64);
  37 #endif
  38 static char ctx_placeholder[sizeof(Context)] ALIGNED(64);
  39
  40 static Context *ctx;
  41 Context *CTX() {
  42   return ctx;
  43 }
  44
  45 Context::Context()
  46   : initialized()
  47   , report_mtx(MutexTypeReport, StatMtxReport)
  48   , nreported()
  49   , nmissed_expected()
  50   , thread_mtx(MutexTypeThreads, StatMtxThreads)
  51   , racy_stacks(MBlockRacyStacks)
  52   , racy_addresses(MBlockRacyAddresses) {
  53 }
  54
  55 // The objects are allocated in TLS, so one may rely on zero-initialization.
  56 ThreadState::ThreadState(Context *ctx, int tid, int unique_id, u64 epoch,
  57                          uptr stk_addr, uptr stk_size,
  58                          uptr tls_addr, uptr tls_size)
  59   : fast_state(tid, epoch)
  60   // Do not touch these, rely on zero initialization,
  61   // they may be accessed before the ctor.
  62   // , fast_ignore_reads()
  63   // , fast_ignore_writes()
  64   // , in_rtl()
  65   , shadow_stack_pos(&shadow_stack[0])
  66   , tid(tid)
  67   , unique_id(unique_id)
  68   , stk_addr(stk_addr)
  69   , stk_size(stk_size)
  70   , tls_addr(tls_addr)
  71   , tls_size(tls_size) {
  72 }
  73
  74 ThreadContext::ThreadContext(int tid)
  75   : tid(tid)
  76   , unique_id()
  77   , user_id()
  78   , thr()
  79   , status(ThreadStatusInvalid)
  80   , detached()
  81   , reuse_count()
  82   , epoch0()
  83   , epoch1()
  84   , dead_info()
  85   , dead_next() {
  86 }
  87
  88 static void WriteMemoryProfile(char *buf, uptr buf_size, int num) {
  89   uptr shadow = GetShadowMemoryConsumption();
  90
  91   int nthread = 0;
  92   int nlivethread = 0;
  93   uptr threadmem = 0;
  94   {
  95     Lock l(&ctx->thread_mtx);
  96     for (unsigned i = 0; i < kMaxTid; i++) {
  97       ThreadContext *tctx = ctx->threads[i];
  98       if (tctx == 0)
  99         continue;
 100       nthread += 1;
 101       threadmem += sizeof(ThreadContext);
 102       if (tctx->status != ThreadStatusRunning)
 103         continue;
 104       nlivethread += 1;
 105       threadmem += sizeof(ThreadState);
 106     }
 107   }
 108
 109   uptr nsync = 0;
 110   uptr syncmem = CTX()->synctab.GetMemoryConsumption(&nsync);
 111
 112   internal_snprintf(buf, buf_size, "%d: shadow=%zuMB"
 113                                    " thread=%zuMB(total=%d/live=%d)"
 114                                    " sync=%zuMB(cnt=%zu)\n",
 115     num,
 116     shadow >> 20,
 117     threadmem >> 20, nthread, nlivethread,
 118     syncmem >> 20, nsync);
 119 }
 120
 121 static void MemoryProfileThread(void *arg) {
 122   ScopedInRtl in_rtl;
 123   fd_t fd = (fd_t)(uptr)arg;
 124   for (int i = 0; ; i++) {
 125     InternalScopedBuffer<char> buf(4096);
 126     WriteMemoryProfile(buf.data(), buf.size(), i);
 127     internal_write(fd, buf.data(), internal_strlen(buf.data()));
 128     SleepForSeconds(1);
 129   }
 130 }
 131
 132 static void InitializeMemoryProfile() {
 133   if (flags()->profile_memory == 0 || flags()->profile_memory[0] == 0)
 134     return;
 135   InternalScopedBuffer<char> filename(4096);
 136   internal_snprintf(filename.data(), filename.size(), "%s.%d",
 137       flags()->profile_memory, GetPid());
 138   fd_t fd = internal_open(filename.data(), true);
 139   if (fd == kInvalidFd) {
 140     TsanPrintf("Failed to open memory profile file '%s'\n", &filename[0]);
 141     Die();
 142   }
 143   internal_start_thread(&MemoryProfileThread, (void*)(uptr)fd);
 144 }
 145
 146 static void MemoryFlushThread(void *arg) {
 147   ScopedInRtl in_rtl;
 148   for (int i = 0; ; i++) {
 149     SleepForMillis(flags()->flush_memory_ms);
 150     FlushShadowMemory();
 151   }
 152 }
 153
 154 static void InitializeMemoryFlush() {
 155   if (flags()->flush_memory_ms == 0)
 156     return;
 157   if (flags()->flush_memory_ms < 100)
 158     flags()->flush_memory_ms = 100;
 159   internal_start_thread(&MemoryFlushThread, 0);
 160 }
 161
 162 void Initialize(ThreadState *thr) {
 163   // Thread safe because done before all threads exist.
 164   static bool is_initialized = false;
 165   if (is_initialized)
 166     return;
 167   is_initialized = true;
 168   // Install tool-specific callbacks in sanitizer_common.
 169   SetCheckFailedCallback(TsanCheckFailed);
 170
 171   ScopedInRtl in_rtl;
 172 #ifndef TSAN_GO
 173   InitializeAllocator();
 174 #endif
 175   InitializeInterceptors();
 176   const char *env = InitializePlatform();
 177   InitializeMutex();
 178   InitializeDynamicAnnotations();
 179   ctx = new(ctx_placeholder) Context;
 180   InitializeShadowMemory();
 181   ctx->dead_list_size = 0;
 182   ctx->dead_list_head = 0;
 183   ctx->dead_list_tail = 0;
 184   InitializeFlags(&ctx->flags, env);
 185   InitializeSuppressions();
 186 #ifndef TSAN_GO
 187   // Initialize external symbolizer before internal threads are started.
 188   const char *external_symbolizer = flags()->external_symbolizer_path;
 189   if (external_symbolizer != 0 && external_symbolizer[0] != '\0') {
 190     InitializeExternalSymbolizer(external_symbolizer);
 191   }
 192 #endif
 193   InitializeMemoryProfile();
 194   InitializeMemoryFlush();
 195
 196   if (ctx->flags.verbosity)
 197     TsanPrintf("***** Running under ThreadSanitizer v2 (pid %d) *****\n",
 198                GetPid());
 199
 200   // Initialize thread 0.
 201   ctx->thread_seq = 0;
 202   int tid = ThreadCreate(thr, 0, 0, true);
 203   CHECK_EQ(tid, 0);
 204   ThreadStart(thr, tid);
 205   CHECK_EQ(thr->in_rtl, 1);
 206   ctx->initialized = true;
 207
 208   if (flags()->stop_on_start) {
 209     TsanPrintf("ThreadSanitizer is suspended at startup (pid %d)."
 210            " Call __tsan_resume().\n",
 211            GetPid());
 212     while (__tsan_resumed == 0);
 213   }
 214 }
 215
 216 int Finalize(ThreadState *thr) {
 217   ScopedInRtl in_rtl;
 218   Context *ctx = __tsan::ctx;
 219   bool failed = false;
 220
 221   ThreadFinalize(thr);
 222
 223   if (ctx->nreported) {
 224     failed = true;
 225     TsanPrintf("ThreadSanitizer: reported %d warnings\n", ctx->nreported);
 226   }
 227
 228   if (ctx->nmissed_expected) {
 229     failed = true;
 230     TsanPrintf("ThreadSanitizer: missed %d expected races\n",
 231         ctx->nmissed_expected);
 232   }
 233
 234   StatOutput(ctx->stat);
 235   return failed ? flags()->exitcode : 0;
 236 }
 237
 238 #ifndef TSAN_GO
 239 u32 CurrentStackId(ThreadState *thr, uptr pc) {
 240   if (thr->shadow_stack_pos == 0)  // May happen during bootstrap.
 241     return 0;
 242   if (pc) {
 243     thr->shadow_stack_pos[0] = pc;
 244     thr->shadow_stack_pos++;
 245   }
 246   u32 id = StackDepotPut(thr->shadow_stack,
 247                          thr->shadow_stack_pos - thr->shadow_stack);
 248   if (pc)
 249     thr->shadow_stack_pos--;
 250   return id;
 251 }
 252 #endif
 253
 254 void TraceSwitch(ThreadState *thr) {
 255   thr->nomalloc++;
 256   ScopedInRtl in_rtl;
 257   Lock l(&thr->trace.mtx);
 258   unsigned trace = (thr->fast_state.epoch() / kTracePartSize) % kTraceParts;
 259   TraceHeader *hdr = &thr->trace.headers[trace];
 260   hdr->epoch0 = thr->fast_state.epoch();
 261   hdr->stack0.ObtainCurrent(thr, 0);
 262   thr->nomalloc--;
 263 }
 264
 265 #ifndef TSAN_GO
 266 extern "C" void __tsan_trace_switch() {
 267   TraceSwitch(cur_thread());
 268 }
 269
 270 extern "C" void __tsan_report_race() {
 271   ReportRace(cur_thread());
 272 }
 273 #endif
 274
 275 ALWAYS_INLINE
 276 static Shadow LoadShadow(u64 *p) {
 277   u64 raw = atomic_load((atomic_uint64_t*)p, memory_order_relaxed);
 278   return Shadow(raw);
 279 }
 280
 281 ALWAYS_INLINE
 282 static void StoreShadow(u64 *sp, u64 s) {
 283   atomic_store((atomic_uint64_t*)sp, s, memory_order_relaxed);
 284 }
 285
 286 ALWAYS_INLINE
 287 static void StoreIfNotYetStored(u64 *sp, u64 *s) {
 288   StoreShadow(sp, *s);
 289   *s = 0;
 290 }
 291
 292 static inline void HandleRace(ThreadState *thr, u64 *shadow_mem,
 293                               Shadow cur, Shadow old) {
 294   thr->racy_state[0] = cur.raw();
 295   thr->racy_state[1] = old.raw();
 296   thr->racy_shadow_addr = shadow_mem;
 297 #ifndef TSAN_GO
 298   HACKY_CALL(__tsan_report_race);
 299 #else
 300   ReportRace(thr);
 301 #endif
 302 }
 303
 304 static inline bool BothReads(Shadow s, int kAccessIsWrite) {
 305   return !kAccessIsWrite && !s.is_write();
 306 }
 307
 308 static inline bool OldIsRWStronger(Shadow old, int kAccessIsWrite) {
 309   return old.is_write() || !kAccessIsWrite;
 310 }
 311
 312 static inline bool OldIsRWWeaker(Shadow old, int kAccessIsWrite) {
 313   return !old.is_write() || kAccessIsWrite;
 314 }
 315
 316 static inline bool OldIsInSameSynchEpoch(Shadow old, ThreadState *thr) {
 317   return old.epoch() >= thr->fast_synch_epoch;
 318 }
 319
 320 static inline bool HappensBefore(Shadow old, ThreadState *thr) {
 321   return thr->clock.get(old.tid()) >= old.epoch();
 322 }
 323
 324 ALWAYS_INLINE
 325 void MemoryAccessImpl(ThreadState *thr, uptr addr,
 326     int kAccessSizeLog, bool kAccessIsWrite, FastState fast_state,
 327     u64 *shadow_mem, Shadow cur) {
 328   StatInc(thr, StatMop);
 329   StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
 330   StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
 331
 332   // This potentially can live in an MMX/SSE scratch register.
 333   // The required intrinsics are:
 334   // __m128i _mm_move_epi64(__m128i*);
 335   // _mm_storel_epi64(u64*, __m128i);
 336   u64 store_word = cur.raw();
 337
 338   // scan all the shadow values and dispatch to 4 categories:
 339   // same, replace, candidate and race (see comments below).
 340   // we consider only 3 cases regarding access sizes:
 341   // equal, intersect and not intersect. initially I considered
 342   // larger and smaller as well, it allowed to replace some
 343   // 'candidates' with 'same' or 'replace', but I think
 344   // it's just not worth it (performance- and complexity-wise).
 345
 346   Shadow old(0);
 347   if (kShadowCnt == 1) {
 348     int idx = 0;
 349 #include "tsan_update_shadow_word_inl.h"
 350   } else if (kShadowCnt == 2) {
 351     int idx = 0;
 352 #include "tsan_update_shadow_word_inl.h"
 353     idx = 1;
 354 #include "tsan_update_shadow_word_inl.h"
 355   } else if (kShadowCnt == 4) {
 356     int idx = 0;
 357 #include "tsan_update_shadow_word_inl.h"
 358     idx = 1;
 359 #include "tsan_update_shadow_word_inl.h"
 360     idx = 2;
 361 #include "tsan_update_shadow_word_inl.h"
 362     idx = 3;
 363 #include "tsan_update_shadow_word_inl.h"
 364   } else if (kShadowCnt == 8) {
 365     int idx = 0;
 366 #include "tsan_update_shadow_word_inl.h"
 367     idx = 1;
 368 #include "tsan_update_shadow_word_inl.h"
 369     idx = 2;
 370 #include "tsan_update_shadow_word_inl.h"
 371     idx = 3;
 372 #include "tsan_update_shadow_word_inl.h"
 373     idx = 4;
 374 #include "tsan_update_shadow_word_inl.h"
 375     idx = 5;
 376 #include "tsan_update_shadow_word_inl.h"
 377     idx = 6;
 378 #include "tsan_update_shadow_word_inl.h"
 379     idx = 7;
 380 #include "tsan_update_shadow_word_inl.h"
 381   } else {
 382     CHECK(false);
 383   }
 384
 385   // we did not find any races and had already stored
 386   // the current access info, so we are done
 387   if (LIKELY(store_word == 0))
 388     return;
 389   // choose a random candidate slot and replace it
 390   StoreShadow(shadow_mem + (cur.epoch() % kShadowCnt), store_word);
 391   StatInc(thr, StatShadowReplace);
 392   return;
 393  RACE:
 394   HandleRace(thr, shadow_mem, cur, old);
 395   return;
 396 }
 397
 398 ALWAYS_INLINE
 399 void MemoryAccess(ThreadState *thr, uptr pc, uptr addr,
 400     int kAccessSizeLog, bool kAccessIsWrite) {
 401   u64 *shadow_mem = (u64*)MemToShadow(addr);
 402   DPrintf2("#%d: tsan::OnMemoryAccess: @%p %p size=%d"
 403       " is_write=%d shadow_mem=%p {%zx, %zx, %zx, %zx}\n",
 404       (int)thr->fast_state.tid(), (void*)pc, (void*)addr,
 405       (int)(1 << kAccessSizeLog), kAccessIsWrite, shadow_mem,
 406       (uptr)shadow_mem[0], (uptr)shadow_mem[1],
 407       (uptr)shadow_mem[2], (uptr)shadow_mem[3]);
 408 #if TSAN_DEBUG
 409   if (!IsAppMem(addr)) {
 410     TsanPrintf("Access to non app mem %zx\n", addr);
 411     DCHECK(IsAppMem(addr));
 412   }
 413   if (!IsShadowMem((uptr)shadow_mem)) {
 414     TsanPrintf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
 415     DCHECK(IsShadowMem((uptr)shadow_mem));
 416   }
 417 #endif
 418
 419   FastState fast_state = thr->fast_state;
 420   if (fast_state.GetIgnoreBit())
 421     return;
 422   fast_state.IncrementEpoch();
 423   thr->fast_state = fast_state;
 424   Shadow cur(fast_state);
 425   cur.SetAddr0AndSizeLog(addr & 7, kAccessSizeLog);
 426   cur.SetWrite(kAccessIsWrite);
 427
 428   // We must not store to the trace if we do not store to the shadow.
 429   // That is, this call must be moved somewhere below.
 430   TraceAddEvent(thr, fast_state.epoch(), EventTypeMop, pc);
 431
 432   MemoryAccessImpl(thr, addr, kAccessSizeLog, kAccessIsWrite, fast_state,
 433       shadow_mem, cur);
 434 }
 435
 436 static void MemoryRangeSet(ThreadState *thr, uptr pc, uptr addr, uptr size,
 437                            u64 val) {
 438   if (size == 0)
 439     return;
 440   // FIXME: fix me.
 441   uptr offset = addr % kShadowCell;
 442   if (offset) {
 443     offset = kShadowCell - offset;
 444     if (size <= offset)
 445       return;
 446     addr += offset;
 447     size -= offset;
 448   }
 449   DCHECK_EQ(addr % 8, 0);
 450   // If a user passes some insane arguments (memset(0)),
 451   // let it just crash as usual.
 452   if (!IsAppMem(addr) || !IsAppMem(addr + size - 1))
 453     return;
 454   (void)thr;
 455   (void)pc;
 456   // Some programs mmap like hundreds of GBs but actually used a small part.
 457   // So, it's better to report a false positive on the memory
 458   // then to hang here senselessly.
 459   const uptr kMaxResetSize = 4ull*1024*1024*1024;
 460   if (size > kMaxResetSize)
 461     size = kMaxResetSize;
 462   size = (size + (kShadowCell - 1)) & ~(kShadowCell - 1);
 463   u64 *p = (u64*)MemToShadow(addr);
 464   CHECK(IsShadowMem((uptr)p));
 465   CHECK(IsShadowMem((uptr)(p + size * kShadowCnt / kShadowCell - 1)));
 466   // FIXME: may overwrite a part outside the region
 467   for (uptr i = 0; i < size * kShadowCnt / kShadowCell;) {
 468     p[i++] = val;
 469     for (uptr j = 1; j < kShadowCnt; j++)
 470       p[i++] = 0;
 471   }
 472 }
 473
 474 void MemoryResetRange(ThreadState *thr, uptr pc, uptr addr, uptr size) {
 475   MemoryRangeSet(thr, pc, addr, size, 0);
 476 }
 477
 478 void MemoryRangeFreed(ThreadState *thr, uptr pc, uptr addr, uptr size) {
 479   MemoryAccessRange(thr, pc, addr, size, true);
 480   Shadow s(thr->fast_state);
 481   s.MarkAsFreed();
 482   s.SetWrite(true);
 483   s.SetAddr0AndSizeLog(0, 3);
 484   MemoryRangeSet(thr, pc, addr, size, s.raw());
 485 }
 486
 487 void MemoryRangeImitateWrite(ThreadState *thr, uptr pc, uptr addr, uptr size) {
 488   Shadow s(thr->fast_state);
 489   s.SetWrite(true);
 490   s.SetAddr0AndSizeLog(0, 3);
 491   MemoryRangeSet(thr, pc, addr, size, s.raw());
 492 }
 493
 494 void FuncEntry(ThreadState *thr, uptr pc) {
 495   DCHECK_EQ(thr->in_rtl, 0);
 496   StatInc(thr, StatFuncEnter);
 497   DPrintf2("#%d: FuncEntry %p\n", (int)thr->fast_state.tid(), (void*)pc);
 498   thr->fast_state.IncrementEpoch();
 499   TraceAddEvent(thr, thr->fast_state.epoch(), EventTypeFuncEnter, pc);
 500
 501   // Shadow stack maintenance can be replaced with
 502   // stack unwinding during trace switch (which presumably must be faster).
 503   DCHECK_GE(thr->shadow_stack_pos, &thr->shadow_stack[0]);
 504 #ifndef TSAN_GO
 505   DCHECK_LT(thr->shadow_stack_pos, &thr->shadow_stack[kShadowStackSize]);
 506 #else
 507   if (thr->shadow_stack_pos == thr->shadow_stack_end) {
 508     const int sz = thr->shadow_stack_end - thr->shadow_stack;
 509     const int newsz = 2 * sz;
 510     uptr *newstack = (uptr*)internal_alloc(MBlockShadowStack,
 511         newsz * sizeof(uptr));
 512     internal_memcpy(newstack, thr->shadow_stack, sz * sizeof(uptr));
 513     internal_free(thr->shadow_stack);
 514     thr->shadow_stack = newstack;
 515     thr->shadow_stack_pos = newstack + sz;
 516     thr->shadow_stack_end = newstack + newsz;
 517   }
 518 #endif
 519   thr->shadow_stack_pos[0] = pc;
 520   thr->shadow_stack_pos++;
 521 }
 522
 523 void FuncExit(ThreadState *thr) {
 524   DCHECK_EQ(thr->in_rtl, 0);
 525   StatInc(thr, StatFuncExit);
 526   DPrintf2("#%d: FuncExit\n", (int)thr->fast_state.tid());
 527   thr->fast_state.IncrementEpoch();
 528   TraceAddEvent(thr, thr->fast_state.epoch(), EventTypeFuncExit, 0);
 529
 530   DCHECK_GT(thr->shadow_stack_pos, &thr->shadow_stack[0]);
 531 #ifndef TSAN_GO
 532   DCHECK_LT(thr->shadow_stack_pos, &thr->shadow_stack[kShadowStackSize]);
 533 #endif
 534   thr->shadow_stack_pos--;
 535 }
 536
 537 void IgnoreCtl(ThreadState *thr, bool write, bool begin) {
 538   DPrintf("#%d: IgnoreCtl(%d, %d)\n", thr->tid, write, begin);
 539   thr->ignore_reads_and_writes += begin ? 1 : -1;
 540   CHECK_GE(thr->ignore_reads_and_writes, 0);
 541   if (thr->ignore_reads_and_writes)
 542     thr->fast_state.SetIgnoreBit();
 543   else
 544     thr->fast_state.ClearIgnoreBit();
 545 }
 546
 547 bool MD5Hash::operator==(const MD5Hash &other) const {
 548   return hash[0] == other.hash[0] && hash[1] == other.hash[1];
 549 }
 550
 551 #if TSAN_DEBUG
 552 void build_consistency_debug() {}
 553 #else
 554 void build_consistency_release() {}
 555 #endif
 556
 557 #if TSAN_COLLECT_STATS
 558 void build_consistency_stats() {}
 559 #else
 560 void build_consistency_nostats() {}
 561 #endif
 562
 563 #if TSAN_SHADOW_COUNT == 1
 564 void build_consistency_shadow1() {}
 565 #elif TSAN_SHADOW_COUNT == 2
 566 void build_consistency_shadow2() {}
 567 #elif TSAN_SHADOW_COUNT == 4
 568 void build_consistency_shadow4() {}
 569 #else
 570 void build_consistency_shadow8() {}
 571 #endif
 572
 573 }  // namespace __tsan
 574
 575 #ifndef TSAN_GO
 576 // Must be included in this file to make sure everything is inlined.
 577 #include "tsan_interface_inl.h"
 578 #endif