libsanitizer/tsan/tsan_rtl_thread.cc

   1 //===-- tsan_rtl_thread.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_placement_new.h"
  13 #include "tsan_rtl.h"
  14 #include "tsan_mman.h"
  15 #include "tsan_platform.h"
  16 #include "tsan_report.h"
  17 #include "tsan_sync.h"
  18
  19 namespace __tsan {
  20
  21 // ThreadContext implementation.
  22
  23 ThreadContext::ThreadContext(int tid)
  24   : ThreadContextBase(tid)
  25   , thr()
  26   , sync()
  27   , epoch0()
  28   , epoch1() {
  29 }
  30
  31 #ifndef SANITIZER_GO
  32 ThreadContext::~ThreadContext() {
  33 }
  34 #endif
  35
  36 void ThreadContext::OnDead() {
  37   CHECK_EQ(sync.size(), 0);
  38 }
  39
  40 void ThreadContext::OnJoined(void *arg) {
  41   ThreadState *caller_thr = static_cast<ThreadState *>(arg);
  42   AcquireImpl(caller_thr, 0, &sync);
  43   sync.Reset(&caller_thr->clock_cache);
  44 }
  45
  46 struct OnCreatedArgs {
  47   ThreadState *thr;
  48   uptr pc;
  49 };
  50
  51 void ThreadContext::OnCreated(void *arg) {
  52   thr = 0;
  53   if (tid == 0)
  54     return;
  55   OnCreatedArgs *args = static_cast<OnCreatedArgs *>(arg);
  56   if (!args->thr)  // GCD workers don't have a parent thread.
  57     return;
  58   args->thr->fast_state.IncrementEpoch();
  59   // Can't increment epoch w/o writing to the trace as well.
  60   TraceAddEvent(args->thr, args->thr->fast_state, EventTypeMop, 0);
  61   ReleaseImpl(args->thr, 0, &sync);
  62   creation_stack_id = CurrentStackId(args->thr, args->pc);
  63   if (reuse_count == 0)
  64     StatInc(args->thr, StatThreadMaxTid);
  65 }
  66
  67 void ThreadContext::OnReset() {
  68   CHECK_EQ(sync.size(), 0);
  69   FlushUnneededShadowMemory(GetThreadTrace(tid), TraceSize() * sizeof(Event));
  70   //!!! FlushUnneededShadowMemory(GetThreadTraceHeader(tid), sizeof(Trace));
  71 }
  72
  73 void ThreadContext::OnDetached(void *arg) {
  74   ThreadState *thr1 = static_cast<ThreadState*>(arg);
  75   sync.Reset(&thr1->clock_cache);
  76 }
  77
  78 struct OnStartedArgs {
  79   ThreadState *thr;
  80   uptr stk_addr;
  81   uptr stk_size;
  82   uptr tls_addr;
  83   uptr tls_size;
  84 };
  85
  86 void ThreadContext::OnStarted(void *arg) {
  87   OnStartedArgs *args = static_cast<OnStartedArgs*>(arg);
  88   thr = args->thr;
  89   // RoundUp so that one trace part does not contain events
  90   // from different threads.
  91   epoch0 = RoundUp(epoch1 + 1, kTracePartSize);
  92   epoch1 = (u64)-1;
  93   new(thr) ThreadState(ctx, tid, unique_id, epoch0, reuse_count,
  94       args->stk_addr, args->stk_size, args->tls_addr, args->tls_size);
  95 #ifndef SANITIZER_GO
  96   thr->shadow_stack = &ThreadTrace(thr->tid)->shadow_stack[0];
  97   thr->shadow_stack_pos = thr->shadow_stack;
  98   thr->shadow_stack_end = thr->shadow_stack + kShadowStackSize;
  99 #else
 100   // Setup dynamic shadow stack.
 101   const int kInitStackSize = 8;
 102   thr->shadow_stack = (uptr*)internal_alloc(MBlockShadowStack,
 103       kInitStackSize * sizeof(uptr));
 104   thr->shadow_stack_pos = thr->shadow_stack;
 105   thr->shadow_stack_end = thr->shadow_stack + kInitStackSize;
 106 #endif
 107 #ifndef SANITIZER_GO
 108   AllocatorThreadStart(thr);
 109 #endif
 110   if (common_flags()->detect_deadlocks) {
 111     thr->dd_pt = ctx->dd->CreatePhysicalThread();
 112     thr->dd_lt = ctx->dd->CreateLogicalThread(unique_id);
 113   }
 114   thr->fast_state.SetHistorySize(flags()->history_size);
 115   // Commit switch to the new part of the trace.
 116   // TraceAddEvent will reset stack0/mset0 in the new part for us.
 117   TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
 118
 119   thr->fast_synch_epoch = epoch0;
 120   AcquireImpl(thr, 0, &sync);
 121   StatInc(thr, StatSyncAcquire);
 122   sync.Reset(&thr->clock_cache);
 123   thr->is_inited = true;
 124   DPrintf("#%d: ThreadStart epoch=%zu stk_addr=%zx stk_size=%zx "
 125           "tls_addr=%zx tls_size=%zx\n",
 126           tid, (uptr)epoch0, args->stk_addr, args->stk_size,
 127           args->tls_addr, args->tls_size);
 128 }
 129
 130 void ThreadContext::OnFinished() {
 131   if (!detached) {
 132     thr->fast_state.IncrementEpoch();
 133     // Can't increment epoch w/o writing to the trace as well.
 134     TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
 135     ReleaseImpl(thr, 0, &sync);
 136   }
 137   epoch1 = thr->fast_state.epoch();
 138
 139   if (common_flags()->detect_deadlocks) {
 140     ctx->dd->DestroyPhysicalThread(thr->dd_pt);
 141     ctx->dd->DestroyLogicalThread(thr->dd_lt);
 142   }
 143   ctx->clock_alloc.FlushCache(&thr->clock_cache);
 144   ctx->metamap.OnThreadIdle(thr);
 145 #ifndef SANITIZER_GO
 146   AllocatorThreadFinish(thr);
 147 #endif
 148   thr->~ThreadState();
 149 #if TSAN_COLLECT_STATS
 150   StatAggregate(ctx->stat, thr->stat);
 151 #endif
 152   thr = 0;
 153 }
 154
 155 #ifndef SANITIZER_GO
 156 struct ThreadLeak {
 157   ThreadContext *tctx;
 158   int count;
 159 };
 160
 161 static void MaybeReportThreadLeak(ThreadContextBase *tctx_base, void *arg) {
 162   Vector<ThreadLeak> &leaks = *(Vector<ThreadLeak>*)arg;
 163   ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base);
 164   if (tctx->detached || tctx->status != ThreadStatusFinished)
 165     return;
 166   for (uptr i = 0; i < leaks.Size(); i++) {
 167     if (leaks[i].tctx->creation_stack_id == tctx->creation_stack_id) {
 168       leaks[i].count++;
 169       return;
 170     }
 171   }
 172   ThreadLeak leak = {tctx, 1};
 173   leaks.PushBack(leak);
 174 }
 175 #endif
 176
 177 #ifndef SANITIZER_GO
 178 static void ReportIgnoresEnabled(ThreadContext *tctx, IgnoreSet *set) {
 179   if (tctx->tid == 0) {
 180     Printf("ThreadSanitizer: main thread finished with ignores enabled\n");
 181   } else {
 182     Printf("ThreadSanitizer: thread T%d %s finished with ignores enabled,"
 183       " created at:\n", tctx->tid, tctx->name);
 184     PrintStack(SymbolizeStackId(tctx->creation_stack_id));
 185   }
 186   Printf("  One of the following ignores was not ended"
 187       " (in order of probability)\n");
 188   for (uptr i = 0; i < set->Size(); i++) {
 189     Printf("  Ignore was enabled at:\n");
 190     PrintStack(SymbolizeStackId(set->At(i)));
 191   }
 192   Die();
 193 }
 194
 195 static void ThreadCheckIgnore(ThreadState *thr) {
 196   if (ctx->after_multithreaded_fork)
 197     return;
 198   if (thr->ignore_reads_and_writes)
 199     ReportIgnoresEnabled(thr->tctx, &thr->mop_ignore_set);
 200   if (thr->ignore_sync)
 201     ReportIgnoresEnabled(thr->tctx, &thr->sync_ignore_set);
 202 }
 203 #else
 204 static void ThreadCheckIgnore(ThreadState *thr) {}
 205 #endif
 206
 207 void ThreadFinalize(ThreadState *thr) {
 208   ThreadCheckIgnore(thr);
 209 #ifndef SANITIZER_GO
 210   if (!flags()->report_thread_leaks)
 211     return;
 212   ThreadRegistryLock l(ctx->thread_registry);
 213   Vector<ThreadLeak> leaks(MBlockScopedBuf);
 214   ctx->thread_registry->RunCallbackForEachThreadLocked(
 215       MaybeReportThreadLeak, &leaks);
 216   for (uptr i = 0; i < leaks.Size(); i++) {
 217     ScopedReport rep(ReportTypeThreadLeak);
 218     rep.AddThread(leaks[i].tctx, true);
 219     rep.SetCount(leaks[i].count);
 220     OutputReport(thr, rep);
 221   }
 222 #endif
 223 }
 224
 225 int ThreadCount(ThreadState *thr) {
 226   uptr result;
 227   ctx->thread_registry->GetNumberOfThreads(0, 0, &result);
 228   return (int)result;
 229 }
 230
 231 int ThreadCreate(ThreadState *thr, uptr pc, uptr uid, bool detached) {
 232   StatInc(thr, StatThreadCreate);
 233   OnCreatedArgs args = { thr, pc };
 234   u32 parent_tid = thr ? thr->tid : kInvalidTid;  // No parent for GCD workers.
 235   int tid =
 236       ctx->thread_registry->CreateThread(uid, detached, parent_tid, &args);
 237   DPrintf("#%d: ThreadCreate tid=%d uid=%zu\n", parent_tid, tid, uid);
 238   StatSet(thr, StatThreadMaxAlive, ctx->thread_registry->GetMaxAliveThreads());
 239   return tid;
 240 }
 241
 242 void ThreadStart(ThreadState *thr, int tid, uptr os_id) {
 243   uptr stk_addr = 0;
 244   uptr stk_size = 0;
 245   uptr tls_addr = 0;
 246   uptr tls_size = 0;
 247 #ifndef SANITIZER_GO
 248   GetThreadStackAndTls(tid == 0, &stk_addr, &stk_size, &tls_addr, &tls_size);
 249
 250   if (tid) {
 251     if (stk_addr && stk_size)
 252       MemoryRangeImitateWrite(thr, /*pc=*/ 1, stk_addr, stk_size);
 253
 254     if (tls_addr && tls_size) {
 255       // Check that the thr object is in tls;
 256       const uptr thr_beg = (uptr)thr;
 257       const uptr thr_end = (uptr)thr + sizeof(*thr);
 258       CHECK_GE(thr_beg, tls_addr);
 259       CHECK_LE(thr_beg, tls_addr + tls_size);
 260       CHECK_GE(thr_end, tls_addr);
 261       CHECK_LE(thr_end, tls_addr + tls_size);
 262       // Since the thr object is huge, skip it.
 263       MemoryRangeImitateWrite(thr, /*pc=*/ 2, tls_addr, thr_beg - tls_addr);
 264       MemoryRangeImitateWrite(thr, /*pc=*/ 2,
 265           thr_end, tls_addr + tls_size - thr_end);
 266     }
 267   }
 268 #endif
 269
 270   ThreadRegistry *tr = ctx->thread_registry;
 271   OnStartedArgs args = { thr, stk_addr, stk_size, tls_addr, tls_size };
 272   tr->StartThread(tid, os_id, &args);
 273
 274   tr->Lock();
 275   thr->tctx = (ThreadContext*)tr->GetThreadLocked(tid);
 276   tr->Unlock();
 277
 278 #ifndef SANITIZER_GO
 279   if (ctx->after_multithreaded_fork) {
 280     thr->ignore_interceptors++;
 281     ThreadIgnoreBegin(thr, 0);
 282     ThreadIgnoreSyncBegin(thr, 0);
 283   }
 284 #endif
 285 }
 286
 287 void ThreadFinish(ThreadState *thr) {
 288   ThreadCheckIgnore(thr);
 289   StatInc(thr, StatThreadFinish);
 290   if (thr->stk_addr && thr->stk_size)
 291     DontNeedShadowFor(thr->stk_addr, thr->stk_size);
 292   if (thr->tls_addr && thr->tls_size)
 293     DontNeedShadowFor(thr->tls_addr, thr->tls_size);
 294   thr->is_dead = true;
 295   ctx->thread_registry->FinishThread(thr->tid);
 296 }
 297
 298 static bool FindThreadByUid(ThreadContextBase *tctx, void *arg) {
 299   uptr uid = (uptr)arg;
 300   if (tctx->user_id == uid && tctx->status != ThreadStatusInvalid) {
 301     tctx->user_id = 0;
 302     return true;
 303   }
 304   return false;
 305 }
 306
 307 int ThreadTid(ThreadState *thr, uptr pc, uptr uid) {
 308   int res = ctx->thread_registry->FindThread(FindThreadByUid, (void*)uid);
 309   DPrintf("#%d: ThreadTid uid=%zu tid=%d\n", thr->tid, uid, res);
 310   return res;
 311 }
 312
 313 void ThreadJoin(ThreadState *thr, uptr pc, int tid) {
 314   CHECK_GT(tid, 0);
 315   CHECK_LT(tid, kMaxTid);
 316   DPrintf("#%d: ThreadJoin tid=%d\n", thr->tid, tid);
 317   ctx->thread_registry->JoinThread(tid, thr);
 318 }
 319
 320 void ThreadDetach(ThreadState *thr, uptr pc, int tid) {
 321   CHECK_GT(tid, 0);
 322   CHECK_LT(tid, kMaxTid);
 323   ctx->thread_registry->DetachThread(tid, thr);
 324 }
 325
 326 void ThreadSetName(ThreadState *thr, const char *name) {
 327   ctx->thread_registry->SetThreadName(thr->tid, name);
 328 }
 329
 330 void MemoryAccessRange(ThreadState *thr, uptr pc, uptr addr,
 331                        uptr size, bool is_write) {
 332   if (size == 0)
 333     return;
 334
 335   u64 *shadow_mem = (u64*)MemToShadow(addr);
 336   DPrintf2("#%d: MemoryAccessRange: @%p %p size=%d is_write=%d\n",
 337       thr->tid, (void*)pc, (void*)addr,
 338       (int)size, is_write);
 339
 340 #if SANITIZER_DEBUG
 341   if (!IsAppMem(addr)) {
 342     Printf("Access to non app mem %zx\n", addr);
 343     DCHECK(IsAppMem(addr));
 344   }
 345   if (!IsAppMem(addr + size - 1)) {
 346     Printf("Access to non app mem %zx\n", addr + size - 1);
 347     DCHECK(IsAppMem(addr + size - 1));
 348   }
 349   if (!IsShadowMem((uptr)shadow_mem)) {
 350     Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
 351     DCHECK(IsShadowMem((uptr)shadow_mem));
 352   }
 353   if (!IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1))) {
 354     Printf("Bad shadow addr %p (%zx)\n",
 355                shadow_mem + size * kShadowCnt / 8 - 1, addr + size - 1);
 356     DCHECK(IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1)));
 357   }
 358 #endif
 359
 360   StatInc(thr, StatMopRange);
 361
 362   if (*shadow_mem == kShadowRodata) {
 363     // Access to .rodata section, no races here.
 364     // Measurements show that it can be 10-20% of all memory accesses.
 365     StatInc(thr, StatMopRangeRodata);
 366     return;
 367   }
 368
 369   FastState fast_state = thr->fast_state;
 370   if (fast_state.GetIgnoreBit())
 371     return;
 372
 373   fast_state.IncrementEpoch();
 374   thr->fast_state = fast_state;
 375   TraceAddEvent(thr, fast_state, EventTypeMop, pc);
 376
 377   bool unaligned = (addr % kShadowCell) != 0;
 378
 379   // Handle unaligned beginning, if any.
 380   for (; addr % kShadowCell && size; addr++, size--) {
 381     int const kAccessSizeLog = 0;
 382     Shadow cur(fast_state);
 383     cur.SetWrite(is_write);
 384     cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
 385     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 386         shadow_mem, cur);
 387   }
 388   if (unaligned)
 389     shadow_mem += kShadowCnt;
 390   // Handle middle part, if any.
 391   for (; size >= kShadowCell; addr += kShadowCell, size -= kShadowCell) {
 392     int const kAccessSizeLog = 3;
 393     Shadow cur(fast_state);
 394     cur.SetWrite(is_write);
 395     cur.SetAddr0AndSizeLog(0, kAccessSizeLog);
 396     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 397         shadow_mem, cur);
 398     shadow_mem += kShadowCnt;
 399   }
 400   // Handle ending, if any.
 401   for (; size; addr++, size--) {
 402     int const kAccessSizeLog = 0;
 403     Shadow cur(fast_state);
 404     cur.SetWrite(is_write);
 405     cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
 406     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 407         shadow_mem, cur);
 408   }
 409 }
 410
 411 }  // namespace __tsan