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