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