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