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   ReleaseMemoryToOS(GetThreadTrace(tid), TraceSize() * sizeof(Event));
  70   //!!! ReleaseMemoryToOS(GetThreadTraceHeader(tid), sizeof(Trace));
  71 }
  72
  73 void ThreadContext::OnDetached(void *arg) {
  74   ThreadState *thr1 = static_cast<ThreadState*>(arg);
  75   sync.Reset(&thr1->proc()->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 #if !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   if (common_flags()->detect_deadlocks)
 108     thr->dd_lt = ctx->dd->CreateLogicalThread(unique_id);
 109   thr->fast_state.SetHistorySize(flags()->history_size);
 110   // Commit switch to the new part of the trace.
 111   // TraceAddEvent will reset stack0/mset0 in the new part for us.
 112   TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
 113
 114   thr->fast_synch_epoch = epoch0;
 115   AcquireImpl(thr, 0, &sync);
 116   StatInc(thr, StatSyncAcquire);
 117   sync.Reset(&thr->proc()->clock_cache);
 118   thr->is_inited = true;
 119   DPrintf("#%d: ThreadStart epoch=%zu stk_addr=%zx stk_size=%zx "
 120           "tls_addr=%zx tls_size=%zx\n",
 121           tid, (uptr)epoch0, args->stk_addr, args->stk_size,
 122           args->tls_addr, args->tls_size);
 123 }
 124
 125 void ThreadContext::OnFinished() {
 126 #if SANITIZER_GO
 127   internal_free(thr->shadow_stack);
 128   thr->shadow_stack = nullptr;
 129   thr->shadow_stack_pos = nullptr;
 130   thr->shadow_stack_end = nullptr;
 131 #endif
 132   if (!detached) {
 133     thr->fast_state.IncrementEpoch();
 134     // Can't increment epoch w/o writing to the trace as well.
 135     TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
 136     ReleaseImpl(thr, 0, &sync);
 137   }
 138   epoch1 = thr->fast_state.epoch();
 139
 140   if (common_flags()->detect_deadlocks)
 141     ctx->dd->DestroyLogicalThread(thr->dd_lt);
 142   thr->~ThreadState();
 143 #if TSAN_COLLECT_STATS
 144   StatAggregate(ctx->stat, thr->stat);
 145 #endif
 146   thr = 0;
 147 }
 148
 149 #if !SANITIZER_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 #if !SANITIZER_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 #if !SANITIZER_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   u32 parent_tid = thr ? thr->tid : kInvalidTid;  // No parent for GCD workers.
 229   int tid =
 230       ctx->thread_registry->CreateThread(uid, detached, parent_tid, &args);
 231   DPrintf("#%d: ThreadCreate tid=%d uid=%zu\n", parent_tid, tid, uid);
 232   StatSet(thr, StatThreadMaxAlive, ctx->thread_registry->GetMaxAliveThreads());
 233   return tid;
 234 }
 235
 236 void ThreadStart(ThreadState *thr, int tid, uptr os_id) {
 237   uptr stk_addr = 0;
 238   uptr stk_size = 0;
 239   uptr tls_addr = 0;
 240   uptr tls_size = 0;
 241 #if !SANITIZER_GO
 242   GetThreadStackAndTls(tid == 0, &stk_addr, &stk_size, &tls_addr, &tls_size);
 243
 244   if (tid) {
 245     if (stk_addr && stk_size)
 246       MemoryRangeImitateWrite(thr, /*pc=*/ 1, stk_addr, stk_size);
 247
 248     if (tls_addr && tls_size) {
 249       // Check that the thr object is in tls;
 250       const uptr thr_beg = (uptr)thr;
 251       const uptr thr_end = (uptr)thr + sizeof(*thr);
 252       CHECK_GE(thr_beg, tls_addr);
 253       CHECK_LE(thr_beg, tls_addr + tls_size);
 254       CHECK_GE(thr_end, tls_addr);
 255       CHECK_LE(thr_end, tls_addr + tls_size);
 256       // Since the thr object is huge, skip it.
 257       MemoryRangeImitateWrite(thr, /*pc=*/ 2, tls_addr, thr_beg - tls_addr);
 258       MemoryRangeImitateWrite(thr, /*pc=*/ 2,
 259           thr_end, tls_addr + tls_size - thr_end);
 260     }
 261   }
 262 #endif
 263
 264   ThreadRegistry *tr = ctx->thread_registry;
 265   OnStartedArgs args = { thr, stk_addr, stk_size, tls_addr, tls_size };
 266   tr->StartThread(tid, os_id, &args);
 267
 268   tr->Lock();
 269   thr->tctx = (ThreadContext*)tr->GetThreadLocked(tid);
 270   tr->Unlock();
 271
 272 #if !SANITIZER_GO
 273   if (ctx->after_multithreaded_fork) {
 274     thr->ignore_interceptors++;
 275     ThreadIgnoreBegin(thr, 0);
 276     ThreadIgnoreSyncBegin(thr, 0);
 277   }
 278 #endif
 279 }
 280
 281 void ThreadFinish(ThreadState *thr) {
 282   ThreadCheckIgnore(thr);
 283   StatInc(thr, StatThreadFinish);
 284   if (thr->stk_addr && thr->stk_size)
 285     DontNeedShadowFor(thr->stk_addr, thr->stk_size);
 286   if (thr->tls_addr && thr->tls_size)
 287     DontNeedShadowFor(thr->tls_addr, thr->tls_size);
 288   thr->is_dead = true;
 289   ctx->thread_registry->FinishThread(thr->tid);
 290 }
 291
 292 static bool FindThreadByUid(ThreadContextBase *tctx, void *arg) {
 293   uptr uid = (uptr)arg;
 294   if (tctx->user_id == uid && tctx->status != ThreadStatusInvalid) {
 295     tctx->user_id = 0;
 296     return true;
 297   }
 298   return false;
 299 }
 300
 301 int ThreadTid(ThreadState *thr, uptr pc, uptr uid) {
 302   int res = ctx->thread_registry->FindThread(FindThreadByUid, (void*)uid);
 303   DPrintf("#%d: ThreadTid uid=%zu tid=%d\n", thr->tid, uid, res);
 304   return res;
 305 }
 306
 307 void ThreadJoin(ThreadState *thr, uptr pc, int tid) {
 308   CHECK_GT(tid, 0);
 309   CHECK_LT(tid, kMaxTid);
 310   DPrintf("#%d: ThreadJoin tid=%d\n", thr->tid, tid);
 311   ctx->thread_registry->JoinThread(tid, thr);
 312 }
 313
 314 void ThreadDetach(ThreadState *thr, uptr pc, int tid) {
 315   CHECK_GT(tid, 0);
 316   CHECK_LT(tid, kMaxTid);
 317   ctx->thread_registry->DetachThread(tid, thr);
 318 }
 319
 320 void ThreadSetName(ThreadState *thr, const char *name) {
 321   ctx->thread_registry->SetThreadName(thr->tid, name);
 322 }
 323
 324 void MemoryAccessRange(ThreadState *thr, uptr pc, uptr addr,
 325                        uptr size, bool is_write) {
 326   if (size == 0)
 327     return;
 328
 329   u64 *shadow_mem = (u64*)MemToShadow(addr);
 330   DPrintf2("#%d: MemoryAccessRange: @%p %p size=%d is_write=%d\n",
 331       thr->tid, (void*)pc, (void*)addr,
 332       (int)size, is_write);
 333
 334 #if SANITIZER_DEBUG
 335   if (!IsAppMem(addr)) {
 336     Printf("Access to non app mem %zx\n", addr);
 337     DCHECK(IsAppMem(addr));
 338   }
 339   if (!IsAppMem(addr + size - 1)) {
 340     Printf("Access to non app mem %zx\n", addr + size - 1);
 341     DCHECK(IsAppMem(addr + size - 1));
 342   }
 343   if (!IsShadowMem((uptr)shadow_mem)) {
 344     Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
 345     DCHECK(IsShadowMem((uptr)shadow_mem));
 346   }
 347   if (!IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1))) {
 348     Printf("Bad shadow addr %p (%zx)\n",
 349                shadow_mem + size * kShadowCnt / 8 - 1, addr + size - 1);
 350     DCHECK(IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1)));
 351   }
 352 #endif
 353
 354   StatInc(thr, StatMopRange);
 355
 356   if (*shadow_mem == kShadowRodata) {
 357     // Access to .rodata section, no races here.
 358     // Measurements show that it can be 10-20% of all memory accesses.
 359     StatInc(thr, StatMopRangeRodata);
 360     return;
 361   }
 362
 363   FastState fast_state = thr->fast_state;
 364   if (fast_state.GetIgnoreBit())
 365     return;
 366
 367   fast_state.IncrementEpoch();
 368   thr->fast_state = fast_state;
 369   TraceAddEvent(thr, fast_state, EventTypeMop, pc);
 370
 371   bool unaligned = (addr % kShadowCell) != 0;
 372
 373   // Handle unaligned beginning, if any.
 374   for (; addr % kShadowCell && size; addr++, size--) {
 375     int const kAccessSizeLog = 0;
 376     Shadow cur(fast_state);
 377     cur.SetWrite(is_write);
 378     cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
 379     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 380         shadow_mem, cur);
 381   }
 382   if (unaligned)
 383     shadow_mem += kShadowCnt;
 384   // Handle middle part, if any.
 385   for (; size >= kShadowCell; addr += kShadowCell, size -= kShadowCell) {
 386     int const kAccessSizeLog = 3;
 387     Shadow cur(fast_state);
 388     cur.SetWrite(is_write);
 389     cur.SetAddr0AndSizeLog(0, kAccessSizeLog);
 390     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 391         shadow_mem, cur);
 392     shadow_mem += kShadowCnt;
 393   }
 394   // Handle ending, if any.
 395   for (; size; addr++, size--) {
 396     int const kAccessSizeLog = 0;
 397     Shadow cur(fast_state);
 398     cur.SetWrite(is_write);
 399     cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
 400     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 401         shadow_mem, cur);
 402   }
 403 }
 404
 405 }  // namespace __tsan