libsanitizer/tsan/tsan_rtl_thread.cpp

   1 //===-- tsan_rtl_thread.cpp -----------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is a part of ThreadSanitizer (TSan), a race detector.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_common/sanitizer_placement_new.h"
  14 #include "tsan_rtl.h"
  15 #include "tsan_mman.h"
  16 #include "tsan_platform.h"
  17 #include "tsan_report.h"
  18 #include "tsan_sync.h"
  19
  20 namespace __tsan {
  21
  22 // ThreadContext implementation.
  23
  24 ThreadContext::ThreadContext(int tid)
  25   : ThreadContextBase(tid)
  26   , thr()
  27   , sync()
  28   , epoch0()
  29   , epoch1() {
  30 }
  31
  32 #if !SANITIZER_GO
  33 ThreadContext::~ThreadContext() {
  34 }
  35 #endif
  36
  37 void ThreadContext::OnDead() {
  38   CHECK_EQ(sync.size(), 0);
  39 }
  40
  41 void ThreadContext::OnJoined(void *arg) {
  42   ThreadState *caller_thr = static_cast<ThreadState *>(arg);
  43   AcquireImpl(caller_thr, 0, &sync);
  44   sync.Reset(&caller_thr->proc()->clock_cache);
  45 }
  46
  47 struct OnCreatedArgs {
  48   ThreadState *thr;
  49   uptr pc;
  50 };
  51
  52 void ThreadContext::OnCreated(void *arg) {
  53   thr = 0;
  54   if (tid == 0)
  55     return;
  56   OnCreatedArgs *args = static_cast<OnCreatedArgs *>(arg);
  57   if (!args->thr)  // GCD workers don't have a parent thread.
  58     return;
  59   args->thr->fast_state.IncrementEpoch();
  60   // Can't increment epoch w/o writing to the trace as well.
  61   TraceAddEvent(args->thr, args->thr->fast_state, EventTypeMop, 0);
  62   ReleaseImpl(args->thr, 0, &sync);
  63   creation_stack_id = CurrentStackId(args->thr, args->pc);
  64   if (reuse_count == 0)
  65     StatInc(args->thr, StatThreadMaxTid);
  66 }
  67
  68 void ThreadContext::OnReset() {
  69   CHECK_EQ(sync.size(), 0);
  70   uptr trace_p = GetThreadTrace(tid);
  71   ReleaseMemoryPagesToOS(trace_p, trace_p + TraceSize() * sizeof(Event));
  72   //!!! ReleaseMemoryToOS(GetThreadTraceHeader(tid), sizeof(Trace));
  73 }
  74
  75 void ThreadContext::OnDetached(void *arg) {
  76   ThreadState *thr1 = static_cast<ThreadState*>(arg);
  77   sync.Reset(&thr1->proc()->clock_cache);
  78 }
  79
  80 struct OnStartedArgs {
  81   ThreadState *thr;
  82   uptr stk_addr;
  83   uptr stk_size;
  84   uptr tls_addr;
  85   uptr tls_size;
  86 };
  87
  88 void ThreadContext::OnStarted(void *arg) {
  89   OnStartedArgs *args = static_cast<OnStartedArgs*>(arg);
  90   thr = args->thr;
  91   // RoundUp so that one trace part does not contain events
  92   // from different threads.
  93   epoch0 = RoundUp(epoch1 + 1, kTracePartSize);
  94   epoch1 = (u64)-1;
  95   new(thr) ThreadState(ctx, tid, unique_id, epoch0, reuse_count,
  96       args->stk_addr, args->stk_size, args->tls_addr, args->tls_size);
  97 #if !SANITIZER_GO
  98   thr->shadow_stack = &ThreadTrace(thr->tid)->shadow_stack[0];
  99   thr->shadow_stack_pos = thr->shadow_stack;
 100   thr->shadow_stack_end = thr->shadow_stack + kShadowStackSize;
 101 #else
 102   // Setup dynamic shadow stack.
 103   const int kInitStackSize = 8;
 104   thr->shadow_stack = (uptr*)internal_alloc(MBlockShadowStack,
 105       kInitStackSize * sizeof(uptr));
 106   thr->shadow_stack_pos = thr->shadow_stack;
 107   thr->shadow_stack_end = thr->shadow_stack + kInitStackSize;
 108 #endif
 109   if (common_flags()->detect_deadlocks)
 110     thr->dd_lt = ctx->dd->CreateLogicalThread(unique_id);
 111   thr->fast_state.SetHistorySize(flags()->history_size);
 112   // Commit switch to the new part of the trace.
 113   // TraceAddEvent will reset stack0/mset0 in the new part for us.
 114   TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
 115
 116   thr->fast_synch_epoch = epoch0;
 117   AcquireImpl(thr, 0, &sync);
 118   StatInc(thr, StatSyncAcquire);
 119   sync.Reset(&thr->proc()->clock_cache);
 120   thr->is_inited = true;
 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 SANITIZER_GO
 129   internal_free(thr->shadow_stack);
 130   thr->shadow_stack = nullptr;
 131   thr->shadow_stack_pos = nullptr;
 132   thr->shadow_stack_end = nullptr;
 133 #endif
 134   if (!detached) {
 135     thr->fast_state.IncrementEpoch();
 136     // Can't increment epoch w/o writing to the trace as well.
 137     TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
 138     ReleaseImpl(thr, 0, &sync);
 139   }
 140   epoch1 = thr->fast_state.epoch();
 141
 142   if (common_flags()->detect_deadlocks)
 143     ctx->dd->DestroyLogicalThread(thr->dd_lt);
 144   thr->clock.ResetCached(&thr->proc()->clock_cache);
 145 #if !SANITIZER_GO
 146   thr->last_sleep_clock.ResetCached(&thr->proc()->clock_cache);
 147 #endif
 148   thr->~ThreadState();
 149 #if TSAN_COLLECT_STATS
 150   StatAggregate(ctx->stat, thr->stat);
 151 #endif
 152   thr = 0;
 153 }
 154
 155 #if !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 #if !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 #if !SANITIZER_GO
 210   if (!flags()->report_thread_leaks)
 211     return;
 212   ThreadRegistryLock l(ctx->thread_registry);
 213   Vector<ThreadLeak> leaks;
 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, tid_t os_id,
 243                  ThreadType thread_type) {
 244   uptr stk_addr = 0;
 245   uptr stk_size = 0;
 246   uptr tls_addr = 0;
 247   uptr tls_size = 0;
 248 #if !SANITIZER_GO
 249   if (thread_type != ThreadType::Fiber)
 250     GetThreadStackAndTls(tid == 0, &stk_addr, &stk_size, &tls_addr, &tls_size);
 251
 252   if (tid) {
 253     if (stk_addr && stk_size)
 254       MemoryRangeImitateWrite(thr, /*pc=*/ 1, stk_addr, stk_size);
 255
 256     if (tls_addr && tls_size) ImitateTlsWrite(thr, tls_addr, tls_size);
 257   }
 258 #endif
 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, thread_type, &args);
 263
 264   tr->Lock();
 265   thr->tctx = (ThreadContext*)tr->GetThreadLocked(tid);
 266   tr->Unlock();
 267
 268 #if !SANITIZER_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 ThreadNotJoined(ThreadState *thr, uptr pc, int tid, uptr uid) {
 317   CHECK_GT(tid, 0);
 318   CHECK_LT(tid, kMaxTid);
 319   ctx->thread_registry->SetThreadUserId(tid, uid);
 320 }
 321
 322 void ThreadSetName(ThreadState *thr, const char *name) {
 323   ctx->thread_registry->SetThreadName(thr->tid, name);
 324 }
 325
 326 void MemoryAccessRange(ThreadState *thr, uptr pc, uptr addr,
 327                        uptr size, bool is_write) {
 328   if (size == 0)
 329     return;
 330
 331   u64 *shadow_mem = (u64*)MemToShadow(addr);
 332   DPrintf2("#%d: MemoryAccessRange: @%p %p size=%d is_write=%d\n",
 333       thr->tid, (void*)pc, (void*)addr,
 334       (int)size, is_write);
 335
 336 #if SANITIZER_DEBUG
 337   if (!IsAppMem(addr)) {
 338     Printf("Access to non app mem %zx\n", addr);
 339     DCHECK(IsAppMem(addr));
 340   }
 341   if (!IsAppMem(addr + size - 1)) {
 342     Printf("Access to non app mem %zx\n", addr + size - 1);
 343     DCHECK(IsAppMem(addr + size - 1));
 344   }
 345   if (!IsShadowMem((uptr)shadow_mem)) {
 346     Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
 347     DCHECK(IsShadowMem((uptr)shadow_mem));
 348   }
 349   if (!IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1))) {
 350     Printf("Bad shadow addr %p (%zx)\n",
 351                shadow_mem + size * kShadowCnt / 8 - 1, addr + size - 1);
 352     DCHECK(IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1)));
 353   }
 354 #endif
 355
 356   StatInc(thr, StatMopRange);
 357
 358   if (*shadow_mem == kShadowRodata) {
 359     DCHECK(!is_write);
 360     // Access to .rodata section, no races here.
 361     // Measurements show that it can be 10-20% of all memory accesses.
 362     StatInc(thr, StatMopRangeRodata);
 363     return;
 364   }
 365
 366   FastState fast_state = thr->fast_state;
 367   if (fast_state.GetIgnoreBit())
 368     return;
 369
 370   fast_state.IncrementEpoch();
 371   thr->fast_state = fast_state;
 372   TraceAddEvent(thr, fast_state, EventTypeMop, pc);
 373
 374   bool unaligned = (addr % kShadowCell) != 0;
 375
 376   // Handle unaligned beginning, if any.
 377   for (; addr % kShadowCell && size; addr++, size--) {
 378     int const kAccessSizeLog = 0;
 379     Shadow cur(fast_state);
 380     cur.SetWrite(is_write);
 381     cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
 382     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 383         shadow_mem, cur);
 384   }
 385   if (unaligned)
 386     shadow_mem += kShadowCnt;
 387   // Handle middle part, if any.
 388   for (; size >= kShadowCell; addr += kShadowCell, size -= kShadowCell) {
 389     int const kAccessSizeLog = 3;
 390     Shadow cur(fast_state);
 391     cur.SetWrite(is_write);
 392     cur.SetAddr0AndSizeLog(0, kAccessSizeLog);
 393     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 394         shadow_mem, cur);
 395     shadow_mem += kShadowCnt;
 396   }
 397   // Handle ending, if any.
 398   for (; size; addr++, size--) {
 399     int const kAccessSizeLog = 0;
 400     Shadow cur(fast_state);
 401     cur.SetWrite(is_write);
 402     cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
 403     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 404         shadow_mem, cur);
 405   }
 406 }
 407
 408 #if !SANITIZER_GO
 409 void FiberSwitchImpl(ThreadState *from, ThreadState *to) {
 410   Processor *proc = from->proc();
 411   ProcUnwire(proc, from);
 412   ProcWire(proc, to);
 413   set_cur_thread(to);
 414 }
 415
 416 ThreadState *FiberCreate(ThreadState *thr, uptr pc, unsigned flags) {
 417   void *mem = internal_alloc(MBlockThreadContex, sizeof(ThreadState));
 418   ThreadState *fiber = static_cast<ThreadState *>(mem);
 419   internal_memset(fiber, 0, sizeof(*fiber));
 420   int tid = ThreadCreate(thr, pc, 0, true);
 421   FiberSwitchImpl(thr, fiber);
 422   ThreadStart(fiber, tid, 0, ThreadType::Fiber);
 423   FiberSwitchImpl(fiber, thr);
 424   return fiber;
 425 }
 426
 427 void FiberDestroy(ThreadState *thr, uptr pc, ThreadState *fiber) {
 428   FiberSwitchImpl(thr, fiber);
 429   ThreadFinish(fiber);
 430   FiberSwitchImpl(fiber, thr);
 431   internal_free(fiber);
 432 }
 433
 434 void FiberSwitch(ThreadState *thr, uptr pc,
 435                  ThreadState *fiber, unsigned flags) {
 436   if (!(flags & FiberSwitchFlagNoSync))
 437     Release(thr, pc, (uptr)fiber);
 438   FiberSwitchImpl(thr, fiber);
 439   if (!(flags & FiberSwitchFlagNoSync))
 440     Acquire(fiber, pc, (uptr)fiber);
 441 }
 442 #endif
 443
 444 }  // namespace __tsan