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 #ifndef TSAN_GO
  22 const int kThreadQuarantineSize = 16;
  23 #else
  24 const int kThreadQuarantineSize = 64;
  25 #endif
  26
  27 static void MaybeReportThreadLeak(ThreadContext *tctx) {
  28   if (tctx->detached)
  29     return;
  30   if (tctx->status != ThreadStatusCreated
  31       && tctx->status != ThreadStatusRunning
  32       && tctx->status != ThreadStatusFinished)
  33     return;
  34   ScopedReport rep(ReportTypeThreadLeak);
  35   rep.AddThread(tctx);
  36   OutputReport(CTX(), rep);
  37 }
  38
  39 void ThreadFinalize(ThreadState *thr) {
  40   CHECK_GT(thr->in_rtl, 0);
  41   if (!flags()->report_thread_leaks)
  42     return;
  43   Context *ctx = CTX();
  44   Lock l(&ctx->thread_mtx);
  45   for (unsigned i = 0; i < kMaxTid; i++) {
  46     ThreadContext *tctx = ctx->threads[i];
  47     if (tctx == 0)
  48       continue;
  49     MaybeReportThreadLeak(tctx);
  50   }
  51 }
  52
  53 int ThreadCount(ThreadState *thr) {
  54   CHECK_GT(thr->in_rtl, 0);
  55   Context *ctx = CTX();
  56   Lock l(&ctx->thread_mtx);
  57   int cnt = 0;
  58   for (unsigned i = 0; i < kMaxTid; i++) {
  59     ThreadContext *tctx = ctx->threads[i];
  60     if (tctx == 0)
  61       continue;
  62     if (tctx->status != ThreadStatusCreated
  63         && tctx->status != ThreadStatusRunning)
  64       continue;
  65     cnt++;
  66   }
  67   return cnt;
  68 }
  69
  70 static void ThreadDead(ThreadState *thr, ThreadContext *tctx) {
  71   Context *ctx = CTX();
  72   CHECK_GT(thr->in_rtl, 0);
  73   CHECK(tctx->status == ThreadStatusRunning
  74       || tctx->status == ThreadStatusFinished);
  75   DPrintf("#%d: ThreadDead uid=%zu\n", thr->tid, tctx->user_id);
  76   tctx->status = ThreadStatusDead;
  77   tctx->user_id = 0;
  78   tctx->sync.Reset();
  79
  80   // Put to dead list.
  81   tctx->dead_next = 0;
  82   if (ctx->dead_list_size == 0)
  83     ctx->dead_list_head = tctx;
  84   else
  85     ctx->dead_list_tail->dead_next = tctx;
  86   ctx->dead_list_tail = tctx;
  87   ctx->dead_list_size++;
  88 }
  89
  90 int ThreadCreate(ThreadState *thr, uptr pc, uptr uid, bool detached) {
  91   CHECK_GT(thr->in_rtl, 0);
  92   Context *ctx = CTX();
  93   Lock l(&ctx->thread_mtx);
  94   StatInc(thr, StatThreadCreate);
  95   int tid = -1;
  96   ThreadContext *tctx = 0;
  97   if (ctx->dead_list_size > kThreadQuarantineSize
  98       || ctx->thread_seq >= kMaxTid) {
  99     // Reusing old thread descriptor and tid.
 100     if (ctx->dead_list_size == 0) {
 101       Printf("ThreadSanitizer: %d thread limit exceeded. Dying.\n",
 102                  kMaxTid);
 103       Die();
 104     }
 105     StatInc(thr, StatThreadReuse);
 106     tctx = ctx->dead_list_head;
 107     ctx->dead_list_head = tctx->dead_next;
 108     ctx->dead_list_size--;
 109     if (ctx->dead_list_size == 0) {
 110       CHECK_EQ(tctx->dead_next, 0);
 111       ctx->dead_list_head = 0;
 112     }
 113     CHECK_EQ(tctx->status, ThreadStatusDead);
 114     tctx->status = ThreadStatusInvalid;
 115     tctx->reuse_count++;
 116     tctx->sync.Reset();
 117     tid = tctx->tid;
 118     DestroyAndFree(tctx->dead_info);
 119     if (tctx->name) {
 120       internal_free(tctx->name);
 121       tctx->name = 0;
 122     }
 123   } else {
 124     // Allocating new thread descriptor and tid.
 125     StatInc(thr, StatThreadMaxTid);
 126     tid = ctx->thread_seq++;
 127     void *mem = internal_alloc(MBlockThreadContex, sizeof(ThreadContext));
 128     tctx = new(mem) ThreadContext(tid);
 129     ctx->threads[tid] = tctx;
 130     MapThreadTrace(GetThreadTrace(tid), TraceSize() * sizeof(Event));
 131   }
 132   CHECK_NE(tctx, 0);
 133   CHECK_GE(tid, 0);
 134   CHECK_LT(tid, kMaxTid);
 135   DPrintf("#%d: ThreadCreate tid=%d uid=%zu\n", thr->tid, tid, uid);
 136   CHECK_EQ(tctx->status, ThreadStatusInvalid);
 137   ctx->alive_threads++;
 138   if (ctx->max_alive_threads < ctx->alive_threads) {
 139     ctx->max_alive_threads++;
 140     CHECK_EQ(ctx->max_alive_threads, ctx->alive_threads);
 141     StatInc(thr, StatThreadMaxAlive);
 142   }
 143   tctx->status = ThreadStatusCreated;
 144   tctx->thr = 0;
 145   tctx->user_id = uid;
 146   tctx->unique_id = ctx->unique_thread_seq++;
 147   tctx->detached = detached;
 148   if (tid) {
 149     thr->fast_state.IncrementEpoch();
 150     // Can't increment epoch w/o writing to the trace as well.
 151     TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
 152     thr->clock.set(thr->tid, thr->fast_state.epoch());
 153     thr->fast_synch_epoch = thr->fast_state.epoch();
 154     thr->clock.release(&tctx->sync);
 155     StatInc(thr, StatSyncRelease);
 156     tctx->creation_stack.ObtainCurrent(thr, pc);
 157     tctx->creation_tid = thr->tid;
 158   }
 159   return tid;
 160 }
 161
 162 void ThreadStart(ThreadState *thr, int tid, uptr os_id) {
 163   CHECK_GT(thr->in_rtl, 0);
 164   uptr stk_addr = 0;
 165   uptr stk_size = 0;
 166   uptr tls_addr = 0;
 167   uptr tls_size = 0;
 168   GetThreadStackAndTls(tid == 0, &stk_addr, &stk_size, &tls_addr, &tls_size);
 169
 170   if (tid) {
 171     if (stk_addr && stk_size) {
 172       MemoryResetRange(thr, /*pc=*/ 1, stk_addr, stk_size);
 173     }
 174
 175     if (tls_addr && tls_size) {
 176       // Check that the thr object is in tls;
 177       const uptr thr_beg = (uptr)thr;
 178       const uptr thr_end = (uptr)thr + sizeof(*thr);
 179       CHECK_GE(thr_beg, tls_addr);
 180       CHECK_LE(thr_beg, tls_addr + tls_size);
 181       CHECK_GE(thr_end, tls_addr);
 182       CHECK_LE(thr_end, tls_addr + tls_size);
 183       // Since the thr object is huge, skip it.
 184       MemoryResetRange(thr, /*pc=*/ 2, tls_addr, thr_beg - tls_addr);
 185       MemoryResetRange(thr, /*pc=*/ 2, thr_end, tls_addr + tls_size - thr_end);
 186     }
 187   }
 188
 189   Lock l(&CTX()->thread_mtx);
 190   ThreadContext *tctx = CTX()->threads[tid];
 191   CHECK_NE(tctx, 0);
 192   CHECK_EQ(tctx->status, ThreadStatusCreated);
 193   tctx->status = ThreadStatusRunning;
 194   tctx->os_id = os_id;
 195   // RoundUp so that one trace part does not contain events
 196   // from different threads.
 197   tctx->epoch0 = RoundUp(tctx->epoch1 + 1, kTracePartSize);
 198   tctx->epoch1 = (u64)-1;
 199   new(thr) ThreadState(CTX(), tid, tctx->unique_id,
 200       tctx->epoch0, stk_addr, stk_size,
 201       tls_addr, tls_size);
 202 #ifdef TSAN_GO
 203   // Setup dynamic shadow stack.
 204   const int kInitStackSize = 8;
 205   thr->shadow_stack = (uptr*)internal_alloc(MBlockShadowStack,
 206       kInitStackSize * sizeof(uptr));
 207   thr->shadow_stack_pos = thr->shadow_stack;
 208   thr->shadow_stack_end = thr->shadow_stack + kInitStackSize;
 209 #endif
 210 #ifndef TSAN_GO
 211   AllocatorThreadStart(thr);
 212 #endif
 213   tctx->thr = thr;
 214   thr->fast_synch_epoch = tctx->epoch0;
 215   thr->clock.set(tid, tctx->epoch0);
 216   thr->clock.acquire(&tctx->sync);
 217   thr->fast_state.SetHistorySize(flags()->history_size);
 218   const uptr trace = (tctx->epoch0 / kTracePartSize) % TraceParts();
 219   thr->trace.headers[trace].epoch0 = tctx->epoch0;
 220   StatInc(thr, StatSyncAcquire);
 221   DPrintf("#%d: ThreadStart epoch=%zu stk_addr=%zx stk_size=%zx "
 222           "tls_addr=%zx tls_size=%zx\n",
 223           tid, (uptr)tctx->epoch0, stk_addr, stk_size, tls_addr, tls_size);
 224   thr->is_alive = true;
 225 }
 226
 227 void ThreadFinish(ThreadState *thr) {
 228   CHECK_GT(thr->in_rtl, 0);
 229   StatInc(thr, StatThreadFinish);
 230   // FIXME: Treat it as write.
 231   if (thr->stk_addr && thr->stk_size)
 232     MemoryResetRange(thr, /*pc=*/ 3, thr->stk_addr, thr->stk_size);
 233   if (thr->tls_addr && thr->tls_size) {
 234     const uptr thr_beg = (uptr)thr;
 235     const uptr thr_end = (uptr)thr + sizeof(*thr);
 236     // Since the thr object is huge, skip it.
 237     MemoryResetRange(thr, /*pc=*/ 4, thr->tls_addr, thr_beg - thr->tls_addr);
 238     MemoryResetRange(thr, /*pc=*/ 5,
 239         thr_end, thr->tls_addr + thr->tls_size - thr_end);
 240   }
 241   thr->is_alive = false;
 242   Context *ctx = CTX();
 243   Lock l(&ctx->thread_mtx);
 244   ThreadContext *tctx = ctx->threads[thr->tid];
 245   CHECK_NE(tctx, 0);
 246   CHECK_EQ(tctx->status, ThreadStatusRunning);
 247   CHECK_GT(ctx->alive_threads, 0);
 248   ctx->alive_threads--;
 249   if (tctx->detached) {
 250     ThreadDead(thr, tctx);
 251   } else {
 252     thr->fast_state.IncrementEpoch();
 253     // Can't increment epoch w/o writing to the trace as well.
 254     TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
 255     thr->clock.set(thr->tid, thr->fast_state.epoch());
 256     thr->fast_synch_epoch = thr->fast_state.epoch();
 257     thr->clock.release(&tctx->sync);
 258     StatInc(thr, StatSyncRelease);
 259     tctx->status = ThreadStatusFinished;
 260   }
 261
 262   // Save from info about the thread.
 263   tctx->dead_info = new(internal_alloc(MBlockDeadInfo, sizeof(ThreadDeadInfo)))
 264       ThreadDeadInfo();
 265   for (uptr i = 0; i < TraceParts(); i++) {
 266     tctx->dead_info->trace.headers[i].epoch0 = thr->trace.headers[i].epoch0;
 267     tctx->dead_info->trace.headers[i].stack0.CopyFrom(
 268         thr->trace.headers[i].stack0);
 269   }
 270   tctx->epoch1 = thr->fast_state.epoch();
 271
 272 #ifndef TSAN_GO
 273   AllocatorThreadFinish(thr);
 274 #endif
 275   thr->~ThreadState();
 276   StatAggregate(ctx->stat, thr->stat);
 277   tctx->thr = 0;
 278 }
 279
 280 int ThreadTid(ThreadState *thr, uptr pc, uptr uid) {
 281   CHECK_GT(thr->in_rtl, 0);
 282   Context *ctx = CTX();
 283   Lock l(&ctx->thread_mtx);
 284   int res = -1;
 285   for (unsigned tid = 0; tid < kMaxTid; tid++) {
 286     ThreadContext *tctx = ctx->threads[tid];
 287     if (tctx != 0 && tctx->user_id == uid
 288         && tctx->status != ThreadStatusInvalid) {
 289       tctx->user_id = 0;
 290       res = tid;
 291       break;
 292     }
 293   }
 294   DPrintf("#%d: ThreadTid uid=%zu tid=%d\n", thr->tid, uid, res);
 295   return res;
 296 }
 297
 298 void ThreadJoin(ThreadState *thr, uptr pc, int tid) {
 299   CHECK_GT(thr->in_rtl, 0);
 300   CHECK_GT(tid, 0);
 301   CHECK_LT(tid, kMaxTid);
 302   DPrintf("#%d: ThreadJoin tid=%d\n", thr->tid, tid);
 303   Context *ctx = CTX();
 304   Lock l(&ctx->thread_mtx);
 305   ThreadContext *tctx = ctx->threads[tid];
 306   if (tctx->status == ThreadStatusInvalid) {
 307     Printf("ThreadSanitizer: join of non-existent thread\n");
 308     return;
 309   }
 310   // FIXME(dvyukov): print message and continue (it's user error).
 311   CHECK_EQ(tctx->detached, false);
 312   CHECK_EQ(tctx->status, ThreadStatusFinished);
 313   thr->clock.acquire(&tctx->sync);
 314   StatInc(thr, StatSyncAcquire);
 315   ThreadDead(thr, tctx);
 316 }
 317
 318 void ThreadDetach(ThreadState *thr, uptr pc, int tid) {
 319   CHECK_GT(thr->in_rtl, 0);
 320   CHECK_GT(tid, 0);
 321   CHECK_LT(tid, kMaxTid);
 322   Context *ctx = CTX();
 323   Lock l(&ctx->thread_mtx);
 324   ThreadContext *tctx = ctx->threads[tid];
 325   if (tctx->status == ThreadStatusInvalid) {
 326     Printf("ThreadSanitizer: detach of non-existent thread\n");
 327     return;
 328   }
 329   if (tctx->status == ThreadStatusFinished) {
 330     ThreadDead(thr, tctx);
 331   } else {
 332     tctx->detached = true;
 333   }
 334 }
 335
 336 void ThreadSetName(ThreadState *thr, const char *name) {
 337   Context *ctx = CTX();
 338   Lock l(&ctx->thread_mtx);
 339   ThreadContext *tctx = ctx->threads[thr->tid];
 340   CHECK_NE(tctx, 0);
 341   CHECK_EQ(tctx->status, ThreadStatusRunning);
 342   if (tctx->name) {
 343     internal_free(tctx->name);
 344     tctx->name = 0;
 345   }
 346   if (name)
 347     tctx->name = internal_strdup(name);
 348 }
 349
 350 void MemoryAccessRange(ThreadState *thr, uptr pc, uptr addr,
 351                        uptr size, bool is_write) {
 352   if (size == 0)
 353     return;
 354
 355   u64 *shadow_mem = (u64*)MemToShadow(addr);
 356   DPrintf2("#%d: MemoryAccessRange: @%p %p size=%d is_write=%d\n",
 357       thr->tid, (void*)pc, (void*)addr,
 358       (int)size, is_write);
 359
 360 #if TSAN_DEBUG
 361   if (!IsAppMem(addr)) {
 362     Printf("Access to non app mem %zx\n", addr);
 363     DCHECK(IsAppMem(addr));
 364   }
 365   if (!IsAppMem(addr + size - 1)) {
 366     Printf("Access to non app mem %zx\n", addr + size - 1);
 367     DCHECK(IsAppMem(addr + size - 1));
 368   }
 369   if (!IsShadowMem((uptr)shadow_mem)) {
 370     Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
 371     DCHECK(IsShadowMem((uptr)shadow_mem));
 372   }
 373   if (!IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1))) {
 374     Printf("Bad shadow addr %p (%zx)\n",
 375                shadow_mem + size * kShadowCnt / 8 - 1, addr + size - 1);
 376     DCHECK(IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1)));
 377   }
 378 #endif
 379
 380   StatInc(thr, StatMopRange);
 381
 382   FastState fast_state = thr->fast_state;
 383   if (fast_state.GetIgnoreBit())
 384     return;
 385
 386   fast_state.IncrementEpoch();
 387   thr->fast_state = fast_state;
 388   TraceAddEvent(thr, fast_state, EventTypeMop, pc);
 389
 390   bool unaligned = (addr % kShadowCell) != 0;
 391
 392   // Handle unaligned beginning, if any.
 393   for (; addr % kShadowCell && size; addr++, size--) {
 394     int const kAccessSizeLog = 0;
 395     Shadow cur(fast_state);
 396     cur.SetWrite(is_write);
 397     cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
 398     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 399         shadow_mem, cur);
 400   }
 401   if (unaligned)
 402     shadow_mem += kShadowCnt;
 403   // Handle middle part, if any.
 404   for (; size >= kShadowCell; addr += kShadowCell, size -= kShadowCell) {
 405     int const kAccessSizeLog = 3;
 406     Shadow cur(fast_state);
 407     cur.SetWrite(is_write);
 408     cur.SetAddr0AndSizeLog(0, kAccessSizeLog);
 409     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 410         shadow_mem, cur);
 411     shadow_mem += kShadowCnt;
 412   }
 413   // Handle ending, if any.
 414   for (; size; addr++, size--) {
 415     int const kAccessSizeLog = 0;
 416     Shadow cur(fast_state);
 417     cur.SetWrite(is_write);
 418     cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
 419     MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false,
 420         shadow_mem, cur);
 421   }
 422 }
 423
 424 void MemoryAccessRangeStep(ThreadState *thr, uptr pc, uptr addr,
 425     uptr size, uptr step, bool is_write) {
 426   if (size == 0)
 427     return;
 428   FastState fast_state = thr->fast_state;
 429   if (fast_state.GetIgnoreBit())
 430     return;
 431   StatInc(thr, StatMopRange);
 432   fast_state.IncrementEpoch();
 433   thr->fast_state = fast_state;
 434   TraceAddEvent(thr, fast_state, EventTypeMop, pc);
 435
 436   for (uptr addr_end = addr + size; addr < addr_end; addr += step) {
 437     u64 *shadow_mem = (u64*)MemToShadow(addr);
 438     Shadow cur(fast_state);
 439     cur.SetWrite(is_write);
 440     cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kSizeLog1);
 441     MemoryAccessImpl(thr, addr, kSizeLog1, is_write, false,
 442         shadow_mem, cur);
 443   }
 444 }
 445 }  // namespace __tsan