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
19namespace __tsan {
20
21// ThreadContext implementation.
22
23ThreadContext::ThreadContext(int tid)
24  : ThreadContextBase(tid)
25  , thr()
26  , sync()
27  , epoch0()
28  , epoch1() {
29}
30
31#ifndef TSAN_GO
32ThreadContext::~ThreadContext() {
33}
34#endif
35
36void ThreadContext::OnDead() {
37  CHECK_EQ(sync.size(), 0);
38}
39
40void 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
46struct OnCreatedArgs {
47  ThreadState *thr;
48  uptr pc;
49};
50
51void 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
65void ThreadContext::OnReset() {
66  CHECK_EQ(sync.size(), 0);
67  FlushUnneededShadowMemory(GetThreadTrace(tid), TraceSize() * sizeof(Event));
68  //!!! FlushUnneededShadowMemory(GetThreadTraceHeader(tid), sizeof(Trace));
69}
70
71void ThreadContext::OnDetached(void *arg) {
72  ThreadState *thr1 = static_cast<ThreadState*>(arg);
73  sync.Reset(&thr1->clock_cache);
74}
75
76struct OnStartedArgs {
77  ThreadState *thr;
78  uptr stk_addr;
79  uptr stk_size;
80  uptr tls_addr;
81  uptr tls_size;
82};
83
84void 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
127void 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
151struct ThreadLeak {
152  ThreadContext *tctx;
153  int count;
154};
155
156static 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
173static 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
190static 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
199static void ThreadCheckIgnore(ThreadState *thr) {}
200#endif
201
202void 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
220int ThreadCount(ThreadState *thr) {
221  uptr result;
222  ctx->thread_registry->GetNumberOfThreads(0, 0, &result);
223  return (int)result;
224}
225
226int 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
235void 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
278void 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
289static 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
298int 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
304void 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
311void 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
317void ThreadSetName(ThreadState *thr, const char *name) {
318  ctx->thread_registry->SetThreadName(thr->tid, name);
319}
320
321void 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
403