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1//===-- tsan_rtl_report.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_common.h"
14#include "sanitizer_common/sanitizer_libc.h"
15#include "sanitizer_common/sanitizer_placement_new.h"
16#include "sanitizer_common/sanitizer_stackdepot.h"
17#include "sanitizer_common/sanitizer_stacktrace.h"
18#include "tsan_fd.h"
19#include "tsan_flags.h"
20#include "tsan_mman.h"
21#include "tsan_platform.h"
22#include "tsan_report.h"
23#include "tsan_rtl.h"
24#include "tsan_suppressions.h"
25#include "tsan_symbolize.h"
26#include "tsan_sync.h"
27
28namespace __tsan {
29
30using namespace __sanitizer;
31
32static ReportStack *SymbolizeStack(StackTrace trace);
33
34// Can be overriden by an application/test to intercept reports.
35#ifdef TSAN_EXTERNAL_HOOKS
36bool OnReport(const ReportDesc *rep, bool suppressed);
37#else
38SANITIZER_WEAK_CXX_DEFAULT_IMPL
39bool OnReport(const ReportDesc *rep, bool suppressed) {
40 (void)rep;
41 return suppressed;
42}
43#endif
44
45SANITIZER_WEAK_DEFAULT_IMPL
46void __tsan_on_report(const ReportDesc *rep) {
47 (void)rep;
48}
49
50static void StackStripMain(SymbolizedStack *frames) {
51 SymbolizedStack *last_frame = nullptr;
52 SymbolizedStack *last_frame2 = nullptr;
53 for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
54 last_frame2 = last_frame;
55 last_frame = cur;
56 }
57
58 if (last_frame2 == 0)
59 return;
60#if !SANITIZER_GO
61 const char *last = last_frame->info.function;
62 const char *last2 = last_frame2->info.function;
63 // Strip frame above 'main'
64 if (last2 && 0 == internal_strcmp(last2, "main")) {
65 last_frame->ClearAll();
66 last_frame2->next = nullptr;
67 // Strip our internal thread start routine.
68 } else if (last && 0 == internal_strcmp(last, "__tsan_thread_start_func")) {
69 last_frame->ClearAll();
70 last_frame2->next = nullptr;
71 // Strip global ctors init, .preinit_array and main caller.
72 } else if (last && (0 == internal_strcmp(last, "__do_global_ctors_aux") ||
73 0 == internal_strcmp(last, "__libc_csu_init") ||
74 0 == internal_strcmp(last, "__libc_start_main"))) {
75 last_frame->ClearAll();
76 last_frame2->next = nullptr;
77 // If both are 0, then we probably just failed to symbolize.
78 } else if (last || last2) {
79 // Ensure that we recovered stack completely. Trimmed stack
80 // can actually happen if we do not instrument some code,
81 // so it's only a debug print. However we must try hard to not miss it
82 // due to our fault.
83 DPrintf("Bottom stack frame is missed\n");
84 }
85#else
86 // The last frame always point into runtime (gosched0, goexit0, runtime.main).
87 last_frame->ClearAll();
88 last_frame2->next = nullptr;
89#endif
90}
91
92ReportStack *SymbolizeStackId(u32 stack_id) {
93 if (stack_id == 0)
94 return 0;
95 StackTrace stack = StackDepotGet(stack_id);
96 if (stack.trace == nullptr)
97 return nullptr;
98 return SymbolizeStack(stack);
99}
100
101static ReportStack *SymbolizeStack(StackTrace trace) {
102 if (trace.size == 0)
103 return 0;
104 SymbolizedStack *top = nullptr;
105 for (uptr si = 0; si < trace.size; si++) {
106 const uptr pc = trace.trace[si];
107 uptr pc1 = pc;
108 // We obtain the return address, but we're interested in the previous
109 // instruction.
110 if ((pc & kExternalPCBit) == 0)
111 pc1 = StackTrace::GetPreviousInstructionPc(pc);
112 SymbolizedStack *ent = SymbolizeCode(pc1);
113 CHECK_NE(ent, 0);
114 SymbolizedStack *last = ent;
115 while (last->next) {
116 last->info.address = pc; // restore original pc for report
117 last = last->next;
118 }
119 last->info.address = pc; // restore original pc for report
120 last->next = top;
121 top = ent;
122 }
123 StackStripMain(top);
124
125 auto *stack = New<ReportStack>();
126 stack->frames = top;
127 return stack;
128}
129
130bool ShouldReport(ThreadState *thr, ReportType typ) {
131 // We set thr->suppress_reports in the fork context.
132 // Taking any locking in the fork context can lead to deadlocks.
133 // If any locks are already taken, it's too late to do this check.
134 CheckedMutex::CheckNoLocks();
135 // For the same reason check we didn't lock thread_registry yet.
136 if (SANITIZER_DEBUG)
137 ThreadRegistryLock l(&ctx->thread_registry);
138 if (!flags()->report_bugs || thr->suppress_reports)
139 return false;
140 switch (typ) {
141 case ReportTypeSignalUnsafe:
142 return flags()->report_signal_unsafe;
143 case ReportTypeThreadLeak:
144#if !SANITIZER_GO
145 // It's impossible to join phantom threads
146 // in the child after fork.
147 if (ctx->after_multithreaded_fork)
148 return false;
149#endif
150 return flags()->report_thread_leaks;
151 case ReportTypeMutexDestroyLocked:
152 return flags()->report_destroy_locked;
153 default:
154 return true;
155 }
156}
157
158ScopedReportBase::ScopedReportBase(ReportType typ, uptr tag) {
159 ctx->thread_registry.CheckLocked();
160 rep_ = New<ReportDesc>();
161 rep_->typ = typ;
162 rep_->tag = tag;
163 ctx->report_mtx.Lock();
164}
165
166ScopedReportBase::~ScopedReportBase() {
167 ctx->report_mtx.Unlock();
168 DestroyAndFree(rep_);
169}
170
171void ScopedReportBase::AddStack(StackTrace stack, bool suppressable) {
172 ReportStack **rs = rep_->stacks.PushBack();
173 *rs = SymbolizeStack(stack);
174 (*rs)->suppressable = suppressable;
175}
176
177void ScopedReportBase::AddMemoryAccess(uptr addr, uptr external_tag, Shadow s,
178 Tid tid, StackTrace stack,
179 const MutexSet *mset) {
180 uptr addr0, size;
181 AccessType typ;
182 s.GetAccess(&addr0, &size, &typ);
183 auto *mop = New<ReportMop>();
184 rep_->mops.PushBack(mop);
185 mop->tid = tid;
186 mop->addr = addr + addr0;
187 mop->size = size;
188 mop->write = !(typ & kAccessRead);
189 mop->atomic = typ & kAccessAtomic;
190 mop->stack = SymbolizeStack(stack);
191 mop->external_tag = external_tag;
192 if (mop->stack)
193 mop->stack->suppressable = true;
194 for (uptr i = 0; i < mset->Size(); i++) {
195 MutexSet::Desc d = mset->Get(i);
196 int id = this->AddMutex(d.addr, d.stack_id);
197 ReportMopMutex mtx = {id, d.write};
198 mop->mset.PushBack(mtx);
199 }
200}
201
202void ScopedReportBase::AddUniqueTid(Tid unique_tid) {
203 rep_->unique_tids.PushBack(unique_tid);
204}
205
206void ScopedReportBase::AddThread(const ThreadContext *tctx, bool suppressable) {
207 for (uptr i = 0; i < rep_->threads.Size(); i++) {
208 if ((u32)rep_->threads[i]->id == tctx->tid)
209 return;
210 }
211 auto *rt = New<ReportThread>();
212 rep_->threads.PushBack(rt);
213 rt->id = tctx->tid;
214 rt->os_id = tctx->os_id;
215 rt->running = (tctx->status == ThreadStatusRunning);
216 rt->name = internal_strdup(tctx->name);
217 rt->parent_tid = tctx->parent_tid;
218 rt->thread_type = tctx->thread_type;
219 rt->stack = 0;
220 rt->stack = SymbolizeStackId(tctx->creation_stack_id);
221 if (rt->stack)
222 rt->stack->suppressable = suppressable;
223}
224
225#if !SANITIZER_GO
226static ThreadContext *FindThreadByTidLocked(Tid tid) {
227 ctx->thread_registry.CheckLocked();
228 return static_cast<ThreadContext *>(
229 ctx->thread_registry.GetThreadLocked(tid));
230}
231
232static bool IsInStackOrTls(ThreadContextBase *tctx_base, void *arg) {
233 uptr addr = (uptr)arg;
234 ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base);
235 if (tctx->status != ThreadStatusRunning)
236 return false;
237 ThreadState *thr = tctx->thr;
238 CHECK(thr);
239 return ((addr >= thr->stk_addr && addr < thr->stk_addr + thr->stk_size) ||
240 (addr >= thr->tls_addr && addr < thr->tls_addr + thr->tls_size));
241}
242
243ThreadContext *IsThreadStackOrTls(uptr addr, bool *is_stack) {
244 ctx->thread_registry.CheckLocked();
245 ThreadContext *tctx =
246 static_cast<ThreadContext *>(ctx->thread_registry.FindThreadContextLocked(
247 IsInStackOrTls, (void *)addr));
248 if (!tctx)
249 return 0;
250 ThreadState *thr = tctx->thr;
251 CHECK(thr);
252 *is_stack = (addr >= thr->stk_addr && addr < thr->stk_addr + thr->stk_size);
253 return tctx;
254}
255#endif
256
257void ScopedReportBase::AddThread(Tid tid, bool suppressable) {
258#if !SANITIZER_GO
259 if (const ThreadContext *tctx = FindThreadByTidLocked(tid))
260 AddThread(tctx, suppressable);
261#endif
262}
263
264int ScopedReportBase::AddMutex(uptr addr, StackID creation_stack_id) {
265 for (uptr i = 0; i < rep_->mutexes.Size(); i++) {
266 if (rep_->mutexes[i]->addr == addr)
267 return rep_->mutexes[i]->id;
268 }
269 auto *rm = New<ReportMutex>();
270 rep_->mutexes.PushBack(rm);
271 rm->id = rep_->mutexes.Size() - 1;
272 rm->addr = addr;
273 rm->stack = SymbolizeStackId(creation_stack_id);
274 return rm->id;
275}
276
277void ScopedReportBase::AddLocation(uptr addr, uptr size) {
278 if (addr == 0)
279 return;
280#if !SANITIZER_GO
281 int fd = -1;
282 Tid creat_tid = kInvalidTid;
283 StackID creat_stack = 0;
284 bool closed = false;
285 if (FdLocation(addr, &fd, &creat_tid, &creat_stack, &closed)) {
286 auto *loc = New<ReportLocation>();
287 loc->type = ReportLocationFD;
288 loc->fd_closed = closed;
289 loc->fd = fd;
290 loc->tid = creat_tid;
291 loc->stack = SymbolizeStackId(creat_stack);
292 rep_->locs.PushBack(loc);
293 AddThread(creat_tid);
294 return;
295 }
296 MBlock *b = 0;
297 uptr block_begin = 0;
298 Allocator *a = allocator();
299 if (a->PointerIsMine((void*)addr)) {
300 block_begin = (uptr)a->GetBlockBegin((void *)addr);
301 if (block_begin)
302 b = ctx->metamap.GetBlock(block_begin);
303 }
304 if (!b)
305 b = JavaHeapBlock(addr, &block_begin);
306 if (b != 0) {
307 auto *loc = New<ReportLocation>();
308 loc->type = ReportLocationHeap;
309 loc->heap_chunk_start = block_begin;
310 loc->heap_chunk_size = b->siz;
311 loc->external_tag = b->tag;
312 loc->tid = b->tid;
313 loc->stack = SymbolizeStackId(b->stk);
314 rep_->locs.PushBack(loc);
315 AddThread(b->tid);
316 return;
317 }
318 bool is_stack = false;
319 if (ThreadContext *tctx = IsThreadStackOrTls(addr, &is_stack)) {
320 auto *loc = New<ReportLocation>();
321 loc->type = is_stack ? ReportLocationStack : ReportLocationTLS;
322 loc->tid = tctx->tid;
323 rep_->locs.PushBack(loc);
324 AddThread(tctx);
325 }
326#endif
327 if (ReportLocation *loc = SymbolizeData(addr)) {
328 loc->suppressable = true;
329 rep_->locs.PushBack(loc);
330 return;
331 }
332}
333
334#if !SANITIZER_GO
335void ScopedReportBase::AddSleep(StackID stack_id) {
336 rep_->sleep = SymbolizeStackId(stack_id);
337}
338#endif
339
340void ScopedReportBase::SetCount(int count) { rep_->count = count; }
341
342void ScopedReportBase::SetSigNum(int sig) { rep_->signum = sig; }
343
344const ReportDesc *ScopedReportBase::GetReport() const { return rep_; }
345
346ScopedReport::ScopedReport(ReportType typ, uptr tag)
347 : ScopedReportBase(typ, tag) {}
348
349ScopedReport::~ScopedReport() {}
350
351// Replays the trace up to last_pos position in the last part
352// or up to the provided epoch/sid (whichever is earlier)
353// and calls the provided function f for each event.
354template <typename Func>
355void TraceReplay(Trace *trace, TracePart *last, Event *last_pos, Sid sid,
356 Epoch epoch, Func f) {
357 TracePart *part = trace->parts.Front();
358 Sid ev_sid = kFreeSid;
359 Epoch ev_epoch = kEpochOver;
360 for (;;) {
361 DCHECK_EQ(part->trace, trace);
362 // Note: an event can't start in the last element.
363 // Since an event can take up to 2 elements,
364 // we ensure we have at least 2 before adding an event.
365 Event *end = &part->events[TracePart::kSize - 1];
366 if (part == last)
367 end = last_pos;
368 f(kFreeSid, kEpochOver, nullptr); // notify about part start
369 for (Event *evp = &part->events[0]; evp < end; evp++) {
370 Event *evp0 = evp;
371 if (!evp->is_access && !evp->is_func) {
372 switch (evp->type) {
373 case EventType::kTime: {
374 auto *ev = reinterpret_cast<EventTime *>(evp);
375 ev_sid = static_cast<Sid>(ev->sid);
376 ev_epoch = static_cast<Epoch>(ev->epoch);
377 if (ev_sid == sid && ev_epoch > epoch)
378 return;
379 break;
380 }
381 case EventType::kAccessExt:
382 FALLTHROUGH;
383 case EventType::kAccessRange:
384 FALLTHROUGH;
385 case EventType::kLock:
386 FALLTHROUGH;
387 case EventType::kRLock:
388 // These take 2 Event elements.
389 evp++;
390 break;
391 case EventType::kUnlock:
392 // This takes 1 Event element.
393 break;
394 }
395 }
396 CHECK_NE(ev_sid, kFreeSid);
397 CHECK_NE(ev_epoch, kEpochOver);
398 f(ev_sid, ev_epoch, evp0);
399 }
400 if (part == last)
401 return;
402 part = trace->parts.Next(part);
403 CHECK(part);
404 }
405 CHECK(0);
406}
407
408static void RestoreStackMatch(VarSizeStackTrace *pstk, MutexSet *pmset,
409 Vector<uptr> *stack, MutexSet *mset, uptr pc,
410 bool *found) {
411 DPrintf2(" MATCHED\n");
412 *pmset = *mset;
413 stack->PushBack(pc);
414 pstk->Init(&(*stack)[0], stack->Size());
415 stack->PopBack();
416 *found = true;
417}
418
419// Checks if addr1|size1 is fully contained in addr2|size2.
420// We check for fully contained instread of just overlapping
421// because a memory access is always traced once, but can be
422// split into multiple accesses in the shadow.
423static constexpr bool IsWithinAccess(uptr addr1, uptr size1, uptr addr2,
424 uptr size2) {
425 return addr1 >= addr2 && addr1 + size1 <= addr2 + size2;
426}
427
428// Replays the trace of slot sid up to the target event identified
429// by epoch/addr/size/typ and restores and returns tid, stack, mutex set
430// and tag for that event. If there are multiple such events, it returns
431// the last one. Returns false if the event is not present in the trace.
432bool RestoreStack(EventType type, Sid sid, Epoch epoch, uptr addr, uptr size,
433 AccessType typ, Tid *ptid, VarSizeStackTrace *pstk,
434 MutexSet *pmset, uptr *ptag) {
435 // This function restores stack trace and mutex set for the thread/epoch.
436 // It does so by getting stack trace and mutex set at the beginning of
437 // trace part, and then replaying the trace till the given epoch.
438 DPrintf2("RestoreStack: sid=%u@%u addr=0x%zx/%zu typ=%x\n",
439 static_cast<int>(sid), static_cast<int>(epoch), addr, size,
440 static_cast<int>(typ));
441 ctx->slot_mtx.CheckLocked(); // needed to prevent trace part recycling
442 ctx->thread_registry.CheckLocked();
443 TidSlot *slot = &ctx->slots[static_cast<uptr>(sid)];
444 Tid tid = kInvalidTid;
445 // Need to lock the slot mutex as it protects slot->journal.
446 slot->mtx.CheckLocked();
447 for (uptr i = 0; i < slot->journal.Size(); i++) {
448 DPrintf2(" journal: epoch=%d tid=%d\n",
449 static_cast<int>(slot->journal[i].epoch), slot->journal[i].tid);
450 if (i == slot->journal.Size() - 1 || slot->journal[i + 1].epoch > epoch) {
451 tid = slot->journal[i].tid;
452 break;
453 }
454 }
455 if (tid == kInvalidTid)
456 return false;
457 *ptid = tid;
458 ThreadContext *tctx =
459 static_cast<ThreadContext *>(ctx->thread_registry.GetThreadLocked(tid));
460 Trace *trace = &tctx->trace;
461 // Snapshot first/last parts and the current position in the last part.
462 TracePart *first_part;
463 TracePart *last_part;
464 Event *last_pos;
465 {
466 Lock lock(&trace->mtx);
467 first_part = trace->parts.Front();
468 if (!first_part) {
469 DPrintf2("RestoreStack: tid=%d trace=%p no trace parts\n", tid, trace);
470 return false;
471 }
472 last_part = trace->parts.Back();
473 last_pos = trace->final_pos;
474 if (tctx->thr)
475 last_pos = (Event *)atomic_load_relaxed(&tctx->thr->trace_pos);
476 }
477 DynamicMutexSet mset;
478 Vector<uptr> stack;
479 uptr prev_pc = 0;
480 bool found = false;
481 bool is_read = typ & kAccessRead;
482 bool is_atomic = typ & kAccessAtomic;
483 bool is_free = typ & kAccessFree;
484 DPrintf2("RestoreStack: tid=%d parts=[%p-%p] last_pos=%p\n", tid,
485 trace->parts.Front(), last_part, last_pos);
486 TraceReplay(
487 trace, last_part, last_pos, sid, epoch,
488 [&](Sid ev_sid, Epoch ev_epoch, Event *evp) {
489 if (evp == nullptr) {
490 // Each trace part is self-consistent, so we reset state.
491 stack.Resize(0);
492 mset->Reset();
493 prev_pc = 0;
494 return;
495 }
496 bool match = ev_sid == sid && ev_epoch == epoch;
497 if (evp->is_access) {
498 if (evp->is_func == 0 && evp->type == EventType::kAccessExt &&
499 evp->_ == 0) // NopEvent
500 return;
501 auto *ev = reinterpret_cast<EventAccess *>(evp);
502 uptr ev_addr = RestoreAddr(ev->addr);
503 uptr ev_size = 1 << ev->size_log;
504 uptr ev_pc =
505 prev_pc + ev->pc_delta - (1 << (EventAccess::kPCBits - 1));
506 prev_pc = ev_pc;
507 DPrintf2(" Access: pc=0x%zx addr=0x%zx/%zu type=%u/%u\n", ev_pc,
508 ev_addr, ev_size, ev->is_read, ev->is_atomic);
509 if (match && type == EventType::kAccessExt &&
510 IsWithinAccess(addr, size, ev_addr, ev_size) &&
511 is_read == ev->is_read && is_atomic == ev->is_atomic && !is_free)
512 RestoreStackMatch(pstk, pmset, &stack, mset, ev_pc, &found);
513 return;
514 }
515 if (evp->is_func) {
516 auto *ev = reinterpret_cast<EventFunc *>(evp);
517 if (ev->pc) {
518 DPrintf2(" FuncEnter: pc=0x%llx\n", ev->pc);
519 stack.PushBack(ev->pc);
520 } else {
521 DPrintf2(" FuncExit\n");
522 // We don't log pathologically large stacks in each part,
523 // if the stack was truncated we can have more func exits than
524 // entries.
525 if (stack.Size())
526 stack.PopBack();
527 }
528 return;
529 }
530 switch (evp->type) {
531 case EventType::kAccessExt: {
532 auto *ev = reinterpret_cast<EventAccessExt *>(evp);
533 uptr ev_addr = RestoreAddr(ev->addr);
534 uptr ev_size = 1 << ev->size_log;
535 prev_pc = ev->pc;
536 DPrintf2(" AccessExt: pc=0x%llx addr=0x%zx/%zu type=%u/%u\n",
537 ev->pc, ev_addr, ev_size, ev->is_read, ev->is_atomic);
538 if (match && type == EventType::kAccessExt &&
539 IsWithinAccess(addr, size, ev_addr, ev_size) &&
540 is_read == ev->is_read && is_atomic == ev->is_atomic &&
541 !is_free)
542 RestoreStackMatch(pstk, pmset, &stack, mset, ev->pc, &found);
543 break;
544 }
545 case EventType::kAccessRange: {
546 auto *ev = reinterpret_cast<EventAccessRange *>(evp);
547 uptr ev_addr = RestoreAddr(ev->addr);
548 uptr ev_size =
549 (ev->size_hi << EventAccessRange::kSizeLoBits) + ev->size_lo;
550 uptr ev_pc = RestoreAddr(ev->pc);
551 prev_pc = ev_pc;
552 DPrintf2(" Range: pc=0x%zx addr=0x%zx/%zu type=%u/%u\n", ev_pc,
553 ev_addr, ev_size, ev->is_read, ev->is_free);
554 if (match && type == EventType::kAccessExt &&
555 IsWithinAccess(addr, size, ev_addr, ev_size) &&
556 is_read == ev->is_read && !is_atomic && is_free == ev->is_free)
557 RestoreStackMatch(pstk, pmset, &stack, mset, ev_pc, &found);
558 break;
559 }
560 case EventType::kLock:
561 FALLTHROUGH;
562 case EventType::kRLock: {
563 auto *ev = reinterpret_cast<EventLock *>(evp);
564 bool is_write = ev->type == EventType::kLock;
565 uptr ev_addr = RestoreAddr(ev->addr);
566 uptr ev_pc = RestoreAddr(ev->pc);
567 StackID stack_id =
568 (ev->stack_hi << EventLock::kStackIDLoBits) + ev->stack_lo;
569 DPrintf2(" Lock: pc=0x%zx addr=0x%zx stack=%u write=%d\n", ev_pc,
570 ev_addr, stack_id, is_write);
571 mset->AddAddr(ev_addr, stack_id, is_write);
572 // Events with ev_pc == 0 are written to the beginning of trace
573 // part as initial mutex set (are not real).
574 if (match && type == EventType::kLock && addr == ev_addr && ev_pc)
575 RestoreStackMatch(pstk, pmset, &stack, mset, ev_pc, &found);
576 break;
577 }
578 case EventType::kUnlock: {
579 auto *ev = reinterpret_cast<EventUnlock *>(evp);
580 uptr ev_addr = RestoreAddr(ev->addr);
581 DPrintf2(" Unlock: addr=0x%zx\n", ev_addr);
582 mset->DelAddr(ev_addr);
583 break;
584 }
585 case EventType::kTime:
586 // TraceReplay already extracted sid/epoch from it,
587 // nothing else to do here.
588 break;
589 }
590 });
591 ExtractTagFromStack(pstk, ptag);
592 return found;
593}
594
595bool RacyStacks::operator==(const RacyStacks &other) const {
596 if (hash[0] == other.hash[0] && hash[1] == other.hash[1])
597 return true;
598 if (hash[0] == other.hash[1] && hash[1] == other.hash[0])
599 return true;
600 return false;
601}
602
603static bool FindRacyStacks(const RacyStacks &hash) {
604 for (uptr i = 0; i < ctx->racy_stacks.Size(); i++) {
605 if (hash == ctx->racy_stacks[i]) {
606 VPrintf(2, "ThreadSanitizer: suppressing report as doubled (stack)\n");
607 return true;
608 }
609 }
610 return false;
611}
612
613static bool HandleRacyStacks(ThreadState *thr, VarSizeStackTrace traces[2]) {
614 if (!flags()->suppress_equal_stacks)
615 return false;
616 RacyStacks hash;
617 hash.hash[0] = md5_hash(traces[0].trace, traces[0].size * sizeof(uptr));
618 hash.hash[1] = md5_hash(traces[1].trace, traces[1].size * sizeof(uptr));
619 {
620 ReadLock lock(&ctx->racy_mtx);
621 if (FindRacyStacks(hash))
622 return true;
623 }
624 Lock lock(&ctx->racy_mtx);
625 if (FindRacyStacks(hash))
626 return true;
627 ctx->racy_stacks.PushBack(hash);
628 return false;
629}
630
631bool OutputReport(ThreadState *thr, const ScopedReport &srep) {
632 // These should have been checked in ShouldReport.
633 // It's too late to check them here, we have already taken locks.
634 CHECK(flags()->report_bugs);
635 CHECK(!thr->suppress_reports);
636 atomic_store_relaxed(&ctx->last_symbolize_time_ns, NanoTime());
637 const ReportDesc *rep = srep.GetReport();
638 CHECK_EQ(thr->current_report, nullptr);
639 thr->current_report = rep;
640 Suppression *supp = 0;
641 uptr pc_or_addr = 0;
642 for (uptr i = 0; pc_or_addr == 0 && i < rep->mops.Size(); i++)
643 pc_or_addr = IsSuppressed(rep->typ, rep->mops[i]->stack, &supp);
644 for (uptr i = 0; pc_or_addr == 0 && i < rep->stacks.Size(); i++)
645 pc_or_addr = IsSuppressed(rep->typ, rep->stacks[i], &supp);
646 for (uptr i = 0; pc_or_addr == 0 && i < rep->threads.Size(); i++)
647 pc_or_addr = IsSuppressed(rep->typ, rep->threads[i]->stack, &supp);
648 for (uptr i = 0; pc_or_addr == 0 && i < rep->locs.Size(); i++)
649 pc_or_addr = IsSuppressed(rep->typ, rep->locs[i], &supp);
650 if (pc_or_addr != 0) {
651 Lock lock(&ctx->fired_suppressions_mtx);
652 FiredSuppression s = {srep.GetReport()->typ, pc_or_addr, supp};
653 ctx->fired_suppressions.push_back(s);
654 }
655 {
656 bool suppressed = OnReport(rep, pc_or_addr != 0);
657 if (suppressed) {
658 thr->current_report = nullptr;
659 return false;
660 }
661 }
662 PrintReport(rep);
663 __tsan_on_report(rep);
664 ctx->nreported++;
665 if (flags()->halt_on_error)
666 Die();
667 thr->current_report = nullptr;
668 return true;
669}
670
671bool IsFiredSuppression(Context *ctx, ReportType type, StackTrace trace) {
672 ReadLock lock(&ctx->fired_suppressions_mtx);
673 for (uptr k = 0; k < ctx->fired_suppressions.size(); k++) {
674 if (ctx->fired_suppressions[k].type != type)
675 continue;
676 for (uptr j = 0; j < trace.size; j++) {
677 FiredSuppression *s = &ctx->fired_suppressions[k];
678 if (trace.trace[j] == s->pc_or_addr) {
679 if (s->supp)
680 atomic_fetch_add(&s->supp->hit_count, 1, memory_order_relaxed);
681 return true;
682 }
683 }
684 }
685 return false;
686}
687
688static bool IsFiredSuppression(Context *ctx, ReportType type, uptr addr) {
689 ReadLock lock(&ctx->fired_suppressions_mtx);
690 for (uptr k = 0; k < ctx->fired_suppressions.size(); k++) {
691 if (ctx->fired_suppressions[k].type != type)
692 continue;
693 FiredSuppression *s = &ctx->fired_suppressions[k];
694 if (addr == s->pc_or_addr) {
695 if (s->supp)
696 atomic_fetch_add(&s->supp->hit_count, 1, memory_order_relaxed);
697 return true;
698 }
699 }
700 return false;
701}
702
703static bool SpuriousRace(Shadow old) {
704 Shadow last(LoadShadow(&ctx->last_spurious_race));
705 return last.sid() == old.sid() && last.epoch() == old.epoch();
706}
707
708void ReportRace(ThreadState *thr, RawShadow *shadow_mem, Shadow cur, Shadow old,
709 AccessType typ0) {
710 CheckedMutex::CheckNoLocks();
711
712 // Symbolizer makes lots of intercepted calls. If we try to process them,
713 // at best it will cause deadlocks on internal mutexes.
714 ScopedIgnoreInterceptors ignore;
715
716 uptr addr = ShadowToMem(shadow_mem);
717 DPrintf("#%d: ReportRace %p\n", thr->tid, (void *)addr);
718 if (!ShouldReport(thr, ReportTypeRace))
719 return;
720 uptr addr_off0, size0;
721 cur.GetAccess(&addr_off0, &size0, nullptr);
722 uptr addr_off1, size1, typ1;
723 old.GetAccess(&addr_off1, &size1, &typ1);
724 if (!flags()->report_atomic_races &&
725 ((typ0 & kAccessAtomic) || (typ1 & kAccessAtomic)) &&
726 !(typ0 & kAccessFree) && !(typ1 & kAccessFree))
727 return;
728 if (SpuriousRace(old))
729 return;
730
731 const uptr kMop = 2;
732 Shadow s[kMop] = {cur, old};
733 uptr addr0 = addr + addr_off0;
734 uptr addr1 = addr + addr_off1;
735 uptr end0 = addr0 + size0;
736 uptr end1 = addr1 + size1;
737 uptr addr_min = min(addr0, addr1);
738 uptr addr_max = max(end0, end1);
739 if (IsExpectedReport(addr_min, addr_max - addr_min))
740 return;
741
742 ReportType rep_typ = ReportTypeRace;
743 if ((typ0 & kAccessVptr) && (typ1 & kAccessFree))
744 rep_typ = ReportTypeVptrUseAfterFree;
745 else if (typ0 & kAccessVptr)
746 rep_typ = ReportTypeVptrRace;
747 else if (typ1 & kAccessFree)
748 rep_typ = ReportTypeUseAfterFree;
749
750 if (IsFiredSuppression(ctx, rep_typ, addr))
751 return;
752
753 VarSizeStackTrace traces[kMop];
754 Tid tids[kMop] = {thr->tid, kInvalidTid};
755 uptr tags[kMop] = {kExternalTagNone, kExternalTagNone};
756
757 ObtainCurrentStack(thr, thr->trace_prev_pc, &traces[0], &tags[0]);
758 if (IsFiredSuppression(ctx, rep_typ, traces[0]))
759 return;
760
761 DynamicMutexSet mset1;
762 MutexSet *mset[kMop] = {&thr->mset, mset1};
763
764 // We need to lock the slot during RestoreStack because it protects
765 // the slot journal.
766 Lock slot_lock(&ctx->slots[static_cast<uptr>(s[1].sid())].mtx);
767 ThreadRegistryLock l0(&ctx->thread_registry);
768 Lock slots_lock(&ctx->slot_mtx);
769 if (SpuriousRace(old))
770 return;
771 if (!RestoreStack(EventType::kAccessExt, s[1].sid(), s[1].epoch(), addr1,
772 size1, typ1, &tids[1], &traces[1], mset[1], &tags[1])) {
773 StoreShadow(&ctx->last_spurious_race, old.raw());
774 return;
775 }
776
777 if (IsFiredSuppression(ctx, rep_typ, traces[1]))
778 return;
779
780 if (HandleRacyStacks(thr, traces))
781 return;
782
783 // If any of the accesses has a tag, treat this as an "external" race.
784 uptr tag = kExternalTagNone;
785 for (uptr i = 0; i < kMop; i++) {
786 if (tags[i] != kExternalTagNone) {
787 rep_typ = ReportTypeExternalRace;
788 tag = tags[i];
789 break;
790 }
791 }
792
793 ScopedReport rep(rep_typ, tag);
794 for (uptr i = 0; i < kMop; i++)
795 rep.AddMemoryAccess(addr, tags[i], s[i], tids[i], traces[i], mset[i]);
796
797 for (uptr i = 0; i < kMop; i++) {
798 ThreadContext *tctx = static_cast<ThreadContext *>(
799 ctx->thread_registry.GetThreadLocked(tids[i]));
800 rep.AddThread(tctx);
801 }
802
803 rep.AddLocation(addr_min, addr_max - addr_min);
804
805 if (flags()->print_full_thread_history) {
806 const ReportDesc *rep_desc = rep.GetReport();
807 for (uptr i = 0; i < rep_desc->threads.Size(); i++) {
808 Tid parent_tid = rep_desc->threads[i]->parent_tid;
809 if (parent_tid == kMainTid || parent_tid == kInvalidTid)
810 continue;
811 ThreadContext *parent_tctx = static_cast<ThreadContext *>(
812 ctx->thread_registry.GetThreadLocked(parent_tid));
813 rep.AddThread(parent_tctx);
814 }
815 }
816
817#if !SANITIZER_GO
818 if (!((typ0 | typ1) & kAccessFree) &&
819 s[1].epoch() <= thr->last_sleep_clock.Get(s[1].sid()))
820 rep.AddSleep(thr->last_sleep_stack_id);
821#endif
822 OutputReport(thr, rep);
823}
824
825void PrintCurrentStack(ThreadState *thr, uptr pc) {
826 VarSizeStackTrace trace;
827 ObtainCurrentStack(thr, pc, &trace);
828 PrintStack(SymbolizeStack(trace));
829}
830
831// Always inlining PrintCurrentStack, because LocatePcInTrace assumes
832// __sanitizer_print_stack_trace exists in the actual unwinded stack, but
833// tail-call to PrintCurrentStack breaks this assumption because
834// __sanitizer_print_stack_trace disappears after tail-call.
835// However, this solution is not reliable enough, please see dvyukov's comment
836// http://reviews.llvm.org/D19148#406208
837// Also see PR27280 comment 2 and 3 for breaking examples and analysis.
838ALWAYS_INLINE USED void PrintCurrentStack(uptr pc, bool fast) {
839#if !SANITIZER_GO
840 uptr bp = GET_CURRENT_FRAME();
841 auto *ptrace = New<BufferedStackTrace>();
842 ptrace->Unwind(pc, bp, nullptr, fast);
843
844 for (uptr i = 0; i < ptrace->size / 2; i++) {
845 uptr tmp = ptrace->trace_buffer[i];
846 ptrace->trace_buffer[i] = ptrace->trace_buffer[ptrace->size - i - 1];
847 ptrace->trace_buffer[ptrace->size - i - 1] = tmp;
848 }
849
850 if (ready_to_symbolize) {
851 PrintStack(SymbolizeStack(*ptrace));
852 } else {
853 Printf(
854 "WARNING: PrintCurrentStack() has been called too early, before "
855 "symbolization is possible. Printing unsymbolized stack trace:\n");
856 for (unsigned int i = 0; i < ptrace->size; i++)
857 Printf(" #%u: 0x%zx\n", i, ptrace->trace[i]);
858 }
859#endif
860}
861
862} // namespace __tsan
863
864using namespace __tsan;
865
866extern "C" {
867SANITIZER_INTERFACE_ATTRIBUTE
868void __sanitizer_print_stack_trace() {
869 PrintCurrentStack(StackTrace::GetCurrentPc(), false);
870}
871} // extern "C"