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1 //===-- tsan_rtl.cc -------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of ThreadSanitizer (TSan), a race detector.
11 //
12 // Main file (entry points) for the TSan run-time.
13 //===----------------------------------------------------------------------===//
14 
15 #include "sanitizer_common/sanitizer_atomic.h"
16 #include "sanitizer_common/sanitizer_common.h"
17 #include "sanitizer_common/sanitizer_libc.h"
18 #include "sanitizer_common/sanitizer_stackdepot.h"
19 #include "sanitizer_common/sanitizer_placement_new.h"
20 #include "sanitizer_common/sanitizer_symbolizer.h"
21 #include "tsan_defs.h"
22 #include "tsan_platform.h"
23 #include "tsan_rtl.h"
24 #include "tsan_mman.h"
25 #include "tsan_suppressions.h"
26 #include "tsan_symbolize.h"
27 #include "ubsan/ubsan_init.h"
28 
29 #ifdef __SSE3__
30 // <emmintrin.h> transitively includes <stdlib.h>,
31 // and it's prohibited to include std headers into tsan runtime.
32 // So we do this dirty trick.
33 #define _MM_MALLOC_H_INCLUDED
34 #define __MM_MALLOC_H
35 #include <emmintrin.h>
36 typedef __m128i m128;
37 #endif
38 
39 volatile int __tsan_resumed = 0;
40 
__tsan_resume()41 extern "C" void __tsan_resume() {
42   __tsan_resumed = 1;
43 }
44 
45 namespace __tsan {
46 
47 #if !defined(SANITIZER_GO) && !SANITIZER_MAC
48 THREADLOCAL char cur_thread_placeholder[sizeof(ThreadState)] ALIGNED(64);
49 #endif
50 static char ctx_placeholder[sizeof(Context)] ALIGNED(64);
51 Context *ctx;
52 
53 // Can be overriden by a front-end.
54 #ifdef TSAN_EXTERNAL_HOOKS
55 bool OnFinalize(bool failed);
56 void OnInitialize();
57 #else
58 SANITIZER_WEAK_CXX_DEFAULT_IMPL
OnFinalize(bool failed)59 bool OnFinalize(bool failed) {
60   return failed;
61 }
62 SANITIZER_WEAK_CXX_DEFAULT_IMPL
OnInitialize()63 void OnInitialize() {}
64 #endif
65 
66 static char thread_registry_placeholder[sizeof(ThreadRegistry)];
67 
CreateThreadContext(u32 tid)68 static ThreadContextBase *CreateThreadContext(u32 tid) {
69   // Map thread trace when context is created.
70   char name[50];
71   internal_snprintf(name, sizeof(name), "trace %u", tid);
72   MapThreadTrace(GetThreadTrace(tid), TraceSize() * sizeof(Event), name);
73   const uptr hdr = GetThreadTraceHeader(tid);
74   internal_snprintf(name, sizeof(name), "trace header %u", tid);
75   MapThreadTrace(hdr, sizeof(Trace), name);
76   new((void*)hdr) Trace();
77   // We are going to use only a small part of the trace with the default
78   // value of history_size. However, the constructor writes to the whole trace.
79   // Unmap the unused part.
80   uptr hdr_end = hdr + sizeof(Trace);
81   hdr_end -= sizeof(TraceHeader) * (kTraceParts - TraceParts());
82   hdr_end = RoundUp(hdr_end, GetPageSizeCached());
83   if (hdr_end < hdr + sizeof(Trace))
84     UnmapOrDie((void*)hdr_end, hdr + sizeof(Trace) - hdr_end);
85   void *mem = internal_alloc(MBlockThreadContex, sizeof(ThreadContext));
86   return new(mem) ThreadContext(tid);
87 }
88 
89 #ifndef SANITIZER_GO
90 static const u32 kThreadQuarantineSize = 16;
91 #else
92 static const u32 kThreadQuarantineSize = 64;
93 #endif
94 
Context()95 Context::Context()
96   : initialized()
97   , report_mtx(MutexTypeReport, StatMtxReport)
98   , nreported()
99   , nmissed_expected()
100   , thread_registry(new(thread_registry_placeholder) ThreadRegistry(
101       CreateThreadContext, kMaxTid, kThreadQuarantineSize, kMaxTidReuse))
102   , racy_mtx(MutexTypeRacy, StatMtxRacy)
103   , racy_stacks(MBlockRacyStacks)
104   , racy_addresses(MBlockRacyAddresses)
105   , fired_suppressions_mtx(MutexTypeFired, StatMtxFired)
106   , fired_suppressions(8) {
107 }
108 
109 // The objects are allocated in TLS, so one may rely on zero-initialization.
ThreadState(Context * ctx,int tid,int unique_id,u64 epoch,unsigned reuse_count,uptr stk_addr,uptr stk_size,uptr tls_addr,uptr tls_size)110 ThreadState::ThreadState(Context *ctx, int tid, int unique_id, u64 epoch,
111                          unsigned reuse_count,
112                          uptr stk_addr, uptr stk_size,
113                          uptr tls_addr, uptr tls_size)
114   : fast_state(tid, epoch)
115   // Do not touch these, rely on zero initialization,
116   // they may be accessed before the ctor.
117   // , ignore_reads_and_writes()
118   // , ignore_interceptors()
119   , clock(tid, reuse_count)
120 #ifndef SANITIZER_GO
121   , jmp_bufs(MBlockJmpBuf)
122 #endif
123   , tid(tid)
124   , unique_id(unique_id)
125   , stk_addr(stk_addr)
126   , stk_size(stk_size)
127   , tls_addr(tls_addr)
128   , tls_size(tls_size)
129 #ifndef SANITIZER_GO
130   , last_sleep_clock(tid)
131 #endif
132 {
133 }
134 
135 #ifndef SANITIZER_GO
MemoryProfiler(Context * ctx,fd_t fd,int i)136 static void MemoryProfiler(Context *ctx, fd_t fd, int i) {
137   uptr n_threads;
138   uptr n_running_threads;
139   ctx->thread_registry->GetNumberOfThreads(&n_threads, &n_running_threads);
140   InternalScopedBuffer<char> buf(4096);
141   WriteMemoryProfile(buf.data(), buf.size(), n_threads, n_running_threads);
142   WriteToFile(fd, buf.data(), internal_strlen(buf.data()));
143 }
144 
BackgroundThread(void * arg)145 static void BackgroundThread(void *arg) {
146   // This is a non-initialized non-user thread, nothing to see here.
147   // We don't use ScopedIgnoreInterceptors, because we want ignores to be
148   // enabled even when the thread function exits (e.g. during pthread thread
149   // shutdown code).
150   cur_thread()->ignore_interceptors++;
151   const u64 kMs2Ns = 1000 * 1000;
152 
153   fd_t mprof_fd = kInvalidFd;
154   if (flags()->profile_memory && flags()->profile_memory[0]) {
155     if (internal_strcmp(flags()->profile_memory, "stdout") == 0) {
156       mprof_fd = 1;
157     } else if (internal_strcmp(flags()->profile_memory, "stderr") == 0) {
158       mprof_fd = 2;
159     } else {
160       InternalScopedString filename(kMaxPathLength);
161       filename.append("%s.%d", flags()->profile_memory, (int)internal_getpid());
162       fd_t fd = OpenFile(filename.data(), WrOnly);
163       if (fd == kInvalidFd) {
164         Printf("ThreadSanitizer: failed to open memory profile file '%s'\n",
165             &filename[0]);
166       } else {
167         mprof_fd = fd;
168       }
169     }
170   }
171 
172   u64 last_flush = NanoTime();
173   uptr last_rss = 0;
174   for (int i = 0;
175       atomic_load(&ctx->stop_background_thread, memory_order_relaxed) == 0;
176       i++) {
177     SleepForMillis(100);
178     u64 now = NanoTime();
179 
180     // Flush memory if requested.
181     if (flags()->flush_memory_ms > 0) {
182       if (last_flush + flags()->flush_memory_ms * kMs2Ns < now) {
183         VPrintf(1, "ThreadSanitizer: periodic memory flush\n");
184         FlushShadowMemory();
185         last_flush = NanoTime();
186       }
187     }
188     // GetRSS can be expensive on huge programs, so don't do it every 100ms.
189     if (flags()->memory_limit_mb > 0) {
190       uptr rss = GetRSS();
191       uptr limit = uptr(flags()->memory_limit_mb) << 20;
192       VPrintf(1, "ThreadSanitizer: memory flush check"
193                  " RSS=%llu LAST=%llu LIMIT=%llu\n",
194               (u64)rss >> 20, (u64)last_rss >> 20, (u64)limit >> 20);
195       if (2 * rss > limit + last_rss) {
196         VPrintf(1, "ThreadSanitizer: flushing memory due to RSS\n");
197         FlushShadowMemory();
198         rss = GetRSS();
199         VPrintf(1, "ThreadSanitizer: memory flushed RSS=%llu\n", (u64)rss>>20);
200       }
201       last_rss = rss;
202     }
203 
204     // Write memory profile if requested.
205     if (mprof_fd != kInvalidFd)
206       MemoryProfiler(ctx, mprof_fd, i);
207 
208     // Flush symbolizer cache if requested.
209     if (flags()->flush_symbolizer_ms > 0) {
210       u64 last = atomic_load(&ctx->last_symbolize_time_ns,
211                              memory_order_relaxed);
212       if (last != 0 && last + flags()->flush_symbolizer_ms * kMs2Ns < now) {
213         Lock l(&ctx->report_mtx);
214         SpinMutexLock l2(&CommonSanitizerReportMutex);
215         SymbolizeFlush();
216         atomic_store(&ctx->last_symbolize_time_ns, 0, memory_order_relaxed);
217       }
218     }
219   }
220 }
221 
StartBackgroundThread()222 static void StartBackgroundThread() {
223   ctx->background_thread = internal_start_thread(&BackgroundThread, 0);
224 }
225 
226 #ifndef __mips__
StopBackgroundThread()227 static void StopBackgroundThread() {
228   atomic_store(&ctx->stop_background_thread, 1, memory_order_relaxed);
229   internal_join_thread(ctx->background_thread);
230   ctx->background_thread = 0;
231 }
232 #endif
233 #endif
234 
DontNeedShadowFor(uptr addr,uptr size)235 void DontNeedShadowFor(uptr addr, uptr size) {
236   uptr shadow_beg = MemToShadow(addr);
237   uptr shadow_end = MemToShadow(addr + size);
238   FlushUnneededShadowMemory(shadow_beg, shadow_end - shadow_beg);
239 }
240 
MapShadow(uptr addr,uptr size)241 void MapShadow(uptr addr, uptr size) {
242   // Global data is not 64K aligned, but there are no adjacent mappings,
243   // so we can get away with unaligned mapping.
244   // CHECK_EQ(addr, addr & ~((64 << 10) - 1));  // windows wants 64K alignment
245   MmapFixedNoReserve(MemToShadow(addr), size * kShadowMultiplier, "shadow");
246 
247   // Meta shadow is 2:1, so tread carefully.
248   static bool data_mapped = false;
249   static uptr mapped_meta_end = 0;
250   uptr meta_begin = (uptr)MemToMeta(addr);
251   uptr meta_end = (uptr)MemToMeta(addr + size);
252   meta_begin = RoundDownTo(meta_begin, 64 << 10);
253   meta_end = RoundUpTo(meta_end, 64 << 10);
254   if (!data_mapped) {
255     // First call maps data+bss.
256     data_mapped = true;
257     MmapFixedNoReserve(meta_begin, meta_end - meta_begin, "meta shadow");
258   } else {
259     // Mapping continous heap.
260     // Windows wants 64K alignment.
261     meta_begin = RoundDownTo(meta_begin, 64 << 10);
262     meta_end = RoundUpTo(meta_end, 64 << 10);
263     if (meta_end <= mapped_meta_end)
264       return;
265     if (meta_begin < mapped_meta_end)
266       meta_begin = mapped_meta_end;
267     MmapFixedNoReserve(meta_begin, meta_end - meta_begin, "meta shadow");
268     mapped_meta_end = meta_end;
269   }
270   VPrintf(2, "mapped meta shadow for (%p-%p) at (%p-%p)\n",
271       addr, addr+size, meta_begin, meta_end);
272 }
273 
MapThreadTrace(uptr addr,uptr size,const char * name)274 void MapThreadTrace(uptr addr, uptr size, const char *name) {
275   DPrintf("#0: Mapping trace at %p-%p(0x%zx)\n", addr, addr + size, size);
276   CHECK_GE(addr, TraceMemBeg());
277   CHECK_LE(addr + size, TraceMemEnd());
278   CHECK_EQ(addr, addr & ~((64 << 10) - 1));  // windows wants 64K alignment
279   uptr addr1 = (uptr)MmapFixedNoReserve(addr, size, name);
280   if (addr1 != addr) {
281     Printf("FATAL: ThreadSanitizer can not mmap thread trace (%p/%p->%p)\n",
282         addr, size, addr1);
283     Die();
284   }
285 }
286 
CheckShadowMapping()287 static void CheckShadowMapping() {
288   uptr beg, end;
289   for (int i = 0; GetUserRegion(i, &beg, &end); i++) {
290     VPrintf(3, "checking shadow region %p-%p\n", beg, end);
291     for (uptr p0 = beg; p0 <= end; p0 += (end - beg) / 4) {
292       for (int x = -1; x <= 1; x++) {
293         const uptr p = p0 + x;
294         if (p < beg || p >= end)
295           continue;
296         const uptr s = MemToShadow(p);
297         const uptr m = (uptr)MemToMeta(p);
298         VPrintf(3, "  checking pointer %p: shadow=%p meta=%p\n", p, s, m);
299         CHECK(IsAppMem(p));
300         CHECK(IsShadowMem(s));
301         CHECK_EQ(p & ~(kShadowCell - 1), ShadowToMem(s));
302         CHECK(IsMetaMem(m));
303       }
304     }
305   }
306 }
307 
Initialize(ThreadState * thr)308 void Initialize(ThreadState *thr) {
309   // Thread safe because done before all threads exist.
310   static bool is_initialized = false;
311   if (is_initialized)
312     return;
313   is_initialized = true;
314   // We are not ready to handle interceptors yet.
315   ScopedIgnoreInterceptors ignore;
316   SanitizerToolName = "ThreadSanitizer";
317   // Install tool-specific callbacks in sanitizer_common.
318   SetCheckFailedCallback(TsanCheckFailed);
319 
320   ctx = new(ctx_placeholder) Context;
321   const char *options = GetEnv(kTsanOptionsEnv);
322   CacheBinaryName();
323   InitializeFlags(&ctx->flags, options);
324   AvoidCVE_2016_2143();
325   InitializePlatformEarly();
326 #ifndef SANITIZER_GO
327   // Re-exec ourselves if we need to set additional env or command line args.
328   MaybeReexec();
329 
330   InitializeAllocator();
331   ReplaceSystemMalloc();
332 #endif
333   if (common_flags()->detect_deadlocks)
334     ctx->dd = DDetector::Create(flags());
335   Processor *proc = ProcCreate();
336   ProcWire(proc, thr);
337   InitializeInterceptors();
338   CheckShadowMapping();
339   InitializePlatform();
340   InitializeMutex();
341   InitializeDynamicAnnotations();
342 #ifndef SANITIZER_GO
343   InitializeShadowMemory();
344   InitializeAllocatorLate();
345 #endif
346   // Setup correct file descriptor for error reports.
347   __sanitizer_set_report_path(common_flags()->log_path);
348   InitializeSuppressions();
349 #ifndef SANITIZER_GO
350   InitializeLibIgnore();
351   Symbolizer::GetOrInit()->AddHooks(EnterSymbolizer, ExitSymbolizer);
352   // On MIPS, TSan initialization is run before
353   // __pthread_initialize_minimal_internal() is finished, so we can not spawn
354   // new threads.
355 #ifndef __mips__
356   StartBackgroundThread();
357   SetSandboxingCallback(StopBackgroundThread);
358 #endif
359 #endif
360 
361   VPrintf(1, "***** Running under ThreadSanitizer v2 (pid %d) *****\n",
362           (int)internal_getpid());
363 
364   // Initialize thread 0.
365   int tid = ThreadCreate(thr, 0, 0, true);
366   CHECK_EQ(tid, 0);
367   ThreadStart(thr, tid, internal_getpid());
368 #if TSAN_CONTAINS_UBSAN
369   __ubsan::InitAsPlugin();
370 #endif
371   ctx->initialized = true;
372 
373 #ifndef SANITIZER_GO
374   Symbolizer::LateInitialize();
375 #endif
376 
377   if (flags()->stop_on_start) {
378     Printf("ThreadSanitizer is suspended at startup (pid %d)."
379            " Call __tsan_resume().\n",
380            (int)internal_getpid());
381     while (__tsan_resumed == 0) {}
382   }
383 
384   OnInitialize();
385 }
386 
Finalize(ThreadState * thr)387 int Finalize(ThreadState *thr) {
388   bool failed = false;
389 
390   if (flags()->atexit_sleep_ms > 0 && ThreadCount(thr) > 1)
391     SleepForMillis(flags()->atexit_sleep_ms);
392 
393   // Wait for pending reports.
394   ctx->report_mtx.Lock();
395   CommonSanitizerReportMutex.Lock();
396   CommonSanitizerReportMutex.Unlock();
397   ctx->report_mtx.Unlock();
398 
399 #ifndef SANITIZER_GO
400   if (Verbosity()) AllocatorPrintStats();
401 #endif
402 
403   ThreadFinalize(thr);
404 
405   if (ctx->nreported) {
406     failed = true;
407 #ifndef SANITIZER_GO
408     Printf("ThreadSanitizer: reported %d warnings\n", ctx->nreported);
409 #else
410     Printf("Found %d data race(s)\n", ctx->nreported);
411 #endif
412   }
413 
414   if (ctx->nmissed_expected) {
415     failed = true;
416     Printf("ThreadSanitizer: missed %d expected races\n",
417         ctx->nmissed_expected);
418   }
419 
420   if (common_flags()->print_suppressions)
421     PrintMatchedSuppressions();
422 #ifndef SANITIZER_GO
423   if (flags()->print_benign)
424     PrintMatchedBenignRaces();
425 #endif
426 
427   failed = OnFinalize(failed);
428 
429 #if TSAN_COLLECT_STATS
430   StatAggregate(ctx->stat, thr->stat);
431   StatOutput(ctx->stat);
432 #endif
433 
434   return failed ? common_flags()->exitcode : 0;
435 }
436 
437 #ifndef SANITIZER_GO
ForkBefore(ThreadState * thr,uptr pc)438 void ForkBefore(ThreadState *thr, uptr pc) {
439   ctx->thread_registry->Lock();
440   ctx->report_mtx.Lock();
441 }
442 
ForkParentAfter(ThreadState * thr,uptr pc)443 void ForkParentAfter(ThreadState *thr, uptr pc) {
444   ctx->report_mtx.Unlock();
445   ctx->thread_registry->Unlock();
446 }
447 
ForkChildAfter(ThreadState * thr,uptr pc)448 void ForkChildAfter(ThreadState *thr, uptr pc) {
449   ctx->report_mtx.Unlock();
450   ctx->thread_registry->Unlock();
451 
452   uptr nthread = 0;
453   ctx->thread_registry->GetNumberOfThreads(0, 0, &nthread /* alive threads */);
454   VPrintf(1, "ThreadSanitizer: forked new process with pid %d,"
455       " parent had %d threads\n", (int)internal_getpid(), (int)nthread);
456   if (nthread == 1) {
457     StartBackgroundThread();
458   } else {
459     // We've just forked a multi-threaded process. We cannot reasonably function
460     // after that (some mutexes may be locked before fork). So just enable
461     // ignores for everything in the hope that we will exec soon.
462     ctx->after_multithreaded_fork = true;
463     thr->ignore_interceptors++;
464     ThreadIgnoreBegin(thr, pc);
465     ThreadIgnoreSyncBegin(thr, pc);
466   }
467 }
468 #endif
469 
470 #ifdef SANITIZER_GO
471 NOINLINE
GrowShadowStack(ThreadState * thr)472 void GrowShadowStack(ThreadState *thr) {
473   const int sz = thr->shadow_stack_end - thr->shadow_stack;
474   const int newsz = 2 * sz;
475   uptr *newstack = (uptr*)internal_alloc(MBlockShadowStack,
476       newsz * sizeof(uptr));
477   internal_memcpy(newstack, thr->shadow_stack, sz * sizeof(uptr));
478   internal_free(thr->shadow_stack);
479   thr->shadow_stack = newstack;
480   thr->shadow_stack_pos = newstack + sz;
481   thr->shadow_stack_end = newstack + newsz;
482 }
483 #endif
484 
CurrentStackId(ThreadState * thr,uptr pc)485 u32 CurrentStackId(ThreadState *thr, uptr pc) {
486   if (!thr->is_inited)  // May happen during bootstrap.
487     return 0;
488   if (pc != 0) {
489 #ifndef SANITIZER_GO
490     DCHECK_LT(thr->shadow_stack_pos, thr->shadow_stack_end);
491 #else
492     if (thr->shadow_stack_pos == thr->shadow_stack_end)
493       GrowShadowStack(thr);
494 #endif
495     thr->shadow_stack_pos[0] = pc;
496     thr->shadow_stack_pos++;
497   }
498   u32 id = StackDepotPut(
499       StackTrace(thr->shadow_stack, thr->shadow_stack_pos - thr->shadow_stack));
500   if (pc != 0)
501     thr->shadow_stack_pos--;
502   return id;
503 }
504 
TraceSwitch(ThreadState * thr)505 void TraceSwitch(ThreadState *thr) {
506   thr->nomalloc++;
507   Trace *thr_trace = ThreadTrace(thr->tid);
508   Lock l(&thr_trace->mtx);
509   unsigned trace = (thr->fast_state.epoch() / kTracePartSize) % TraceParts();
510   TraceHeader *hdr = &thr_trace->headers[trace];
511   hdr->epoch0 = thr->fast_state.epoch();
512   ObtainCurrentStack(thr, 0, &hdr->stack0);
513   hdr->mset0 = thr->mset;
514   thr->nomalloc--;
515 }
516 
ThreadTrace(int tid)517 Trace *ThreadTrace(int tid) {
518   return (Trace*)GetThreadTraceHeader(tid);
519 }
520 
TraceTopPC(ThreadState * thr)521 uptr TraceTopPC(ThreadState *thr) {
522   Event *events = (Event*)GetThreadTrace(thr->tid);
523   uptr pc = events[thr->fast_state.GetTracePos()];
524   return pc;
525 }
526 
TraceSize()527 uptr TraceSize() {
528   return (uptr)(1ull << (kTracePartSizeBits + flags()->history_size + 1));
529 }
530 
TraceParts()531 uptr TraceParts() {
532   return TraceSize() / kTracePartSize;
533 }
534 
535 #ifndef SANITIZER_GO
__tsan_trace_switch()536 extern "C" void __tsan_trace_switch() {
537   TraceSwitch(cur_thread());
538 }
539 
__tsan_report_race()540 extern "C" void __tsan_report_race() {
541   ReportRace(cur_thread());
542 }
543 #endif
544 
545 ALWAYS_INLINE
LoadShadow(u64 * p)546 Shadow LoadShadow(u64 *p) {
547   u64 raw = atomic_load((atomic_uint64_t*)p, memory_order_relaxed);
548   return Shadow(raw);
549 }
550 
551 ALWAYS_INLINE
StoreShadow(u64 * sp,u64 s)552 void StoreShadow(u64 *sp, u64 s) {
553   atomic_store((atomic_uint64_t*)sp, s, memory_order_relaxed);
554 }
555 
556 ALWAYS_INLINE
StoreIfNotYetStored(u64 * sp,u64 * s)557 void StoreIfNotYetStored(u64 *sp, u64 *s) {
558   StoreShadow(sp, *s);
559   *s = 0;
560 }
561 
562 ALWAYS_INLINE
HandleRace(ThreadState * thr,u64 * shadow_mem,Shadow cur,Shadow old)563 void HandleRace(ThreadState *thr, u64 *shadow_mem,
564                               Shadow cur, Shadow old) {
565   thr->racy_state[0] = cur.raw();
566   thr->racy_state[1] = old.raw();
567   thr->racy_shadow_addr = shadow_mem;
568 #ifndef SANITIZER_GO
569   HACKY_CALL(__tsan_report_race);
570 #else
571   ReportRace(thr);
572 #endif
573 }
574 
HappensBefore(Shadow old,ThreadState * thr)575 static inline bool HappensBefore(Shadow old, ThreadState *thr) {
576   return thr->clock.get(old.TidWithIgnore()) >= old.epoch();
577 }
578 
579 ALWAYS_INLINE
MemoryAccessImpl1(ThreadState * thr,uptr addr,int kAccessSizeLog,bool kAccessIsWrite,bool kIsAtomic,u64 * shadow_mem,Shadow cur)580 void MemoryAccessImpl1(ThreadState *thr, uptr addr,
581     int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic,
582     u64 *shadow_mem, Shadow cur) {
583   StatInc(thr, StatMop);
584   StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
585   StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
586 
587   // This potentially can live in an MMX/SSE scratch register.
588   // The required intrinsics are:
589   // __m128i _mm_move_epi64(__m128i*);
590   // _mm_storel_epi64(u64*, __m128i);
591   u64 store_word = cur.raw();
592 
593   // scan all the shadow values and dispatch to 4 categories:
594   // same, replace, candidate and race (see comments below).
595   // we consider only 3 cases regarding access sizes:
596   // equal, intersect and not intersect. initially I considered
597   // larger and smaller as well, it allowed to replace some
598   // 'candidates' with 'same' or 'replace', but I think
599   // it's just not worth it (performance- and complexity-wise).
600 
601   Shadow old(0);
602 
603   // It release mode we manually unroll the loop,
604   // because empirically gcc generates better code this way.
605   // However, we can't afford unrolling in debug mode, because the function
606   // consumes almost 4K of stack. Gtest gives only 4K of stack to death test
607   // threads, which is not enough for the unrolled loop.
608 #if SANITIZER_DEBUG
609   for (int idx = 0; idx < 4; idx++) {
610 #include "tsan_update_shadow_word_inl.h"
611   }
612 #else
613   int idx = 0;
614 #include "tsan_update_shadow_word_inl.h"
615   idx = 1;
616 #include "tsan_update_shadow_word_inl.h"
617   idx = 2;
618 #include "tsan_update_shadow_word_inl.h"
619   idx = 3;
620 #include "tsan_update_shadow_word_inl.h"
621 #endif
622 
623   // we did not find any races and had already stored
624   // the current access info, so we are done
625   if (LIKELY(store_word == 0))
626     return;
627   // choose a random candidate slot and replace it
628   StoreShadow(shadow_mem + (cur.epoch() % kShadowCnt), store_word);
629   StatInc(thr, StatShadowReplace);
630   return;
631  RACE:
632   HandleRace(thr, shadow_mem, cur, old);
633   return;
634 }
635 
UnalignedMemoryAccess(ThreadState * thr,uptr pc,uptr addr,int size,bool kAccessIsWrite,bool kIsAtomic)636 void UnalignedMemoryAccess(ThreadState *thr, uptr pc, uptr addr,
637     int size, bool kAccessIsWrite, bool kIsAtomic) {
638   while (size) {
639     int size1 = 1;
640     int kAccessSizeLog = kSizeLog1;
641     if (size >= 8 && (addr & ~7) == ((addr + 7) & ~7)) {
642       size1 = 8;
643       kAccessSizeLog = kSizeLog8;
644     } else if (size >= 4 && (addr & ~7) == ((addr + 3) & ~7)) {
645       size1 = 4;
646       kAccessSizeLog = kSizeLog4;
647     } else if (size >= 2 && (addr & ~7) == ((addr + 1) & ~7)) {
648       size1 = 2;
649       kAccessSizeLog = kSizeLog2;
650     }
651     MemoryAccess(thr, pc, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic);
652     addr += size1;
653     size -= size1;
654   }
655 }
656 
657 ALWAYS_INLINE
ContainsSameAccessSlow(u64 * s,u64 a,u64 sync_epoch,bool is_write)658 bool ContainsSameAccessSlow(u64 *s, u64 a, u64 sync_epoch, bool is_write) {
659   Shadow cur(a);
660   for (uptr i = 0; i < kShadowCnt; i++) {
661     Shadow old(LoadShadow(&s[i]));
662     if (Shadow::Addr0AndSizeAreEqual(cur, old) &&
663         old.TidWithIgnore() == cur.TidWithIgnore() &&
664         old.epoch() > sync_epoch &&
665         old.IsAtomic() == cur.IsAtomic() &&
666         old.IsRead() <= cur.IsRead())
667       return true;
668   }
669   return false;
670 }
671 
672 #if defined(__SSE3__)
673 #define SHUF(v0, v1, i0, i1, i2, i3) _mm_castps_si128(_mm_shuffle_ps( \
674     _mm_castsi128_ps(v0), _mm_castsi128_ps(v1), \
675     (i0)*1 + (i1)*4 + (i2)*16 + (i3)*64))
676 ALWAYS_INLINE
ContainsSameAccessFast(u64 * s,u64 a,u64 sync_epoch,bool is_write)677 bool ContainsSameAccessFast(u64 *s, u64 a, u64 sync_epoch, bool is_write) {
678   // This is an optimized version of ContainsSameAccessSlow.
679   // load current access into access[0:63]
680   const m128 access     = _mm_cvtsi64_si128(a);
681   // duplicate high part of access in addr0:
682   // addr0[0:31]        = access[32:63]
683   // addr0[32:63]       = access[32:63]
684   // addr0[64:95]       = access[32:63]
685   // addr0[96:127]      = access[32:63]
686   const m128 addr0      = SHUF(access, access, 1, 1, 1, 1);
687   // load 4 shadow slots
688   const m128 shadow0    = _mm_load_si128((__m128i*)s);
689   const m128 shadow1    = _mm_load_si128((__m128i*)s + 1);
690   // load high parts of 4 shadow slots into addr_vect:
691   // addr_vect[0:31]    = shadow0[32:63]
692   // addr_vect[32:63]   = shadow0[96:127]
693   // addr_vect[64:95]   = shadow1[32:63]
694   // addr_vect[96:127]  = shadow1[96:127]
695   m128 addr_vect        = SHUF(shadow0, shadow1, 1, 3, 1, 3);
696   if (!is_write) {
697     // set IsRead bit in addr_vect
698     const m128 rw_mask1 = _mm_cvtsi64_si128(1<<15);
699     const m128 rw_mask  = SHUF(rw_mask1, rw_mask1, 0, 0, 0, 0);
700     addr_vect           = _mm_or_si128(addr_vect, rw_mask);
701   }
702   // addr0 == addr_vect?
703   const m128 addr_res   = _mm_cmpeq_epi32(addr0, addr_vect);
704   // epoch1[0:63]       = sync_epoch
705   const m128 epoch1     = _mm_cvtsi64_si128(sync_epoch);
706   // epoch[0:31]        = sync_epoch[0:31]
707   // epoch[32:63]       = sync_epoch[0:31]
708   // epoch[64:95]       = sync_epoch[0:31]
709   // epoch[96:127]      = sync_epoch[0:31]
710   const m128 epoch      = SHUF(epoch1, epoch1, 0, 0, 0, 0);
711   // load low parts of shadow cell epochs into epoch_vect:
712   // epoch_vect[0:31]   = shadow0[0:31]
713   // epoch_vect[32:63]  = shadow0[64:95]
714   // epoch_vect[64:95]  = shadow1[0:31]
715   // epoch_vect[96:127] = shadow1[64:95]
716   const m128 epoch_vect = SHUF(shadow0, shadow1, 0, 2, 0, 2);
717   // epoch_vect >= sync_epoch?
718   const m128 epoch_res  = _mm_cmpgt_epi32(epoch_vect, epoch);
719   // addr_res & epoch_res
720   const m128 res        = _mm_and_si128(addr_res, epoch_res);
721   // mask[0] = res[7]
722   // mask[1] = res[15]
723   // ...
724   // mask[15] = res[127]
725   const int mask        = _mm_movemask_epi8(res);
726   return mask != 0;
727 }
728 #endif
729 
730 ALWAYS_INLINE
ContainsSameAccess(u64 * s,u64 a,u64 sync_epoch,bool is_write)731 bool ContainsSameAccess(u64 *s, u64 a, u64 sync_epoch, bool is_write) {
732 #if defined(__SSE3__)
733   bool res = ContainsSameAccessFast(s, a, sync_epoch, is_write);
734   // NOTE: this check can fail if the shadow is concurrently mutated
735   // by other threads. But it still can be useful if you modify
736   // ContainsSameAccessFast and want to ensure that it's not completely broken.
737   // DCHECK_EQ(res, ContainsSameAccessSlow(s, a, sync_epoch, is_write));
738   return res;
739 #else
740   return ContainsSameAccessSlow(s, a, sync_epoch, is_write);
741 #endif
742 }
743 
744 ALWAYS_INLINE USED
MemoryAccess(ThreadState * thr,uptr pc,uptr addr,int kAccessSizeLog,bool kAccessIsWrite,bool kIsAtomic)745 void MemoryAccess(ThreadState *thr, uptr pc, uptr addr,
746     int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic) {
747   u64 *shadow_mem = (u64*)MemToShadow(addr);
748   DPrintf2("#%d: MemoryAccess: @%p %p size=%d"
749       " is_write=%d shadow_mem=%p {%zx, %zx, %zx, %zx}\n",
750       (int)thr->fast_state.tid(), (void*)pc, (void*)addr,
751       (int)(1 << kAccessSizeLog), kAccessIsWrite, shadow_mem,
752       (uptr)shadow_mem[0], (uptr)shadow_mem[1],
753       (uptr)shadow_mem[2], (uptr)shadow_mem[3]);
754 #if SANITIZER_DEBUG
755   if (!IsAppMem(addr)) {
756     Printf("Access to non app mem %zx\n", addr);
757     DCHECK(IsAppMem(addr));
758   }
759   if (!IsShadowMem((uptr)shadow_mem)) {
760     Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr);
761     DCHECK(IsShadowMem((uptr)shadow_mem));
762   }
763 #endif
764 
765   if (kCppMode && *shadow_mem == kShadowRodata) {
766     // Access to .rodata section, no races here.
767     // Measurements show that it can be 10-20% of all memory accesses.
768     StatInc(thr, StatMop);
769     StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
770     StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
771     StatInc(thr, StatMopRodata);
772     return;
773   }
774 
775   FastState fast_state = thr->fast_state;
776   if (fast_state.GetIgnoreBit()) {
777     StatInc(thr, StatMop);
778     StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
779     StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
780     StatInc(thr, StatMopIgnored);
781     return;
782   }
783 
784   Shadow cur(fast_state);
785   cur.SetAddr0AndSizeLog(addr & 7, kAccessSizeLog);
786   cur.SetWrite(kAccessIsWrite);
787   cur.SetAtomic(kIsAtomic);
788 
789   if (LIKELY(ContainsSameAccess(shadow_mem, cur.raw(),
790       thr->fast_synch_epoch, kAccessIsWrite))) {
791     StatInc(thr, StatMop);
792     StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
793     StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
794     StatInc(thr, StatMopSame);
795     return;
796   }
797 
798   if (kCollectHistory) {
799     fast_state.IncrementEpoch();
800     thr->fast_state = fast_state;
801     TraceAddEvent(thr, fast_state, EventTypeMop, pc);
802     cur.IncrementEpoch();
803   }
804 
805   MemoryAccessImpl1(thr, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic,
806       shadow_mem, cur);
807 }
808 
809 // Called by MemoryAccessRange in tsan_rtl_thread.cc
810 ALWAYS_INLINE USED
MemoryAccessImpl(ThreadState * thr,uptr addr,int kAccessSizeLog,bool kAccessIsWrite,bool kIsAtomic,u64 * shadow_mem,Shadow cur)811 void MemoryAccessImpl(ThreadState *thr, uptr addr,
812     int kAccessSizeLog, bool kAccessIsWrite, bool kIsAtomic,
813     u64 *shadow_mem, Shadow cur) {
814   if (LIKELY(ContainsSameAccess(shadow_mem, cur.raw(),
815       thr->fast_synch_epoch, kAccessIsWrite))) {
816     StatInc(thr, StatMop);
817     StatInc(thr, kAccessIsWrite ? StatMopWrite : StatMopRead);
818     StatInc(thr, (StatType)(StatMop1 + kAccessSizeLog));
819     StatInc(thr, StatMopSame);
820     return;
821   }
822 
823   MemoryAccessImpl1(thr, addr, kAccessSizeLog, kAccessIsWrite, kIsAtomic,
824       shadow_mem, cur);
825 }
826 
MemoryRangeSet(ThreadState * thr,uptr pc,uptr addr,uptr size,u64 val)827 static void MemoryRangeSet(ThreadState *thr, uptr pc, uptr addr, uptr size,
828                            u64 val) {
829   (void)thr;
830   (void)pc;
831   if (size == 0)
832     return;
833   // FIXME: fix me.
834   uptr offset = addr % kShadowCell;
835   if (offset) {
836     offset = kShadowCell - offset;
837     if (size <= offset)
838       return;
839     addr += offset;
840     size -= offset;
841   }
842   DCHECK_EQ(addr % 8, 0);
843   // If a user passes some insane arguments (memset(0)),
844   // let it just crash as usual.
845   if (!IsAppMem(addr) || !IsAppMem(addr + size - 1))
846     return;
847   // Don't want to touch lots of shadow memory.
848   // If a program maps 10MB stack, there is no need reset the whole range.
849   size = (size + (kShadowCell - 1)) & ~(kShadowCell - 1);
850   // UnmapOrDie/MmapFixedNoReserve does not work on Windows,
851   // so we do it only for C/C++.
852   if (kGoMode || size < common_flags()->clear_shadow_mmap_threshold) {
853     u64 *p = (u64*)MemToShadow(addr);
854     CHECK(IsShadowMem((uptr)p));
855     CHECK(IsShadowMem((uptr)(p + size * kShadowCnt / kShadowCell - 1)));
856     // FIXME: may overwrite a part outside the region
857     for (uptr i = 0; i < size / kShadowCell * kShadowCnt;) {
858       p[i++] = val;
859       for (uptr j = 1; j < kShadowCnt; j++)
860         p[i++] = 0;
861     }
862   } else {
863     // The region is big, reset only beginning and end.
864     const uptr kPageSize = GetPageSizeCached();
865     u64 *begin = (u64*)MemToShadow(addr);
866     u64 *end = begin + size / kShadowCell * kShadowCnt;
867     u64 *p = begin;
868     // Set at least first kPageSize/2 to page boundary.
869     while ((p < begin + kPageSize / kShadowSize / 2) || ((uptr)p % kPageSize)) {
870       *p++ = val;
871       for (uptr j = 1; j < kShadowCnt; j++)
872         *p++ = 0;
873     }
874     // Reset middle part.
875     u64 *p1 = p;
876     p = RoundDown(end, kPageSize);
877     UnmapOrDie((void*)p1, (uptr)p - (uptr)p1);
878     MmapFixedNoReserve((uptr)p1, (uptr)p - (uptr)p1);
879     // Set the ending.
880     while (p < end) {
881       *p++ = val;
882       for (uptr j = 1; j < kShadowCnt; j++)
883         *p++ = 0;
884     }
885   }
886 }
887 
MemoryResetRange(ThreadState * thr,uptr pc,uptr addr,uptr size)888 void MemoryResetRange(ThreadState *thr, uptr pc, uptr addr, uptr size) {
889   MemoryRangeSet(thr, pc, addr, size, 0);
890 }
891 
MemoryRangeFreed(ThreadState * thr,uptr pc,uptr addr,uptr size)892 void MemoryRangeFreed(ThreadState *thr, uptr pc, uptr addr, uptr size) {
893   // Processing more than 1k (4k of shadow) is expensive,
894   // can cause excessive memory consumption (user does not necessary touch
895   // the whole range) and most likely unnecessary.
896   if (size > 1024)
897     size = 1024;
898   CHECK_EQ(thr->is_freeing, false);
899   thr->is_freeing = true;
900   MemoryAccessRange(thr, pc, addr, size, true);
901   thr->is_freeing = false;
902   if (kCollectHistory) {
903     thr->fast_state.IncrementEpoch();
904     TraceAddEvent(thr, thr->fast_state, EventTypeMop, pc);
905   }
906   Shadow s(thr->fast_state);
907   s.ClearIgnoreBit();
908   s.MarkAsFreed();
909   s.SetWrite(true);
910   s.SetAddr0AndSizeLog(0, 3);
911   MemoryRangeSet(thr, pc, addr, size, s.raw());
912 }
913 
MemoryRangeImitateWrite(ThreadState * thr,uptr pc,uptr addr,uptr size)914 void MemoryRangeImitateWrite(ThreadState *thr, uptr pc, uptr addr, uptr size) {
915   if (kCollectHistory) {
916     thr->fast_state.IncrementEpoch();
917     TraceAddEvent(thr, thr->fast_state, EventTypeMop, pc);
918   }
919   Shadow s(thr->fast_state);
920   s.ClearIgnoreBit();
921   s.SetWrite(true);
922   s.SetAddr0AndSizeLog(0, 3);
923   MemoryRangeSet(thr, pc, addr, size, s.raw());
924 }
925 
926 ALWAYS_INLINE USED
FuncEntry(ThreadState * thr,uptr pc)927 void FuncEntry(ThreadState *thr, uptr pc) {
928   StatInc(thr, StatFuncEnter);
929   DPrintf2("#%d: FuncEntry %p\n", (int)thr->fast_state.tid(), (void*)pc);
930   if (kCollectHistory) {
931     thr->fast_state.IncrementEpoch();
932     TraceAddEvent(thr, thr->fast_state, EventTypeFuncEnter, pc);
933   }
934 
935   // Shadow stack maintenance can be replaced with
936   // stack unwinding during trace switch (which presumably must be faster).
937   DCHECK_GE(thr->shadow_stack_pos, thr->shadow_stack);
938 #ifndef SANITIZER_GO
939   DCHECK_LT(thr->shadow_stack_pos, thr->shadow_stack_end);
940 #else
941   if (thr->shadow_stack_pos == thr->shadow_stack_end)
942     GrowShadowStack(thr);
943 #endif
944   thr->shadow_stack_pos[0] = pc;
945   thr->shadow_stack_pos++;
946 }
947 
948 ALWAYS_INLINE USED
FuncExit(ThreadState * thr)949 void FuncExit(ThreadState *thr) {
950   StatInc(thr, StatFuncExit);
951   DPrintf2("#%d: FuncExit\n", (int)thr->fast_state.tid());
952   if (kCollectHistory) {
953     thr->fast_state.IncrementEpoch();
954     TraceAddEvent(thr, thr->fast_state, EventTypeFuncExit, 0);
955   }
956 
957   DCHECK_GT(thr->shadow_stack_pos, thr->shadow_stack);
958 #ifndef SANITIZER_GO
959   DCHECK_LT(thr->shadow_stack_pos, thr->shadow_stack_end);
960 #endif
961   thr->shadow_stack_pos--;
962 }
963 
ThreadIgnoreBegin(ThreadState * thr,uptr pc)964 void ThreadIgnoreBegin(ThreadState *thr, uptr pc) {
965   DPrintf("#%d: ThreadIgnoreBegin\n", thr->tid);
966   thr->ignore_reads_and_writes++;
967   CHECK_GT(thr->ignore_reads_and_writes, 0);
968   thr->fast_state.SetIgnoreBit();
969 #ifndef SANITIZER_GO
970   if (!ctx->after_multithreaded_fork)
971     thr->mop_ignore_set.Add(CurrentStackId(thr, pc));
972 #endif
973 }
974 
ThreadIgnoreEnd(ThreadState * thr,uptr pc)975 void ThreadIgnoreEnd(ThreadState *thr, uptr pc) {
976   DPrintf("#%d: ThreadIgnoreEnd\n", thr->tid);
977   thr->ignore_reads_and_writes--;
978   CHECK_GE(thr->ignore_reads_and_writes, 0);
979   if (thr->ignore_reads_and_writes == 0) {
980     thr->fast_state.ClearIgnoreBit();
981 #ifndef SANITIZER_GO
982     thr->mop_ignore_set.Reset();
983 #endif
984   }
985 }
986 
ThreadIgnoreSyncBegin(ThreadState * thr,uptr pc)987 void ThreadIgnoreSyncBegin(ThreadState *thr, uptr pc) {
988   DPrintf("#%d: ThreadIgnoreSyncBegin\n", thr->tid);
989   thr->ignore_sync++;
990   CHECK_GT(thr->ignore_sync, 0);
991 #ifndef SANITIZER_GO
992   if (!ctx->after_multithreaded_fork)
993     thr->sync_ignore_set.Add(CurrentStackId(thr, pc));
994 #endif
995 }
996 
ThreadIgnoreSyncEnd(ThreadState * thr,uptr pc)997 void ThreadIgnoreSyncEnd(ThreadState *thr, uptr pc) {
998   DPrintf("#%d: ThreadIgnoreSyncEnd\n", thr->tid);
999   thr->ignore_sync--;
1000   CHECK_GE(thr->ignore_sync, 0);
1001 #ifndef SANITIZER_GO
1002   if (thr->ignore_sync == 0)
1003     thr->sync_ignore_set.Reset();
1004 #endif
1005 }
1006 
operator ==(const MD5Hash & other) const1007 bool MD5Hash::operator==(const MD5Hash &other) const {
1008   return hash[0] == other.hash[0] && hash[1] == other.hash[1];
1009 }
1010 
1011 #if SANITIZER_DEBUG
build_consistency_debug()1012 void build_consistency_debug() {}
1013 #else
build_consistency_release()1014 void build_consistency_release() {}
1015 #endif
1016 
1017 #if TSAN_COLLECT_STATS
build_consistency_stats()1018 void build_consistency_stats() {}
1019 #else
build_consistency_nostats()1020 void build_consistency_nostats() {}
1021 #endif
1022 
1023 }  // namespace __tsan
1024 
1025 #ifndef SANITIZER_GO
1026 // Must be included in this file to make sure everything is inlined.
1027 #include "tsan_interface_inl.h"
1028 #endif
1029