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-rw-r--r--lib/tsan/rtl/tsan_rtl_report.cpp757
1 files changed, 757 insertions, 0 deletions
diff --git a/lib/tsan/rtl/tsan_rtl_report.cpp b/lib/tsan/rtl/tsan_rtl_report.cpp
new file mode 100644
index 000000000000..949beac1c551
--- /dev/null
+++ b/lib/tsan/rtl/tsan_rtl_report.cpp
@@ -0,0 +1,757 @@
+//===-- tsan_rtl_report.cpp -----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of ThreadSanitizer (TSan), a race detector.
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_libc.h"
+#include "sanitizer_common/sanitizer_placement_new.h"
+#include "sanitizer_common/sanitizer_stackdepot.h"
+#include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_stacktrace.h"
+#include "tsan_platform.h"
+#include "tsan_rtl.h"
+#include "tsan_suppressions.h"
+#include "tsan_symbolize.h"
+#include "tsan_report.h"
+#include "tsan_sync.h"
+#include "tsan_mman.h"
+#include "tsan_flags.h"
+#include "tsan_fd.h"
+
+namespace __tsan {
+
+using namespace __sanitizer;
+
+static ReportStack *SymbolizeStack(StackTrace trace);
+
+void TsanCheckFailed(const char *file, int line, const char *cond,
+ u64 v1, u64 v2) {
+ // There is high probability that interceptors will check-fail as well,
+ // on the other hand there is no sense in processing interceptors
+ // since we are going to die soon.
+ ScopedIgnoreInterceptors ignore;
+#if !SANITIZER_GO
+ cur_thread()->ignore_sync++;
+ cur_thread()->ignore_reads_and_writes++;
+#endif
+ Printf("FATAL: ThreadSanitizer CHECK failed: "
+ "%s:%d \"%s\" (0x%zx, 0x%zx)\n",
+ file, line, cond, (uptr)v1, (uptr)v2);
+ PrintCurrentStackSlow(StackTrace::GetCurrentPc());
+ Die();
+}
+
+// Can be overriden by an application/test to intercept reports.
+#ifdef TSAN_EXTERNAL_HOOKS
+bool OnReport(const ReportDesc *rep, bool suppressed);
+#else
+SANITIZER_WEAK_CXX_DEFAULT_IMPL
+bool OnReport(const ReportDesc *rep, bool suppressed) {
+ (void)rep;
+ return suppressed;
+}
+#endif
+
+SANITIZER_WEAK_DEFAULT_IMPL
+void __tsan_on_report(const ReportDesc *rep) {
+ (void)rep;
+}
+
+static void StackStripMain(SymbolizedStack *frames) {
+ SymbolizedStack *last_frame = nullptr;
+ SymbolizedStack *last_frame2 = nullptr;
+ for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
+ last_frame2 = last_frame;
+ last_frame = cur;
+ }
+
+ if (last_frame2 == 0)
+ return;
+#if !SANITIZER_GO
+ const char *last = last_frame->info.function;
+ const char *last2 = last_frame2->info.function;
+ // Strip frame above 'main'
+ if (last2 && 0 == internal_strcmp(last2, "main")) {
+ last_frame->ClearAll();
+ last_frame2->next = nullptr;
+ // Strip our internal thread start routine.
+ } else if (last && 0 == internal_strcmp(last, "__tsan_thread_start_func")) {
+ last_frame->ClearAll();
+ last_frame2->next = nullptr;
+ // Strip global ctors init.
+ } else if (last && 0 == internal_strcmp(last, "__do_global_ctors_aux")) {
+ last_frame->ClearAll();
+ last_frame2->next = nullptr;
+ // If both are 0, then we probably just failed to symbolize.
+ } else if (last || last2) {
+ // Ensure that we recovered stack completely. Trimmed stack
+ // can actually happen if we do not instrument some code,
+ // so it's only a debug print. However we must try hard to not miss it
+ // due to our fault.
+ DPrintf("Bottom stack frame is missed\n");
+ }
+#else
+ // The last frame always point into runtime (gosched0, goexit0, runtime.main).
+ last_frame->ClearAll();
+ last_frame2->next = nullptr;
+#endif
+}
+
+ReportStack *SymbolizeStackId(u32 stack_id) {
+ if (stack_id == 0)
+ return 0;
+ StackTrace stack = StackDepotGet(stack_id);
+ if (stack.trace == nullptr)
+ return nullptr;
+ return SymbolizeStack(stack);
+}
+
+static ReportStack *SymbolizeStack(StackTrace trace) {
+ if (trace.size == 0)
+ return 0;
+ SymbolizedStack *top = nullptr;
+ for (uptr si = 0; si < trace.size; si++) {
+ const uptr pc = trace.trace[si];
+ uptr pc1 = pc;
+ // We obtain the return address, but we're interested in the previous
+ // instruction.
+ if ((pc & kExternalPCBit) == 0)
+ pc1 = StackTrace::GetPreviousInstructionPc(pc);
+ SymbolizedStack *ent = SymbolizeCode(pc1);
+ CHECK_NE(ent, 0);
+ SymbolizedStack *last = ent;
+ while (last->next) {
+ last->info.address = pc; // restore original pc for report
+ last = last->next;
+ }
+ last->info.address = pc; // restore original pc for report
+ last->next = top;
+ top = ent;
+ }
+ StackStripMain(top);
+
+ ReportStack *stack = ReportStack::New();
+ stack->frames = top;
+ return stack;
+}
+
+ScopedReportBase::ScopedReportBase(ReportType typ, uptr tag) {
+ ctx->thread_registry->CheckLocked();
+ void *mem = internal_alloc(MBlockReport, sizeof(ReportDesc));
+ rep_ = new(mem) ReportDesc;
+ rep_->typ = typ;
+ rep_->tag = tag;
+ ctx->report_mtx.Lock();
+}
+
+ScopedReportBase::~ScopedReportBase() {
+ ctx->report_mtx.Unlock();
+ DestroyAndFree(rep_);
+ rep_ = nullptr;
+}
+
+void ScopedReportBase::AddStack(StackTrace stack, bool suppressable) {
+ ReportStack **rs = rep_->stacks.PushBack();
+ *rs = SymbolizeStack(stack);
+ (*rs)->suppressable = suppressable;
+}
+
+void ScopedReportBase::AddMemoryAccess(uptr addr, uptr external_tag, Shadow s,
+ StackTrace stack, const MutexSet *mset) {
+ void *mem = internal_alloc(MBlockReportMop, sizeof(ReportMop));
+ ReportMop *mop = new(mem) ReportMop;
+ rep_->mops.PushBack(mop);
+ mop->tid = s.tid();
+ mop->addr = addr + s.addr0();
+ mop->size = s.size();
+ mop->write = s.IsWrite();
+ mop->atomic = s.IsAtomic();
+ mop->stack = SymbolizeStack(stack);
+ mop->external_tag = external_tag;
+ if (mop->stack)
+ mop->stack->suppressable = true;
+ for (uptr i = 0; i < mset->Size(); i++) {
+ MutexSet::Desc d = mset->Get(i);
+ u64 mid = this->AddMutex(d.id);
+ ReportMopMutex mtx = {mid, d.write};
+ mop->mset.PushBack(mtx);
+ }
+}
+
+void ScopedReportBase::AddUniqueTid(int unique_tid) {
+ rep_->unique_tids.PushBack(unique_tid);
+}
+
+void ScopedReportBase::AddThread(const ThreadContext *tctx, bool suppressable) {
+ for (uptr i = 0; i < rep_->threads.Size(); i++) {
+ if ((u32)rep_->threads[i]->id == tctx->tid)
+ return;
+ }
+ void *mem = internal_alloc(MBlockReportThread, sizeof(ReportThread));
+ ReportThread *rt = new(mem) ReportThread;
+ rep_->threads.PushBack(rt);
+ rt->id = tctx->tid;
+ rt->os_id = tctx->os_id;
+ rt->running = (tctx->status == ThreadStatusRunning);
+ rt->name = internal_strdup(tctx->name);
+ rt->parent_tid = tctx->parent_tid;
+ rt->thread_type = tctx->thread_type;
+ rt->stack = 0;
+ rt->stack = SymbolizeStackId(tctx->creation_stack_id);
+ if (rt->stack)
+ rt->stack->suppressable = suppressable;
+}
+
+#if !SANITIZER_GO
+static bool FindThreadByUidLockedCallback(ThreadContextBase *tctx, void *arg) {
+ int unique_id = *(int *)arg;
+ return tctx->unique_id == (u32)unique_id;
+}
+
+static ThreadContext *FindThreadByUidLocked(int unique_id) {
+ ctx->thread_registry->CheckLocked();
+ return static_cast<ThreadContext *>(
+ ctx->thread_registry->FindThreadContextLocked(
+ FindThreadByUidLockedCallback, &unique_id));
+}
+
+static ThreadContext *FindThreadByTidLocked(int tid) {
+ ctx->thread_registry->CheckLocked();
+ return static_cast<ThreadContext*>(
+ ctx->thread_registry->GetThreadLocked(tid));
+}
+
+static bool IsInStackOrTls(ThreadContextBase *tctx_base, void *arg) {
+ uptr addr = (uptr)arg;
+ ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base);
+ if (tctx->status != ThreadStatusRunning)
+ return false;
+ ThreadState *thr = tctx->thr;
+ CHECK(thr);
+ return ((addr >= thr->stk_addr && addr < thr->stk_addr + thr->stk_size) ||
+ (addr >= thr->tls_addr && addr < thr->tls_addr + thr->tls_size));
+}
+
+ThreadContext *IsThreadStackOrTls(uptr addr, bool *is_stack) {
+ ctx->thread_registry->CheckLocked();
+ ThreadContext *tctx = static_cast<ThreadContext*>(
+ ctx->thread_registry->FindThreadContextLocked(IsInStackOrTls,
+ (void*)addr));
+ if (!tctx)
+ return 0;
+ ThreadState *thr = tctx->thr;
+ CHECK(thr);
+ *is_stack = (addr >= thr->stk_addr && addr < thr->stk_addr + thr->stk_size);
+ return tctx;
+}
+#endif
+
+void ScopedReportBase::AddThread(int unique_tid, bool suppressable) {
+#if !SANITIZER_GO
+ if (const ThreadContext *tctx = FindThreadByUidLocked(unique_tid))
+ AddThread(tctx, suppressable);
+#endif
+}
+
+void ScopedReportBase::AddMutex(const SyncVar *s) {
+ for (uptr i = 0; i < rep_->mutexes.Size(); i++) {
+ if (rep_->mutexes[i]->id == s->uid)
+ return;
+ }
+ void *mem = internal_alloc(MBlockReportMutex, sizeof(ReportMutex));
+ ReportMutex *rm = new(mem) ReportMutex;
+ rep_->mutexes.PushBack(rm);
+ rm->id = s->uid;
+ rm->addr = s->addr;
+ rm->destroyed = false;
+ rm->stack = SymbolizeStackId(s->creation_stack_id);
+}
+
+u64 ScopedReportBase::AddMutex(u64 id) {
+ u64 uid = 0;
+ u64 mid = id;
+ uptr addr = SyncVar::SplitId(id, &uid);
+ SyncVar *s = ctx->metamap.GetIfExistsAndLock(addr, true);
+ // Check that the mutex is still alive.
+ // Another mutex can be created at the same address,
+ // so check uid as well.
+ if (s && s->CheckId(uid)) {
+ mid = s->uid;
+ AddMutex(s);
+ } else {
+ AddDeadMutex(id);
+ }
+ if (s)
+ s->mtx.Unlock();
+ return mid;
+}
+
+void ScopedReportBase::AddDeadMutex(u64 id) {
+ for (uptr i = 0; i < rep_->mutexes.Size(); i++) {
+ if (rep_->mutexes[i]->id == id)
+ return;
+ }
+ void *mem = internal_alloc(MBlockReportMutex, sizeof(ReportMutex));
+ ReportMutex *rm = new(mem) ReportMutex;
+ rep_->mutexes.PushBack(rm);
+ rm->id = id;
+ rm->addr = 0;
+ rm->destroyed = true;
+ rm->stack = 0;
+}
+
+void ScopedReportBase::AddLocation(uptr addr, uptr size) {
+ if (addr == 0)
+ return;
+#if !SANITIZER_GO
+ int fd = -1;
+ int creat_tid = kInvalidTid;
+ u32 creat_stack = 0;
+ if (FdLocation(addr, &fd, &creat_tid, &creat_stack)) {
+ ReportLocation *loc = ReportLocation::New(ReportLocationFD);
+ loc->fd = fd;
+ loc->tid = creat_tid;
+ loc->stack = SymbolizeStackId(creat_stack);
+ rep_->locs.PushBack(loc);
+ ThreadContext *tctx = FindThreadByUidLocked(creat_tid);
+ if (tctx)
+ AddThread(tctx);
+ return;
+ }
+ MBlock *b = 0;
+ Allocator *a = allocator();
+ if (a->PointerIsMine((void*)addr)) {
+ void *block_begin = a->GetBlockBegin((void*)addr);
+ if (block_begin)
+ b = ctx->metamap.GetBlock((uptr)block_begin);
+ }
+ if (b != 0) {
+ ThreadContext *tctx = FindThreadByTidLocked(b->tid);
+ ReportLocation *loc = ReportLocation::New(ReportLocationHeap);
+ loc->heap_chunk_start = (uptr)allocator()->GetBlockBegin((void *)addr);
+ loc->heap_chunk_size = b->siz;
+ loc->external_tag = b->tag;
+ loc->tid = tctx ? tctx->tid : b->tid;
+ loc->stack = SymbolizeStackId(b->stk);
+ rep_->locs.PushBack(loc);
+ if (tctx)
+ AddThread(tctx);
+ return;
+ }
+ bool is_stack = false;
+ if (ThreadContext *tctx = IsThreadStackOrTls(addr, &is_stack)) {
+ ReportLocation *loc =
+ ReportLocation::New(is_stack ? ReportLocationStack : ReportLocationTLS);
+ loc->tid = tctx->tid;
+ rep_->locs.PushBack(loc);
+ AddThread(tctx);
+ }
+#endif
+ if (ReportLocation *loc = SymbolizeData(addr)) {
+ loc->suppressable = true;
+ rep_->locs.PushBack(loc);
+ return;
+ }
+}
+
+#if !SANITIZER_GO
+void ScopedReportBase::AddSleep(u32 stack_id) {
+ rep_->sleep = SymbolizeStackId(stack_id);
+}
+#endif
+
+void ScopedReportBase::SetCount(int count) { rep_->count = count; }
+
+const ReportDesc *ScopedReportBase::GetReport() const { return rep_; }
+
+ScopedReport::ScopedReport(ReportType typ, uptr tag)
+ : ScopedReportBase(typ, tag) {}
+
+ScopedReport::~ScopedReport() {}
+
+void RestoreStack(int tid, const u64 epoch, VarSizeStackTrace *stk,
+ MutexSet *mset, uptr *tag) {
+ // This function restores stack trace and mutex set for the thread/epoch.
+ // It does so by getting stack trace and mutex set at the beginning of
+ // trace part, and then replaying the trace till the given epoch.
+ Trace* trace = ThreadTrace(tid);
+ ReadLock l(&trace->mtx);
+ const int partidx = (epoch / kTracePartSize) % TraceParts();
+ TraceHeader* hdr = &trace->headers[partidx];
+ if (epoch < hdr->epoch0 || epoch >= hdr->epoch0 + kTracePartSize)
+ return;
+ CHECK_EQ(RoundDown(epoch, kTracePartSize), hdr->epoch0);
+ const u64 epoch0 = RoundDown(epoch, TraceSize());
+ const u64 eend = epoch % TraceSize();
+ const u64 ebegin = RoundDown(eend, kTracePartSize);
+ DPrintf("#%d: RestoreStack epoch=%zu ebegin=%zu eend=%zu partidx=%d\n",
+ tid, (uptr)epoch, (uptr)ebegin, (uptr)eend, partidx);
+ Vector<uptr> stack;
+ stack.Resize(hdr->stack0.size + 64);
+ for (uptr i = 0; i < hdr->stack0.size; i++) {
+ stack[i] = hdr->stack0.trace[i];
+ DPrintf2(" #%02zu: pc=%zx\n", i, stack[i]);
+ }
+ if (mset)
+ *mset = hdr->mset0;
+ uptr pos = hdr->stack0.size;
+ Event *events = (Event*)GetThreadTrace(tid);
+ for (uptr i = ebegin; i <= eend; i++) {
+ Event ev = events[i];
+ EventType typ = (EventType)(ev >> kEventPCBits);
+ uptr pc = (uptr)(ev & ((1ull << kEventPCBits) - 1));
+ DPrintf2(" %zu typ=%d pc=%zx\n", i, typ, pc);
+ if (typ == EventTypeMop) {
+ stack[pos] = pc;
+ } else if (typ == EventTypeFuncEnter) {
+ if (stack.Size() < pos + 2)
+ stack.Resize(pos + 2);
+ stack[pos++] = pc;
+ } else if (typ == EventTypeFuncExit) {
+ if (pos > 0)
+ pos--;
+ }
+ if (mset) {
+ if (typ == EventTypeLock) {
+ mset->Add(pc, true, epoch0 + i);
+ } else if (typ == EventTypeUnlock) {
+ mset->Del(pc, true);
+ } else if (typ == EventTypeRLock) {
+ mset->Add(pc, false, epoch0 + i);
+ } else if (typ == EventTypeRUnlock) {
+ mset->Del(pc, false);
+ }
+ }
+ for (uptr j = 0; j <= pos; j++)
+ DPrintf2(" #%zu: %zx\n", j, stack[j]);
+ }
+ if (pos == 0 && stack[0] == 0)
+ return;
+ pos++;
+ stk->Init(&stack[0], pos);
+ ExtractTagFromStack(stk, tag);
+}
+
+static bool HandleRacyStacks(ThreadState *thr, VarSizeStackTrace traces[2],
+ uptr addr_min, uptr addr_max) {
+ bool equal_stack = false;
+ RacyStacks hash;
+ bool equal_address = false;
+ RacyAddress ra0 = {addr_min, addr_max};
+ {
+ ReadLock lock(&ctx->racy_mtx);
+ if (flags()->suppress_equal_stacks) {
+ hash.hash[0] = md5_hash(traces[0].trace, traces[0].size * sizeof(uptr));
+ hash.hash[1] = md5_hash(traces[1].trace, traces[1].size * sizeof(uptr));
+ for (uptr i = 0; i < ctx->racy_stacks.Size(); i++) {
+ if (hash == ctx->racy_stacks[i]) {
+ VPrintf(2,
+ "ThreadSanitizer: suppressing report as doubled (stack)\n");
+ equal_stack = true;
+ break;
+ }
+ }
+ }
+ if (flags()->suppress_equal_addresses) {
+ for (uptr i = 0; i < ctx->racy_addresses.Size(); i++) {
+ RacyAddress ra2 = ctx->racy_addresses[i];
+ uptr maxbeg = max(ra0.addr_min, ra2.addr_min);
+ uptr minend = min(ra0.addr_max, ra2.addr_max);
+ if (maxbeg < minend) {
+ VPrintf(2, "ThreadSanitizer: suppressing report as doubled (addr)\n");
+ equal_address = true;
+ break;
+ }
+ }
+ }
+ }
+ if (!equal_stack && !equal_address)
+ return false;
+ if (!equal_stack) {
+ Lock lock(&ctx->racy_mtx);
+ ctx->racy_stacks.PushBack(hash);
+ }
+ if (!equal_address) {
+ Lock lock(&ctx->racy_mtx);
+ ctx->racy_addresses.PushBack(ra0);
+ }
+ return true;
+}
+
+static void AddRacyStacks(ThreadState *thr, VarSizeStackTrace traces[2],
+ uptr addr_min, uptr addr_max) {
+ Lock lock(&ctx->racy_mtx);
+ if (flags()->suppress_equal_stacks) {
+ RacyStacks hash;
+ hash.hash[0] = md5_hash(traces[0].trace, traces[0].size * sizeof(uptr));
+ hash.hash[1] = md5_hash(traces[1].trace, traces[1].size * sizeof(uptr));
+ ctx->racy_stacks.PushBack(hash);
+ }
+ if (flags()->suppress_equal_addresses) {
+ RacyAddress ra0 = {addr_min, addr_max};
+ ctx->racy_addresses.PushBack(ra0);
+ }
+}
+
+bool OutputReport(ThreadState *thr, const ScopedReport &srep) {
+ if (!flags()->report_bugs || thr->suppress_reports)
+ return false;
+ atomic_store_relaxed(&ctx->last_symbolize_time_ns, NanoTime());
+ const ReportDesc *rep = srep.GetReport();
+ CHECK_EQ(thr->current_report, nullptr);
+ thr->current_report = rep;
+ Suppression *supp = 0;
+ uptr pc_or_addr = 0;
+ for (uptr i = 0; pc_or_addr == 0 && i < rep->mops.Size(); i++)
+ pc_or_addr = IsSuppressed(rep->typ, rep->mops[i]->stack, &supp);
+ for (uptr i = 0; pc_or_addr == 0 && i < rep->stacks.Size(); i++)
+ pc_or_addr = IsSuppressed(rep->typ, rep->stacks[i], &supp);
+ for (uptr i = 0; pc_or_addr == 0 && i < rep->threads.Size(); i++)
+ pc_or_addr = IsSuppressed(rep->typ, rep->threads[i]->stack, &supp);
+ for (uptr i = 0; pc_or_addr == 0 && i < rep->locs.Size(); i++)
+ pc_or_addr = IsSuppressed(rep->typ, rep->locs[i], &supp);
+ if (pc_or_addr != 0) {
+ Lock lock(&ctx->fired_suppressions_mtx);
+ FiredSuppression s = {srep.GetReport()->typ, pc_or_addr, supp};
+ ctx->fired_suppressions.push_back(s);
+ }
+ {
+ bool old_is_freeing = thr->is_freeing;
+ thr->is_freeing = false;
+ bool suppressed = OnReport(rep, pc_or_addr != 0);
+ thr->is_freeing = old_is_freeing;
+ if (suppressed) {
+ thr->current_report = nullptr;
+ return false;
+ }
+ }
+ PrintReport(rep);
+ __tsan_on_report(rep);
+ ctx->nreported++;
+ if (flags()->halt_on_error)
+ Die();
+ thr->current_report = nullptr;
+ return true;
+}
+
+bool IsFiredSuppression(Context *ctx, ReportType type, StackTrace trace) {
+ ReadLock lock(&ctx->fired_suppressions_mtx);
+ for (uptr k = 0; k < ctx->fired_suppressions.size(); k++) {
+ if (ctx->fired_suppressions[k].type != type)
+ continue;
+ for (uptr j = 0; j < trace.size; j++) {
+ FiredSuppression *s = &ctx->fired_suppressions[k];
+ if (trace.trace[j] == s->pc_or_addr) {
+ if (s->supp)
+ atomic_fetch_add(&s->supp->hit_count, 1, memory_order_relaxed);
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+static bool IsFiredSuppression(Context *ctx, ReportType type, uptr addr) {
+ ReadLock lock(&ctx->fired_suppressions_mtx);
+ for (uptr k = 0; k < ctx->fired_suppressions.size(); k++) {
+ if (ctx->fired_suppressions[k].type != type)
+ continue;
+ FiredSuppression *s = &ctx->fired_suppressions[k];
+ if (addr == s->pc_or_addr) {
+ if (s->supp)
+ atomic_fetch_add(&s->supp->hit_count, 1, memory_order_relaxed);
+ return true;
+ }
+ }
+ return false;
+}
+
+static bool RaceBetweenAtomicAndFree(ThreadState *thr) {
+ Shadow s0(thr->racy_state[0]);
+ Shadow s1(thr->racy_state[1]);
+ CHECK(!(s0.IsAtomic() && s1.IsAtomic()));
+ if (!s0.IsAtomic() && !s1.IsAtomic())
+ return true;
+ if (s0.IsAtomic() && s1.IsFreed())
+ return true;
+ if (s1.IsAtomic() && thr->is_freeing)
+ return true;
+ return false;
+}
+
+void ReportRace(ThreadState *thr) {
+ CheckNoLocks(thr);
+
+ // Symbolizer makes lots of intercepted calls. If we try to process them,
+ // at best it will cause deadlocks on internal mutexes.
+ ScopedIgnoreInterceptors ignore;
+
+ if (!flags()->report_bugs)
+ return;
+ if (!flags()->report_atomic_races && !RaceBetweenAtomicAndFree(thr))
+ return;
+
+ bool freed = false;
+ {
+ Shadow s(thr->racy_state[1]);
+ freed = s.GetFreedAndReset();
+ thr->racy_state[1] = s.raw();
+ }
+
+ uptr addr = ShadowToMem((uptr)thr->racy_shadow_addr);
+ uptr addr_min = 0;
+ uptr addr_max = 0;
+ {
+ uptr a0 = addr + Shadow(thr->racy_state[0]).addr0();
+ uptr a1 = addr + Shadow(thr->racy_state[1]).addr0();
+ uptr e0 = a0 + Shadow(thr->racy_state[0]).size();
+ uptr e1 = a1 + Shadow(thr->racy_state[1]).size();
+ addr_min = min(a0, a1);
+ addr_max = max(e0, e1);
+ if (IsExpectedReport(addr_min, addr_max - addr_min))
+ return;
+ }
+
+ ReportType typ = ReportTypeRace;
+ if (thr->is_vptr_access && freed)
+ typ = ReportTypeVptrUseAfterFree;
+ else if (thr->is_vptr_access)
+ typ = ReportTypeVptrRace;
+ else if (freed)
+ typ = ReportTypeUseAfterFree;
+
+ if (IsFiredSuppression(ctx, typ, addr))
+ return;
+
+ const uptr kMop = 2;
+ VarSizeStackTrace traces[kMop];
+ uptr tags[kMop] = {kExternalTagNone};
+ uptr toppc = TraceTopPC(thr);
+ if (toppc >> kEventPCBits) {
+ // This is a work-around for a known issue.
+ // The scenario where this happens is rather elaborate and requires
+ // an instrumented __sanitizer_report_error_summary callback and
+ // a __tsan_symbolize_external callback and a race during a range memory
+ // access larger than 8 bytes. MemoryAccessRange adds the current PC to
+ // the trace and starts processing memory accesses. A first memory access
+ // triggers a race, we report it and call the instrumented
+ // __sanitizer_report_error_summary, which adds more stuff to the trace
+ // since it is intrumented. Then a second memory access in MemoryAccessRange
+ // also triggers a race and we get here and call TraceTopPC to get the
+ // current PC, however now it contains some unrelated events from the
+ // callback. Most likely, TraceTopPC will now return a EventTypeFuncExit
+ // event. Later we subtract -1 from it (in GetPreviousInstructionPc)
+ // and the resulting PC has kExternalPCBit set, so we pass it to
+ // __tsan_symbolize_external_ex. __tsan_symbolize_external_ex is within its
+ // rights to crash since the PC is completely bogus.
+ // test/tsan/double_race.cpp contains a test case for this.
+ toppc = 0;
+ }
+ ObtainCurrentStack(thr, toppc, &traces[0], &tags[0]);
+ if (IsFiredSuppression(ctx, typ, traces[0]))
+ return;
+
+ // MutexSet is too large to live on stack.
+ Vector<u64> mset_buffer;
+ mset_buffer.Resize(sizeof(MutexSet) / sizeof(u64) + 1);
+ MutexSet *mset2 = new(&mset_buffer[0]) MutexSet();
+
+ Shadow s2(thr->racy_state[1]);
+ RestoreStack(s2.tid(), s2.epoch(), &traces[1], mset2, &tags[1]);
+ if (IsFiredSuppression(ctx, typ, traces[1]))
+ return;
+
+ if (HandleRacyStacks(thr, traces, addr_min, addr_max))
+ return;
+
+ // If any of the accesses has a tag, treat this as an "external" race.
+ uptr tag = kExternalTagNone;
+ for (uptr i = 0; i < kMop; i++) {
+ if (tags[i] != kExternalTagNone) {
+ typ = ReportTypeExternalRace;
+ tag = tags[i];
+ break;
+ }
+ }
+
+ ThreadRegistryLock l0(ctx->thread_registry);
+ ScopedReport rep(typ, tag);
+ for (uptr i = 0; i < kMop; i++) {
+ Shadow s(thr->racy_state[i]);
+ rep.AddMemoryAccess(addr, tags[i], s, traces[i],
+ i == 0 ? &thr->mset : mset2);
+ }
+
+ for (uptr i = 0; i < kMop; i++) {
+ FastState s(thr->racy_state[i]);
+ ThreadContext *tctx = static_cast<ThreadContext*>(
+ ctx->thread_registry->GetThreadLocked(s.tid()));
+ if (s.epoch() < tctx->epoch0 || s.epoch() > tctx->epoch1)
+ continue;
+ rep.AddThread(tctx);
+ }
+
+ rep.AddLocation(addr_min, addr_max - addr_min);
+
+#if !SANITIZER_GO
+ {
+ Shadow s(thr->racy_state[1]);
+ if (s.epoch() <= thr->last_sleep_clock.get(s.tid()))
+ rep.AddSleep(thr->last_sleep_stack_id);
+ }
+#endif
+
+ if (!OutputReport(thr, rep))
+ return;
+
+ AddRacyStacks(thr, traces, addr_min, addr_max);
+}
+
+void PrintCurrentStack(ThreadState *thr, uptr pc) {
+ VarSizeStackTrace trace;
+ ObtainCurrentStack(thr, pc, &trace);
+ PrintStack(SymbolizeStack(trace));
+}
+
+// Always inlining PrintCurrentStackSlow, because LocatePcInTrace assumes
+// __sanitizer_print_stack_trace exists in the actual unwinded stack, but
+// tail-call to PrintCurrentStackSlow breaks this assumption because
+// __sanitizer_print_stack_trace disappears after tail-call.
+// However, this solution is not reliable enough, please see dvyukov's comment
+// http://reviews.llvm.org/D19148#406208
+// Also see PR27280 comment 2 and 3 for breaking examples and analysis.
+ALWAYS_INLINE
+void PrintCurrentStackSlow(uptr pc) {
+#if !SANITIZER_GO
+ uptr bp = GET_CURRENT_FRAME();
+ BufferedStackTrace *ptrace =
+ new(internal_alloc(MBlockStackTrace, sizeof(BufferedStackTrace)))
+ BufferedStackTrace();
+ ptrace->Unwind(pc, bp, nullptr, false);
+
+ for (uptr i = 0; i < ptrace->size / 2; i++) {
+ uptr tmp = ptrace->trace_buffer[i];
+ ptrace->trace_buffer[i] = ptrace->trace_buffer[ptrace->size - i - 1];
+ ptrace->trace_buffer[ptrace->size - i - 1] = tmp;
+ }
+ PrintStack(SymbolizeStack(*ptrace));
+#endif
+}
+
+} // namespace __tsan
+
+using namespace __tsan;
+
+extern "C" {
+SANITIZER_INTERFACE_ATTRIBUTE
+void __sanitizer_print_stack_trace() {
+ PrintCurrentStackSlow(StackTrace::GetCurrentPc());
+}
+} // extern "C"