//===-- tsan_rtl_thread.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_placement_new.h" #include "tsan_rtl.h" #include "tsan_mman.h" #include "tsan_platform.h" #include "tsan_report.h" #include "tsan_sync.h" namespace __tsan { // ThreadContext implementation. ThreadContext::ThreadContext(int tid) : ThreadContextBase(tid) , thr() , sync() , epoch0() , epoch1() { } #if !SANITIZER_GO ThreadContext::~ThreadContext() { } #endif void ThreadContext::OnDead() { CHECK_EQ(sync.size(), 0); } void ThreadContext::OnJoined(void *arg) { ThreadState *caller_thr = static_cast(arg); AcquireImpl(caller_thr, 0, &sync); sync.Reset(&caller_thr->proc()->clock_cache); } struct OnCreatedArgs { ThreadState *thr; uptr pc; }; void ThreadContext::OnCreated(void *arg) { thr = 0; if (tid == 0) return; OnCreatedArgs *args = static_cast(arg); if (!args->thr) // GCD workers don't have a parent thread. return; args->thr->fast_state.IncrementEpoch(); // Can't increment epoch w/o writing to the trace as well. TraceAddEvent(args->thr, args->thr->fast_state, EventTypeMop, 0); ReleaseImpl(args->thr, 0, &sync); creation_stack_id = CurrentStackId(args->thr, args->pc); if (reuse_count == 0) StatInc(args->thr, StatThreadMaxTid); } void ThreadContext::OnReset() { CHECK_EQ(sync.size(), 0); uptr trace_p = GetThreadTrace(tid); ReleaseMemoryPagesToOS(trace_p, trace_p + TraceSize() * sizeof(Event)); //!!! ReleaseMemoryToOS(GetThreadTraceHeader(tid), sizeof(Trace)); } void ThreadContext::OnDetached(void *arg) { ThreadState *thr1 = static_cast(arg); sync.Reset(&thr1->proc()->clock_cache); } struct OnStartedArgs { ThreadState *thr; uptr stk_addr; uptr stk_size; uptr tls_addr; uptr tls_size; }; void ThreadContext::OnStarted(void *arg) { OnStartedArgs *args = static_cast(arg); thr = args->thr; // RoundUp so that one trace part does not contain events // from different threads. epoch0 = RoundUp(epoch1 + 1, kTracePartSize); epoch1 = (u64)-1; new(thr) ThreadState(ctx, tid, unique_id, epoch0, reuse_count, args->stk_addr, args->stk_size, args->tls_addr, args->tls_size); #if !SANITIZER_GO thr->shadow_stack = &ThreadTrace(thr->tid)->shadow_stack[0]; thr->shadow_stack_pos = thr->shadow_stack; thr->shadow_stack_end = thr->shadow_stack + kShadowStackSize; #else // Setup dynamic shadow stack. const int kInitStackSize = 8; thr->shadow_stack = (uptr*)internal_alloc(MBlockShadowStack, kInitStackSize * sizeof(uptr)); thr->shadow_stack_pos = thr->shadow_stack; thr->shadow_stack_end = thr->shadow_stack + kInitStackSize; #endif if (common_flags()->detect_deadlocks) thr->dd_lt = ctx->dd->CreateLogicalThread(unique_id); thr->fast_state.SetHistorySize(flags()->history_size); // Commit switch to the new part of the trace. // TraceAddEvent will reset stack0/mset0 in the new part for us. TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0); thr->fast_synch_epoch = epoch0; AcquireImpl(thr, 0, &sync); StatInc(thr, StatSyncAcquire); sync.Reset(&thr->proc()->clock_cache); thr->is_inited = true; DPrintf("#%d: ThreadStart epoch=%zu stk_addr=%zx stk_size=%zx " "tls_addr=%zx tls_size=%zx\n", tid, (uptr)epoch0, args->stk_addr, args->stk_size, args->tls_addr, args->tls_size); } void ThreadContext::OnFinished() { #if SANITIZER_GO internal_free(thr->shadow_stack); thr->shadow_stack = nullptr; thr->shadow_stack_pos = nullptr; thr->shadow_stack_end = nullptr; #endif if (!detached) { thr->fast_state.IncrementEpoch(); // Can't increment epoch w/o writing to the trace as well. TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0); ReleaseImpl(thr, 0, &sync); } epoch1 = thr->fast_state.epoch(); if (common_flags()->detect_deadlocks) ctx->dd->DestroyLogicalThread(thr->dd_lt); thr->clock.ResetCached(&thr->proc()->clock_cache); #if !SANITIZER_GO thr->last_sleep_clock.ResetCached(&thr->proc()->clock_cache); #endif #if !SANITIZER_GO PlatformCleanUpThreadState(thr); #endif thr->~ThreadState(); #if TSAN_COLLECT_STATS StatAggregate(ctx->stat, thr->stat); #endif thr = 0; } #if !SANITIZER_GO struct ThreadLeak { ThreadContext *tctx; int count; }; static void MaybeReportThreadLeak(ThreadContextBase *tctx_base, void *arg) { Vector &leaks = *(Vector*)arg; ThreadContext *tctx = static_cast(tctx_base); if (tctx->detached || tctx->status != ThreadStatusFinished) return; for (uptr i = 0; i < leaks.Size(); i++) { if (leaks[i].tctx->creation_stack_id == tctx->creation_stack_id) { leaks[i].count++; return; } } ThreadLeak leak = {tctx, 1}; leaks.PushBack(leak); } #endif #if !SANITIZER_GO static void ReportIgnoresEnabled(ThreadContext *tctx, IgnoreSet *set) { if (tctx->tid == 0) { Printf("ThreadSanitizer: main thread finished with ignores enabled\n"); } else { Printf("ThreadSanitizer: thread T%d %s finished with ignores enabled," " created at:\n", tctx->tid, tctx->name); PrintStack(SymbolizeStackId(tctx->creation_stack_id)); } Printf(" One of the following ignores was not ended" " (in order of probability)\n"); for (uptr i = 0; i < set->Size(); i++) { Printf(" Ignore was enabled at:\n"); PrintStack(SymbolizeStackId(set->At(i))); } Die(); } static void ThreadCheckIgnore(ThreadState *thr) { if (ctx->after_multithreaded_fork) return; if (thr->ignore_reads_and_writes) ReportIgnoresEnabled(thr->tctx, &thr->mop_ignore_set); if (thr->ignore_sync) ReportIgnoresEnabled(thr->tctx, &thr->sync_ignore_set); } #else static void ThreadCheckIgnore(ThreadState *thr) {} #endif void ThreadFinalize(ThreadState *thr) { ThreadCheckIgnore(thr); #if !SANITIZER_GO if (!flags()->report_thread_leaks) return; ThreadRegistryLock l(ctx->thread_registry); Vector leaks; ctx->thread_registry->RunCallbackForEachThreadLocked( MaybeReportThreadLeak, &leaks); for (uptr i = 0; i < leaks.Size(); i++) { ScopedReport rep(ReportTypeThreadLeak); rep.AddThread(leaks[i].tctx, true); rep.SetCount(leaks[i].count); OutputReport(thr, rep); } #endif } int ThreadCount(ThreadState *thr) { uptr result; ctx->thread_registry->GetNumberOfThreads(0, 0, &result); return (int)result; } int ThreadCreate(ThreadState *thr, uptr pc, uptr uid, bool detached) { StatInc(thr, StatThreadCreate); OnCreatedArgs args = { thr, pc }; u32 parent_tid = thr ? thr->tid : kInvalidTid; // No parent for GCD workers. int tid = ctx->thread_registry->CreateThread(uid, detached, parent_tid, &args); DPrintf("#%d: ThreadCreate tid=%d uid=%zu\n", parent_tid, tid, uid); StatSet(thr, StatThreadMaxAlive, ctx->thread_registry->GetMaxAliveThreads()); return tid; } void ThreadStart(ThreadState *thr, int tid, tid_t os_id, ThreadType thread_type) { uptr stk_addr = 0; uptr stk_size = 0; uptr tls_addr = 0; uptr tls_size = 0; #if !SANITIZER_GO if (thread_type != ThreadType::Fiber) GetThreadStackAndTls(tid == 0, &stk_addr, &stk_size, &tls_addr, &tls_size); if (tid) { if (stk_addr && stk_size) MemoryRangeImitateWrite(thr, /*pc=*/ 1, stk_addr, stk_size); if (tls_addr && tls_size) ImitateTlsWrite(thr, tls_addr, tls_size); } #endif ThreadRegistry *tr = ctx->thread_registry; OnStartedArgs args = { thr, stk_addr, stk_size, tls_addr, tls_size }; tr->StartThread(tid, os_id, thread_type, &args); tr->Lock(); thr->tctx = (ThreadContext*)tr->GetThreadLocked(tid); tr->Unlock(); #if !SANITIZER_GO if (ctx->after_multithreaded_fork) { thr->ignore_interceptors++; ThreadIgnoreBegin(thr, 0); ThreadIgnoreSyncBegin(thr, 0); } #endif } void ThreadFinish(ThreadState *thr) { ThreadCheckIgnore(thr); StatInc(thr, StatThreadFinish); if (thr->stk_addr && thr->stk_size) DontNeedShadowFor(thr->stk_addr, thr->stk_size); if (thr->tls_addr && thr->tls_size) DontNeedShadowFor(thr->tls_addr, thr->tls_size); thr->is_dead = true; ctx->thread_registry->FinishThread(thr->tid); } struct ConsumeThreadContext { uptr uid; ThreadContextBase *tctx; }; static bool ConsumeThreadByUid(ThreadContextBase *tctx, void *arg) { ConsumeThreadContext *findCtx = (ConsumeThreadContext *)arg; if (tctx->user_id == findCtx->uid && tctx->status != ThreadStatusInvalid) { if (findCtx->tctx) { // Ensure that user_id is unique. If it's not the case we are screwed. // Something went wrong before, but now there is no way to recover. // Returning a wrong thread is not an option, it may lead to very hard // to debug false positives (e.g. if we join a wrong thread). Report("ThreadSanitizer: dup thread with used id 0x%zx\n", findCtx->uid); Die(); } findCtx->tctx = tctx; tctx->user_id = 0; } return false; } int ThreadConsumeTid(ThreadState *thr, uptr pc, uptr uid) { ConsumeThreadContext findCtx = {uid, nullptr}; ctx->thread_registry->FindThread(ConsumeThreadByUid, &findCtx); int tid = findCtx.tctx ? findCtx.tctx->tid : ThreadRegistry::kUnknownTid; DPrintf("#%d: ThreadTid uid=%zu tid=%d\n", thr->tid, uid, tid); return tid; } void ThreadJoin(ThreadState *thr, uptr pc, int tid) { CHECK_GT(tid, 0); CHECK_LT(tid, kMaxTid); DPrintf("#%d: ThreadJoin tid=%d\n", thr->tid, tid); ctx->thread_registry->JoinThread(tid, thr); } void ThreadDetach(ThreadState *thr, uptr pc, int tid) { CHECK_GT(tid, 0); CHECK_LT(tid, kMaxTid); ctx->thread_registry->DetachThread(tid, thr); } void ThreadNotJoined(ThreadState *thr, uptr pc, int tid, uptr uid) { CHECK_GT(tid, 0); CHECK_LT(tid, kMaxTid); ctx->thread_registry->SetThreadUserId(tid, uid); } void ThreadSetName(ThreadState *thr, const char *name) { ctx->thread_registry->SetThreadName(thr->tid, name); } void MemoryAccessRange(ThreadState *thr, uptr pc, uptr addr, uptr size, bool is_write) { if (size == 0) return; u64 *shadow_mem = (u64*)MemToShadow(addr); DPrintf2("#%d: MemoryAccessRange: @%p %p size=%d is_write=%d\n", thr->tid, (void*)pc, (void*)addr, (int)size, is_write); #if SANITIZER_DEBUG if (!IsAppMem(addr)) { Printf("Access to non app mem %zx\n", addr); DCHECK(IsAppMem(addr)); } if (!IsAppMem(addr + size - 1)) { Printf("Access to non app mem %zx\n", addr + size - 1); DCHECK(IsAppMem(addr + size - 1)); } if (!IsShadowMem((uptr)shadow_mem)) { Printf("Bad shadow addr %p (%zx)\n", shadow_mem, addr); DCHECK(IsShadowMem((uptr)shadow_mem)); } if (!IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1))) { Printf("Bad shadow addr %p (%zx)\n", shadow_mem + size * kShadowCnt / 8 - 1, addr + size - 1); DCHECK(IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1))); } #endif StatInc(thr, StatMopRange); if (*shadow_mem == kShadowRodata) { DCHECK(!is_write); // Access to .rodata section, no races here. // Measurements show that it can be 10-20% of all memory accesses. StatInc(thr, StatMopRangeRodata); return; } FastState fast_state = thr->fast_state; if (fast_state.GetIgnoreBit()) return; fast_state.IncrementEpoch(); thr->fast_state = fast_state; TraceAddEvent(thr, fast_state, EventTypeMop, pc); bool unaligned = (addr % kShadowCell) != 0; // Handle unaligned beginning, if any. for (; addr % kShadowCell && size; addr++, size--) { int const kAccessSizeLog = 0; Shadow cur(fast_state); cur.SetWrite(is_write); cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog); MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false, shadow_mem, cur); } if (unaligned) shadow_mem += kShadowCnt; // Handle middle part, if any. for (; size >= kShadowCell; addr += kShadowCell, size -= kShadowCell) { int const kAccessSizeLog = 3; Shadow cur(fast_state); cur.SetWrite(is_write); cur.SetAddr0AndSizeLog(0, kAccessSizeLog); MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false, shadow_mem, cur); shadow_mem += kShadowCnt; } // Handle ending, if any. for (; size; addr++, size--) { int const kAccessSizeLog = 0; Shadow cur(fast_state); cur.SetWrite(is_write); cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog); MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, false, shadow_mem, cur); } } #if !SANITIZER_GO void FiberSwitchImpl(ThreadState *from, ThreadState *to) { Processor *proc = from->proc(); ProcUnwire(proc, from); ProcWire(proc, to); set_cur_thread(to); } ThreadState *FiberCreate(ThreadState *thr, uptr pc, unsigned flags) { void *mem = internal_alloc(MBlockThreadContex, sizeof(ThreadState)); ThreadState *fiber = static_cast(mem); internal_memset(fiber, 0, sizeof(*fiber)); int tid = ThreadCreate(thr, pc, 0, true); FiberSwitchImpl(thr, fiber); ThreadStart(fiber, tid, 0, ThreadType::Fiber); FiberSwitchImpl(fiber, thr); return fiber; } void FiberDestroy(ThreadState *thr, uptr pc, ThreadState *fiber) { FiberSwitchImpl(thr, fiber); ThreadFinish(fiber); FiberSwitchImpl(fiber, thr); internal_free(fiber); } void FiberSwitch(ThreadState *thr, uptr pc, ThreadState *fiber, unsigned flags) { if (!(flags & FiberSwitchFlagNoSync)) Release(thr, pc, (uptr)fiber); FiberSwitchImpl(thr, fiber); if (!(flags & FiberSwitchFlagNoSync)) Acquire(fiber, pc, (uptr)fiber); } #endif } // namespace __tsan