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1//===-- asan_thread.h -------------------------------------------*- C++ -*-===//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-exception6//7//===----------------------------------------------------------------------===//8//9// This file is a part of AddressSanitizer, an address sanity checker.10//11// ASan-private header for asan_thread.cpp.12//===----------------------------------------------------------------------===//13 14#ifndef ASAN_THREAD_H15#define ASAN_THREAD_H16 17#include "asan_allocator.h"18#include "asan_fake_stack.h"19#include "asan_internal.h"20#include "asan_stats.h"21#include "sanitizer_common/sanitizer_common.h"22#include "sanitizer_common/sanitizer_libc.h"23#include "sanitizer_common/sanitizer_thread_arg_retval.h"24#include "sanitizer_common/sanitizer_thread_registry.h"25 26namespace __sanitizer {27struct DTLS;28} // namespace __sanitizer29 30namespace __asan {31 32class AsanThread;33 34// These objects are created for every thread and are never deleted,35// so we can find them by tid even if the thread is long dead.36class AsanThreadContext final : public ThreadContextBase {37 public:38 explicit AsanThreadContext(int tid)39 : ThreadContextBase(tid),40 announced(false),41 destructor_iterations(GetPthreadDestructorIterations()),42 thread(nullptr) {}43 bool announced;44 u8 destructor_iterations;45 AsanThread *thread;46 47 void OnCreated(void *arg) override;48 void OnFinished() override;49};50 51// AsanThreadContext objects are never freed, so we need many of them.52COMPILER_CHECK(sizeof(AsanThreadContext) <= 256);53 54#if defined(_MSC_VER) && !defined(__clang__)55// MSVC raises a warning about a nonstandard extension being used for the 056// sized element in this array. Disable this for warn-as-error builds.57# pragma warning(push)58# pragma warning(disable : 4200)59#endif60 61// AsanThread are stored in TSD and destroyed when the thread dies.62class AsanThread {63 public:64 template <typename T>65 static AsanThread *Create(const T &data, u32 parent_tid, StackTrace *stack,66 bool detached) {67 return Create(&data, sizeof(data), parent_tid, stack, detached);68 }69 static AsanThread *Create(u32 parent_tid, StackTrace *stack, bool detached) {70 return Create(nullptr, 0, parent_tid, stack, detached);71 }72 static void TSDDtor(void *tsd);73 void Destroy();74 75 struct InitOptions;76 void Init(const InitOptions *options = nullptr);77 78 void ThreadStart(ThreadID os_id);79 thread_return_t RunThread();80 81 uptr stack_top();82 uptr stack_bottom();83 uptr stack_size();84 uptr tls_begin() { return tls_begin_; }85 uptr tls_end() { return tls_end_; }86 DTLS *dtls() { return dtls_; }87 u32 tid() { return context_->tid; }88 AsanThreadContext *context() { return context_; }89 void set_context(AsanThreadContext *context) { context_ = context; }90 91 struct StackFrameAccess {92 uptr offset;93 uptr frame_pc;94 const char *frame_descr;95 };96 bool GetStackFrameAccessByAddr(uptr addr, StackFrameAccess *access);97 98 // Returns a pointer to the start of the stack variable's shadow memory.99 uptr GetStackVariableShadowStart(uptr addr);100 101 bool AddrIsInStack(uptr addr);102 103 void DeleteFakeStack(int tid) {104 if (!fake_stack_) return;105 FakeStack *t = fake_stack_;106 fake_stack_ = nullptr;107 ResetTLSFakeStack();108 t->Destroy(tid);109 }110 111 void StartSwitchFiber(FakeStack **fake_stack_save, uptr bottom, uptr size);112 void FinishSwitchFiber(FakeStack *fake_stack_save, uptr *bottom_old,113 uptr *size_old);114 115 FakeStack *get_fake_stack() {116 if (atomic_load(&stack_switching_, memory_order_relaxed))117 return nullptr;118 if (reinterpret_cast<uptr>(fake_stack_) <= 1)119 return nullptr;120 return fake_stack_;121 }122 123 FakeStack *get_or_create_fake_stack() {124 if (atomic_load(&stack_switching_, memory_order_relaxed))125 return nullptr;126 if (reinterpret_cast<uptr>(fake_stack_) <= 1)127 return AsyncSignalSafeLazyInitFakeStack();128 return fake_stack_;129 }130 131 // True is this thread is currently unwinding stack (i.e. collecting a stack132 // trace). Used to prevent deadlocks on platforms where libc unwinder calls133 // malloc internally. See PR17116 for more details.134 bool isUnwinding() const { return unwinding_; }135 void setUnwinding(bool b) { unwinding_ = b; }136 137 AsanThreadLocalMallocStorage &malloc_storage() { return malloc_storage_; }138 AsanStats &stats() { return stats_; }139 140 void *extra_spill_area() { return &extra_spill_area_; }141 142 template <typename T>143 void GetStartData(T &data) const {144 GetStartData(&data, sizeof(data));145 }146 147 private:148 // NOTE: There is no AsanThread constructor. It is allocated149 // via mmap() and *must* be valid in zero-initialized state.150 151 static AsanThread *Create(const void *start_data, uptr data_size,152 u32 parent_tid, StackTrace *stack, bool detached);153 154 void SetThreadStackAndTls(const InitOptions *options);155 156 void ClearShadowForThreadStackAndTLS();157 FakeStack *AsyncSignalSafeLazyInitFakeStack();158 159 struct StackBounds {160 uptr bottom;161 uptr top;162 };163 StackBounds GetStackBounds() const;164 165 void GetStartData(void *out, uptr out_size) const;166 167 AsanThreadContext *context_;168 169 uptr stack_top_;170 uptr stack_bottom_;171 // these variables are used when the thread is about to switch stack172 uptr next_stack_top_;173 uptr next_stack_bottom_;174 // true if switching is in progress175 atomic_uint8_t stack_switching_;176 177 uptr tls_begin_;178 uptr tls_end_;179 DTLS *dtls_;180 181 FakeStack *fake_stack_;182 AsanThreadLocalMallocStorage malloc_storage_;183 AsanStats stats_;184 bool unwinding_;185 uptr extra_spill_area_;186 187 char start_data_[];188};189 190#if defined(_MSC_VER) && !defined(__clang__)191# pragma warning(pop)192#endif193 194// Returns a single instance of registry.195ThreadRegistry &asanThreadRegistry();196ThreadArgRetval &asanThreadArgRetval();197 198// Must be called under ThreadRegistryLock.199AsanThreadContext *GetThreadContextByTidLocked(u32 tid);200 201// Get the current thread. May return 0.202AsanThread *GetCurrentThread();203void SetCurrentThread(AsanThread *t);204u32 GetCurrentTidOrInvalid();205AsanThread *FindThreadByStackAddress(uptr addr);206 207// Used to handle fork().208void EnsureMainThreadIDIsCorrect();209} // namespace __asan210 211#endif // ASAN_THREAD_H212