128 lines · cpp
1#include "dfsan_thread.h"2 3#include <pthread.h>4 5#include "dfsan.h"6#include "sanitizer_common/sanitizer_tls_get_addr.h"7 8using namespace __dfsan;9 10DFsanThread *DFsanThread::Create(thread_callback_t start_routine, void *arg,11 bool track_origins) {12 uptr PageSize = GetPageSizeCached();13 uptr size = RoundUpTo(sizeof(DFsanThread), PageSize);14 DFsanThread *thread = (DFsanThread *)MmapOrDie(size, __func__);15 thread->start_routine_ = start_routine;16 thread->arg_ = arg;17 thread->track_origins_ = track_origins;18 thread->destructor_iterations_ = GetPthreadDestructorIterations();19 20 return thread;21}22 23void DFsanThread::SetThreadStackAndTls() {24 GetThreadStackAndTls(IsMainThread(), &stack_.bottom, &stack_.top, &tls_begin_,25 &tls_end_);26 int local;27 CHECK(AddrIsInStack((uptr)&local));28}29 30void DFsanThread::ClearShadowForThreadStackAndTLS() {31 dfsan_set_label(0, (void *)stack_.bottom, stack_.top - stack_.bottom);32 if (tls_begin_ != tls_end_)33 dfsan_set_label(0, (void *)tls_begin_, tls_end_ - tls_begin_);34 DTLS *dtls = DTLS_Get();35 CHECK_NE(dtls, 0);36 ForEachDVT(dtls, [](const DTLS::DTV &dtv, int id) {37 dfsan_set_label(0, (void *)(dtv.beg), dtv.size);38 });39}40 41void DFsanThread::Init() {42 SetThreadStackAndTls();43 ClearShadowForThreadStackAndTLS();44}45 46void DFsanThread::TSDDtor(void *tsd) {47 DFsanThread *t = (DFsanThread *)tsd;48 t->Destroy();49}50 51void DFsanThread::Destroy() {52 malloc_storage().CommitBack();53 // We also clear the shadow on thread destruction because54 // some code may still be executing in later TSD destructors55 // and we don't want it to have any poisoned stack.56 ClearShadowForThreadStackAndTLS();57 uptr size = RoundUpTo(sizeof(DFsanThread), GetPageSizeCached());58 UnmapOrDie(this, size);59 DTLS_Destroy();60}61 62thread_return_t DFsanThread::ThreadStart() {63 if (!start_routine_) {64 // start_routine_ == 0 if we're on the main thread or on one of the65 // OS X libdispatch worker threads. But nobody is supposed to call66 // ThreadStart() for the worker threads.67 return 0;68 }69 70 // The only argument is void* arg.71 //72 // We have never supported propagating the pointer arg as tainted,73 // __dfsw_pthread_create/__dfso_pthread_create ignore the taint label.74 // Note that the bytes pointed-to (probably the much more common case)75 // can still have taint labels attached to them.76 dfsan_clear_thread_local_state();77 78 return start_routine_(arg_);79}80 81DFsanThread::StackBounds DFsanThread::GetStackBounds() const {82 return {stack_.bottom, stack_.top};83}84 85uptr DFsanThread::stack_top() { return GetStackBounds().top; }86 87uptr DFsanThread::stack_bottom() { return GetStackBounds().bottom; }88 89bool DFsanThread::AddrIsInStack(uptr addr) {90 const auto bounds = GetStackBounds();91 return addr >= bounds.bottom && addr < bounds.top;92}93 94static pthread_key_t tsd_key;95static bool tsd_key_inited = false;96 97void __dfsan::DFsanTSDInit(void (*destructor)(void *tsd)) {98 CHECK(!tsd_key_inited);99 tsd_key_inited = true;100 CHECK_EQ(0, pthread_key_create(&tsd_key, destructor));101}102 103static THREADLOCAL DFsanThread *dfsan_current_thread;104 105DFsanThread *__dfsan::GetCurrentThread() { return dfsan_current_thread; }106 107void __dfsan::SetCurrentThread(DFsanThread *t) {108 // Make sure we do not reset the current DFsanThread.109 CHECK_EQ(0, dfsan_current_thread);110 dfsan_current_thread = t;111 // Make sure that DFsanTSDDtor gets called at the end.112 CHECK(tsd_key_inited);113 pthread_setspecific(tsd_key, t);114}115 116void __dfsan::DFsanTSDDtor(void *tsd) {117 DFsanThread *t = (DFsanThread *)tsd;118 if (t->destructor_iterations_ > 1) {119 t->destructor_iterations_--;120 CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));121 return;122 }123 dfsan_current_thread = nullptr;124 // Make sure that signal handler can not see a stale current thread pointer.125 atomic_signal_fence(memory_order_seq_cst);126 DFsanThread::TSDDtor(tsd);127}128