1 files changed, 134 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/dfsan/dfsan_thread.cpp b/contrib/llvm-project/compiler-rt/lib/dfsan/dfsan_thread.cpp
new file mode 100644
index 000000000000..e64f0f818fb8
--- /dev/null
+++ b/contrib/llvm-project/compiler-rt/lib/dfsan/dfsan_thread.cpp
@@ -0,0 +1,134 @@
+#include "dfsan_thread.h"
+
+#include <pthread.h>
+
+#include "dfsan.h"
+#include "sanitizer_common/sanitizer_tls_get_addr.h"
+
+namespace __dfsan {
+
+DFsanThread *DFsanThread::Create(thread_callback_t start_routine, void *arg,
+                                 bool track_origins) {
+  uptr PageSize = GetPageSizeCached();
+  uptr size = RoundUpTo(sizeof(DFsanThread), PageSize);
+  DFsanThread *thread = (DFsanThread *)MmapOrDie(size, __func__);
+  thread->start_routine_ = start_routine;
+  thread->arg_ = arg;
+  thread->track_origins_ = track_origins;
+  thread->destructor_iterations_ = GetPthreadDestructorIterations();
+
+  return thread;
+}
+
+void DFsanThread::SetThreadStackAndTls() {
+  uptr tls_size = 0;
+  uptr stack_size = 0;
+  GetThreadStackAndTls(IsMainThread(), &stack_.bottom, &stack_size, &tls_begin_,
+                       &tls_size);
+  stack_.top = stack_.bottom + stack_size;
+  tls_end_ = tls_begin_ + tls_size;
+
+  int local;
+  CHECK(AddrIsInStack((uptr)&local));
+}
+
+void DFsanThread::ClearShadowForThreadStackAndTLS() {
+  dfsan_set_label(0, (void *)stack_.bottom, stack_.top - stack_.bottom);
+  if (tls_begin_ != tls_end_)
+    dfsan_set_label(0, (void *)tls_begin_, tls_end_ - tls_begin_);
+  DTLS *dtls = DTLS_Get();
+  CHECK_NE(dtls, 0);
+  ForEachDVT(dtls, [](const DTLS::DTV &dtv, int id) {
+    dfsan_set_label(0, (void *)(dtv.beg), dtv.size);
+  });
+}
+
+void DFsanThread::Init() {
+  SetThreadStackAndTls();
+  ClearShadowForThreadStackAndTLS();
+}
+
+void DFsanThread::TSDDtor(void *tsd) {
+  DFsanThread *t = (DFsanThread *)tsd;
+  t->Destroy();
+}
+
+void DFsanThread::Destroy() {
+  malloc_storage().CommitBack();
+  // We also clear the shadow on thread destruction because
+  // some code may still be executing in later TSD destructors
+  // and we don't want it to have any poisoned stack.
+  ClearShadowForThreadStackAndTLS();
+  uptr size = RoundUpTo(sizeof(DFsanThread), GetPageSizeCached());
+  UnmapOrDie(this, size);
+  DTLS_Destroy();
+}
+
+thread_return_t DFsanThread::ThreadStart() {
+  if (!start_routine_) {
+    // start_routine_ == 0 if we're on the main thread or on one of the
+    // OS X libdispatch worker threads. But nobody is supposed to call
+    // ThreadStart() for the worker threads.
+    return 0;
+  }
+
+  // The only argument is void* arg.
+  //
+  // We have never supported propagating the pointer arg as tainted,
+  // __dfsw_pthread_create/__dfso_pthread_create ignore the taint label.
+  // Note that the bytes pointed-to (probably the much more common case)
+  // can still have taint labels attached to them.
+  dfsan_clear_thread_local_state();
+
+  return start_routine_(arg_);
+}
+
+DFsanThread::StackBounds DFsanThread::GetStackBounds() const {
+  return {stack_.bottom, stack_.top};
+}
+
+uptr DFsanThread::stack_top() { return GetStackBounds().top; }
+
+uptr DFsanThread::stack_bottom() { return GetStackBounds().bottom; }
+
+bool DFsanThread::AddrIsInStack(uptr addr) {
+  const auto bounds = GetStackBounds();
+  return addr >= bounds.bottom && addr < bounds.top;
+}
+
+static pthread_key_t tsd_key;
+static bool tsd_key_inited = false;
+
+void DFsanTSDInit(void (*destructor)(void *tsd)) {
+  CHECK(!tsd_key_inited);
+  tsd_key_inited = true;
+  CHECK_EQ(0, pthread_key_create(&tsd_key, destructor));
+}
+
+static THREADLOCAL DFsanThread *dfsan_current_thread;
+
+DFsanThread *GetCurrentThread() { return dfsan_current_thread; }
+
+void SetCurrentThread(DFsanThread *t) {
+  // Make sure we do not reset the current DFsanThread.
+  CHECK_EQ(0, dfsan_current_thread);
+  dfsan_current_thread = t;
+  // Make sure that DFsanTSDDtor gets called at the end.
+  CHECK(tsd_key_inited);
+  pthread_setspecific(tsd_key, t);
+}
+
+void DFsanTSDDtor(void *tsd) {
+  DFsanThread *t = (DFsanThread *)tsd;
+  if (t->destructor_iterations_ > 1) {
+    t->destructor_iterations_--;
+    CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));
+    return;
+  }
+  dfsan_current_thread = nullptr;
+  // Make sure that signal handler can not see a stale current thread pointer.
+  atomic_signal_fence(memory_order_seq_cst);
+  DFsanThread::TSDDtor(tsd);
+}
+
+}  // namespace __dfsan