1 files changed, 50 insertions, 8 deletions

diff --git a/compiler-rt/lib/msan/msan_thread.cpp b/compiler-rt/lib/msan/msan_thread.cpp
index 0ba499350064..6ae012acd9a2 100644
--- a/compiler-rt/lib/msan/msan_thread.cpp
+++ b/compiler-rt/lib/msan/msan_thread.cpp
@@ -22,9 +22,9 @@ MsanThread *MsanThread::Create(thread_callback_t start_routine,
 void MsanThread::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;
+  GetThreadStackAndTls(IsMainThread(), &stack_.bottom, &stack_size, &tls_begin_,
+                       &tls_size);
+  stack_.top = stack_.bottom + stack_size;
   tls_end_ = tls_begin_ + tls_size;
 
   int local;
@@ -32,19 +32,20 @@ void MsanThread::SetThreadStackAndTls() {
 }
 
 void MsanThread::ClearShadowForThreadStackAndTLS() {
-  __msan_unpoison((void *)stack_bottom_, stack_top_ - stack_bottom_);
+  __msan_unpoison((void *)stack_.bottom, stack_.top - stack_.bottom);
   if (tls_begin_ != tls_end_)
     __msan_unpoison((void *)tls_begin_, tls_end_ - tls_begin_);
   DTLS *dtls = DTLS_Get();
   CHECK_NE(dtls, 0);
-  for (uptr i = 0; i < dtls->dtv_size; ++i)
-    __msan_unpoison((void *)(dtls->dtv[i].beg), dtls->dtv[i].size);
+  ForEachDVT(dtls, [](const DTLS::DTV &dtv, int id) {
+    __msan_unpoison((void *)(dtv.beg), dtv.size);
+  });
 }
 
 void MsanThread::Init() {
   SetThreadStackAndTls();
-  CHECK(MEM_IS_APP(stack_bottom_));
-  CHECK(MEM_IS_APP(stack_top_ - 1));
+  CHECK(MEM_IS_APP(stack_.bottom));
+  CHECK(MEM_IS_APP(stack_.top - 1));
   ClearShadowForThreadStackAndTLS();
 }
 
@@ -79,4 +80,45 @@ thread_return_t MsanThread::ThreadStart() {
   return res;
 }
 
+MsanThread::StackBounds MsanThread::GetStackBounds() const {
+  if (!stack_switching_)
+    return {stack_.bottom, stack_.top};
+  const uptr cur_stack = GET_CURRENT_FRAME();
+  // Note: need to check next stack first, because FinishSwitchFiber
+  // may be in process of overwriting stack_.top/bottom_. But in such case
+  // we are already on the next stack.
+  if (cur_stack >= next_stack_.bottom && cur_stack < next_stack_.top)
+    return {next_stack_.bottom, next_stack_.top};
+  return {stack_.bottom, stack_.top};
+}
+
+uptr MsanThread::stack_top() { return GetStackBounds().top; }
+
+uptr MsanThread::stack_bottom() { return GetStackBounds().bottom; }
+
+bool MsanThread::AddrIsInStack(uptr addr) {
+  const auto bounds = GetStackBounds();
+  return addr >= bounds.bottom && addr < bounds.top;
+}
+
+void MsanThread::StartSwitchFiber(uptr bottom, uptr size) {
+  CHECK(!stack_switching_);
+  next_stack_.bottom = bottom;
+  next_stack_.top = bottom + size;
+  stack_switching_ = true;
+}
+
+void MsanThread::FinishSwitchFiber(uptr *bottom_old, uptr *size_old) {
+  CHECK(stack_switching_);
+  if (bottom_old)
+    *bottom_old = stack_.bottom;
+  if (size_old)
+    *size_old = stack_.top - stack_.bottom;
+  stack_.bottom = next_stack_.bottom;
+  stack_.top = next_stack_.top;
+  stack_switching_ = false;
+  next_stack_.top = 0;
+  next_stack_.bottom = 0;
+}
+
 } // namespace __msan