[asan] fix one more case where stack-use-after-return is not async-signal-safe (during thread startup). beef-up the test to give it a chance to catch regressions. Also relax the lint to make C++11 more usable.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@304598 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 4 deletions

diff --git a/lib/asan/asan_thread.cc b/lib/asan/asan_thread.cc
index f41ee2df2..714496d5c 100644
--- a/lib/asan/asan_thread.cc
+++ b/lib/asan/asan_thread.cc
@@ -166,16 +166,19 @@ void AsanThread::FinishSwitchFiber(FakeStack *fake_stack_save,
 }
 
 inline AsanThread::StackBounds AsanThread::GetStackBounds() const {
-  if (!atomic_load(&stack_switching_, memory_order_acquire))
-    return StackBounds{stack_bottom_, stack_top_};  // NOLINT
+  if (!atomic_load(&stack_switching_, memory_order_acquire)) {
+    // Make sure the stack bounds are fully initialized.
+    if (stack_bottom_ >= stack_top_) return {0, 0};
+    return {stack_bottom_, stack_top_};
+  }
   char local;
   const uptr cur_stack = (uptr)&local;
   // 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 StackBounds{next_stack_bottom_, next_stack_top_};  // NOLINT
-  return StackBounds{stack_bottom_, stack_top_};              // NOLINT
+    return {next_stack_bottom_, next_stack_top_};
+  return {stack_bottom_, stack_top_};
 }
 
 uptr AsanThread::stack_top() {
@@ -197,6 +200,7 @@ FakeStack *AsanThread::AsyncSignalSafeLazyInitFakeStack() {
   uptr stack_size = this->stack_size();
   if (stack_size == 0)  // stack_size is not yet available, don't use FakeStack.
     return nullptr;
+  CHECK_LE(stack_size, 0x10000000);
   uptr old_val = 0;
   // fake_stack_ has 3 states:
   // 0   -- not initialized