Index: llvm/lib/ExecutionEngine/Orc/Core.cpp
===================================================================
--- llvm/lib/ExecutionEngine/Orc/Core.cpp
+++ llvm/lib/ExecutionEngine/Orc/Core.cpp
@@ -1611,11 +1611,13 @@
 }
 
 JITDylib *ExecutionSession::getJITDylibByName(std::string Name) {
-  for (auto &JD : JDs) {
-    if (JD->getName() == Name)
-      return JD.get();
-  }
-  return nullptr;
+  return runSessionLocked([&, this]() -> JITDylib * {
+    for (auto &JD : JDs) {
+      if (JD->getName() == Name)
+        return JD.get();
+    }
+    return nullptr;
+  });
 }
 
 JITDylib &ExecutionSession::createJITDylib(std::string Name,