src/cpu/x86/vm/sharedRuntime_x86_64.cpp

@@ -2444,11 +2444,11 @@
 
     __ lea(lock_reg, Address(rsp, lock_slot_offset * VMRegImpl::stack_slot_size));
 
     // Load the oop from the handle
     __ movptr(obj_reg, Address(oop_handle_reg, 0));
-
+    oopDesc::bs()->interpreter_write_barrier(masm, obj_reg);
     if (UseBiasedLocking) {
       __ biased_locking_enter(lock_reg, obj_reg, swap_reg, rscratch1, false, lock_done, &slow_path_lock);
     }
 
     // Load immediate 1 into swap_reg %rax

@@ -2613,10 +2613,11 @@
   Label slow_path_unlock;
   if (method->is_synchronized()) {
 
     // Get locked oop from the handle we passed to jni
     __ movptr(obj_reg, Address(oop_handle_reg, 0));
+    oopDesc::bs()->interpreter_write_barrier(masm, obj_reg);
 
     Label done;
 
     if (UseBiasedLocking) {
       __ biased_locking_exit(obj_reg, old_hdr, done);