--- old/src/hotspot/share/prims/jvmtiThreadState.cpp	2020-06-24 15:18:09.899191817 +0900
+++ new/src/hotspot/share/prims/jvmtiThreadState.cpp	2020-06-24 15:18:09.822189926 +0900
@@ -216,13 +216,15 @@
 
 // Helper routine used in several places
 int JvmtiThreadState::count_frames() {
+  Thread *current_thread = Thread::current();
   guarantee(SafepointSynchronize::is_at_safepoint() ||
-    (JavaThread *)Thread::current() == get_thread(),
-    "must be current thread or at safepoint");
+    current_thread == get_thread() ||
+    (current_thread->is_Java_thread() && (current_thread == get_thread()->active_handshaker())),
+    "must be at safepoint or target thread is suspended");
 
   if (!get_thread()->has_last_Java_frame()) return 0;  // no Java frames
 
-  ResourceMark rm;
+  ResourceMark rm(current_thread);
   RegisterMap reg_map(get_thread());
   javaVFrame *jvf = get_thread()->last_java_vframe(&reg_map);
   int n = 0;