diff -r c2f6dd6c9628 -r e2e6f03308f9 hotspot/src/share/vm/prims/jvmtiEnv.cpp --- a/hotspot/src/share/vm/prims/jvmtiEnv.cpp Mon Feb 03 15:24:20 2014 +0100 +++ b/hotspot/src/share/vm/prims/jvmtiEnv.cpp Tue Feb 04 19:41:46 2014 -0800 @@ -1360,8 +1360,10 @@ if (state == NULL) { return JVMTI_ERROR_THREAD_NOT_ALIVE; } - uint32_t debug_bits = 0; - if (is_thread_fully_suspended(java_thread, true, &debug_bits)) { + + // It is only safe to perform the direct operation on the current + // thread. All other usage needs to use a vm-safepoint-op for safety. + if (java_thread == JavaThread::current()) { err = get_frame_count(state, count_ptr); } else { // get java stack frame count at safepoint. @@ -1476,9 +1478,10 @@ jvmtiError JvmtiEnv::GetFrameLocation(JavaThread* java_thread, jint depth, jmethodID* method_ptr, jlocation* location_ptr) { jvmtiError err = JVMTI_ERROR_NONE; - uint32_t debug_bits = 0; - - if (is_thread_fully_suspended(java_thread, true, &debug_bits)) { + + // It is only safe to perform the direct operation on the current + // thread. All other usage needs to use a vm-safepoint-op for safety. + if (java_thread == JavaThread::current()) { err = get_frame_location(java_thread, depth, method_ptr, location_ptr); } else { // JVMTI get java stack frame location at safepoint.