diff -r 468f0664cb39 src/hotspot/share/prims/jvmtiExport.cpp
--- a/src/hotspot/share/prims/jvmtiExport.cpp	Tue Sep 26 06:53:35 2017 -0400
+++ b/src/hotspot/share/prims/jvmtiExport.cpp	Wed Sep 27 00:35:24 2017 +0900
@@ -2475,7 +2475,7 @@
 
 jint JvmtiExport::load_agent_library(const char *agent, const char *absParam,
                                      const char *options, outputStream* st) {
-  char ebuf[1024];
+  char ebuf[1024] = {0};
   char buffer[JVM_MAXPATHLEN];
   void* library = NULL;
   jint result = JNI_ERR;
@@ -2525,6 +2525,8 @@
       if (!agent_lib->is_static_lib()) {
         os::dll_unload(library);
       }
+      st->print_cr("%s is not available in %s",
+                   on_attach_symbols[0], agent_lib->name());
       delete agent_lib;
     } else {
       // Invoke the Agent_OnAttach function
@@ -2539,6 +2541,8 @@
 
       // Agent_OnAttach may have used JNI
       if (HAS_PENDING_EXCEPTION) {
+        java_lang_Throwable::print(PENDING_EXCEPTION, st);
+        st->cr();
         CLEAR_PENDING_EXCEPTION;
       }
 
@@ -2550,11 +2554,16 @@
         delete agent_lib;
       }
 
-      // Agent_OnAttach executed so completion status is JNI_OK
-      st->print_cr("%d", result);
+      st->print_cr("return code: %d", result);
       result = JNI_OK;
     }
+  } else {
+    st->print_cr("%s was not loaded.", agent);
+    if (*ebuf != '\0') {
+      st->print_cr("%s", ebuf);
+    }
   }
+
   return result;
 }
 
diff -r 468f0664cb39 src/jdk.attach/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
--- a/src/jdk.attach/share/classes/sun/tools/attach/HotSpotVirtualMachine.java	Tue Sep 26 06:53:35 2017 -0400
+++ b/src/jdk.attach/share/classes/sun/tools/attach/HotSpotVirtualMachine.java	Wed Sep 27 00:35:24 2017 +0900
@@ -40,6 +40,8 @@
 import java.security.PrivilegedAction;
 import java.util.Properties;
 import java.util.stream.Collectors;
+import java.util.regex.Pattern;
+import java.util.regex.Matcher;
 
 /*
  * The HotSpot implementation of com.sun.tools.attach.VirtualMachine.
@@ -86,18 +88,26 @@
     private void loadAgentLibrary(String agentLibrary, boolean isAbsolute, String options)
         throws AgentLoadException, AgentInitializationException, IOException
     {
-        InputStream in = execute("load",
-                                 agentLibrary,
-                                 isAbsolute ? "true" : "false",
-                                 options);
-        try {
-            int result = readInt(in);
-            if (result != 0) {
-                throw new AgentInitializationException("Agent_OnAttach failed", result);
+        try (BufferedReader reader = new BufferedReader(
+                   new InputStreamReader(
+                            execute("load", agentLibrary,
+                                     Boolean.toString(isAbsolute), options)))) {
+            String result = reader.readLine();
+            if (result == null) {
+                throw new AgentLoadException("Target VM did not respond");
+            } else {
+                Matcher matcher = Pattern.compile("^return code: (\\d+)$")
+                                         .matcher(result);
+                if (matcher.matches()) {
+                    int retCode = Integer.parseInt(matcher.group(1));
+                    if (retCode != 0) {
+                        throw new AgentInitializationException(
+                                              "Agent_OnAttach failed", retCode);
+                    }
+                } else {
+                    throw new AgentLoadException(result);
+                }
             }
-        } finally {
-            in.close();
-
         }
     }
 
diff -r 468f0664cb39 test/jdk/com/sun/tools/attach/StartManagementAgent.java
--- a/test/jdk/com/sun/tools/attach/StartManagementAgent.java	Tue Sep 26 06:53:35 2017 -0400
+++ b/test/jdk/com/sun/tools/attach/StartManagementAgent.java	Wed Sep 27 00:35:24 2017 +0900
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -99,7 +99,7 @@
         } catch(AttachOperationFailedException ex) {
             // We expect parsing of "apa" above to fail, but if the file path
             // can't be read we get a different exception message
-            if (!ex.getMessage().contains("Invalid com.sun.management.jmxremote.port number")) {
+            if (!ex.getMessage().contains("For input string: \"apa\"")) {
                 throw ex;
             }
             ex.printStackTrace(System.err);