# HG changeset patch

# User sgehwolf

# Date 1611565076 0

#      Mon Jan 25 08:57:56 2021 +0000

# Node ID 61c497b3b886f671646aec9d6e4cf3f44c422f99

# Parent  59a62286b0b2a3057040df83640f38ea9499a60c

8258836: JNI local refs exceed capacity getDiagnosticCommandInfo

Reviewed-by: cjplummer, shade

diff --git a/src/jdk.management/share/native/libmanagement_ext/DiagnosticCommandImpl.c b/src/jdk.management/share/native/libmanagement_ext/DiagnosticCommandImpl.c

--- a/src/jdk.management/share/native/libmanagement_ext/DiagnosticCommandImpl.c

+++ b/src/jdk.management/share/native/libmanagement_ext/DiagnosticCommandImpl.c

@@ -1,5 +1,5 @@

 /*

- * Copyright (c) 2013, 2016, Oracle and/or its affiliates. All rights reserved.

+ * Copyright (c) 2013, 2021, 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

@@ -45,12 +45,21 @@

   return jmm_interface->GetDiagnosticCommands(env);

 }

-#define EXCEPTION_CHECK_AND_FREE(x) do { \

-                                        if ((*env)->ExceptionCheck(env)) { \

-                                            free(x); \

-                                            return NULL; \

-                                        } \

-                                    } while(0)

+//

+// Checks for an exception and if one occurred,

+// pops 'pops' local frames and frees 'x' before

+// returning NULL

+//

+#define POP_EXCEPTION_CHECK_AND_FREE(pops, x) do { \

+                                                  if ((*env)->ExceptionCheck(env)) { \

+                                                      int i; \

+                                                      for (i = 0; i < pops; i++) { \

+                                                          (*env)->PopLocalFrame(env, NULL); \

+                                                      } \

+                                                      free(x); \

+                                                      return NULL; \

+                                                  } \

+                                              } while(0)

 jobject getDiagnosticCommandArgumentInfoArray(JNIEnv *env, jstring command,

                                               int num_arg) {

@@ -73,10 +82,7 @@

                                                    dcmd_arg_info_array);

   dcmdArgInfoCls = (*env)->FindClass(env,

                                      "com/sun/management/internal/DiagnosticCommandArgumentInfo");

-  if ((*env)->ExceptionCheck(env)) {

-    free(dcmd_arg_info_array);

-    return NULL;

-  }

+  POP_EXCEPTION_CHECK_AND_FREE(0, dcmd_arg_info_array);

   result = (*env)->NewObjectArray(env, num_arg, dcmdArgInfoCls, NULL);

   if (result == NULL) {

@@ -84,19 +90,21 @@

     return NULL;

   }

   for (i=0; i

-    jstring jname, jdesc,jtype,jdefStr;

+    // Capacity for 5 local refs: jname, jdesc, jtype, jdefStr and obj

+    (*env)->PushLocalFrame(env, 5);

+    jstring jname, jdesc, jtype, jdefStr;

     jname = (*env)->NewStringUTF(env,dcmd_arg_info_array[i].name);

-    EXCEPTION_CHECK_AND_FREE(dcmd_arg_info_array);

+    POP_EXCEPTION_CHECK_AND_FREE(1, dcmd_arg_info_array);

     jdesc = (*env)->NewStringUTF(env,dcmd_arg_info_array[i].description);

-    EXCEPTION_CHECK_AND_FREE(dcmd_arg_info_array);

+    POP_EXCEPTION_CHECK_AND_FREE(1, dcmd_arg_info_array);

     jtype = (*env)->NewStringUTF(env,dcmd_arg_info_array[i].type);

-    EXCEPTION_CHECK_AND_FREE(dcmd_arg_info_array);

+    POP_EXCEPTION_CHECK_AND_FREE(1, dcmd_arg_info_array);

     jdefStr = (*env)->NewStringUTF(env, dcmd_arg_info_array[i].default_string);

-    EXCEPTION_CHECK_AND_FREE(dcmd_arg_info_array);

+    POP_EXCEPTION_CHECK_AND_FREE(1, dcmd_arg_info_array);

     obj = JNU_NewObjectByName(env,

                               "com/sun/management/internal/DiagnosticCommandArgumentInfo",

                               "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ZZZI)V",

@@ -107,11 +115,13 @@

                               dcmd_arg_info_array[i].multiple,

                               dcmd_arg_info_array[i].position);

     if (obj == NULL) {

+      (*env)->PopLocalFrame(env, NULL);

       free(dcmd_arg_info_array);

       return NULL;

     }

+    obj = (*env)->PopLocalFrame(env, obj);

     (*env)->SetObjectArrayElement(env, result, i, obj);

-    EXCEPTION_CHECK_AND_FREE(dcmd_arg_info_array);

+    POP_EXCEPTION_CHECK_AND_FREE(0, dcmd_arg_info_array);

   }

   free(dcmd_arg_info_array);

   arraysCls = (*env)->FindClass(env, "java/util/Arrays");

@@ -144,51 +154,67 @@

   jint ret = jmm_interface->GetOptionalSupport(env, &mos;;

   jsize num_commands;

   dcmdInfo* dcmd_info_array;

-  jstring jname, jdesc, jimpact;

+  jstring jname, jdesc, jimpact, cmd;

   if (commands == NULL) {

       JNU_ThrowNullPointerException(env, "Invalid String Array");

       return NULL;

   }

   num_commands = (*env)->GetArrayLength(env, commands);

+  // Ensure capacity for 2 + num_commands local refs:

+  //  2 => dcmdInfoCls, result

+  //  num_commmands => one obj per command

+  (*env)->PushLocalFrame(env, 2 + num_commands);

   dcmdInfoCls = (*env)->FindClass(env,

                                   "com/sun/management/internal/DiagnosticCommandInfo");

   if ((*env)->ExceptionCheck(env)) {

+    (*env)->PopLocalFrame(env, NULL);

     return NULL;

   }

   result = (*env)->NewObjectArray(env, num_commands, dcmdInfoCls, NULL);

   if (result == NULL) {

+      (*env)->PopLocalFrame(env, NULL);

       return NULL;

   }

   if (num_commands == 0) {

+      result = (*env)->PopLocalFrame(env, result);

       /* Handle the 'zero commands' case specially to avoid calling 'malloc()' */

       /* with a zero argument because that may legally return a NULL pointer.  */

       return result;

   }

   dcmd_info_array = (dcmdInfo*) malloc(num_commands * sizeof(dcmdInfo));

   if (dcmd_info_array == NULL) {

+      (*env)->PopLocalFrame(env, NULL);

       JNU_ThrowOutOfMemoryError(env, NULL);

       return NULL;

   }

   jmm_interface->GetDiagnosticCommandInfo(env, commands, dcmd_info_array);

   for (i=0; i

+      // Ensure capacity for 6 + 3 local refs:

+      //  6 => jname, jdesc, jimpact, cmd, args, obj

+      //  3 => permission class, name, action

+      (*env)->PushLocalFrame(env, 6 + 3);

+

+      cmd = (*env)->GetObjectArrayElement(env, commands, i);

       args = getDiagnosticCommandArgumentInfoArray(env,

-                                                   (*env)->GetObjectArrayElement(env,commands,i),

+                                                   cmd,

                                                    dcmd_info_array[i].num_arguments);

       if (args == NULL) {

+          (*env)->PopLocalFrame(env, NULL);

+          (*env)->PopLocalFrame(env, NULL);

           free(dcmd_info_array);

           return NULL;

       }

       jname = (*env)->NewStringUTF(env,dcmd_info_array[i].name);

-      EXCEPTION_CHECK_AND_FREE(dcmd_info_array);

+      POP_EXCEPTION_CHECK_AND_FREE(2, dcmd_info_array);

       jdesc = (*env)->NewStringUTF(env,dcmd_info_array[i].description);

-      EXCEPTION_CHECK_AND_FREE(dcmd_info_array);

+      POP_EXCEPTION_CHECK_AND_FREE(2, dcmd_info_array);

       jimpact = (*env)->NewStringUTF(env,dcmd_info_array[i].impact);

-      EXCEPTION_CHECK_AND_FREE(dcmd_info_array);

+      POP_EXCEPTION_CHECK_AND_FREE(2, dcmd_info_array);

       obj = JNU_NewObjectByName(env,

                                 "com/sun/management/internal/DiagnosticCommandInfo",

@@ -200,13 +226,17 @@

                                 dcmd_info_array[i].enabled,

                                 args);

       if (obj == NULL) {

+          (*env)->PopLocalFrame(env, NULL);

+          (*env)->PopLocalFrame(env, NULL);

           free(dcmd_info_array);

           return NULL;

       }

+      obj = (*env)->PopLocalFrame(env, obj);

       (*env)->SetObjectArrayElement(env, result, i, obj);

-      EXCEPTION_CHECK_AND_FREE(dcmd_info_array);

+      POP_EXCEPTION_CHECK_AND_FREE(1, dcmd_info_array);

   }

+  result = (*env)->PopLocalFrame(env, result);

   free(dcmd_info_array);

   return result;

 }

diff --git a/test/jdk/com/sun/management/DiagnosticCommandMBean/DcmdMBeanTestCheckJni.java b/test/jdk/com/sun/management/DiagnosticCommandMBean/DcmdMBeanTestCheckJni.java

new file mode 100644

--- /dev/null

+++ b/test/jdk/com/sun/management/DiagnosticCommandMBean/DcmdMBeanTestCheckJni.java

@@ -0,0 +1,84 @@

+/*

+ * Copyright (c) 2021, Red Hat, Inc.

+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

+ *

+ * This code is free software; you can redistribute it and/or modify it

+ * under the terms of the GNU General Public License version 2 only, as

+ * published by the Free Software Foundation.

+ *

+ * This code is distributed in the hope that it will be useful, but WITHOUT

+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

+ * version 2 for more details (a copy is included in the LICENSE file that

+ * accompanied this code).

+ *

+ * You should have received a copy of the GNU General Public License version

+ * 2 along with this work; if not, write to the Free Software Foundation,

+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

+ *

+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

+ * or visit www.oracle.com if you need additional information or have any

+ * questions.

+ */

+

+/*

+ * @test

+ * @bug     8258836

+ * @summary JNI local refs exceed capacity getDiagnosticCommandInfo

+ * @library /test/lib

+ * @run main/othervm DcmdMBeanTestCheckJni

+ */

+

+import java.lang.management.ManagementFactory;

+import javax.management.MBeanServer;

+import javax.management.ObjectName;

+import javax.management.MBeanServerConnection;

+import javax.management.remote.JMXConnectorFactory;

+import javax.management.remote.JMXConnector;

+import javax.management.remote.JMXConnectorServerFactory;

+import javax.management.remote.JMXServiceURL;

+import javax.management.remote.JMXConnectorServer;

+

+import jdk.test.lib.process.OutputAnalyzer;

+import jdk.test.lib.process.ProcessTools;

+

+public class DcmdMBeanTestCheckJni {

+

+    public static void main(String[] args) throws Exception {

+        OutputAnalyzer out = ProcessTools.executeTestJvm(

+            "-Xcheck:jni",

+            DcmdMBeanRunner.class.getName());

+        out.shouldNotMatch("WARNING: JNI local refs: \\d+, exceeds capacity: \\d+")

+           .shouldContain("DcmdMBeanRunner COMPLETE")

+           .shouldHaveExitValue(0);

+    }

+

+}

+

+class DcmdMBeanRunner {

+

+    private static final String HOTSPOT_DIAGNOSTIC_MXBEAN_NAME =

+        "com.sun.management:type=DiagnosticCommand";

+

+    public static void main(String[] args) throws Exception {

+        MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();

+        JMXServiceURL url = new JMXServiceURL("rmi", null, 0);

+        JMXConnectorServer cs = null;

+        JMXConnector cc = null;

+        try {

+            cs = JMXConnectorServerFactory.newJMXConnectorServer(url, null, mbs);

+            cs.start();

+            JMXServiceURL addr = cs.getAddress();

+            cc = JMXConnectorFactory.connect(addr);

+            MBeanServerConnection mbsc = cc.getMBeanServerConnection();

+            ObjectName name = new ObjectName(HOTSPOT_DIAGNOSTIC_MXBEAN_NAME);

+            System.out.println("DiagnosticCommand MBean: " + name);

+            System.out.println("DcmdMBeanRunner COMPLETE");

+        } finally {

+            try {

+                cc.close();

+                cs.stop();

+            } catch (Exception e) { /* ignored */ }

+        }

+    }

+}