Override IndyBootstrapDispatcher class module (#1468)

CHANGELOG.asciidoc

@@ -49,6 +49,8 @@ endif::[]
 * Fix ability to disable agent on startup wasn't working for runtime attach {pull}1444[1444]
 * Avoid `UnsupportedOperationException` on some spring application startup {pull}1464[1464]
 * Fix ignored runtime attach `config_file` {pull}1469[1469]
+* Fix `IllegalAccessError: Module 'java.base' no access to: package 'java.lang'...` in J9 VMs of Java version >= 9 -
+  {pull}1468[#1468]
 
 ===== Refactors
 * Migrate some plugins to indy dispatcher {pull}1404[1404] {pull}1411[1411]

apm-agent-core/pom.xml

@@ -3,8 +3,8 @@
     <modelVersion>4.0.0</modelVersion>
 
     <parent>
-        <groupId>co.elastic.apm</groupId>
         <artifactId>apm-agent-parent</artifactId>
+        <groupId>co.elastic.apm</groupId>
         <version>1.18.2-SNAPSHOT</version>
     </parent>
 
@@ -72,6 +72,12 @@
             <version>2.1.11</version>
         </dependency>
 
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>apm-indy-bootstrap-module</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>com.squareup.okhttp3</groupId>
             <artifactId>okhttp</artifactId>

apm-agent-core/src/main/java/co/elastic/apm/agent/bci/ElasticApmAgent.java

@@ -424,7 +424,7 @@ private static AgentBuilder.Transformer.ForAdvice getTransformer(final ElasticAp
         if (!(instrumentation instanceof TracerAwareInstrumentation)
             || ((TracerAwareInstrumentation) instrumentation).indyPlugin()) {
             validateAdvice(instrumentation.getAdviceClass());
-            withCustomMapping = withCustomMapping.bootstrap(IndyBootstrap.getIndyBootstrapMethod());
+            withCustomMapping = withCustomMapping.bootstrap(IndyBootstrap.getIndyBootstrapMethod(logger));
         }
         return new AgentBuilder.Transformer.ForAdvice(withCustomMapping)
             .advice(new ElementMatcher<MethodDescription>() {

apm-agent-core/src/main/java/co/elastic/apm/agent/bci/IndyBootstrap.java

@@ -32,8 +32,10 @@
 import co.elastic.apm.agent.util.PackageScanner;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.dynamic.loading.ClassInjector;
+import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.stagemonitor.util.IOUtils;
+import sun.misc.Unsafe;
 
 import javax.annotation.Nullable;
 import java.io.IOException;
@@ -166,9 +168,14 @@ public class IndyBootstrap {
      * Starts with {@code java.lang} so that OSGi class loaders don't restrict access to it
      */
     private static final String INDY_BOOTSTRAP_CLASS_NAME = "java.lang.IndyBootstrapDispatcher";
+    /**
+     * Needs to be loaded from the bootstrap CL because it uses {@link Unsafe}.
+     * In addition, needs to be loaded explicitly by name only when running on Java 9, because compiled with Java 9
+     */
+    private static final String INDY_BOOTSTRAP_MODULE_SETTER_CLASS_NAME = "co.elastic.apm.agent.bci.IndyBootstrapDispatcherModuleSetter";
     /**
      * The class file of {@code java.lang.IndyBootstrapDispatcher}.
-     * Ends with {@code clazz} because if it ended with {@code clazz}, it would be loaded like a regular class.
+     * Ends with {@code clazz} because if it ended with {@code class}, it would be loaded like a regular class.
      */
     private static final String INDY_BOOTSTRAP_RESOURCE = "bootstrap/IndyBootstrapDispatcher.clazz";
     /**
@@ -178,12 +185,12 @@ public class IndyBootstrap {
     @Nullable
     static Method indyBootstrapMethod;
 
-    public static Method getIndyBootstrapMethod() {
+    public static Method getIndyBootstrapMethod(final Logger logger) {
         if (indyBootstrapMethod != null) {
             return indyBootstrapMethod;
         }
         try {
-            Class<?> indyBootstrapClass = initIndyBootstrap();
+            Class<?> indyBootstrapClass = initIndyBootstrap(logger);
             indyBootstrapClass
                 .getField("bootstrap")
                 .set(null, IndyBootstrap.class.getMethod("bootstrap", MethodHandles.Lookup.class, String.class, MethodType.class, Object[].class));
@@ -196,14 +203,40 @@ public static Method getIndyBootstrapMethod() {
     /**
      * Injects the {@code java.lang.IndyBootstrapDispatcher} class into the bootstrap class loader if it wasn't already.
      */
-    private static Class<?> initIndyBootstrap() throws Exception {
+    private static Class<?> initIndyBootstrap(final Logger logger) throws Exception {
+        Class<?> indyBootstrapDispatcherClass;
         try {
-            return Class.forName(INDY_BOOTSTRAP_CLASS_NAME, false, null);
+            indyBootstrapDispatcherClass = Class.forName(INDY_BOOTSTRAP_CLASS_NAME, false, null);
         } catch (ClassNotFoundException e) {
             byte[] bootstrapClass = IOUtils.readToBytes(ClassLoader.getSystemClassLoader().getResourceAsStream(INDY_BOOTSTRAP_RESOURCE));
             ClassInjector.UsingUnsafe.ofBootLoader().injectRaw(Collections.singletonMap(INDY_BOOTSTRAP_CLASS_NAME, bootstrapClass));
+            indyBootstrapDispatcherClass = Class.forName(INDY_BOOTSTRAP_CLASS_NAME, false, null);
+        }
+
+        if (JvmRuntimeInfo.getMajorVersion() >= 9 && JvmRuntimeInfo.isJ9VM()) {
+            try {
+                logger.info("Overriding IndyBootstrapDispatcher class's module to java.base module. This is required in J9 VMs.");
+                setJavaBaseModule(indyBootstrapDispatcherClass);
+            } catch (Throwable throwable) {
+                logger.warn("Failed to setup proper module for the IndyBootstrapDispatcher class, instrumentation may fail", throwable);
+            }
         }
-        return Class.forName(INDY_BOOTSTRAP_CLASS_NAME, false, null);
+        return indyBootstrapDispatcherClass;
+    }
+
+    /**
+     * A package-private method for unit-testing of the module overriding functionality
+     *
+     * @param targetClass class for which module should be overridden with the {@code java.base} module
+     * @throws Throwable in case of any failure related to module overriding
+     */
+    static void setJavaBaseModule(Class<?> targetClass) throws Throwable {
+        // In order to override the original unnamed module assigned to the IndyBootstrapDispatcher, we rely on the
+        // Unsafe API, which requires the caller to be loaded by the Bootstrap CL
+        Class<?> moduleSetterClass = Class.forName(INDY_BOOTSTRAP_MODULE_SETTER_CLASS_NAME, false, null);
+        MethodHandles.lookup()
+            .findStatic(moduleSetterClass, "setJavaBaseModule", MethodType.methodType(void.class, Class.class))
+            .invoke(targetClass);
     }
 
     /**

apm-agent-core/src/main/java/co/elastic/apm/agent/util/JvmRuntimeInfo.java

@@ -37,6 +37,7 @@ public class JvmRuntimeInfo {
     private static int updateVersion;
     private static boolean isHotSpot;
     private static boolean isIbmJ9;
+    private static boolean isJ9;
 
     static {
         parseVmInfo(System.getProperty("java.version"), System.getProperty("java.vm.name"), System.getProperty("java.vm.version"));
@@ -91,6 +92,7 @@ static void parseVmInfo(String version, String vmName, @Nullable String vmVersio
 
         isHotSpot = vmName.contains("HotSpot(TM)") || vmName.contains("OpenJDK");
         isIbmJ9 = vmName.contains("IBM J9");
+        isJ9 = vmName.contains("J9");
     }
 
     public static String getJavaVersion() {
@@ -110,6 +112,10 @@ public static int getMajorVersion() {
         return majorVersion;
     }
 
+    public static boolean isJ9VM() {
+        return isJ9;
+    }
+
     /**
      * Checks if a given version of the JVM is likely supported by this agent.
      * <br>

apm-agent-core/src/test/java/co/elastic/apm/agent/bci/IndyBootstrapTest.java

@@ -0,0 +1,53 @@
+/*-
+ * #%L
+ * Elastic APM Java agent
+ * %%
+ * Copyright (C) 2018 - 2020 Elastic and contributors
+ * %%
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * #L%
+ */
+package co.elastic.apm.agent.bci;
+
+import co.elastic.apm.agent.AbstractInstrumentationTest;
+import net.bytebuddy.dynamic.loading.ClassInjector;
+import org.junit.jupiter.api.Test;
+import org.stagemonitor.util.IOUtils;
+
+import java.io.InputStream;
+import java.util.Collections;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class IndyBootstrapTest extends AbstractInstrumentationTest {
+
+    @Test
+    void testSetJavaBaseModule() throws Throwable {
+        Module javaBaseModule = Class.class.getModule();
+        assertThat(IndyBootstrapTest.class.getModule()).isNotEqualTo(javaBaseModule);
+
+        // In order to test this functionality, IndyBootstrapDispatcherModuleSetter needs to be loaded from the Boot CL.
+        // We don't mind loading it with the test's class loader as well only to get it's class file
+        InputStream classFileAsStream = IndyBootstrapDispatcherModuleSetter.class.getResourceAsStream("IndyBootstrapDispatcherModuleSetter.class");
+        byte[] bootstrapClass = IOUtils.readToBytes(classFileAsStream);
+        ClassInjector.UsingUnsafe.ofBootLoader().injectRaw(Collections.singletonMap(IndyBootstrapDispatcherModuleSetter.class.getName(), bootstrapClass));
+
+        IndyBootstrap.setJavaBaseModule(IndyBootstrapTest.class);
+        assertThat(IndyBootstrapTest.class.getModule()).isEqualTo(javaBaseModule);
+    }
+}

apm-agent-plugins/apm-jdk-httpclient-plugin/src/main/java/co/elastic/apm/agent/httpclient/HttpClientInstrumentation.java

@@ -25,10 +25,12 @@
 package co.elastic.apm.agent.httpclient;
 
 import co.elastic.apm.agent.impl.transaction.Span;
+import co.elastic.apm.agent.util.JvmRuntimeInfo;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.NamedElement;
 import net.bytebuddy.description.method.MethodDescription;
 import net.bytebuddy.description.type.TypeDescription;
+import net.bytebuddy.matcher.BooleanMatcher;
 import net.bytebuddy.matcher.ElementMatcher;
 
 import javax.annotation.Nullable;
@@ -44,7 +46,7 @@ public class HttpClientInstrumentation extends AbstractHttpClientInstrumentation
 
     @Override
     public ElementMatcher<? super NamedElement> getTypeMatcherPreFilter() {
-        return nameContains("HttpClient");
+        return new BooleanMatcher<>(JvmRuntimeInfo.getMajorVersion() >= 11).and(nameContains("HttpClient"));
     }
 
     @Override

apm-indy-bootstrap-module/pom.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <artifactId>apm-agent-parent</artifactId>
+        <groupId>co.elastic.apm</groupId>
+        <version>1.18.2-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>apm-indy-bootstrap-module</artifactId>
+    <name>${project.groupId}:${project.artifactId}</name>
+
+    <properties>
+        <apm-agent-parent.base.dir>${project.basedir}/..</apm-agent-parent.base.dir>
+
+        <maven.compiler.target>9</maven.compiler.target>
+
+        <!-- using release to enforce java 9 API (animal sniffer not supported) -->
+        <maven.compiler.release>${maven.compiler.target}</maven.compiler.release>
+
+        <!-- not supported/relevant beyond java9, see https://github.com/mojohaus/animal-sniffer/issues/62
+        now enforced through the maven.compiler.release property -->
+        <animal.sniffer.skip>true</animal.sniffer.skip>
+    </properties>
+</project>

apm-indy-bootstrap-module/src/main/java/co/elastic/apm/agent/bci/IndyBootstrapDispatcherModuleSetter.java

@@ -0,0 +1,50 @@
+/*-
+ * #%L
+ * Elastic APM Java agent
+ * %%
+ * Copyright (C) 2018 - 2020 Elastic and contributors
+ * %%
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ * #L%
+ */
+package co.elastic.apm.agent.bci;
+
+import sun.misc.Unsafe;
+
+import java.lang.reflect.Field;
+
+/**
+ * Overrides the module assigned to the class in with the {@code java.base} module.
+ * <p>
+ * NOTE: This class is compiled with Java 9 so it must only be loaded though reflection and only when running on Java 9.
+ * In addition, since it relies on the {@link Unsafe} API, it must be loaded by the bootstrap or platform class loaders.
+ */
+@SuppressWarnings("unused")
+public class IndyBootstrapDispatcherModuleSetter {
+
+    public static void setJavaBaseModule(Class<?> indyBootstrapDispatcherClass) throws Exception {
+        Field moduleField = Class.class.getDeclaredField("module");
+        if (moduleField.getType() == Module.class) {
+            Module javaBaseModule = Class.class.getModule();
+            Unsafe unsafe = Unsafe.getUnsafe();
+            unsafe.putObject(indyBootstrapDispatcherClass, unsafe.objectFieldOffset(moduleField), javaBaseModule);
+        } else {
+            throw new IllegalStateException("Unexpected module field type: " + moduleField.getType().getName());
+        }
+    }
+}

elastic-apm-agent/pom.xml

@@ -27,6 +27,11 @@
             <artifactId>apm-agent-core</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>apm-indy-bootstrap-module</artifactId>
+            <version>${project.version}</version>
+        </dependency>
 
         <!--Agent plugins, sorted alphabetically -->
         <dependency>

pom.xml

@@ -63,6 +63,7 @@
         <module>integration-tests</module>
         <module>apm-agent-attach</module>
         <module>apm-agent-plugin-sdk</module>
+        <module>apm-indy-bootstrap-module</module>
     </modules>
 
     <properties>