use MethodHandles.Lookup IMPL_LOOKUP to support define class after jd…

…k 17. #2659
alibaba · Nov 24, 2023 · 82ab95c · 82ab95c
1 parent 6a43273
commit 82ab95c
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diff --git a/common/src/main/java/com/taobao/arthas/common/ReflectException.java b/common/src/main/java/com/taobao/arthas/common/ReflectException.java
@@ -6,7 +6,7 @@ public class ReflectException extends RuntimeException {
     private Throwable cause;
 
     public ReflectException(Throwable cause) {
-        super(cause.getClass().getName() + "-->" + cause.getMessage());
+        super(cause != null ? cause.getClass().getName() + "-->" + cause.getMessage() : "");
         this.cause = cause;
     }
 

diff --git a/common/src/main/java/com/taobao/arthas/common/ReflectUtils.java b/common/src/main/java/com/taobao/arthas/common/ReflectUtils.java
@@ -3,7 +3,9 @@
 import java.beans.IntrospectionException;
 import java.beans.Introspector;
 import java.beans.PropertyDescriptor;
+import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodHandles.Lookup;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
@@ -429,6 +431,29 @@ public static Class defineClass(String className, byte[] b, ClassLoader loader,
 
         Class c = null;
 
+        // 在 jdk 17之后，需要hack方式来调用 #2659
+        if (c == null && classLoaderDefineClassMethod != null) {
+            Lookup implLookup = UnsafeUtils.implLookup();
+            MethodHandle unreflect = implLookup.unreflect(classLoaderDefineClassMethod);
+
+            if (protectionDomain == null) {
+                protectionDomain = PROTECTION_DOMAIN;
+            }
+            try {
+                c = (Class) unreflect.invoke(loader, className, b, 0, b.length, protectionDomain);
+            } catch (InvocationTargetException ex) {
+                throw new ReflectException(ex.getTargetException());
+            } catch (Throwable ex) {
+                // Fall through if setAccessible fails with InaccessibleObjectException on JDK
+                // 9+
+                // (on the module path and/or with a JVM bootstrapped with
+                // --illegal-access=deny)
+                if (!ex.getClass().getName().endsWith("InaccessibleObjectException")) {
+                    throw new ReflectException(ex);
+                }
+            }
+        }
+
         // Preferred option: JDK 9+ Lookup.defineClass API if ClassLoader matches
         if (contextClass != null && contextClass.getClassLoader() == loader && privateLookupInMethod != null
                         && lookupDefineClassMethod != null) {

diff --git a/common/src/main/java/com/taobao/arthas/common/UnsafeUtils.java b/common/src/main/java/com/taobao/arthas/common/UnsafeUtils.java
@@ -0,0 +1,44 @@
+package com.taobao.arthas.common;
+
+
+import java.lang.invoke.MethodHandles;
+import java.lang.reflect.Field;
+
+import sun.misc.Unsafe;
+
+/**
+ * 
+ * @author hengyunabc 2023-09-21
+ *
+ */
+public class UnsafeUtils {
+    public static final Unsafe UNSAFE;
+    private static MethodHandles.Lookup IMPL_LOOKUP;
+
+    static {
+        Unsafe unsafe = null;
+        try {
+            Field theUnsafeField = Unsafe.class.getDeclaredField("theUnsafe");
+            theUnsafeField.setAccessible(true);
+            unsafe = (Unsafe) theUnsafeField.get(null);
+        } catch (Throwable ignored) {
+            // ignored
+        }
+        UNSAFE = unsafe;
+    }
+
+    public static MethodHandles.Lookup implLookup() {
+        if (IMPL_LOOKUP == null) {
+            Class<MethodHandles.Lookup> lookupClass = MethodHandles.Lookup.class;
+
+            try {
+                Field implLookupField = lookupClass.getDeclaredField("IMPL_LOOKUP");
+                long offset = UNSAFE.staticFieldOffset(implLookupField);
+                IMPL_LOOKUP = (MethodHandles.Lookup) UNSAFE.getObject(UNSAFE.staticFieldBase(implLookupField), offset);
+            } catch (Throwable e) {
+                // ignored
+            }
+        }
+        return IMPL_LOOKUP;
+    }
+}