From: Dominik Stadler Date: Sat, 2 Mar 2019 09:19:45 +0000 (+0000) Subject: Bug 62151: Fix warnings about illegal reflective access in Java 9+ by X-Git-Tag: REL_4_1_0~59 X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=53a30d796e27cf44eff2fdecf173b42e89430f61;p=poi.git Bug 62151: Fix warnings about illegal reflective access in Java 9+ by using a similar approach as Apache Hadoop via a CleanerUtil class which encapsulates the two different approaches for Java <= 8 and Java >= 9 git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1854630 13f79535-47bb-0310-9956-ffa450edef68 --- diff --git a/src/java/org/apache/poi/poifs/nio/CleanerUtil.java b/src/java/org/apache/poi/poifs/nio/CleanerUtil.java new file mode 100644 index 0000000000..9c70ee69e1 --- /dev/null +++ b/src/java/org/apache/poi/poifs/nio/CleanerUtil.java @@ -0,0 +1,201 @@ +/* ==================================================================== + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF 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. +==================================================================== */ + +package org.apache.poi.poifs.nio; + +import org.apache.poi.util.SuppressForbidden; + +import java.io.IOException; +import java.lang.invoke.MethodHandle; +import java.lang.invoke.MethodHandles; +import java.lang.reflect.Field; +import java.lang.reflect.Method; +import java.nio.ByteBuffer; +import java.security.AccessController; +import java.security.PrivilegedAction; +import java.util.Objects; + +import static java.lang.invoke.MethodHandles.constant; +import static java.lang.invoke.MethodHandles.dropArguments; +import static java.lang.invoke.MethodHandles.filterReturnValue; +import static java.lang.invoke.MethodHandles.guardWithTest; +import static java.lang.invoke.MethodType.methodType; + +/** + * This is taken from Hadoop at https://issues.apache.org/jira/browse/HADOOP-12760 and + * https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/CleanerUtil.java + * Unfortunately this is not available in some general utility library yet, but hopefully will be at some point. + * + * sun.misc.Cleaner has moved in OpenJDK 9 and + * sun.misc.Unsafe#invokeCleaner(ByteBuffer) is the replacement. + * This class is a hack to use sun.misc.Cleaner in Java 8 and + * use the replacement in Java 9+. + * This implementation is inspired by LUCENE-6989. + */ +public final class CleanerUtil { + + // Prevent instantiation + private CleanerUtil(){} + + /** + * true, if this platform supports unmapping mmapped files. + */ + public static final boolean UNMAP_SUPPORTED; + + /** + * if {@link #UNMAP_SUPPORTED} is {@code false}, this contains the reason + * why unmapping is not supported. + */ + public static final String UNMAP_NOT_SUPPORTED_REASON; + + + private static final BufferCleaner CLEANER; + + /** + * Reference to a BufferCleaner that does unmapping. + * @return {@code null} if not supported. + */ + public static BufferCleaner getCleaner() { + return CLEANER; + } + + static { + final Object hack = AccessController.doPrivileged( + (PrivilegedAction) CleanerUtil::unmapHackImpl); + if (hack instanceof BufferCleaner) { + CLEANER = (BufferCleaner) hack; + UNMAP_SUPPORTED = true; + UNMAP_NOT_SUPPORTED_REASON = null; + } else { + CLEANER = null; + UNMAP_SUPPORTED = false; + UNMAP_NOT_SUPPORTED_REASON = hack.toString(); + } + } + + @SuppressForbidden("Java 9 Jigsaw whitelists access to sun.misc.Cleaner, so setAccessible works") + private static Object unmapHackImpl() { + final MethodHandles.Lookup lookup = MethodHandles.lookup(); + try { + try { + // *** sun.misc.Unsafe unmapping (Java 9+) *** + final Class unsafeClass = Class.forName("sun.misc.Unsafe"); + // first check if Unsafe has the right method, otherwise we can + // give up without doing any security critical stuff: + final MethodHandle unmapper = lookup.findVirtual(unsafeClass, + "invokeCleaner", methodType(void.class, ByteBuffer.class)); + // fetch the unsafe instance and bind it to the virtual MH: + final Field f = unsafeClass.getDeclaredField("theUnsafe"); + f.setAccessible(true); + final Object theUnsafe = f.get(null); + return newBufferCleaner(ByteBuffer.class, unmapper.bindTo(theUnsafe)); + } catch (SecurityException se) { + // rethrow to report errors correctly (we need to catch it here, + // as we also catch RuntimeException below!): + throw se; + } catch (ReflectiveOperationException | RuntimeException e) { + // *** sun.misc.Cleaner unmapping (Java 8) *** + final Class directBufferClass = + Class.forName("java.nio.DirectByteBuffer"); + + final Method m = directBufferClass.getMethod("cleaner"); + m.setAccessible(true); + final MethodHandle directBufferCleanerMethod = lookup.unreflect(m); + final Class cleanerClass = + directBufferCleanerMethod.type().returnType(); + + /* + * "Compile" a MethodHandle that basically is equivalent + * to the following code: + * + * void unmapper(ByteBuffer byteBuffer) { + * sun.misc.Cleaner cleaner = + * ((java.nio.DirectByteBuffer) byteBuffer).cleaner(); + * if (Objects.nonNull(cleaner)) { + * cleaner.clean(); + * } else { + * // the noop is needed because MethodHandles#guardWithTest + * // always needs ELSE + * noop(cleaner); + * } + * } + */ + final MethodHandle cleanMethod = lookup.findVirtual( + cleanerClass, "clean", methodType(void.class)); + final MethodHandle nonNullTest = lookup.findStatic(Objects.class, + "nonNull", methodType(boolean.class, Object.class)) + .asType(methodType(boolean.class, cleanerClass)); + final MethodHandle noop = dropArguments( + constant(Void.class, null).asType(methodType(void.class)), + 0, cleanerClass); + final MethodHandle unmapper = filterReturnValue( + directBufferCleanerMethod, + guardWithTest(nonNullTest, cleanMethod, noop)) + .asType(methodType(void.class, ByteBuffer.class)); + return newBufferCleaner(directBufferClass, unmapper); + } + } catch (SecurityException se) { + return "Unmapping is not supported, because not all required " + + "permissions are given to the Hadoop JAR file: " + se + + " [Please grant at least the following permissions: " + + "RuntimePermission(\"accessClassInPackage.sun.misc\") " + + " and ReflectPermission(\"suppressAccessChecks\")]"; + } catch (ReflectiveOperationException | RuntimeException e) { + return "Unmapping is not supported on this platform, " + + "because internal Java APIs are not compatible with " + + "this Hadoop version: " + e; + } + } + + private static BufferCleaner newBufferCleaner( + final Class unmappableBufferClass, final MethodHandle unmapper) { + assert Objects.equals( + methodType(void.class, ByteBuffer.class), unmapper.type()); + return buffer -> { + if (!buffer.isDirect()) { + throw new IllegalArgumentException( + "unmapping only works with direct buffers"); + } + if (!unmappableBufferClass.isInstance(buffer)) { + throw new IllegalArgumentException("buffer is not an instance of " + + unmappableBufferClass.getName()); + } + final Throwable error = AccessController.doPrivileged( + (PrivilegedAction) () -> { + try { + unmapper.invokeExact(buffer); + return null; + } catch (Throwable t) { + return t; + } + }); + if (error != null) { + throw new IOException("Unable to unmap the mapped buffer", error); + } + }; + } + + /** + * Pass in an implementation of this interface to cleanup ByteBuffers. + * CleanerUtil implements this to allow unmapping of bytebuffers + * with private Java APIs. + */ + @FunctionalInterface + public interface BufferCleaner { + void freeBuffer(ByteBuffer b) throws IOException; + } +} diff --git a/src/java/org/apache/poi/poifs/nio/FileBackedDataSource.java b/src/java/org/apache/poi/poifs/nio/FileBackedDataSource.java index f9549cf542..ee08de13d7 100644 --- a/src/java/org/apache/poi/poifs/nio/FileBackedDataSource.java +++ b/src/java/org/apache/poi/poifs/nio/FileBackedDataSource.java @@ -17,26 +17,22 @@ package org.apache.poi.poifs.nio; +import org.apache.poi.util.IOUtils; +import org.apache.poi.util.POILogFactory; +import org.apache.poi.util.POILogger; + import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.OutputStream; import java.io.RandomAccessFile; -import java.lang.reflect.Method; import java.nio.ByteBuffer; import java.nio.channels.Channels; import java.nio.channels.FileChannel; import java.nio.channels.WritableByteChannel; -import java.security.AccessController; -import java.security.PrivilegedAction; import java.util.ArrayList; import java.util.List; -import org.apache.poi.util.IOUtils; -import org.apache.poi.util.POILogFactory; -import org.apache.poi.util.POILogger; -import org.apache.poi.util.SuppressForbidden; - /** * A POIFS {@link DataSource} backed by a File */ @@ -171,22 +167,14 @@ public class FileBackedDataSource extends DataSource { return; } - AccessController.doPrivileged(new PrivilegedAction() { - @Override - @SuppressForbidden("Java 9 Jigsaw whitelists access to sun.misc.Cleaner, so setAccessible works") - public Void run() { - try { - final Method getCleanerMethod = buffer.getClass().getMethod("cleaner"); - getCleanerMethod.setAccessible(true); - final Object cleaner = getCleanerMethod.invoke(buffer); - if (cleaner != null) { - cleaner.getClass().getMethod("clean").invoke(cleaner); - } - } catch (Exception e) { - logger.log(POILogger.WARN, "Unable to unmap memory mapped ByteBuffer.", e); - } - return null; // Void + if (CleanerUtil.UNMAP_SUPPORTED) { + try { + CleanerUtil.getCleaner().freeBuffer(buffer); + } catch (IOException e) { + logger.log(POILogger.WARN, "Failed to unmap the buffer", e); } - }); - } + } else { + logger.log(POILogger.DEBUG, CleanerUtil.UNMAP_NOT_SUPPORTED_REASON); + } + } }