Preload classes before calling native OnLoad function to prevent clas… (#11215)

Motivation:

It turns out it is quite easy to cause a classloader deadlock in more recent java updates if you cause classloading while you are in native code. Because of this we should just workaround this issue by pre-load all the classes that needs to be accessed in the OnLoad function.

Modifications:

- Preload all classes that would otherwise be loaded by native OnLoad functions.

Result:

Workaround for https://github.com/netty/netty/issues/11209 and https://bugs.openjdk.java.net/browse/JDK-8266310
This commit is contained in:
Norman Maurer 2021-05-03 10:22:22 +02:00
parent 467dc29442
commit 968dfbb378
17 changed files with 135 additions and 0 deletions

View File

@ -0,0 +1,48 @@
/*
* Copyright 2021 The Netty Project
*
* The Netty Project 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:
*
* https://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 io.netty.util.internal;
/**
* Utility which ensures that classes are loaded by the {@link ClassLoader}.
*/
public final class ClassInitializerUtil {
private ClassInitializerUtil() { }
/**
* Preload the given classes and so ensure the {@link ClassLoader} has these loaded after this method call.
*
* @param loadingClass the {@link Class} that wants to load the classes.
* @param classes the classes to load.
*/
public static void tryLoadClasses(Class<?> loadingClass, Class<?>... classes) {
ClassLoader loader = PlatformDependent.getClassLoader(loadingClass);
for (Class<?> clazz: classes) {
tryLoadClass(loader, clazz.getName());
}
}
private static void tryLoadClass(ClassLoader classLoader, String className) {
try {
// Load the class and also ensure we init it which means its linked etc.
Class.forName(className, true, classLoader);
} catch (ClassNotFoundException ignore) {
// Ignore
} catch (SecurityException ignore) {
// Ignore
}
}
}

View File

@ -162,6 +162,8 @@ static void netty_resolver_dns_native_macos_JNI_OnUnLoad(JNIEnv* env) {
}
}
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// MacOSDnsServerAddressStreamProvider to reflect that.
static jint netty_resolver_dns_native_macos_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
int ret = JNI_ERR;
int providerRegistered = 0;

View File

@ -19,6 +19,7 @@ import io.netty.resolver.dns.DnsServerAddressStream;
import io.netty.resolver.dns.DnsServerAddressStreamProvider;
import io.netty.resolver.dns.DnsServerAddressStreamProviders;
import io.netty.resolver.dns.DnsServerAddresses;
import io.netty.util.internal.ClassInitializerUtil;
import io.netty.util.internal.NativeLibraryLoader;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.StringUtil;
@ -51,6 +52,16 @@ public final class MacOSDnsServerAddressStreamProvider implements DnsServerAddre
private static final long REFRESH_INTERVAL = TimeUnit.SECONDS.toNanos(10);
static {
// Preload all classes that will be used in the OnLoad(...) function of JNI to eliminate the possiblity of a
// class-loader deadlock. This is a workaround for https://github.com/netty/netty/issues/11209.
// This needs to match all the classes that are loaded via NETTY_JNI_UTIL_LOAD_CLASS or looked up via
// NETTY_JNI_UTIL_FIND_CLASS.
ClassInitializerUtil.tryLoadClasses(MacOSDnsServerAddressStreamProvider.class,
// netty_resolver_dns_macos
byte[].class, String.class
);
Throwable cause = null;
try {
loadNativeLibrary();

View File

@ -746,6 +746,8 @@ error:
// JNI Method Registration Table End
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Native to reflect that.
jint netty_epoll_linuxsocket_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
int ret = JNI_ERR;
char* nettyClassName = NULL;

View File

@ -699,6 +699,8 @@ error:
// JNI Method Registration Table End
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Native to reflect that.
static jint netty_epoll_native_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
int ret = JNI_ERR;
int staticallyRegistered = 0;

View File

@ -15,9 +15,12 @@
*/
package io.netty.channel.epoll;
import io.netty.channel.DefaultFileRegion;
import io.netty.channel.unix.FileDescriptor;
import io.netty.channel.unix.PeerCredentials;
import io.netty.channel.unix.Socket;
import io.netty.channel.unix.Unix;
import io.netty.util.internal.ClassInitializerUtil;
import io.netty.util.internal.NativeLibraryLoader;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.SystemPropertyUtil;
@ -26,6 +29,7 @@ import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.io.IOException;
import java.nio.channels.FileChannel;
import java.nio.channels.Selector;
import java.util.Locale;
@ -61,6 +65,19 @@ public final class Native {
} catch (IOException ignore) {
// Just ignore
}
// Preload all classes that will be used in the OnLoad(...) function of JNI to eliminate the possiblity of a
// class-loader deadlock. This is a workaround for https://github.com/netty/netty/issues/11209.
// This needs to match all the classes that are loaded via NETTY_JNI_UTIL_LOAD_CLASS or looked up via
// NETTY_JNI_UTIL_FIND_CLASS.
ClassInitializerUtil.tryLoadClasses(Native.class,
// netty_epoll_linuxsocket
PeerCredentials.class, DefaultFileRegion.class, FileChannel.class, java.io.FileDescriptor.class,
// netty_epoll_native
NativeDatagramPacketArray.NativeDatagramPacket.class
);
try {
// First, try calling a side-effect free JNI method to see if the library was already
// loaded by the application.

View File

@ -238,6 +238,8 @@ error:
// JNI Method Registration Table End
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Native to reflect that.
jint netty_kqueue_bsdsocket_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
int ret = JNI_ERR;
char* nettyClassName = NULL;

View File

@ -38,6 +38,8 @@ static const jint fixed_method_table_size = sizeof(fixed_method_table) / sizeof(
// JNI Method Registration Table End
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Native to reflect that.
jint netty_kqueue_eventarray_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
if (netty_jni_util_register_natives(env,
packagePrefix,

View File

@ -281,6 +281,8 @@ static const JNINativeMethod fixed_method_table[] = {
static const jint fixed_method_table_size = sizeof(fixed_method_table) / sizeof(fixed_method_table[0]);
// JNI Method Registration Table End
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Native to reflect that.
static jint netty_kqueue_native_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
int staticallyRegistered = 0;
int nativeRegistered = 0;

View File

@ -15,8 +15,11 @@
*/
package io.netty.channel.kqueue;
import io.netty.channel.DefaultFileRegion;
import io.netty.channel.unix.FileDescriptor;
import io.netty.channel.unix.PeerCredentials;
import io.netty.channel.unix.Unix;
import io.netty.util.internal.ClassInitializerUtil;
import io.netty.util.internal.NativeLibraryLoader;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.SystemPropertyUtil;
@ -25,6 +28,7 @@ import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.io.IOException;
import java.nio.channels.FileChannel;
import java.util.Locale;
import static io.netty.channel.kqueue.KQueueStaticallyReferencedJniMethods.evAdd;
@ -51,6 +55,16 @@ final class Native {
private static final InternalLogger logger = InternalLoggerFactory.getInstance(Native.class);
static {
// Preload all classes that will be used in the OnLoad(...) function of JNI to eliminate the possiblity of a
// class-loader deadlock. This is a workaround for https://github.com/netty/netty/issues/11209.
// This needs to match all the classes that are loaded via NETTY_JNI_UTIL_LOAD_CLASS or looked up via
// NETTY_JNI_UTIL_FIND_CLASS.
ClassInitializerUtil.tryLoadClasses(Native.class,
// netty_kqueue_bsdsocket
PeerCredentials.class, DefaultFileRegion.class, FileChannel.class, java.io.FileDescriptor.class
);
try {
// First, try calling a side-effect free JNI method to see if the library was already
// loaded by the application.

View File

@ -22,6 +22,8 @@
#include "netty_unix_socket.h"
#include "netty_unix_util.h"
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Unix to reflect that.
jint netty_unix_register(JNIEnv* env, const char* packagePrefix) {
int limitsOnLoadCalled = 0;
int errorsOnLoadCalled = 0;

View File

@ -39,6 +39,8 @@ static const JNINativeMethod statically_referenced_fixed_method_table[] = {
static const jint statically_referenced_fixed_method_table_size = sizeof(statically_referenced_fixed_method_table) / sizeof(statically_referenced_fixed_method_table[0]);
// JNI Method Registration Table End
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Unix to reflect that.
jint netty_unix_buffer_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
// We must register the statically referenced methods first!
if (netty_jni_util_register_natives(env,

View File

@ -212,6 +212,8 @@ static const JNINativeMethod statically_referenced_fixed_method_table[] = {
static const jint statically_referenced_fixed_method_table_size = sizeof(statically_referenced_fixed_method_table) / sizeof(statically_referenced_fixed_method_table[0]);
// JNI Method Registration Table End
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Unix to reflect that.
jint netty_unix_errors_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
char* nettyClassName = NULL;
// We must register the statically referenced methods first!

View File

@ -278,6 +278,8 @@ static const JNINativeMethod method_table[] = {
static const jint method_table_size = sizeof(method_table) / sizeof(method_table[0]);
// JNI Method Registration Table End
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Unix to reflect that.
jint netty_unix_filedescriptor_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
int ret = JNI_ERR;
void* mem = NULL;

View File

@ -69,6 +69,8 @@ static const JNINativeMethod statically_referenced_fixed_method_table[] = {
static const jint statically_referenced_fixed_method_table_size = sizeof(statically_referenced_fixed_method_table) / sizeof(statically_referenced_fixed_method_table[0]);
// JNI Method Registration Table End
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Unix to reflect that.
jint netty_unix_limits_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
// We must register the statically referenced methods first!
if (netty_jni_util_register_natives(env,

View File

@ -1011,6 +1011,8 @@ error:
// JNI Method Registration Table End
// IMPORTANT: If you add any NETTY_JNI_UTIL_LOAD_CLASS or NETTY_JNI_UTIL_FIND_CLASS calls you also need to update
// Unix to reflect that.
jint netty_unix_socket_JNI_OnLoad(JNIEnv* env, const char* packagePrefix) {
int ret = JNI_ERR;
char* nettyClassName = NULL;

View File

@ -15,8 +15,13 @@
*/
package io.netty.channel.unix;
import io.netty.util.internal.ClassInitializerUtil;
import io.netty.util.internal.UnstableApi;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.PortUnreachableException;
import java.nio.channels.ClosedChannelException;
import java.util.concurrent.atomic.AtomicBoolean;
/**
@ -26,6 +31,22 @@ import java.util.concurrent.atomic.AtomicBoolean;
public final class Unix {
private static final AtomicBoolean registered = new AtomicBoolean();
static {
// Preload all classes that will be used in the OnLoad(...) function of JNI to eliminate the possiblity of a
// class-loader deadlock. This is a workaround for https://github.com/netty/netty/issues/11209.
// This needs to match all the classes that are loaded via NETTY_JNI_UTIL_LOAD_CLASS or looked up via
// NETTY_JNI_UTIL_FIND_CLASS.
ClassInitializerUtil.tryLoadClasses(Unix.class,
// netty_unix_errors
OutOfMemoryError.class, RuntimeException.class, ClosedChannelException.class,
IOException.class, PortUnreachableException.class,
// netty_unix_socket
DatagramSocketAddress.class, InetSocketAddress.class
);
}
/**
* Internal method... Should never be called from the user.
*