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Jdk17 classloader #9

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Merged
Tennessene merged 2 commits into from
Aug 17, 2023
Merged

Jdk17 classloader #9

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6ef85b2
Do not assume ClassLoader concrete type when dynamically loading classes
pietrygamat Aug 13, 2023
ad155b3
Prevent illegal reflective access when dynamically loading classes
pietrygamat Aug 13, 2023
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29 changes: 22 additions & 7 deletions jdosbox/src/main/java/jdos/cpu/core_dynamic/Compiler.java
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Original file line number Diff line number Diff line change
Expand Up @@ -7425,7 +7425,7 @@ public void close() {
static private Op compileMethod(Op op, StringBuilder method, boolean jump) {
//System.out.println(method.toString());
try {
String className = "CacheBlock" + (count++);
String className = "jdos.cpu.core_dynamic.CacheBlock" + (count++);
// :TODO: research using a new pool for each block since the classes don't need to see each other
CtClass codeBlock = pool.makeClass(className);
codeBlock.setSuperclass(pool.getCtClass("jdos.cpu.core_dynamic.Op"));
Expand All @@ -7444,21 +7444,36 @@ static private Op compileMethod(Op op, StringBuilder method, boolean jump) {
if (cycle<1) {
cycle=1;
}
CtConstructor c = CtNewConstructor.make("public "+className+"(){this.cycle="+cycle+";}", codeBlock);
CtConstructor c = CtNewConstructor.make("public "+codeBlock.getSimpleName()+"(){this.cycle="+cycle+";}", codeBlock);
codeBlock.addConstructor(c);

// Make the dynamic class belong to its own class loader so that when we
// release the decoder block the class and class loader will be unloaded
URLClassLoader cl = (URLClassLoader) codeBlock.getClass().getClassLoader();
cl = URLClassLoader.newInstance(cl.getURLs(), cl);
Class clazz = codeBlock.toClass(cl, null);
ClassLoader cl = new URLClassLoader(
new URL[]{ Compiler.class.getProtectionDomain().getCodeSource().getLocation()},
codeBlock.getClass().getClassLoader());

// Create second copy of Compiler class inside custom classloader as "neighbour".
// CtClass.toClass(neighbour) does not cause illegal reflective access in JDK17.
Class clazz = codeBlock.toClass(cl.loadClass(Compiler.class.getName()));
Op compiledCode = (Op) clazz.newInstance();
codeBlock.detach();
if (saveClasses) {
if (op instanceof DecodeBlock) {
DecodeBlock block = (DecodeBlock)op;
String header = "package jdos.cpu.core_dynamic;\n\nimport jdos.cpu.core_dynamic.*;\nimport jdos.cpu.*;\nimport jdos.fpu.*;\nimport jdos.hardware.*;\nimport jdos.util.*;\nimport jdos.cpu.core_normal.*;\nimport jdos.cpu.core_share.*;\n\npublic final class "+className+" extends Op {\npublic int call() {";
Loader.add(codeBlock.getName(), codeBlock.toBytecode(), block.codeStart, getOpCode(block.codeStart, block.codeLen), header+method.toString()+"\n}");
String classBody =
"package " + codeBlock.getPackageName() + ";\n\n" +
"import jdos.cpu.core_dynamic.*;\n" +
"import jdos.cpu.*;\n" +
"import jdos.fpu.*;\n" +
"import jdos.hardware.*;\n" +
"import jdos.util.*;\n" +
"import jdos.cpu.core_normal.*;\n" +
"import jdos.cpu.core_share.*;\n\n" +
"public final class " + codeBlock.getSimpleName() + " extends " + codeBlock.getSuperclass().getName() + " {\n" +
" public int call() { " + method + "} \n" +
"}";
Loader.add(codeBlock.getName(), codeBlock.toBytecode(), block.codeStart, getOpCode(block.codeStart, block.codeLen), classBody);
} else {
Log.exit("Tried to save an incomplete code block");
}
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2 changes: 1 addition & 1 deletion pom.xml
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Expand Up @@ -42,7 +42,7 @@
<dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
<version>3.14.0-GA</version>
<version>3.29.2-GA</version>
</dependency>
<dependency>
<groupId>jnetpcap</groupId>
Expand Down