[HARMONY-4052] [drlvm][classloader] Compatibility: ClassLodert.defineClass() throws ClassFormatError for class with incorrect name only when -Xverify option is set while RI always throws this error

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Component/s: DRLVM
• Environment: Windows and Linux
• Patch Info: Patch Available
• Assignee: Gregory Shimansky
• Reporter: Vera Petrashkova
• Created: 06/Jun/07 05:38
• Updated: 15/Jun/07 14:23
• Resolved: 14/Jun/07 13:28

Description

According to J2SE specification ClassLoader.defineClass(String name, byte[] b, int off, int len) method throws ClassFormatError if the data did not contain a valid class.
When the data contain some class with incorrect class name then DRLVM throws ClassFormatError only if -Xverify option was set.
Otherwise it throws VerifyError when name is not null and LinkageError when name equals null.

RI always throws ClassFormatError when used class contains wrong name.
The following test demonstrates this issue. It uses synthetic class aaa which are placed to the attachment
--------------------a1.java---------------------
import java.io.*;
public class a1 {

public static void main (String[] args) {
byte[] bbb1 = new byte[11];
byte[] bbb2 = new byte[500];
int lastBytes = 0;
String name = "";
String name1 = "";
try {
Class firstCl = Class.forName("aaa");

InputStream is = firstCl.getResourceAsStream("aaa.class");
if (is == null)

{ System.err.println("Can not open InputStream : aaa.class"); return; }

DataInputStream dIn = new DataInputStream(is);
dIn.read(bbb1, 0, 11);
dIn.readUTF();
lastBytes = dIn.read(bbb2, 0, bbb2.length);
dIn.close();
} catch (Throwable e)

{ e.printStackTrace(); System.err.println("Test failed"); return; }

myClassLoader cLoad = new myClassLoader();

try

{ name = "[Zaaabbb"; name1 = name; System.err.println("Use name: "+name1); ByteArrayOutputStream bos = new ByteArrayOutputStream(); DataOutputStream dOut = new DataOutputStream(bos); dOut.write(bbb1, 0, 11); dOut.writeUTF(name); dOut.write(bbb2, 0, lastBytes); dOut.close(); byte[] b1 = bos.toByteArray(); Class cl = cLoad.defineKlass(name, b1, 0, b1.length); System.err.println("Test failed: ClassFormError was not thrown as expected"); }

catch (ClassFormatError e)

{ e.printStackTrace(); System.err.println("Test passed"); } catch (Throwable e) { e.printStackTrace(); System.err.println("Test failed"); }
try { name = "[Zaaabbb"; name1 = null; System.err.println("Use name: "+name1); ByteArrayOutputStream bos = new ByteArrayOutputStream(); DataOutputStream dOut = new DataOutputStream(bos); dOut.write(bbb1, 0, 11); dOut.writeUTF(name); dOut.write(bbb2, 0, lastBytes); dOut.close(); byte[] b1 = bos.toByteArray(); Class cl = cLoad.defineKlass(name, b1, 0, b1.length); System.err.println("Test failed: ClassFormError was not thrown as expected"); } catch (ClassFormatError e) { e.printStackTrace(); System.err.println("Test passed"); }

catch (Throwable e)

{ e.printStackTrace(); System.err.println("Test failed"); }

}
}

class myClassLoader extends ClassLoader {

public Class defineKlass(String name, byte[] ar, int st, int len)

{ return super.defineClass(name, ar, st, len); }

}
--------------------------aaa.ccode-----------------------
magic = xCAFEBABE
minor_version = 3
major_version = 45
constant_pool_count = 12
constant_pool {
/* #1 */ UTF8 = "aaa"
/* #2 */ Class = #3
/* #3 */ UTF8 = "java/lang/Object"
/* #4 */ Class = #1
/* #5 */ UTF8 = "<init>"
/* #6 */ UTF8 = "()V"
/* #7 */ UTF8 = "Code"
/* #8 */ Method = #2 #9
/* #9 */ NameAndType = #5 #6
/* #10 */ UTF8 = "I"
/* #11 */ UTF8 = "testF"
}
access_flags = PUBLIC SUPER
this_class = #4
super_class = #2
interfaces_count = 0
fields_count = 1
fields {
field

{ access_flag = PUBLIC name_index = #11 descriptor_index = #10 attributes_count = 0 }

}
methods_count = 1
methods {
method {
access_flag = PUBLIC
name_index = #5
descriptor_index = #6
attributes_count = 1
attributes {
attribute Code {
attribute_name_index = #7
attribute_length = 17
max_stack = 1
max_locals = 1
code_length = 5
code asm

{ 0: aload_0 1: invokespecial #8 4: return }

exception_table_length = 0
attributes_count = 0
}
}
}
}
attributes_count = 0
----------------------------------------
Run test
java a1
java -Xverify a1

Output on RI:
=============
java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
Java HotSpot(TM) Client VM (build 1.5.0_06-b05, mixed mode)

Use name: [Zaaabbb
java.lang.ClassFormatError: Illegal class name "[Zaaabbb" in class file [Zaaabbb
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at java.lang.ClassLoader.defineClass(ClassLoader.java:465)
at myClassLoader.defineKlass(a1.java:80)
at a1.main(a1.java:41)
Test passed
Use name: null
java.lang.ClassFormatError: Illegal class name "[Zaaabbb" in class file [Zaaabbb
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at java.lang.ClassLoader.defineClass(ClassLoader.java:465)
at myClassLoader.defineKlass(a1.java:80)
at a1.main(a1.java:62)
Test passed

java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
Java HotSpot(TM) Client VM (build 1.5.0_06-b05, mixed mode)

Use name: [Zaaabbb
java.lang.ClassFormatError: Illegal class name "[Zaaabbb" in class file [Zaaabbb
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at java.lang.ClassLoader.defineClass(ClassLoader.java:465)
at myClassLoader.defineKlass(a1.java:80)
at a1.main(a1.java:41)
Test passed
Use name: null
java.lang.ClassFormatError: Illegal class name "[Zaaabbb" in class file [Zaaabbb
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at java.lang.ClassLoader.defineClass(ClassLoader.java:465)
at myClassLoader.defineKlass(a1.java:80)
at a1.main(a1.java:62)
Test passed

Output on DRLVM:
===============
Apache Harmony Launcher : (c) Copyright 1991, 2006 The Apache Software Foundation or its licensors, as applicable.
java version "1.5.0"
pre-alpha : not complete or compatible
svn = r544083, (Jun 4 2007), Windows/ia32/msvc 1310, debug build
http://harmony.apache.org
Use name: [Zaaabbb
java.lang.VerifyError: (class: [Zaaabbb, method: <init>()V) Constructor must be invoked
at java.lang.ClassLoader.defineClass0(ClassLoader.java)
at java.lang.ClassLoader.defineClass(ClassLoader.java:437)
at java.lang.ClassLoader.defineClass(ClassLoader.java:378)
at myClassLoader.defineKlass(a1.java:80)
at a1.main(a1.java:41)
Test failed
Use name: null
java.lang.LinkageError: Illegal attempt to redefine class : [Zaaabbb
at java.lang.ClassLoader.defineClass0(ClassLoader.java)
at java.lang.ClassLoader.defineClass(ClassLoader.java:437)
at java.lang.ClassLoader.defineClass(ClassLoader.java:378)
at myClassLoader.defineKlass(a1.java:80)
at a1.main(a1.java:62)
Test failed

Apache Harmony Launcher : (c) Copyright 1991, 2006 The Apache Software Foundation or its licensors, as applicable.
java version "1.5.0"
pre-alpha : not complete or compatible
svn = r544083, (Jun 4 2007), Windows/ia32/msvc 1310, debug build
http://harmony.apache.org
Use name: [Zaaabbb
java.lang.ClassFormatError: [Zaaabbb: illegal CONSTANT_Class name "[Zaaabbb"
at java.lang.ClassLoader.defineClass0(ClassLoader.java)
at java.lang.ClassLoader.defineClass(ClassLoader.java:437)
at java.lang.ClassLoader.defineClass(ClassLoader.java:378)
at myClassLoader.defineKlass(a1.java:80)
at a1.main(a1.java:41)
Test passed
Use name: null
java.lang.ClassFormatError: [Zaaabbb: illegal CONSTANT_Class name "[Zaaabbb"
at java.lang.ClassLoader.defineClass0(ClassLoader.java)
at java.lang.ClassLoader.defineClass(ClassLoader.java:437)
at java.lang.ClassLoader.defineClass(ClassLoader.java:378)
at myClassLoader.defineKlass(a1.java:80)
at a1.main(a1.java:62)
Test passed

This bug causes the failures of the tests from Stress test suite (https://issues.apache.org/jira/browse/HARMONY-3536)

stress.org.apache.harmony.test.stress.classloader.MixSynchThreads.LargeClassName.testLargeClassName_W1
stress.org.apache.harmony.test.stress.classloader.MixThreads.LargeClassName.testLargeClassName_W2
stress.org.apache.harmony.test.stress.classloader.NotSynchThreads.LargeClassName.testLargeClassName_W1
stress.org.apache.harmony.test.stress.classloader.NotSynchThreads.LargeClassName.testLargeClassName_W2
stress.org.apache.harmony.test.stress.classloader.OneThread.LargeClassName.testLargeClassName_W1
stress.org.apache.harmony.test.stress.classloader.OneThread.LargeClassName.testLargeClassName_W2
stress.org.apache.harmony.test.stress.classloader.SynchThreads.LargeClassName.testLargeClassName_W1
stress.org.apache.harmony.test.stress.classloader.SynchThreads.LargeClassName.testLargeClassName_W2

Issue Links

• blocks: HARMONY-4108 [M2] umbrella task for 98% pass rate of Stress tests - HARMONY-3536; no regression since M1