[Bug 134] New: Segmentation fault when debugging SableVM with Valgrind

http://sablevm.org/bugs/show_bug.cgi?id=134

           Summary: Segmentation fault when debugging SableVM with Valgrind
           Product: SableVM
           Version: 1.11[.x]
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: default
        AssignedTo: [email protected]
        ReportedBy: [email protected]
         QAContact: [email protected]


Hi all, 

While developping an application, I used some memory debuggers (Valgrind and
Electric Fence) to do some investigation about a weird behaviour. My application
is a Java application (Bridge.java) that launches another application
(Hello.java) via reflection. This happens with versions 1.11.3 and 1.11.3-1 of
SableVM.

The normal output of my program is "Nizar found a bug". When I run Valgrind on
SableVM, I get the following output:
==3904== Memcheck, a memory error detector for x86-linux.
==3904== Copyright (C) 2002-2004, and GNU GPL'd, by Julian Seward et al.
==3904== Using valgrind-2.2.0, a program supervision framework for x86-linux.
==3904== Copyright (C) 2000-2004, and GNU GPL'd, by Julian Seward et al.
==3904== For more details, rerun with: -v
==3904== 
==3904== Thread 2:
==3904== Use of uninitialised value of size 4
==3904==    at 0x1B91573D: _svmh_resuming_java (thread.c:1075)
==3904==    by 0x1B9A9969: Java_java_lang_VMThread_currentThread
(java_lang_VMThread.c:216)
==3904==    by 0x1BB587FA: ffi_call_SYSV (in /usr/lib/libffi.so.2.0.0)
==3904==    by 0x1BB58486: ffi_call (in /usr/lib/libffi.so.2.0.0)
==3904== 
==3904== Thread 2:
==3904== Invalid read of size 4
==3904==    at 0x1B91573D: _svmh_resuming_java (thread.c:1075)
==3904==    by 0x1B9A9969: Java_java_lang_VMThread_currentThread
(java_lang_VMThread.c:216)
==3904==    by 0x1BB587FA: ffi_call_SYSV (in /usr/lib/libffi.so.2.0.0)
==3904==    by 0x1BB58486: ffi_call (in /usr/lib/libffi.so.2.0.0)
==3904==  Address 0x8ACC5004 is not stack'd, malloc'd or (recently) free'd
==3904== 
==3904== Process terminating with default action of signal 11 (SIGSEGV)
==3904==    at 0x1B91573D: _svmh_resuming_java (thread.c:1075)
==3904==    by 0x1B9A9969: Java_java_lang_VMThread_currentThread
(java_lang_VMThread.c:216)
==3904==    by 0x1BB587FA: ffi_call_SYSV (in /usr/lib/libffi.so.2.0.0)
==3904==    by 0x1BB58486: ffi_call (in /usr/lib/libffi.so.2.0.0)
==3904== 
==3904== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 33 from 1)
==3904== malloc/free: in use at exit: 20827577 bytes in 8600 blocks.
==3904== malloc/free: 23615 allocs, 15015 frees, 22123764 bytes allocated.
==3904== For a detailed leak analysis,  rerun with: --leak-check=yes
==3904== For counts of detected errors, rerun with: -v
/export/nobackup/localhost/nizar/svm/lib/sablevm/bin/java: line 260:  3904
Segmentation fault      valgrind $JVM $VER $OPTS $REST $MAIN "$@"
Error: unable to execute /export/nobackup/localhost/nizar/svm/bin/sablevm.

I can force it to dump a core file and its backtrace is:
(gdb) bt
#0  0x1b91573d in _svmh_resuming_java (env=0x0) at thread.c:1075
#1  0x00000000 in ?? ()

This is obtained while compiling sableVM with --enable-debugging-features. The
default compilation returns the same output plus a large amount of other errors
(certainly due to the use of signals). I enclosed my source code to allow you to
reproduce the bug. Compile and run it with: 
 valgrind sablevm -Y Bridge
Or simply replace the following line in the java wrapper (i.e.
{JAVA-HOME}/bin/java-sablevm):
 exec $JVM $VER $OPTS $REST $MAIN "$@"
with: 
 valgrind $JVM $VER $OPTS $REST $MAIN "$@"

First, I was not sure wether the problem was from Valgrind or SableVM, so i ran
the same example with another JVM and it worked fine. Unfortunately, I do not
have enough time to go further on this bug...

Thanks,

Nizar

/*
***********************
* Bridge.java
***********************
*/

import java.lang.reflect.*;

class Hello2 extends Thread {

	private Class mainClass;
	private String className;
	private Method mainMethod;
	private String[] parameters;
	private Class[] parameterTypes;
	private Object[] parameterList;

	public Hello2(String className, String[] parameters) {
		this.className = className;
		this.parameters = parameters;
		this.parameterTypes = new Class[1];
		this.parameterList = new Object[1];
		this.parameterList[0] = parameters;
	}

	boolean setup() {

		/* get the class whose name has been passed in parameters */
		try {
			mainClass = Class.forName(this.className);
		} catch (Exception e) {
			System.out.println("Error: exception thrown during class access!");
			return false;
		}

		/* get the passed parameters type */
		this.parameterTypes[0] = this.parameters.getClass();

		/* get the main */
		try {
			mainMethod = mainClass.getMethod("main", parameterTypes);
		} catch (Exception e) {
			System.out.println("Error: exception thrown during method access!");
			return false;
		}
		return true;
	}

	public void run() {
		/* call the main method */
		/* as main is static, one can invoke it from the Class not the instance */

		try {
			mainMethod.invoke(null, this.parameterList);
		} catch (Exception e) {
			System.out.println("Error: exception thrown running method !" + e);
			System.exit(0);
		}
	}
}

public class Bridge {
	static Hello2 helper;

	/* main */
	public static void main(String[] args) {
		Bridge bridge = new Bridge();
		String start;

		start = "Hello";
		//System.out.println("start " + start);

		//System.out.println("JAVA : helper creation");
		helper = new Hello2(start, args);

		//System.out.println("JAVA : helper setup");
		if (helper.setup() == false) {
			System.out.println("Error: an error occured during class setup!");
			System.exit(0);
		}

		//System.out.println("JAVA : helper start");
		helper.start();
	}
}


/*
***********************
* Hello.java
***********************
*/

public class Hello {

	public static void main(String[] args) {
		System.out.println ("Nizar found a bug");
	}
}



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