debugging a core dump generated from Java with JNI

debugging a core dump generated from Java with JNI

[John Que]

Hello,
I am developing a java application which calls a procedure in "C"
using JNI.

It is developed on a Linux RedHat 9 x86 intel box.
Sometimes this procedure crashes and a coredeump (core.pid) file is created.
So I wanted to know how to debug it; So i changed that "c" method so the 
only thing
it does now is call abort() so it will make a core dump.

I had build my c code with -g flag.

When I opened gdb like thus:

gdb /usr/java/usr/java/j2sdk1.4.2_06/bin/java core.pid

and performedc bt I did not see source code;
So I upgraded to latest version of gdb (6.3) and tried again.

what I see is :

Core was generated by `/opt/JBuilderX/jdk1.4/bin/java -classpath 
/work/dev/transcode/release:/opt/JBui'.
Program terminated with signal 6, Aborted.
#0  0x400a9671 in ?? ()
Setting up the environment for debugging gdb.
Function "internal_error" not defined.
Function "info_command" not defined.
No breakpoint number 0.
(gdb)
(gdb)
(gdb)
(gdb)
(gdb) bt
#0  0x400a9671 in ?? ()
#1  0x40035afd in ?? ()
#2  0x0000426e in ?? ()
#3  0x00000006 in ?? ()
#4  0x00000001 in ?? ()
#5  0x4003c378 in ?? ()
#6  0x00000006 in ?? ()
#7  0x4d34ceb0 in ?? ()
#8  0x4d34cd2c in ?? ()
#9  0x40035e9b in ?? ()
#10 0x0002c00c in ?? ()
#11 0x00000006 in ?? ()
#12 0x00000001 in ?? ()
#13 0x00000000 in ?? ()
#14 0x401b6980 in ?? ()
#15 0x00000006 in ?? ()
#16 0x4d34cd4c in ?? ()
#17 0x400a9414 in ?? ()
#18 0x00000006 in ?? ()
#19 0x4d34ceb0 in ?? ()
#20 0x4d34cd4c in ?? ()
#21 0x40033f25 in ?? ()
#22 0x401b6980 in ?? ()
---Type <return> to continue, or q <return> to quit---q
Quit
(gdb)


Why am I not seeing source code so I can know where it occured ?
what should I do in order to see the source code in a debug session with gdb
and a crasg from java program running jni?

Regads,
John Q.

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Re: debugging a core dump generated from Java with JNI

[Daniel Jacobowitz]

On Wed, Feb 23, 2005 at 06:55:15PM +0200, John Que wrote:
> Hello,
> I am developing a java application which calls a procedure in "C"
> using JNI.
> 
> It is developed on a Linux RedHat 9 x86 intel box.
> Sometimes this procedure crashes and a coredeump (core.pid) file is created.
> So I wanted to know how to debug it; So i changed that "c" method so the 
> only thing
> it does now is call abort() so it will make a core dump.
> 
> I had build my c code with -g flag.
> 
> When I opened gdb like thus:
> 
> gdb /usr/java/usr/java/j2sdk1.4.2_06/bin/java core.pid

Sorry, but it looks like the JDK loads objects in a way that GDB
doesn't understand.  You'd have to use a debugger that supported the
Sun JDK to debug this.

-- 
Daniel Jacobowitz
CodeSourcery, LLC