Looking for directions about compiling and tracing OpenJDK

[Amos Shapira]

I'd expect to need the source code to make sense from the gdb output, and
maybe also to get the debug symbols.

I thunk I already found at least part of the code path in the source, why
shouldn't I take advantage of this info?

What I wanted to know in my original question is whether anyone in this
forum have been through the process of downloading and compiling this
source code - which file should I download (I found multiple repositories
on the official source web site) and where are useful practical steps to
compile it with debug symbols?

Thanks!

Amos
On Oct 9, 2012 10:41 PM, "Elazar Leibovich" <elazarl at gmail.com> wrote:

> Why do you need the Java source for that? Can't you use gdb, find out the
> the address of the mmap'ed area, and add a watchpoint there (scripted to
> log access and continue).
>
> On Tue, Oct 9, 2012 at 1:06 PM, Amos Shapira <amos.shapira at gmail.com>wrote:
>
>> Thanks to both of you.
>>
>> To give more details of what I'm after - I want to know whether the class
>> bytecode address points into the mmap(2)'ed jar file or into malloc(3)'ed
>> memory. I think I found part of the code path inside the jdk source which
>> does this and now I'm trying to determine what are the situations in which
>> each option is taken.
>> Can JMX do that? The code I'm looking at is written in pure C.
>>
>> Amos
>> On Oct 9, 2012 10:00 PM, "Jonathan Ben Avraham" <yba at tkos.co.il> wrote:
>>
>>> Hi Amos,
>>> I did something like this with the JarSigner code in order to reverse
>>> engineer it in C, which in the end I was able to do. IMHO, gdb is too high
>>> a granularity to get anything usable out of the JVM execution. I suspect
>>> that there is no alternative to sowing System.out.print's throughout the
>>> code.
>>> Regards,
>>>
>>>  - yba
>>>
>>>
>>> On Tue, 9 Oct 2012, Amos Shapira wrote:
>>>
>>>  Date: Tue, 9 Oct 2012 10:57:29 +1100
>>>> From: Amos Shapira <amos.shapira at gmail.com>
>>>> To: linux-il <linux-il at cs.huji.ac.il>
>>>> Subject: Looking for directions about compiling and tracing OpenJDK
>>>>
>>>> Hi,
>>>>
>>>> I have an idea which involves going somewhat deep into the bowls of the
>>>> Java Jar class loader when using the official Oracle JDK 6 (and soon 7).
>>>> To verify this I started looking at the JDK source code but it's not
>>>> small and I'd like to try to trace through it while it executes Java
>>>> programs.
>>>>
>>>> Does anyone here have experience in doing something like this and can
>>>> give me some useful pointers on how to do this?
>>>>
>>>> I'd like to be able to do "gdb java -jar HelloWorld.jar" and
>>>> single-step through the class loader while it loads HelloWorld.jar.
>>>>
>>>> Thanks,
>>>>
>>>> --Amos
>>>>
>>>>
>>>>
>>>>
>>> --
>>>  EE 77 7F 30 4A 64 2E C5  83 5F E7 49 A6 82 29 BA    ~. .~   Tk Open
>>> Systems
>>> =}----------------------------**--------------------ooO--U--**
>>> Ooo------------{=
>>>      - yba at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
>>>
>>
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>>
>
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