Re: Looking for directions about compiling and tracing OpenJDK
Quoting Amos Shapira, from the post of Tue, 09 Oct: 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. My humble opinion - gdb will catch way too much crap. Is it so low in the stack that you can't provision it with JMX and trace it through that? -- Ben and Jerry's love child Ira Abramov http://ira.abramov.org/email/ ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: Looking for directions about compiling and tracing OpenJDK
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.shap...@gmail.com
To: linux-il linux-il@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{=
- y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
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Re: Looking for directions about compiling and tracing OpenJDK
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 y...@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.shap...@gmail.com
To: linux-il linux-il@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{=
- y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
___
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Re: Looking for directions about compiling and tracing OpenJDK
Hi Amos,
Pardon me, what does the class loader have to do with JMX?
- yba
On Tue, 9 Oct 2012, Amos Shapira wrote:
Date: Tue, 9 Oct 2012 22:06:16 +1100
From: Amos Shapira amos.shap...@gmail.com
To: Jonathan Ben Avraham y...@tkos.co.il
Cc: linux-il linux-il@cs.huji.ac.il
Subject: Re: Looking for directions about compiling and tracing OpenJDK
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 y...@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.shap...@gmail.com
To: linux-il linux-il@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{=
- y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
--
EE 77 7F 30 4A 64 2E C5 83 5F E7 49 A6 82 29 BA~. .~ Tk Open Systems
=}ooO--U--Ooo{=
- y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -___
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Re: Looking for directions about compiling and tracing OpenJDK
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.shap...@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 y...@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.shap...@gmail.com
To: linux-il linux-il@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{=
- y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
___
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Re: Looking for directions about compiling and tracing OpenJDK
Quoting Amos Shapira, from the post of Tue, 09 Oct: 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. if that information is exposed to the java objects in the VM, then maybe. otherwise, I guess it's a case of getting your fingers dirty with GDB... -- The secret to happiness Ira Abramov http://ira.abramov.org/email/ ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: Looking for directions about compiling and tracing OpenJDK
I was responding to Ira's suggestion to try to use JMX for that.
On Oct 9, 2012 10:22 PM, Jonathan Ben Avraham y...@tkos.co.il wrote:
Hi Amos,
Pardon me, what does the class loader have to do with JMX?
- yba
On Tue, 9 Oct 2012, Amos Shapira wrote:
Date: Tue, 9 Oct 2012 22:06:16 +1100
From: Amos Shapira amos.shap...@gmail.com
To: Jonathan Ben Avraham y...@tkos.co.il
Cc: linux-il linux-il@cs.huji.ac.il
Subject: Re: Looking for directions about compiling and tracing OpenJDK
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 y...@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.shap...@gmail.com
To: linux-il linux-il@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{=
- y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il-
--
EE 77 7F 30 4A 64 2E C5 83 5F E7 49 A6 82 29 BA~. .~ Tk Open
Systems
=}**ooO--U--**
Ooo{=
- y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
___
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Re: Looking for directions about compiling and tracing OpenJDK
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 elaz...@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.shap...@gmail.comwrote:
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 y...@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.shap...@gmail.com
To: linux-il linux-il@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{=
- y...@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -
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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 ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
