[kaffe] verifier patch status

[Dalibor Topic]

Hi Robert,
--- gonzo <Robert.N.Gonzalez at williams.edu> wrote:
> i've finished porting the patch to 1.0.7 (see
>
http://www.kaffe.org/pipermail/kaffe/2001-August/007391.html),
> and am
> pretty sure i've done so correctly (most of the
> files that were patched
> were nearly identical to those in 1.0.6).  however,
> it finds HelloWorld to
> be a malicious program :-D.  so it's more incomplete
> than i had hoped (or 
> i messed up somewhere in the patch update), though
> its inclusion would
> make kaffe *very* secure ;)

Cool. Could you post it to the list  including the
"malicious" HelloWorld.class ? Maybe someone can help.

> i've been thinking about the JIT situation, and
> unless we're willing to  
> pay the overhead of doing some data-flow analysis
> twice (the verifier and
> codeinfo building methods are very similar, which is
> probably why they
> were combined originally) then i'm not sure that the
> API will work out.
> that is, the API would require that a verifier not
> only verifies code but
> returns some information used by our JITs on the
> code.

I believe that currently the interpreter suffers from
the codeinfo generation overhead. ;)

I don't think that a verifier API which  makes
requirements for JIT information is desirable. When
you are doing verifier research you shouldn't have to
know about the innards of the JIT implementation ...

There should also be some numbers on a couple of
platforms for doing two separate verification and
codeinfo steps vs. a single united one before there
can be an informed decision. ;)

> so for now i'm going to concentrate on completing
> the verifier (passes 2
> and 3) in the existing framework.  when it's done
> i'll have a better idea
> of whether we can separate verification and codeinfo
> generation for the
> JIT stuff (which would ideally allow us to plugin
> any verifier we wanted).

Sounds like a good plan to me. Are you using the patch
you ported above, or starting from what's in the CVS
now?

best regards,
dalibor topic

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