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From: Denis Vlasenko <vda@port.imtp.ilyichevsk.odessa.ua>
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To: Horst von Brand <vonbrand@inf.utfsm.cl>,
       Szakacsits Szabolcs <szaka@sienet.hu>
Subject: Re: 2.5.63 accesses below %esp (was: Re: ntfs OOPS (2.5.63))
Date: Fri, 14 Mar 2003 09:14:59 +0200
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On 13 March 2003 23:04, Horst von Brand wrote:
> Szakacsits Szabolcs <szaka@sienet.hu> said:
> > On Wed, 12 Mar 2003, Horst von Brand wrote:
> > > It is _hard_ to do with variable length instructions (CISC,
> > > remember?), the code is designed to be easily decoded forward,
> > > noone executes code going backwards.
> >
> > Of course, it's a bad approach. You start earlier and stop at EIP.
> > Repeat this for max(instruction length) different offsets and you
> > will have the winner. Figure it out from the context after EIP.
>
> By hand, OK. Automatically, no.

Why not? Disassemble from, say, EIP-16 and check whether you
have an instruction starting exactly at EIP. If no, repeat from EIP-15, -14...
You are guaranteed to succeed at EIP-0  ;)
--
vda