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From: "Dave Korn" <dave DOT korn AT artimi DOT com>
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Subject: RE: Bug: C-prog from Win dies in fork; gdb.exe also won't run
Date: Wed, 12 Mar 2008 17:06:20 -0000
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Corinna Vinschen wrote on 12 March 2008 16:23:

> On Mar 12 16:13, Dave Korn wrote:
> > Brian Dessent wrote on 12 March 2008 15:59:
> > > Dave Korn wrote:
> > > >   Now, who supposes you could work around the restriction by writing
> > > > 
> > > >   * (WORD *) 0x004000dc = POSIX_CUI;
> > > > 
> > > > just before calling NtSetInformation?
> > > 
> > > How are you going to fool the executive by poking around in the PE
> > > header from userspace long after the process has initialized?  The
> > > executive fundamentally knows which subsystem any given process is
> > > running in because it created it and manages the low level process
> > > table.
> > 
> >   This is not just any code - this is MS code.
> > 
> >   Given that, it's therefore going to have been done as quickly and
> > cheaply as possible, so why should we assume they wouldn't they just
> > check the value in the PE header at the start of
> > NtSetInformationProcess? 
> 
> Is that just an assumption or do you know that this would work?

  It's neither.  It's a question, which I raise on the basis of an educated
guess about what is possible.  I don't have Vista or I'd already have
reversed the ker^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H written a test program to
see if it works or not.

    cheers,
      DaveK
-- 
Can't think of a witty .sigline today....


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