delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp-workers/2001/12/10/14:29:16

X-Authentication-Warning: delorie.com: mailnull set sender to djgpp-workers-bounces using -f
Date: Mon, 10 Dec 2001 21:26:09 +0200
From: "Eli Zaretskii" <eliz AT is DOT elta DOT co DOT il>
Sender: halo1 AT zahav DOT net DOT il
To: sandmann AT clio DOT rice DOT edu
Message-Id: <3099-Mon10Dec2001212608+0200-eliz@is.elta.co.il>
X-Mailer: emacs 21.1.50 (via feedmail 8 I) and Blat ver 1.8.9
CC: djgpp-workers AT delorie DOT com, acottrel AT ihug DOT com DOT au
In-reply-to: <10112101841.AA17909@clio.rice.edu> (sandmann@clio.rice.edu)
Subject: Re: go32-v2 memory chompage [was: Re: v2.03 refresh ...]
References: <10112101841 DOT AA17909 AT clio DOT rice DOT edu>
Reply-To: djgpp-workers AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: djgpp-workers AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com

> From: sandmann AT clio DOT rice DOT edu (Charles Sandmann)
> Date: Mon, 10 Dec 2001 12:41:06 -0600 (CST)
> 
> go32-v2 allocates dos memory to pass the command line
> v2load allocates dos memory for the environment and command line
> v2load allocates dos memory for the transfer buffer
> 
> (I think this explains the 3 sizes of blocks observed).

Yes.  Sorry, I should have remembered that, as I wrote most of that
stuff.

> Now, we pass the child a stubinfo psp returned from a dos memory block
> allocation... but it doesn't look like a valid DPMI psp selector to me.

So, are you saying that the W2K DPMI host returns a bogus selector
when we allocate DOS memory?  Another W2K bug? ;-)

> We let the child "exit" back to us.  During that exit the child passes 
> this bogus psp to NT as a set psp - what happens?  Then the child may 
> do some operations to NTVDM/DPMI with an invalid psp?

I think the ``exit back to us'' part needs closer scrutiny.  IIRC,
the way  a child program invoked via v2load exits is different from a
normal nesting via dosexec.  Sorry, I forget the details, and don't
have time to look them up, but perhaps the comments in go32-v2.c's
`main' function will help.

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019