From:	sandmann AT clio DOT rice DOT edu (Charles Sandmann)
Message-Id:	<9608281856.AA04883@clio.rice.edu>
Subject:	Re: Emacs crashes on NT
To:	eliz AT is DOT elta DOT co DOT il (Eli Zaretskii)
Date:	Wed, 28 Aug 1996 13:56:28 -0600 (CDT)
Cc:	djgpp-workers AT delorie DOT com
In-Reply-To:	<Pine.SUN.3.91.960828192327.14804A-100000@is> from "Eli Zaretskii" at Aug 28, 96 07:29:13 pm

> A user wrote to me telling that he cannot run Emacs compiled with DJGPP 
> in a DOS box on NT, because Emacs crashes like this:
> 
> E:\emacs-19.33\bin>emacs
> Exiting due to signal SIGSEGV
> General Protection Fault at eip=000041f7
> eax=000001ff ebx=003abef8 ecx=00000000 edx=000001ff esi=003a00d7 edi=003abf34
> ebp=003a2948 esp=00002942 cs=00c7 ds=00b7 es=00d7 fs=0197 gs=01f7 ss=00b7
> Call frame traceback EIPs:
>   0x000041f7   _syms_of_frame_1+259, line 113 of frame.c
> 
> The above traceback is either bogus or points to the DPMI host instead of 
> Emacs (`syms_of_frame_1' isn't called at all in the dumped Emacs).  He 
> told me temacs crashes in the same way, so it's not something special to 
> the dumped executable either.
> 
> Does somebody know any special problems of DPMI on NT that could cause a 
> crash?  That guy says he could run almost the entire build process on NT 
> (except that temacs crashed, so he couldn't dump), so obviously gcc, Make 
> and the rest of the tools run on NT.

1) NT does not support fat DS or non-move-sbrk.  You need to make sure you
   are using unixy sbrk() and don't use near pointers.
2) The trace above is valid - The DS=ES=SS, which looks like us, and the CS
   is close after it.  ESP is garbage (or maybe on the internal exception 
   handler stack ...)
3) EBX,ESI,EDI,EBP all point to roughly the same area in memory (probably the 
   real stack)

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