From:	dcasale AT my-deja DOT com
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: GP fault on a new -- why?
Date:	Thu, 08 Feb 2001 18:40:37 GMT
Organization:	Deja.com
Lines:	60
Message-ID:	<95up73$63a$1@nnrp1.deja.com>
References:	<Pine DOT SUN DOT 3 DOT 91 DOT 1010208102939 DOT 20284Y-100000 AT is>
NNTP-Posting-Host:	199.249.234.30
X-Article-Creation-Date:	Thu Feb 08 18:40:37 2001 GMT
X-Http-User-Agent:	Mozilla/4.0 (compatible; MSIE 5.5; Windows 98)
X-Http-Proxy:	1.1 x67.deja.com:80 (Squid/1.1.22) for client 199.249.234.30
X-MyDeja-Info:	XMYDJUIDdcasale
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp
Reply-To:	djgpp AT delorie DOT com

In article <Pine DOT SUN DOT 3 DOT 91 DOT 1010208102939 DOT 20284Y-100000 AT is>,
  djgpp AT delorie DOT com wrote:
>
> On Wed, 7 Feb 2001 dcasale AT my-deja DOT com wrote:
>
> > Okay, here's all it gives me.  No stack trace or anything.
> >
> > General Protection Fault at eip-3af9d; flags=3046
> > eax=00043406 ebx=000100af ecx=00af00a7 edx=0000001c esi=00af00bf
> > edi=00000000 ebp=0004342c esp=0000227a cs=a7 ds=a7 es=af fs=bf gs=bf
> > ss=33 error=0000
>
> You will see in section 12.2 that this message comes from CWSDPMI.  It
> means you crashed the machine so badly that CWSDPMI aborted itself.

Section 12.2 of the FAQ only referred to CWSDPMI in connection with a
_Page Fault_.  This was a _General Protection Fault_.  If the FAQ
doesn't specifically say that General Protection Faults can also come
from CWSDPMI, how am I supposed to know?

> > I don't know if this'll be any help, tho...
>
> It's of _great_ help.
>
> The code which crashes is at 0x3af9d.  Can you see what's there?  One
> way is to load the program into GDB, then type "list *0x3af9d".  You
> should see the listing of several source lines around the point where
> it crashes.  If "list" doesn't work, try "disassemble 0x3af9d", which
> should at least say inside what function did it happen.

I disassembled it, and it says it's from __djgpp_exception_table.
Specifically, it's crashing on the following line (excerpted from
src/libc/go32/excepn.S):

exception_handler:
	pushl	%ebx
	pushl	%ds
   	.byte	0x2e				/* CS: */
	cmpb	$0, forced
	je	not_forced
	call	limitFix
   	.byte	0x2e				/* CS: */
	movzbl	forced,%ebx
	movl	%ebx,8(%esp)			/* replace EXCEPNO */
not_forced:
	movw	%cs:___djgpp_our_DS, %ds
	movl	$0x10000, forced  <-----	/* its zero now, flag
inuse */
	movl	$exception_state, %ebx

I still have no idea what this means.  I'm guessing that it crashed
while trying to throw an exception, but that doesn't tell me what I
need to do to fix the problem.  *shrugs*

Damon Casale, damon AT WRONG DOT redshift DOT com (remove the obvious)
"Number five alive!  No disassemble." -- Number 5, "Short Circuit"


Sent via Deja.com
http://www.deja.com/

- Raw text -