Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!pcserver2!kdenning
From: kdenning@pcserver2.naitc.com (Karl Denninger)
Newsgroups: comp.unix.sysv386
Subject: Re: -Xp optionin ISC cc
Summary: Don't even consider using -Xp on ISC 2.2 or 2.2.1
Keywords: startup code in /lib for ISC cc
Message-ID: <1991Apr23.235313.28216@pcserver2.naitc.com>
Date: 23 Apr 91 23:53:13 GMT
References: <1991Apr23.145657.8672@cs.rochester.edu>
Organization: AC Nielsen, Bannockburn IL USA
Lines: 51

In article <1991Apr23.145657.8672@cs.rochester.edu> lubkin@cs.rochester.edu (Saul Lubkin) writes:
>The ISC cc links in some startup code from /lib -- I think crt[01].o
>-- on invocation.  Apparantly, when "-Xp" is used, alternative POSIX
>compliant startup code is used instead -- perhaps crtp[01].o, or 
>something else.
>
>/lib contains crt[01].o, crtn.o, crtp[01].o, mcrt[01].o, mcrtp1.o,
>pcrt[01].o and pcrtp1.o.
>
>Could someone enlighten me as to which of these are linked in when?
>
>This is relevant to my trying to create a useable job control support
>version of bash for ISC 2.2.  I have made a job control bash -- but it
>causes a system panic when vpix is run under it.
>
>				Sincerely,
>
>				Saul Lubkin

The panics aren't surprising to me.

Any application compiled on ISC with '-Xp' is likely to do this.  Trn 
does it.  Others do it.  The problem is with a null pointer dereference 
in the kernel routine "namei()".  There is an "unofficial" fix which was
posted to the net, but I have no idea if it does the "right thing" if it
detects the null dereference (it does stop the panics).

I have reported it.  The word is that it will be fixed in the 2.3 release,
which has no firm release date at this time, or a cost for upgrade.  There
are no current plans for a patch from what I have been told.

The bottom line:
	POSIX anything does not work at all on ISC 2.2.  Don't even bother
	trying; you'll end up like me (had a machine crashing daily for a
	week and a half before I realized that it was posix that had caused
	the troubles).

	It is likely to be months before there is a fix available for this
	problem.  I would (of course) like to see something sooner.

I've backed out all POSIX applications on both my home system and all
ISC machines here at Nielsen.  Panics aren't something that are a lot of 
fun on a system with 1.5GB of disk space (45 minute + reboot times bite).

--
Karl Denninger - AC Nielsen, Bannockburn IL (708) 317-3285
kdenning@nis.naitc.com

"The most dangerous command on any computer is the carriage return."
Disclaimer:  The opinions here are solely mine and may or may not reflect
  	     those of the company.