Xref: utzoo comp.unix.microport:3016 comp.unix.questions:12391
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!ucsd!rutgers!cmcl2!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn )
Newsgroups: comp.unix.microport,comp.unix.questions
Subject: Re: C bug causes double fault
Message-ID: <9910@smoke.BRL.MIL>
Date: 23 Mar 89 15:53:51 GMT
References: <244@tree.UUCP> <9884@smoke.BRL.MIL> <27245@cci632.UUCP> <9900@smoke.BRL.MIL> <660@micropen>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 15

In article <660@micropen> dave@micropen (David F. Carlson) writes:
>Begging your pardon, but although the 80286 has an odd segmented scheme for
>memory management, it is not non-protected when running Unix SV ...

I stand corrected.  I had been informed (apparently erroneously) that
the PC/AT did not have a hardware memory management unit.  I steer
clear of the whole IBM PC family myself..

>The truth is that Microport early versions had the potential to corrupt the
>kernel stack on floating point exceptions, which is what this should be.
>This was supposedly fixed several versions ago and I never had saw this again.

Someone else informed me the same, except they neglected to mention that
the problem had been fixed.  Apparently there are at least three forms of
floating-point processors, plus software emulation, available for such PCs.