Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!comp.vuw.ac.nz!virtue!ccc_ldo
From: ccc_ldo@waikato.ac.nz (Lawrence D'Oliveiro, Waikato University)
Newsgroups: comp.sys.mac.system
Subject: Re: Protected-mode snake oil
Message-ID: <1252.26cbdffa@waikato.ac.nz>
Date: 17 Aug 90 00:15:54 GMT
References: <1210.26c694ed@waikato.ac.nz> <BARNETT.90Aug13093544@grymoire.crd.ge.com> <8099@jarthur.Claremont.EDU> <1990Aug14.010751.20050@NCoast.ORG>
Followup-To: comp.sys.mac.system
Organization: University of Waikato, Hamilton, New Zealand
Lines: 22

In <1990Aug14.010751.20050@NCoast.ORG>, allbery@NCoast.ORG (Brandon S.
Allbery KB8JRR/KT) says, in response to a comment by
wilkins@jarthur.Claremont.EDU (Mark Wilkins):

"The point *he* [i e I] was making is that all of this is done with
USER-mode code and therefore can't crash the system...."

Mark has got it right, and Brandon hasn't. My point was that,
whether these things are done in user-mode code or not, they can
still make the system unusable. A hook that allows replacement of the
system text-drawing routines can, if misused, turn much of the display
into garbage; a screen-saver hook can be used to destroy the display
completely. And so on.

Whether such behaviour is technically a "crash" or not is
irrelevant. The end result to the user is pretty much the same.

Lawrence D'Oliveiro                       fone: +64-71-562-889
Computer Services Dept                     fax: +64-71-384-066
University of Waikato            electric mail: ldo@waikato.ac.nz
Hamilton, New Zealand    37^ 47' 26" S, 175^ 19' 7" E, GMT+12:00
"Are you calling me a lawyer?"