Path: utzoo!yunexus!geac!daveb
From: daveb@geac.UUCP (David Collier-Brown)
Newsgroups: comp.std.c
Subject: Re: Invalid pointer addresses
Message-ID: <3216@geac.UUCP>
Date: 11 Sep 88 17:12:56 GMT
Article-I.D.: geac.3216
References: <1988Sep9.164419.12461@utzoo.uucp>
Organization: GEAC Computers, Toronto, CANADA
Lines: 19

In article <12088@steinmetz.ge.com> davidsen@crdos1.UUCP (bill davidsen) writes:
|   I recently proofread a manual which stated that even calculating the
| value of an invalid address could cause a memory fault...
 
From article <1988Sep9.164419.12461@utzoo.uucp>, by henry@utzoo.uucp (Henry Spencer):
|  This is correct.  On single-linear-address-space machines, computing an
|  invalid address just generates a meaningless number.   [...]
|  It depends on whether the designers were segment purists or not, and on
|  precisely how they defined the format of an address and the semantics
|  of arithmetic on it.

Minor point: if you underflow one one linear-address-space machine,
you get the "impossible" (too high) address error. 

-dave (manufacturer unnamed to protect the guilty) c-b 
-- 
 David Collier-Brown.  | yunexus!lethe!dave
 78 Hillcrest Ave,.    | He's so smart he's dumb.
 Willowdale, Ontario.  |        --Joyce C-B