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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.micro.68k,net.arch
Subject: Re: 68000 Memory Managment (Bechtolsheim patent) (SUID Patent)
Message-ID: <7181@utzoo.UUCP>
Date: Sat, 4-Oct-86 01:32:02 EDT
Article-I.D.: utzoo.7181
Posted: Sat Oct  4 01:32:02 1986
Date-Received: Sat, 4-Oct-86 01:32:02 EDT
References: <508@elmgate.UUCP> <64@mit-prep.ARPA>, <4794@ukma.uky.csnet>
Organization: U of Toronto Zoology
Lines: 17
Keywords: (SUID Patent)

> hmmmm... I guess the patent office didn't know about JACCT on TOPS-10...
> 
> The first time I hears of the SUID I thought "what a nifty general
> way to do JACCT".  Is there a difference?

The generalization is precisely the invention that justifies the patent.
Any number of systems had magic bits saying "run this as root".  Dennis
was the first one to notice that the facility could be made much more
versatile -- among other things, it could safely be made available to
the ordinary users -- if it meant "run this as the owner of the file"
instead.  This means one can have protected subsystems without each and
every one needing to be trusted with (transient) superuser privileges.
The generalization looks obvious and trivial only after you've been told
about it and gotten used to the idea.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,decvax,pyramid}!utzoo!henry