Xref: utzoo comp.unix.wizards:15193 comp.bugs.sys5:818
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn )
Newsgroups: comp.unix.wizards,comp.bugs.sys5
Subject: Re: setuid (euid) after setuid (uid) on System 5
Message-ID: <9915@smoke.BRL.MIL>
Date: 24 Mar 89 14:45:30 GMT
References: <123@cat.Fulcrum.BT.CO.UK> <280@cbnewsc.ATT.COM> <1196@auspex.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 9

In article <1196@auspex.UUCP> guy@auspex.UUCP (Guy Harris) writes:
>Both BSD and S5 flavors of "setuid" can be implemented atop "setreuid".

I don't think the "saved set-UID" feature can be emulated using setreuid().
Ron Natalie and I looked into this a few years ago and decided that a
simple semantic extension to setreuid() could be made that would enable
full emulation of saved set-UID, and that our extension would not cause
any new security holes.  However, we never got around to it and I have
since forgotten the details.  Maybe for 4.4BSD?