Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!wuarchive!uunet!ns-mx!umaxc.weeg.uiowa.edu!williams
From: williams@umaxc.weeg.uiowa.edu (Kent Williams)
Newsgroups: comp.binaries.ibm.pc.d
Subject: Re: v09i191: popadbug, test for 386 CPU bug
Summary: Dont Worry, Be Happy
Message-ID: <3799@ns-mx.uiowa.edu>
Date: 5 Jan 91 15:17:09 GMT
References: <336@aplcomm.JHUAPL.EDU> <1991Jan5.000042.19703@cunixf.cc.columbia.edu>
Sender: news@ns-mx.uiowa.edu
Reply-To: williams@umaxc.weeg.uiowa.edu.UUCP (Kent Williams)
Organization: U of Iowa, Iowa City, IA
Lines: 24

The POPAD bug is, I think, documented in the Intel Errata sheets.  As near
as I can tell, some of the register contents are invalid at the instruction
just after a POPAD.  You can insert a NOP, or any kind of branch and you're
OK.

The Intel guys probably missed it because they always did a

		POPAD
		IRET

or
		POPAD
		RET

which works fine.

Take a pill and chill, dudes.  All 386en probably fail the POPAD test,
and it don't matter.


--
             Kent Williams --- williams@umaxc.weeg.uiowa.edu 
"'Is this heaven?' --- 'No, this is Iowa'" - from the movie "Field of Dreams"
"This isn't heaven, ... this is Cleveland" - Harry Allard, in "The Stupids Die"