Date: Mon, 10 Nov 1997 07:37:17 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: jbryant@tfs.net Cc: plm@xs4all.nl, freebsd-hackers@FreeBSD.ORG Subject: Re: Newest Pentium bug (fatal) Message-ID: <199711100737.AAA10415@usr06.primenet.com> In-Reply-To: <199711100650.AAA07487@argus.tfs.net> from "Jim Bryant" at Nov 10, 97 00:50:40 am
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> LOCK CMPXCHG8B EDX:EAX, ECX:EBX ; crash... pp 25-72 to > ; 25-73 of intel's arch & prog > ; manual for the pentium The same manual states that the CMPXCHG8B asserts a "#LOCK" signal, as does the "#LOCK" command. Also some paging situations, and "XCHG". It looks to me like they took the 486 macrocell, and extended it (easiest way to get binary compatability), and "forgot" the new registers when implementing the "#LOCK" assert test. I can verify that using non-extended registers doesn't crash. As someone else noticed, ther emay also be a cache fetch interaction (page fault was another thing referenced by #LOCK). Clearly, it's self-deadlocking trying to assert #LOCK. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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