From owner-freebsd-bugs Sun Jan 7 01:41:05 1996 Return-Path: owner-bugs Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id BAA00197 for bugs-outgoing; Sun, 7 Jan 1996 01:41:05 -0800 (PST) Received: from ra.dkuug.dk (ra.dkuug.dk [193.88.44.193]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id BAA00178 for ; Sun, 7 Jan 1996 01:40:56 -0800 (PST) Received: from critter.tfs.com ([193.88.44.194]) by ra.dkuug.dk (8.6.12/8.6.12) with ESMTP id KAA06898; Sun, 7 Jan 1996 10:38:53 +0100 Received: from localhost.tfs.com (localhost.tfs.com [127.0.0.1]) by critter.tfs.com (8.6.12/8.6.12) with SMTP id KAA05528; Sun, 7 Jan 1996 10:04:13 +0100 X-Authentication-Warning: critter.tfs.com: Host localhost.tfs.com didn't use HELO protocol To: davidg@Root.COM cc: aagero@aage.aage.priv.no, freebsd-bugs@freefall.freebsd.org Subject: Re: kern/901: busy pages get free'd by vm_page_free In-reply-to: Your message of "Sat, 06 Jan 1996 15:17:45 PST." <199601062317.PAA13971@corbin.Root.COM> Date: Sun, 07 Jan 1996 10:04:12 +0100 Message-ID: <5526.821005452@critter.tfs.com> From: Poul-Henning Kamp Sender: owner-bugs@FreeBSD.ORG Precedence: bulk > I just looked at my own changes and they are considerably different from > Poul-Henning's. The correct solution for this problem I believe is what I've > attached to this message. Basically, if "from" is already page-aligned and is > the base address of the buffer, and if the bp->b_data contains an offset (as > it sometimes does), then the subtraction will be negative and the machine wil l > panic. The solution is to page truncate bp->b_data first before subtracting. Hmm, sounds like you understand this A LOT better than me. pass me the hat. -- Poul-Henning Kamp | phk@FreeBSD.ORG FreeBSD Core-team. http://www.freebsd.org/~phk | phk@login.dknet.dk Private mailbox. whois: [PHK] | phk@ref.tfs.com TRW Financial Systems, Inc. Future will arrive by its own means, progress not so.