From owner-freebsd-stable Fri Mar 2 15:35:56 2001 Delivered-To: freebsd-stable@freebsd.org Received: from earth.backplane.com (earth-nat-cw.backplane.com [208.161.114.67]) by hub.freebsd.org (Postfix) with ESMTP id C7DB337B71B for ; Fri, 2 Mar 2001 15:35:50 -0800 (PST) (envelope-from dillon@earth.backplane.com) Received: (from dillon@localhost) by earth.backplane.com (8.11.2/8.9.3) id f22NX7H10972; Fri, 2 Mar 2001 15:33:07 -0800 (PST) (envelope-from dillon) Date: Fri, 2 Mar 2001 15:33:07 -0800 (PST) From: Matt Dillon Message-Id: <200103022333.f22NX7H10972@earth.backplane.com> To: Jonathan Lemon Cc: Mike Tancsa , Bosko Milekic , stable@FreeBSD.ORG, jlemon@flugsvamp.com, phk@critter.freebsd.dk Subject: Re: Continued panics on a recent STABLE machine References: <01a101c0a1ea$77a64b20$becbca18@jehovah> <4.2.2.20010228114855.03d28be0@marble.sentex.net> <4.2.2.20010301151110.01de4650@marble.sentex.net> <200103022307.f22N76Z10552@earth.backplane.com> <20010302171910.J25974@prism.flugsvamp.com> Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :That being said, my suspicion is that something is writing one word :past the end of the (physically contigious) previous mbuf. This would :be caused by something screwing up a length calculation in the kernel, :or if a network driver just happened to DMA in a bit of extra garbage :at the end of a network packet. : :To test this theory, I'm using the following patch to leave a bit of :unused space at the end of the mbuf. So far, the site that was having :problems hasn't crashed yet, but the jury is still out. :-- :Jonathan Ok. A real test of this suspicion would be to augment your patch to zero out the pad area and then panic if it detects non-zero data there. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message