From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie webb Subject: Re: PROBLEM: tg3 spitting out uninitialized memory Date: Fri, 13 Apr 2007 18:51:40 +0100 Message-ID: <461FC32C.4060309@jwebb.sygneca.com> References: <461D57E9.3000300@jwebb.sygneca.com> <1176410380.11425.5.camel@dell> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Andi Kleen , netdev@vger.kernel.org To: Michael Chan Return-path: Received: from mercury.sygneca.com ([83.142.230.29]:45418 "EHLO mx2.sygneca.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754100AbXDMRvp (ORCPT ); Fri, 13 Apr 2007 13:51:45 -0400 In-Reply-To: <1176410380.11425.5.camel@dell> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Michael Chan wrote: > On Thu, 2007-04-12 at 16:50 +0200, Andi Kleen wrote: >> Jamie webb writes: >> >>> Hi there >>> >>> I have a Dell PE860 with built-in BCM5721, which is reported as >>> working fine with the tg3 driver, however I have been getting sporadic >>> data corruption, mostly evident as SSH MAC errors. >> FWIW i also saw this (data corruption with tg3) occasionally, >> but never repeatable or with a packet dump. >> > My suggestion is to try turning tx checksum off (ethtool -K eth0 tx off) > to see if it makes a difference. I'm not aware of checksum problem on > 5721, but it is worth trying. See if the other end is reporting TCP > checksum errors also. Well, so far so good. I'll let you know if it happens again, but it looks like that's fixed it. Further testing showed that I also had to disable rx checksumming, otherwise I was getting random kernel crashes. Presumably it was not only reading data from random memory locations, but also writing in the wrong place... So, do I understand correctly that this is causing the CPU rather than the NIC to do the checksumming? Is this a reasonable permanent solution? Crashing aside, I'm a little nervous about putting into production a box that might for example randomly decide to serve up its SSL private keys halfway through an email message... Cheers /J