From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [v2,PCI] move ICHx GbE NVM write-protection from e1000e to PCI quirk Date: Mon, 17 Nov 2008 12:20:49 -0800 (PST) Message-ID: <20081117.122049.241398620.davem@davemloft.net> References: <4921C8B0.9060301@redhat.com> <20081117.114952.81357471.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: csnook@redhat.com, jeffrey.t.kirsher@intel.com, netdev@vger.kernel.org To: bruce.w.allan@intel.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:41873 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752018AbYKQUUt (ORCPT ); Mon, 17 Nov 2008 15:20:49 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: "Allan, Bruce W" Date: Mon, 17 Nov 2008 12:02:32 -0800 > Well, no, not for every device with an NVRAM; just those LOM parts > in the ICH-based family of products that has an unprotected region of > NVRAM and a not-so-difficult set of steps necessary to corrupt the > NVRAM by taking advantage of that. By leaving the write-protection in > the driver, the NVRAM can still be damaged before the driver loads (as > seen with corruptions from ftrace in 2.6.27) or if the driver is never > loaded. > > Once the NVRAM is write-protected the driver cannot revoke that > protection, only a system reset will do that. The kernel command > line option to disable the write protection is so that if/when a > user needs to change a value in the NVRAM it can still be done. It seems to me the ftrace case could have triggered before PCI even initializes. Why not, therefore, write a very-early-initcall mini-driver that does this instead?