From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755037AbcAHLqd (ORCPT ); Fri, 8 Jan 2016 06:46:33 -0500 Received: from unicorn.mansr.com ([81.2.72.234]:43011 "EHLO unicorn.mansr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755019AbcAHLqb convert rfc822-to-8bit (ORCPT ); Fri, 8 Jan 2016 06:46:31 -0500 From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Borislav Petkov Cc: Thomas Voegtle , Markus Trippelsdorf , linux-kernel@vger.kernel.org Subject: Re: x86/microcode update on systems without INITRD References: <20151119214301.GA318@x4> <20151119215543.GA4926@pd.tnic> <20151119225828.GB4926@pd.tnic> <20151120071920.GA321@x4> <20151120082716.GA4028@pd.tnic> <20160107121841.GB16472@pd.tnic> <20160108105900.GA14673@pd.tnic> <20160108113641.GE14673@pd.tnic> Date: Fri, 08 Jan 2016 11:46:28 +0000 In-Reply-To: <20160108113641.GE14673@pd.tnic> (Borislav Petkov's message of "Fri, 8 Jan 2016 12:36:41 +0100") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Borislav Petkov writes: > On Fri, Jan 08, 2016 at 11:18:51AM +0000, Måns Rullgård wrote: >> Neither "depends on" nor "select" makes sense to me here. The driver >> apparently works without it, > > The driver works without it if you build your microcode into the kernel. > > There are use cases where building microcode into the kernel is *not* a > viable option so we have to support both builtin microcode and microcode > from the initrd. How is an initrd different from a real filesystem as seen by the microcode update driver? >> and simply having BLK_DEV_INITRD enabled doesn't prevent improper >> (according to some people) use of the driver. If updating microcode >> is inherently unsafe when a real disk is mounted, the driver ought >> to detect this and refuse the operation (possibly with an override >> option). > > Huh, what? > > -ENOPARSE. The objection against removing the dependency was that updating microcode "late" isn't safe. I don't see how turning on BLK_DEV_INITRD stops anyone doing those allegedly unsafe updates anyway. -- Måns Rullgård