From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946184AbbGQIwF (ORCPT ); Fri, 17 Jul 2015 04:52:05 -0400 Received: from mail-wg0-f50.google.com ([74.125.82.50]:34149 "EHLO mail-wg0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1945984AbbGQIwA (ORCPT ); Fri, 17 Jul 2015 04:52:00 -0400 Date: Fri, 17 Jul 2015 10:51:55 +0200 From: Ingo Molnar To: Dave Hansen Cc: linux-kernel@vger.kernel.org, Andy Lutomirski , Borislav Petkov , Fenghua Yu , "H. Peter Anvin" , Linus Torvalds , Oleg Nesterov , Thomas Gleixner , Ross Zwisler Subject: Re: [REGRESSION] 4.2-rc2: early boot memory corruption from FPU rework Message-ID: <20150717085155.GA2332@gmail.com> References: <1430848300-27877-1-git-send-email-mingo@kernel.org> <1430848300-27877-19-git-send-email-mingo@kernel.org> <55A56709.6020201@linux.intel.com> <20150715110726.GA26611@gmail.com> <55A6FC31.5010102@linux.intel.com> <20150717074555.GA31873@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150717074555.GA31873@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar wrote: > > The least we can do is detect that the kernel undersized the buffer and > > disable support for the features that do not fit. A very lightly tested patch > > to do that is attached. I'm not super eager to put that in to an -rc2 kernel > > though. > > Ok, this approach looks good to me as an interim fix. I'll give it a whirl on > older hardware. I agree with you that it needs to be sized dynamically. Hm, so this patch crashed the boot of 2 out of 3 systems that I tried :-/ But it does not really matter, as I think the dynamic allocation is the right fix in any case (your last patch), so this patch should be moot. Thanks, Ingo