From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751862AbcHLFuR (ORCPT ); Fri, 12 Aug 2016 01:50:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:49090 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750935AbcHLFuP (ORCPT ); Fri, 12 Aug 2016 01:50:15 -0400 Date: Fri, 12 Aug 2016 07:49:13 +0200 From: Borislav Petkov To: Thomas Garnier , "Rafael J . Wysocki" Cc: Len Brown , Pavel Machek , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, keescook@chromium.org, kernel-hardening@lists.openwall.com, jikos@kernel.org, yinghai@kernel.org Subject: Re: [PATCH v1] x86/power/64: Restore processor state before using per-cpu variables Message-ID: <20160812054913.GA24303@nazgul.tnic> References: <1470952169-39061-1-git-send-email-thgarnie@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1470952169-39061-1-git-send-email-thgarnie@google.com> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 11, 2016 at 02:49:29PM -0700, Thomas Garnier wrote: > Restore the processor state before calling any other function to ensure > per-cpu variables can be used with KASLR memory randomization. > > Tracing functions use per-cpu variables (gs based) and one was called > just before restoring the processor state fully. It resulted in a double > fault when both the tracing & the exception handler functions tried to > use a per-cpu variable. > > Signed-off-by: Thomas Garnier > --- > Based on next-20160808 Ok, I believe before I test this, I need to apply another patch from Rafael. I think it is the "Always create temporary identity mapping correctly" thing. Yes, no? Rafael, can you please apply everything on a test branch for us to run? Thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --