From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752017AbeAZMgU (ORCPT ); Fri, 26 Jan 2018 07:36:20 -0500 Received: from 8bytes.org ([81.169.241.247]:52810 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751775AbeAZMgS (ORCPT ); Fri, 26 Jan 2018 07:36:18 -0500 Date: Fri, 26 Jan 2018 13:36:16 +0100 From: Joerg Roedel To: Alan Cox Cc: Nadav Amit , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , the arch/x86 maintainers , LKML , "open list:MEMORY MANAGEMENT" , Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , aliguori@amazon.com, daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, Andrea Arcangeli , Waiman Long , jroedel@suse.de Subject: Re: [RFC PATCH 00/16] PTI support for x86-32 Message-ID: <20180126123616.GK28161@8bytes.org> References: <1516120619-1159-1-git-send-email-joro@8bytes.org> <5D89F55C-902A-4464-A64E-7157FF55FAD0@gmail.com> <886C924D-668F-4007-98CA-555DB6279E4F@gmail.com> <9CF1DD34-7C66-4F11-856D-B5E896988E16@gmail.com> <20180122085625.GE28161@8bytes.org> <20180125170925.1d72d587@alans-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180125170925.1d72d587@alans-desktop> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Alan, On Thu, Jan 25, 2018 at 05:09:25PM +0000, Alan Cox wrote: > On Mon, 22 Jan 2018 09:56:25 +0100 > Joerg Roedel wrote: > > > Hey Nadav, > > > > On Sun, Jan 21, 2018 at 03:46:24PM -0800, Nadav Amit wrote: > > > It does seem that segmentation provides sufficient protection from Meltdown. > > > > Thanks for testing this, if this turns out to be true for all affected > > uarchs it would be a great and better way of protection than enabling > > PTI. > > > > But I'd like an official statement from Intel on that one, as their > > recommended fix is still to use PTI. > > It is: we don't think segmentation works on all processors as a defence. Thanks for checking and the official statement. So the official mitigation recommendation is still to use PTI. Regards, Joerg From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id C284F6B0029 for ; Fri, 26 Jan 2018 07:36:23 -0500 (EST) Received: by mail-wm0-f71.google.com with SMTP id j13so250592wmh.3 for ; Fri, 26 Jan 2018 04:36:23 -0800 (PST) Received: from theia.8bytes.org (8bytes.org. [2a01:238:4383:600:38bc:a715:4b6d:a889]) by mx.google.com with ESMTPS id 5si1357509edb.158.2018.01.26.04.36.18 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 26 Jan 2018 04:36:18 -0800 (PST) Date: Fri, 26 Jan 2018 13:36:16 +0100 From: Joerg Roedel Subject: Re: [RFC PATCH 00/16] PTI support for x86-32 Message-ID: <20180126123616.GK28161@8bytes.org> References: <1516120619-1159-1-git-send-email-joro@8bytes.org> <5D89F55C-902A-4464-A64E-7157FF55FAD0@gmail.com> <886C924D-668F-4007-98CA-555DB6279E4F@gmail.com> <9CF1DD34-7C66-4F11-856D-B5E896988E16@gmail.com> <20180122085625.GE28161@8bytes.org> <20180125170925.1d72d587@alans-desktop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180125170925.1d72d587@alans-desktop> Sender: owner-linux-mm@kvack.org List-ID: To: Alan Cox Cc: Nadav Amit , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , the arch/x86 maintainers , LKML , "open list:MEMORY MANAGEMENT" , Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , aliguori@amazon.com, daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, Andrea Arcangeli , Waiman Long , jroedel@suse.de Hi Alan, On Thu, Jan 25, 2018 at 05:09:25PM +0000, Alan Cox wrote: > On Mon, 22 Jan 2018 09:56:25 +0100 > Joerg Roedel wrote: > > > Hey Nadav, > > > > On Sun, Jan 21, 2018 at 03:46:24PM -0800, Nadav Amit wrote: > > > It does seem that segmentation provides sufficient protection from Meltdown. > > > > Thanks for testing this, if this turns out to be true for all affected > > uarchs it would be a great and better way of protection than enabling > > PTI. > > > > But I'd like an official statement from Intel on that one, as their > > recommended fix is still to use PTI. > > It is: we don't think segmentation works on all processors as a defence. Thanks for checking and the official statement. So the official mitigation recommendation is still to use PTI. Regards, Joerg -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org