From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f71.google.com (mail-lf0-f71.google.com [209.85.215.71]) by kanga.kvack.org (Postfix) with ESMTP id 7152D6B0253 for ; Sat, 16 Jul 2016 05:16:48 -0400 (EDT) Received: by mail-lf0-f71.google.com with SMTP id p41so86903298lfi.0 for ; Sat, 16 Jul 2016 02:16:48 -0700 (PDT) Received: from 1wt.eu (wtarreau.pck.nerim.net. [62.212.114.60]) by mx.google.com with ESMTP id i83si2439436wma.27.2016.07.16.02.16.46 for ; Sat, 16 Jul 2016 02:16:46 -0700 (PDT) Date: Sat, 16 Jul 2016 11:15:43 +0200 From: Willy Tarreau Subject: Re: [PATCH 3.10.y 04/12] x86/mm: Add barriers and document switch_mm()-vs-flush synchronization Message-ID: <20160716091543.GA22375@1wt.eu> References: <1468607194-3879-1-git-send-email-ciwillia@brocade.com> <1468607194-3879-4-git-send-email-ciwillia@brocade.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1468607194-3879-4-git-send-email-ciwillia@brocade.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Charles (Chas) Williams" Cc: stable@vger.kernel.org, Andy Lutomirski , Andrew Morton , Andy Lutomirski , Borislav Petkov , Brian Gerst , Dave Hansen , Denys Vlasenko , "H. Peter Anvin" , Linus Torvalds , Peter Zijlstra , Rik van Riel , Thomas Gleixner , linux-mm@kvack.org, Ingo Molnar , Luis Henriques Hi Chas, On Fri, Jul 15, 2016 at 02:26:26PM -0400, Charles (Chas) Williams wrote: > From: Andy Lutomirski > > commit 71b3c126e61177eb693423f2e18a1914205b165e upstream. > > When switch_mm() activates a new PGD, it also sets a bit that > tells other CPUs that the PGD is in use so that TLB flush IPIs > will be sent. In order for that to work correctly, the bit > needs to be visible prior to loading the PGD and therefore > starting to fill the local TLB. > > Document all the barriers that make this work correctly and add > a couple that were missing. > > CVE-2016-2069 I'm fine with queuing these patches for 3.10, but patches 4, 9 and 12 of your series are not in 3.14, and I only apply patches to 3.10 if they are already present in 3.14 (or if there's a good reason of course). Please could you check that you already submitted them ? If so I'll just wait for them to pop up there. It's important for us to ensure that users upgrading from extended LTS kernels to normal LTS kernels are never hit by a bug that was previously fixed in the older one and not yet in the newer one. Thanks, Willy -- 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