From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756114AbaIQQLX (ORCPT ); Wed, 17 Sep 2014 12:11:23 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:34565 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755842AbaIQQLV (ORCPT ); Wed, 17 Sep 2014 12:11:21 -0400 Message-ID: <1410970272.15235.32.camel@fourier> Subject: Re: [PATCH 3.13 044/187] x86_64/entry/xen: Do not invoke espfix64 on Xen From: Kamal Mostafa To: Ben Hutchings Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com, Andy Lutomirski , "H. Peter Anvin" Date: Wed, 17 Sep 2014 09:11:12 -0700 In-Reply-To: <1410953151.3040.101.camel@decadent.org.uk> References: <1410818997-9432-1-git-send-email-kamal@canonical.com> <1410818997-9432-45-git-send-email-kamal@canonical.com> <1410953151.3040.101.camel@decadent.org.uk> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2014-09-17 at 12:25 +0100, Ben Hutchings wrote: > On Mon, 2014-09-15 at 15:07 -0700, Kamal Mostafa wrote: > > 3.13.11.7 -stable review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Andy Lutomirski > > > > commit 7209a75d2009dbf7745e2fd354abf25c3deb3ca3 upstream. > > > > This moves the espfix64 logic into native_iret. To make this work, > > it gets rid of the native patch for INTERRUPT_RETURN: > > INTERRUPT_RETURN on native kernels is now 'jmp native_iret'. > > > > This changes the 16-bit SS behavior on Xen from OOPSing to leaking > > some bits of the Xen hypervisor's RSP (I think). > > > > [ hpa: this is a nonzero cost on native, but probably not enough to > > measure. Xen needs to fix this in their own code, probably doing > > something equivalent to espfix64. ] > > > > Signed-off-by: Andy Lutomirski > > Link: http://lkml.kernel.org/r/7b8f1d8ef6597cb16ae004a43c56980a7de3cf94.1406129132.git.luto@amacapital.net > > Signed-off-by: H. Peter Anvin > > Signed-off-by: Kamal Mostafa > [...] > > There's another fix related to espfix on Xen, commit 8762e5092828 > ("x86/espfix/xen: Fix allocation of pages for paravirt page tables"). > But I'm not sure whether it's actually needed after this. > > Ben. > I have now queued that one up for 3.13.11.7 also. Thanks yet again, Ben! -Kamal