From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752865AbbKPVzv (ORCPT ); Mon, 16 Nov 2015 16:55:51 -0500 Received: from terminus.zytor.com ([198.137.202.10]:59235 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751649AbbKPVzu (ORCPT ); Mon, 16 Nov 2015 16:55:50 -0500 Subject: Re: [PATCH] xen/x86: Adjust stack pointer in xen_sysexit To: Borislav Petkov , Andy Lutomirski References: <1447456706-24347-1-git-send-email-boris.ostrovsky@oracle.com> <56468D24.8030801@oracle.com> <564A0371.2040104@oracle.com> <20151116195906.GB20137@pd.tnic> <20151116202232.GC20137@pd.tnic> Cc: Boris Ostrovsky , "linux-kernel@vger.kernel.org" , xen-devel , David Vrabel , Konrad Rzeszutek Wilk From: "H. Peter Anvin" Message-ID: <564A50C3.1000200@zytor.com> Date: Mon, 16 Nov 2015 13:55:15 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151116202232.GC20137@pd.tnic> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/16/15 12:22, Borislav Petkov wrote: > > Huh, so what's wrong with a jump: > > jmp 1f > swapgs > 1: > What is the point of that jump? >> If it would make you feel better, it could be X86_BUG_XENPV :-p > > That doesn't matter - I just don't want to open the flood gates on > pseudo feature bits. > > hpa, what do you think? Pseudo feature bits are fine, we already have plenty of them. They make sense as they let us reuse a lot of infrastructure. -hpa