From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759038AbYGKNra (ORCPT ); Fri, 11 Jul 2008 09:47:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754572AbYGKNrU (ORCPT ); Fri, 11 Jul 2008 09:47:20 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:43873 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754499AbYGKNrT (ORCPT ); Fri, 11 Jul 2008 09:47:19 -0400 Date: Fri, 11 Jul 2008 15:47:06 +0200 From: Ingo Molnar To: Jeremy Fitzhardinge Cc: the arch/x86 maintainers , Linux Kernel Mailing List Subject: Re: [PATCH 2/2] xen64: disable 32-bit syscall/sysenter if not supported. Message-ID: <20080711134706.GB32159@elte.hu> References: <48769A18.4030402@goop.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48769A18.4030402@goop.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jeremy Fitzhardinge wrote: > Old versions of Xen (3.1 and before) don't support sysenter or syscall > from 32-bit compat userspaces. If we can't set the appropriate > syscall callback, then disable the corresponding feature bit, which > will cause the vdso32 setup to fall back appropriately. > > Linux assumes that syscall is always available to 32-bit userspace, > and installs it by default if sysenter isn't available. In that case, > we just disable vdso altogether, forcing userspace libc to fall back > to int $0x80. merged the latest version of tip/x86/core to tip/xen-64bit and then added this patch to tip/xen-64bit - thanks Jeremy. Ingo