From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933236AbXCEMOh (ORCPT ); Mon, 5 Mar 2007 07:14:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933266AbXCEMOh (ORCPT ); Mon, 5 Mar 2007 07:14:37 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:55466 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933236AbXCEMOh (ORCPT ); Mon, 5 Mar 2007 07:14:37 -0500 Date: Mon, 5 Mar 2007 13:06:31 +0100 From: Ingo Molnar To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Roland McGrath , Andi Kleen , Rusty Russell Subject: [patch] paravirt: VDSO page is essential Message-ID: <20070305120631.GA14105@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Subject: [patch] paravirt: VDSO page is essential From: Ingo Molnar commit 3bbf54725467d604698721384d858b5983b87e8f disables the VDSO for CONFIG_PARAVIRT kernels. This #ifdeffery was a bad change: the VDSO is an essential component of Linux, and this change forces all of them to use int $0x80 - including sane ones like KVM. (If a hypervisor does not handle the VDSO properly then it can work things around via the vdso=0 boot option. Or CONFIG_PARAVIRT should not have been merged. But in any case, it is a basic taste issue: we DO NOT #ifdef around core features like this!) Signed-off-by: Ingo Molnar --- arch/i386/kernel/sysenter.c | 4 ---- 1 file changed, 4 deletions(-) Index: linux/arch/i386/kernel/sysenter.c =================================================================== --- linux.orig/arch/i386/kernel/sysenter.c +++ linux/arch/i386/kernel/sysenter.c @@ -27,11 +27,7 @@ * Should the kernel map a VDSO page into processes and pass its * address down to glibc upon exec()? */ -#ifdef CONFIG_PARAVIRT -unsigned int __read_mostly vdso_enabled = 0; -#else unsigned int __read_mostly vdso_enabled = 1; -#endif EXPORT_SYMBOL_GPL(vdso_enabled);