From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754802AbYCYK4T (ORCPT ); Tue, 25 Mar 2008 06:56:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753257AbYCYK4L (ORCPT ); Tue, 25 Mar 2008 06:56:11 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:49677 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752966AbYCYK4K (ORCPT ); Tue, 25 Mar 2008 06:56:10 -0400 Date: Tue, 25 Mar 2008 11:56:00 +0100 From: Ingo Molnar To: Jeremy Fitzhardinge Cc: Linux Kernel Mailing List Subject: Re: [PATCH FIXED] x86: only enable interrupts when kernel state has been set up Message-ID: <20080325105559.GA3729@elte.hu> References: <47E83C99.3040800@goop.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <47E83C99.3040800@goop.org> User-Agent: Mutt/1.5.17 (2007-11-01) 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: 0.0022] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jeremy Fitzhardinge wrote: > The sysenter path tries to enable interrupts immediately. > Unfortunately this doesn't work in a paravirt environment, because not > enough kernel state has been set up at that point (namely, pointing > %fs to the kernel percpu data segment). To fix this, defer > ENABLE_INTERRUPTS until after the kernel state has been set up. > > Unfortunately this means that we're running with interrupts disabled > for a while without calling the IRQ tracing code, but that can't be > called without setting up %fs either. > > [ Fix since last posting: make sure saved eflags has interrupts > enabled. ] thanks Jeremy - will give it a shot. Ingo