From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753900AbYIJMMi (ORCPT ); Wed, 10 Sep 2008 08:12:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752085AbYIJMMa (ORCPT ); Wed, 10 Sep 2008 08:12:30 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:51200 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751779AbYIJMM3 (ORCPT ); Wed, 10 Sep 2008 08:12:29 -0400 Date: Wed, 10 Sep 2008 14:12:17 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: Nick Piggin , Linux Kernel Mailing List Subject: Re: [patch] x86: some lock annotations for user copy paths Message-ID: <20080910121217.GA16013@elte.hu> References: <20080910113717.GB16811@wotan.suse.de> <1221046892.30429.85.camel@twins.programming.kicks-ass.net> <20080910114755.GA9696@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080910114755.GA9696@elte.hu> 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 * Ingo Molnar wrote: > > shouldn't some of that be conditional on pagefault_disable() 'n > > such? > > i dont think so - those have their own special __atomic user-copy > primitives which Nick didnt touch. hm, but the prefetch bits were touched, and -tip testing stumbled upon this false positive: [ 66.187448] PM: Adding info for No Bus:vcsa12 [ 67.138685] evbug.c: Event. Dev: input0, Type: 20, Code: 0, Value: 500 [ 80.149087] BUG: sleeping function called from invalid context at arch/x86/mm/fault.c:122 [ 80.157344] in_atomic(): 1, irqs_disabled(): 0, pid: 6811, name: gam_server [ 80.164315] no locks held by gam_server/6811. [ 80.168685] Pid: 6811, comm: gam_server Not tainted 2.6.27-rc6-tip-00187-gbfd4ed7-dirty #2 [ 80.177013] Call Trace: [ 80.179454] [] ? __debug_show_held_locks+0x22/0x24 [ 80.185876] [] __might_sleep+0x104/0x109 [ 80.191430] [] is_prefetch+0xe8/0x228 [ 80.196760] [] do_page_fault+0x5d8/0x9a9 [ 80.202361] [] ? sys_newstat+0x36/0x41 [ 80.207774] [] error_exit+0x0/0xb9 so i've excluded these commits for now. (once there's a fix i can continue testing it) Ingo