From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750958AbWA2NGK (ORCPT ); Sun, 29 Jan 2006 08:06:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750961AbWA2NGK (ORCPT ); Sun, 29 Jan 2006 08:06:10 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:57509 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S1750958AbWA2NGI (ORCPT ); Sun, 29 Jan 2006 08:06:08 -0500 Date: Sun, 29 Jan 2006 14:06:48 +0100 From: Ingo Molnar To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Arjan van de Ven Subject: Re: [patch] warn on release_region() from irq context Message-ID: <20060129130648.GA22590@elte.hu> References: <20060128144357.GA6881@elte.hu> <20060128150006.GA10660@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060128150006.GA10660@elte.hu> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: -2.2 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.2 required=5.9 tests=ALL_TRUSTED,AWL autolearn=no SpamAssassin version=3.0.3 -2.8 ALL_TRUSTED Did not pass through any untrusted hosts 0.6 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar wrote: > ============================ > [ BUG: illegal lock usage! ] > ---------------------------- > illegal {softirq-on} -> {in-softirq} usage. > rcu_torture_rea/264 [HC0[0]:SC1[2]:HE1:SE0] takes: > (resource_lock){+-}, at: [] __release_region+0x37/0xf0 > {softirq-on} state was registered at: > [] irq_exit+0x45/0x50 > hardirqs last enabled at: [] vprintk+0x32e/0x3e0 > softirqs last enabled at: [] irq_exit+0x45/0x50 > > other info that might help us debug this: > no locks held by rcu_torture_rea/264. > > stack backtrace: > [] show_trace+0xd/0x10 > [] dump_stack+0x17/0x20 > [] print_usage_bug+0x1d8/0x230 > [] mark_lock+0x366/0x3a0 > [] debug_lock_chain+0x493/0x1090 > [] debug_lock_chain_spin+0x3d/0x60 > [] _raw_write_lock+0x32/0x1a0 > [] _write_lock+0x8/0x10 > [] __release_region+0x37/0xf0 > [] floppy_release_irq_and_dma+0x140/0x200 > [] set_dor+0xc7/0x1b0 > [] motor_off_callback+0x21/0x30 > [] run_timer_softirq+0xf5/0x1f0 > [] __do_softirq+0x97/0x130 > [] do_softirq+0x69/0x100 btw., Arjan discovered that this bug is not theoretical, and the deadlock scenario is experienced by users: http://i15.photobucket.com/albums/a396/johnny_blue/fedora-devel/28012006026.jpg Ingo