Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755312AbXEQKGZ (ORCPT ); Thu, 17 May 2007 06:06:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754394AbXEQKGS (ORCPT ); Thu, 17 May 2007 06:06:18 -0400 Received: from www.osadl.org ([213.239.205.134]:59972 "EHLO mail.tglx.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754305AbXEQKGS (ORCPT ); Thu, 17 May 2007 06:06:18 -0400 Subject: Re: bug seen with dynticks from CONFIG_HARDIRQS_SW_RESEND From: Thomas Gleixner To: "Woodruff, Richard" Cc: linux-kernel@vger.kernel.org, Ingo Molnar In-Reply-To: <3B6D69C3A9EBCA4BA5DA60D913027429010253CD@dlee13.ent.ti.com> References: <3B6D69C3A9EBCA4BA5DA60D913027429010253CD@dlee13.ent.ti.com> Content-Type: text/plain Date: Thu, 17 May 2007 12:10:59 +0200 Message-Id: <1179396659.3764.40.camel@chaos> Mime-Version: 1.0 X-Mailer: Evolution 2.8.3 (2.8.3-2.fc6) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 935 Lines: 24 On Wed, 2007-05-16 at 18:20 -0500, Woodruff, Richard wrote: > The crashes were because the frame pointer per_cpu____irq_regs value was > 0. That code does a user_mode(get_irq_regs()). Currently regs is set > only upon real hardware entry on an irq. > > The crash path shows resend_irqs() could be called with in a context > where set_irq_regs() was not executed. In one specific case this was > from > softirq->tasklet_action(resend_tasklet)->resend_irqs->handle_level_irq-> > handle_IRQ_event->...->profile_tick. > > It seems anyone calling kernel/irq/manage.c:enable_irq() at the wrong > time can trigger this crash. which code is disabling / enabling the timer interrupt ? tglx - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/