Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750715AbWEWPds (ORCPT ); Tue, 23 May 2006 11:33:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750713AbWEWPds (ORCPT ); Tue, 23 May 2006 11:33:48 -0400 Received: from gateway-1237.mvista.com ([63.81.120.158]:40456 "EHLO gateway-1237.mvista.com") by vger.kernel.org with ESMTP id S1750715AbWEWPdr (ORCPT ); Tue, 23 May 2006 11:33:47 -0400 Subject: Re: Ingo's realtime_preempt patch causes kernel oops From: Daniel Walker To: Steven Rostedt Cc: Yann.LEPROVOST@wavecom.fr, linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar In-Reply-To: <1148393971.4997.24.camel@localhost.localdomain> References: <1148393971.4997.24.camel@localhost.localdomain> Content-Type: text/plain Date: Tue, 23 May 2006 08:33:44 -0700 Message-Id: <1148398425.3535.92.camel@c-67-180-134-207.hsd1.ca.comcast.net> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1212 Lines: 36 On Tue, 2006-05-23 at 10:19 -0400, Steven Rostedt wrote: > > The fault is at 0x40 and looking at profile_tick it calls > user_mode(regs). user_mode(x) is defined in arm as > (((regs)->ARM_cpsr & 0xf) == 0) > > And ARM_cpsr is uregs[16] So if arm has 4 byte words and regs was NULL, > it would fault on 16*4 = 64 or 0x40 > > It looks like the timer interrupt on this board is having a NULL regs > passed to it when hard interrupts are threads. Which might mean that > the timer interrupt is itself a thread. Hmm, well usually ARM timer interrupts have the SA_TIMER flag .. In realtime ARM changes SA_TIMER includes SA_NODELAY .. In 2.6.17-rc4 arch/arm/mach-at91rm9200/time.c static struct irqaction at91rm9200_timer_irq = { .name = "at91_tick", .flags = SA_SHIRQ | SA_INTERRUPT, .handler = at91rm9200_timer_interrupt }; No SA_TIMER, and no SA_NODELAY , so i'd imagine it's is in a thread .. Daniel - 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/