From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Weinberger Subject: Re: linux-next: User Mode Linux broken Date: Fri, 22 Oct 2010 12:50:49 +0200 Message-ID: References: <201010211315.26679.richard@nod.at> <201010212122.38437.richard@nod.at> <201010212227.12919.richard@nod.at> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from a.ns.miles-group.at ([95.130.255.143]:60011 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754086Ab0JVKuz (ORCPT ); Fri, 22 Oct 2010 06:50:55 -0400 In-Reply-To: Sender: linux-next-owner@vger.kernel.org List-ID: To: Thomas Gleixner Cc: peterz@infradead.org, hpa@zytor.com, mingo@elte.hu, linux-kernel@vger.kernel.org, linux-next@vger.kernel.org On Fri, 22 Oct 2010 09:03:44 +0200 (CEST), Thomas Gleixner wrote: > On Thu, 21 Oct 2010, Richard Weinberger wrote: >> Am Donnerstag 21 Oktober 2010, 21:45:35 schrieb Thomas Gleixner: >> > Why shold it solve it ? irq_enable is set to compat_irq_enable which >> > in turn calls chip->enable. >> > >> > So how's that different ? >> >> I took a closer look on the issue. >> >> check_irq_resend() gets called before irq_chip_set_defaults(). >> In the first call to check_irq_resend() desc->irq_data.chip->irq_enable is >> NULL. UML dies due to a NULL-pointer dereference... >> >> I don't know why check_irq_resend() is called before irq_chip_set_defaults(). >> It's your code. ;-) > > Well, but it only gets called via enable_irq(). So that means > something is calling enable_irq _before_ request/setup_irq(). > > arch/um/kernel/irq.c:init_IRQ() does that :) Sorry I'm not very familiar with the IRQ stuff. Does that mean init_IRQ() is not allowed to call enable_irq()? Thanks, //richard > Thanks, > > tglx