From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754461AbbFEKGR (ORCPT ); Fri, 5 Jun 2015 06:06:17 -0400 Received: from www.linutronix.de ([62.245.132.108]:34815 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752768AbbFEKGO (ORCPT ); Fri, 5 Jun 2015 06:06:14 -0400 Date: Fri, 5 Jun 2015 12:06:19 +0200 (CEST) From: Thomas Gleixner To: Jiang Liu cc: Linux Kernel Mailing List Subject: Re: Possible race window when walking irq descriptors In-Reply-To: <5571706A.60009@linux.intel.com> Message-ID: References: <5571706A.60009@linux.intel.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 5 Jun 2015, Jiang Liu wrote: > 4) Called during cpu_up() > kernel/irq/chip.c:irq_cpu_online() > arch/x86/kernel/apic/vector.c:__setup_vector_irq() > > 5) Called from free running process context > arch/x86/kernel/topology.c: arch_register_cpu() > arch/x86/kernel/apic/io_apic.c: print_IO_APICs() > kernel/irq/autoprobe.c: probe_irq_on()/probe_irq_mask()/probe_irq_off() > > 6) Called from free running interrupt context > kernel/irq/spurious.c: poll_spurious_irqs()/misrouted_irq() > > So seems something needs to done to protect 4), 5) and 6). Is this > analysis correct? If so, I will try to work out some patches for it. Yes, you are right. We noticed that years ago and completely forgot about it. Thanks, tglx