From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756730Ab2FFPUs (ORCPT ); Wed, 6 Jun 2012 11:20:48 -0400 Received: from terminus.zytor.com ([198.137.202.10]:39947 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754061Ab2FFPUq (ORCPT ); Wed, 6 Jun 2012 11:20:46 -0400 Date: Wed, 6 Jun 2012 08:20:33 -0700 From: tip-bot for Tomoki Sekiyama Message-ID: Cc: linux-kernel@vger.kernel.org, agordeev@redhat.com, hpa@zytor.com, mingo@kernel.org, yinghai@kernel.org, tomoki.sekiyama.qu@hitachi.com, suresh.b.siddha@intel.com, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, agordeev@redhat.com, linux-kernel@vger.kernel.org, yinghai@kernel.org, suresh.b.siddha@intel.com, tglx@linutronix.de, tomoki.sekiyama.qu@hitachi.com In-Reply-To: <4FC340BE.7080101@hitachi.com> References: <4FC340BE.7080101@hitachi.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/ioapic: Fix NULL pointer dereference on CPU hotplug after disabling irqs Git-Commit-ID: f6175f5bfb4c9f2ed32758c95f765b529b1a7f15 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Wed, 06 Jun 2012 08:20:39 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: f6175f5bfb4c9f2ed32758c95f765b529b1a7f15 Gitweb: http://git.kernel.org/tip/f6175f5bfb4c9f2ed32758c95f765b529b1a7f15 Author: Tomoki Sekiyama AuthorDate: Mon, 28 May 2012 18:09:18 +0900 Committer: Ingo Molnar CommitDate: Wed, 6 Jun 2012 12:03:25 +0200 x86/ioapic: Fix NULL pointer dereference on CPU hotplug after disabling irqs In current Linux, percpu variable `vector_irq' is not cleared on offlined cpus while disabling devices' irqs. If the cpu that has the disabled irqs in vector_irq is hotplugged, __setup_vector_irq() hits invalid irq vector and may crash. This bug can be reproduced as following; # echo 0 > /sys/devices/system/cpu/cpu7/online # modprobe -r some_driver_using_interrupts # vector_irq@cpu7 uncleared # echo 1 > /sys/devices/system/cpu/cpu7/online # kernel may crash This patch fixes this bug by clearing vector_irq in __clear_irq_vector() even if the cpu is offlined. Signed-off-by: Tomoki Sekiyama Acked-by: Thomas Gleixner Cc: yrl.pp-manager.tt@hitachi.com Cc: ltc-kernel@ml.yrl.intra.hitachi.co.jp Cc: Suresh Siddha Cc: Yinghai Lu Cc: Alexander Gordeev Link: http://lkml.kernel.org/r/4FC340BE.7080101@hitachi.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/io_apic.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index ac96561..5f0ff59 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -1195,7 +1195,7 @@ static void __clear_irq_vector(int irq, struct irq_cfg *cfg) BUG_ON(!cfg->vector); vector = cfg->vector; - for_each_cpu_and(cpu, cfg->domain, cpu_online_mask) + for_each_cpu(cpu, cfg->domain) per_cpu(vector_irq, cpu)[vector] = -1; cfg->vector = 0; @@ -1203,7 +1203,7 @@ static void __clear_irq_vector(int irq, struct irq_cfg *cfg) if (likely(!cfg->move_in_progress)) return; - for_each_cpu_and(cpu, cfg->old_domain, cpu_online_mask) { + for_each_cpu(cpu, cfg->old_domain) { for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) { if (per_cpu(vector_irq, cpu)[vector] != irq)