Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932292AbbFCMKa (ORCPT ); Wed, 3 Jun 2015 08:10:30 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57298 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752126AbbFCMKG (ORCPT ); Wed, 3 Jun 2015 08:10:06 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Vrabel Subject: [PATCH 3.14 13/64] xen/events: dont bind non-percpu VIRQs with percpu chip Date: Wed, 3 Jun 2015 20:42:41 +0900 Message-Id: <20150603063929.036123333@linuxfoundation.org> X-Mailer: git-send-email 2.4.2 In-Reply-To: <20150603063928.472620468@linuxfoundation.org> References: <20150603063928.472620468@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3521 Lines: 98 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Vrabel commit 77bb3dfdc0d554befad58fdefbc41be5bc3ed38a upstream. A non-percpu VIRQ (e.g., VIRQ_CONSOLE) may be freed on a different VCPU than it is bound to. This can result in a race between handle_percpu_irq() and removing the action in __free_irq() because handle_percpu_irq() does not take desc->lock. The interrupt handler sees a NULL action and oopses. Only use the percpu chip/handler for per-CPU VIRQs (like VIRQ_TIMER). # cat /proc/interrupts | grep virq 40: 87246 0 xen-percpu-virq timer0 44: 0 0 xen-percpu-virq debug0 47: 0 20995 xen-percpu-virq timer1 51: 0 0 xen-percpu-virq debug1 69: 0 0 xen-dyn-virq xen-pcpu 74: 0 0 xen-dyn-virq mce 75: 29 0 xen-dyn-virq hvc_console Signed-off-by: David Vrabel Signed-off-by: Greg Kroah-Hartman --- drivers/tty/hvc/hvc_xen.c | 2 +- drivers/xen/events/events_base.c | 12 ++++++++---- include/xen/events.h | 2 +- 3 files changed, 10 insertions(+), 6 deletions(-) --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -289,7 +289,7 @@ static int xen_initial_domain_console_in return -ENOMEM; } - info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0); + info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0, false); info->vtermno = HVC_COOKIE; spin_lock(&xencons_lock); --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -973,7 +973,7 @@ unsigned xen_evtchn_nr_channels(void) } EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels); -int bind_virq_to_irq(unsigned int virq, unsigned int cpu) +int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu) { struct evtchn_bind_virq bind_virq; int evtchn, irq, ret; @@ -987,8 +987,12 @@ int bind_virq_to_irq(unsigned int virq, if (irq < 0) goto out; - irq_set_chip_and_handler_name(irq, &xen_percpu_chip, - handle_percpu_irq, "virq"); + if (percpu) + irq_set_chip_and_handler_name(irq, &xen_percpu_chip, + handle_percpu_irq, "virq"); + else + irq_set_chip_and_handler_name(irq, &xen_dynamic_chip, + handle_edge_irq, "virq"); bind_virq.virq = virq; bind_virq.vcpu = cpu; @@ -1078,7 +1082,7 @@ int bind_virq_to_irqhandler(unsigned int { int irq, retval; - irq = bind_virq_to_irq(virq, cpu); + irq = bind_virq_to_irq(virq, cpu, irqflags & IRQF_PERCPU); if (irq < 0) return irq; retval = request_irq(irq, handler, irqflags, devname, dev_id); --- a/include/xen/events.h +++ b/include/xen/events.h @@ -14,7 +14,7 @@ int bind_evtchn_to_irqhandler(unsigned i irq_handler_t handler, unsigned long irqflags, const char *devname, void *dev_id); -int bind_virq_to_irq(unsigned int virq, unsigned int cpu); +int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu); int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu, irq_handler_t handler, unsigned long irqflags, const char *devname, -- 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/