From patchwork Thu Mar 5 09:38:24 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean Delvare X-Patchwork-Id: 10001 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n259cbBG012350 for ; Thu, 5 Mar 2009 09:38:37 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753135AbZCEJih (ORCPT ); Thu, 5 Mar 2009 04:38:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751524AbZCEJih (ORCPT ); Thu, 5 Mar 2009 04:38:37 -0500 Received: from zone0.gcu-squad.org ([212.85.147.21]:47719 "EHLO services.gcu-squad.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751236AbZCEJig (ORCPT ); Thu, 5 Mar 2009 04:38:36 -0500 Received: from jdelvare.pck.nerim.net ([62.212.121.182] helo=hyperion.delvare) by services.gcu-squad.org (GCU Mailer Daemon) with esmtpsa id 1LfB6G-00011w-3z (TLSv1:AES256-SHA:256) (envelope-from ) for linux-media@vger.kernel.org; Thu, 05 Mar 2009 11:46:48 +0100 Date: Thu, 5 Mar 2009 10:38:24 +0100 From: Jean Delvare To: LMML Subject: [PATCH] cx88: Prevent general protection fault on rmmod Message-ID: <20090305103824.351d0110@hyperion.delvare> X-Mailer: Claws Mail 3.5.0 (GTK+ 2.14.4; x86_64-suse-linux-gnu) Mime-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Jean Delvare Subject: cx88: Prevent general protection fault on rmmod When unloading the cx8800 driver I sometimes get a general protection fault. Analysis revealed a race in cx88_ir_stop(). It can be solved by using a delayed work instead of a timer for infrared input polling. This fixes kernel.org bug #12802. Signed-off-by: Jean Delvare --- linux/drivers/media/video/cx88/cx88-input.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) --- v4l-dvb.orig/linux/drivers/media/video/cx88/cx88-input.c 2009-03-04 09:52:20.000000000 +0100 +++ v4l-dvb/linux/drivers/media/video/cx88/cx88-input.c 2009-03-04 19:03:17.000000000 +0100 @@ -49,8 +49,12 @@ struct cx88_IR { /* poll external decoder */ int polling; +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) struct work_struct work; struct timer_list timer; +#else + struct delayed_work work; +#endif u32 gpio_addr; u32 last_gpio; u32 mask_keycode; @@ -144,6 +148,7 @@ static void cx88_ir_handle_key(struct cx } } +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) static void ir_timer(unsigned long data) { struct cx88_IR *ir = (struct cx88_IR *)data; @@ -151,7 +156,6 @@ static void ir_timer(unsigned long data) schedule_work(&ir->work); } -#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) static void cx88_ir_work(void *data) #else static void cx88_ir_work(struct work_struct *work) @@ -160,23 +164,30 @@ static void cx88_ir_work(struct work_str #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) struct cx88_IR *ir = data; #else - struct cx88_IR *ir = container_of(work, struct cx88_IR, work); + struct delayed_work *dwork = container_of(work, struct delayed_work, + work); + struct cx88_IR *ir = container_of(dwork, struct cx88_IR, work); #endif cx88_ir_handle_key(ir); +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) mod_timer(&ir->timer, jiffies + msecs_to_jiffies(ir->polling)); +#else + schedule_delayed_work(dwork, msecs_to_jiffies(ir->polling)); +#endif } void cx88_ir_start(struct cx88_core *core, struct cx88_IR *ir) { if (ir->polling) { - setup_timer(&ir->timer, ir_timer, (unsigned long)ir); #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) + setup_timer(&ir->timer, ir_timer, (unsigned long)ir); INIT_WORK(&ir->work, cx88_ir_work, ir); + schedule_work(&ir->work); #else - INIT_WORK(&ir->work, cx88_ir_work); + INIT_DELAYED_WORK(&ir->work, cx88_ir_work); + schedule_delayed_work(&ir->work, msecs_to_jiffies(ir->polling)); #endif - schedule_work(&ir->work); } if (ir->sampling) { core->pci_irqmask |= PCI_INT_IR_SMPINT; @@ -193,8 +204,12 @@ void cx88_ir_stop(struct cx88_core *core } if (ir->polling) { +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20) del_timer_sync(&ir->timer); flush_scheduled_work(); +#else + cancel_delayed_work_sync(&ir->work); +#endif } }