Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753391AbdLMQlx (ORCPT ); Wed, 13 Dec 2017 11:41:53 -0500 Received: from mx2.bahnhof.se ([213.80.101.12]:42131 "EHLO mx2.bahnhof.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750916AbdLMQlu (ORCPT ); Wed, 13 Dec 2017 11:41:50 -0500 X-Greylist: delayed 1400 seconds by postgrey-1.27 at vger.kernel.org; Wed, 13 Dec 2017 11:41:50 EST Message-ID: <5A3152C4.4070802@gaisler.com> Date: Wed, 13 Dec 2017 17:18:12 +0100 From: Andreas Larsson Organization: Cobham Gaisler AB User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Jia-Ju Bai , linus.walleij@linaro.org CC: linux-gpio@vger.kernel.org, Linux Kernel Mailing List Subject: Re: [BUG] drivers/gpio: some possible sleep-in-atomic bugs References: <0bcab5c0-d938-9eb6-d21d-6b8416d75a65@gmail.com> In-Reply-To: <0bcab5c0-d938-9eb6-d21d-6b8416d75a65@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1080 Lines: 40 On 2017-12-12 04:59, Jia-Ju Bai wrote: > According to drivers/gpio/gpio-grgpio.c, the kernel module may sleep > under a spinlock. > The function call paths are: > grgpio_remove (acquire the spinlock) > gpiochip_remove > gpiochip_sysfs_unregister > device_unregister --> may sleep > mutex_lock --> may sleep > > grgpio_remove (acquire the spinlock) > gpiochip_remove > gpiochip_sysfs_unregister > gpiod_free > __gpiod_free > gpiod_unexport > device_unregister --> may sleep > mutex_lock --> may sleep > > grgpio_remove (acquire the spinlock) > irq_domain_remove > mutex_lock --> may sleep > > grgpio_irq_map (acquire the spinlock) > request_irq --> may sleep > > grgpio_irq_unmap (acquire the spinlock) > free_irq --> may sleep > > > I do not find a good way to fix them, so I only report. > These possible bugs is found by my static analysis tool (DSAC) and > checked by my code review. Hi! Thank you for reporting this. I will take a look at it. -- Best Regards, Andreas Larsson