From: Andreas Larsson <andreas@gaisler.com>
To: Jia-Ju Bai <baijiaju1990@gmail.com>, linus.walleij@linaro.org
Cc: linux-gpio@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [BUG] drivers/gpio: some possible sleep-in-atomic bugs
Date: Wed, 13 Dec 2017 17:18:12 +0100 [thread overview]
Message-ID: <5A3152C4.4070802@gaisler.com> (raw)
In-Reply-To: <0bcab5c0-d938-9eb6-d21d-6b8416d75a65@gmail.com>
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
prev parent reply other threads:[~2017-12-13 16:41 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-12 3:59 [BUG] drivers/gpio: some possible sleep-in-atomic bugs Jia-Ju Bai
2017-12-13 16:18 ` Andreas Larsson [this message]
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