Groups > linux.kernel > #1208463

Re: Deadlock in grgpio_irq_unmap()

From	Alexandre Courbot <gnurou@gmail.com>
Newsgroups	linux.kernel
Subject	Re: Deadlock in grgpio_irq_unmap()
Date	2015-08-17 10:30 +0200
Message-ID	<pYnXQ-1P5-9@gated-at.bofh.it> (permalink)
References	<pT49s-Ha-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Mon, Aug 3, 2015 at 1:15 AM, Alexey Khoroshilov
<khoroshilov@ispras.ru> wrote:
> Dear colleagus,
>
> grgpio_irq_unmap() code looks quite suspicious regarding usage of
> priv->bgc.lock spinlock.
>
> It locks the spinlock in line 310:
>         spin_lock_irqsave(&priv->bgc.lock, flags);
> and then it can call grgpio_set_imask() in line 317:
>         grgpio_set_imask(priv, i, 0);
>
> But grgpio_set_imask() unconditionally locks the spinlock by itself.

Indeed, this looks plain wrong. I have sent a fix that moves the
spinlock acquisition outside of grgpio_set_imask().
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Re: Deadlock in grgpio_irq_unmap() Alexandre Courbot <gnurou@gmail.com> - 2015-08-17 10:30 +0200

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