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Subject: Re: [PATCH v3 3/3] uio: fix crash after the device is unregistered
To:     xiubli@redhat.com, gregkh@linuxfoundation.org,
        linux-kernel@vger.kernel.org
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        pkalever@redhat.com, pkarampu@redhat.com, atumball@redhat.com,
        sabose@redhat.com
From:   Mike Christie <mchristi@redhat.com>
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Date:   Fri, 6 Jul 2018 13:58:57 -0500
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On 07/05/2018 09:57 PM, xiubli@redhat.com wrote:
>  void uio_event_notify(struct uio_info *info)
>  {
> -	struct uio_device *idev = info->uio_dev;
> +	struct uio_device *idev;
> +
> +	if (!info)
> +		return;
> +
> +	idev = info->uio_dev;
>  

For this one too, I am not sure if it is needed.

uio_interrupt -> uio_event_notify. See other mail.

driver XYZ -> uio_event_notify. I think drivers need to handle this and
set some bits and/or perform some cleanup to make sure they are not
calling uio_event_notify after it has called uio_unregister_device. The
problem with the above test is if they do not they could have called
uio_unregister_device right after the info test so you could still hit
the problem.