Re: [BUG] ati_remote2.c: possible mutex_lock without mutex_unlock

Dmitry Torokhov
2009-10-14T07:15:11Z

On Wed, Oct 14, 2009 at 09:11:06AM +0200, Jiri Kosina wrote:
> On Tue, 13 Oct 2009, Dmitry Torokhov wrote:
>
> > Umm, I don't like assuming that EAGAIN can only mean that
> > mutex_lock_interruptible() failed, seq_file core may theoretically
> > return -EAGAIN too. In fact, looking through seq_file.c traverse() does
> > return -EAGAIN in certain cases...
>
> Damn, you are right -- I explicitly checked for this, but have completely
> overlooked the "Eoveflow:" branch in traverse(), which returns EAGAIN. So
> my previous patch is of course incorrect.
>
> > Input: fix locking issue in /proc/bus/input/ handlers
> >
> > From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> >
> > input_devices_seq_start() uses mutex_lock_interruptible() to acquire
> > the input_mutex, but doesn't properly handle the situation when the
> > call fails (for example due to interrupt). Instead of returning NULL
> > (which indicates that there is no more data) we should return
> > ERR_PTR()-encoded error.
> >
> > We also need explicit flag indicating whether input_mutex was acquired
> > since input_devices_seq_stop() is called whether input_devices_seq_start()
> > was successful or not.
> >
> > The same applies to input_handlers_seq_start().
> >
> > Reported-by: iceberg <strakh@ispras.ru>
> > Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
>
> Yup, looks OK to me.
>

Putting you as "Reviewed-by.." then, OK?

--
Dmitry