Re: possible locking bug in tty_open

From: Arnd Bergmann
Date: Tue May 04 2010 - 16:26:47 EST


On Tuesday 04 May 2010 21:42:36 Alan Cox wrote:
> On Sun, 2 May 2010 22:47:33 +0200
> Arnd Bergmann <arnd@xxxxxxxx> wrote:

> > After the "retry_open:" label, we first get the tty_mutex
> > and then the BKL. However a the end of tty_open, we jump
> > back to retry_open with the BKL still held. If we run into
> > this case, the tty_open function will be left with the BKL
> > still held.

> I think all we need is probably this
>
> tty: Fix unbalanced BKL handling in error path
>
> Arnd noted:
>
> After the "retry_open:" label, we first get the tty_mutex
> and then the BKL. However a the end of tty_open, we jump
> back to retry_open with the BKL still held. If we run into
> this case, the tty_open function will be left with the BKL
> still held.

Yes, looks good.

>
> Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
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