Messages in this thread | | | Date | Tue, 23 Jun 2009 16:30:06 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH v2 1/1] Char: tty, fix tty_port_block_til_ready waiting |
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On Thu, 18 Jun 2009 09:46:13 +0200 Jiri Slaby <jirislaby@gmail.com> wrote:
> Use DEFINE_WAIT instead DECLARE_WAITQUEUE, because we use > prepare/finish_wait since commit > 3e3b5c087799e536871c8261b05bc28e4783c8da > (tty: use prepare/finish_wait) > > Otherwise we would oops in finish_wait. >
<scratches head for a while>
OK, here's a better changelog:
Since commit 3e3b5c087799e536871c8261b05bc28e4783c8da ("tty: use prepare/finish_wait"), tty_port_block_til_ready() is using prepare_to_wait()/finish_wait(). Those functions require that the wait_queue_t be initialised with .func=autoremove_wake_function, via DEFINE_WAIT().
But the conversion from DECLARE_WAITQUEUE() to DEFINE_WAIT() was not made, so this code will oops in finish_wait().
> > diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c > index 62dadfc..4e862a7 100644 > --- a/drivers/char/tty_port.c > +++ b/drivers/char/tty_port.c > @@ -193,7 +193,7 @@ int tty_port_block_til_ready(struct tty_port *port, > { > int do_clocal = 0, retval; > unsigned long flags; > - DECLARE_WAITQUEUE(wait, current); > + DEFINE_WAIT(wait); > int cd; > > /* block if port is in the process of being closed */
Why is nobody reporting the oopses?
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