From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Zdenek Kabelac <zdenek.kabelac@gmail.com>
Cc: Chuck Ebbert <cebbert@redhat.com>,
"Mario 'BitKoenig' Holbe" <Mario.Holbe@tu-ilmenau.de>,
linux-kernel@vger.kernel.org
Subject: Re: kernel BUG and freeze on cat /proc/tty/driver/serial
Date: Fri, 25 May 2012 00:09:34 +0100 [thread overview]
Message-ID: <20120525000934.78136313@pyramind.ukuu.org.uk> (raw)
In-Reply-To: <CAJJYPdnTMZiTi6OT2cqk_h_e8+m8iGZqVK_zazLM39eFWLf5xw@mail.gmail.com>
> - struct tty_ldisc *ld = tty_ldisc_ref(port->tty);
> + struct tty_ldisc *ld = port ? tty_ldisc_ref(port->tty) : NULL;
> struct pps_event_time ts;
>
> if (ld && ld->ops->dcd_change)
> @@ -2465,7 +2465,7 @@ void uart_handle_dcd_change(struct uart_port
> *uport, unsigned int status)
> hardpps();
> #endif
>
> - if (port->flags & ASYNC_CHECK_CD) {
> + if (port && port->flags & ASYNC_CHECK_CD) {
> if (status)
> wake_up_interruptible(&port->open_wait);
> else if (port->tty)
Probably should be using tty krefs for this
tty = tty_port_tty_get( ..) / tty_kref_put
etc, and yes the NULL check is needed. The reference is needed so the tty
can't be freed under you.
next prev parent reply other threads:[~2012-05-24 23:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-16 16:17 Mario 'BitKoenig' Holbe
2011-03-08 16:10 ` Mario 'BitKoenig' Holbe
2011-03-10 6:49 ` Chuck Ebbert
2011-09-02 18:23 ` Zdenek Kabelac
2012-05-24 21:09 ` Zdenek Kabelac
2012-05-24 23:09 ` Alan Cox [this message]
2012-05-25 8:23 ` Zdenek Kabelac
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