Messages in this thread | | | Date | Thu, 03 Apr 2014 08:10:52 +0200 | From | Takashi Iwai <> | Subject | Re: [PATCH 1/2] ttyprintk: Fix wrong tty_unregister_driver() call in the error path |
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At Wed, 02 Apr 2014 14:24:33 +0200, Jean Delvare wrote: > > Le Wednesday 02 April 2014 à 12:29 +0200, Takashi Iwai a écrit : > > ttyprintk driver calls tty_unregister_driver() wrongly in the error > > path of tty_register_driver(). Also, setting ttyprintk_driver to NULL > > is utterly superfluous, so let's get rid of it, too. > > > > Reported-by: Jean Delvare <jdelvare@suse.de> > > Signed-off-by: Takashi Iwai <tiwai@suse.de> > > --- > > drivers/char/ttyprintk.c | 2 -- > > 1 file changed, 2 deletions(-) > > > > diff --git a/drivers/char/ttyprintk.c b/drivers/char/ttyprintk.c > > index daea84c41743..2a39c5790364 100644 > > --- a/drivers/char/ttyprintk.c > > +++ b/drivers/char/ttyprintk.c > > @@ -210,10 +210,8 @@ static int __init ttyprintk_init(void) > > return 0; > > > > error: > > - tty_unregister_driver(ttyprintk_driver); > > put_tty_driver(ttyprintk_driver); > > tty_port_destroy(&tpk_port.port); > > - ttyprintk_driver = NULL; > > return ret; > > } > > device_initcall(ttyprintk_init); > > Reviewed-by: Jean Delvare <jdelvare@suse.de>
Meanwhile, I found that tty_unregister_driver() was added intentionally in the commit f06fb543c1d0, TTY: ttyprintk, unregister tty driver on failure
When the tty_printk driver fails to create a node in sysfs, the system crashes. It is because the driver registers a tty driver and frees it without deregistering it first. The fix is easy: add a call to tty_unregister_driver to the fail path.
But, I failed to see why this is needed in the current code.
Jiri, is your fix still valid at all?
thanks,
Takashi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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