On 12/03/2012 06:41 PM, Peter Hurley wrote:
The lock logic for tty_set_ldisc() is wrong. Despite existing code in tty_set_ldisc() and tty_ldisc_hangup(), the ldisc_mutex does **not** (and should not) play a role in acquiring or releasing ldisc references. The only thing that needs to happen here is below (don't actually use below because I just hand-edited it):
Hmm. What about I stay in sync with the code that is already in tree and if the wrong locking gets removed in both places later on? Alan, what do you prefer?
See http://lkml.org/lkml/2012/11/21/347 drivers/tty/tty_ldisc.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index 0f2a2c5..fb76818 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -930,16 +930,21 @@ void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty) */ - tty_lock_pair(tty, o_tty); tty_ldisc_halt(tty); tty_ldisc_flush_works(tty);+ tty_lock_pair(tty, o_tty); /* This will need doing differently if we need to lock */ tty_ldisc_kill(tty); - if (o_tty) tty_ldisc_kill(o_tty);
Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
