Message ID | 201107012328.46256.arnd@arndb.de |
---|---|
State | Accepted, archived |
Delegated to: | David Miller |
Headers | show |
From: Arnd Bergmann <arnd@arndb.de> Date: Fri, 1 Jul 2011 23:28:46 +0200 > Lockdep found a locking inconsistency in the mkiss_close function: > >> kernel: [ INFO: inconsistent lock state ] >> kernel: 2.6.39.1 #3 >> kernel: --------------------------------- >> kernel: inconsistent {IN-SOFTIRQ-R} -> {SOFTIRQ-ON-W} usage. >> kernel: ax25ipd/2813 [HC0[0]:SC0[0]:HE1:SE1] takes: >> kernel: (disc_data_lock){+++?.-}, at: [<ffffffffa018552b>] mkiss_close+0x1b/0x90 [mkiss] >> kernel: {IN-SOFTIRQ-R} state was registered at: > > The message hints that disc_data_lock is aquired with softirqs disabled, > but does not itself disable softirqs, which can in rare circumstances > lead to a deadlock. > The same problem is present in the 6pack driver, this patch fixes both > by using write_lock_bh instead of write_lock. > > Reported-by: Bernard F6BVP <f6bvp@free.fr> > Tested-by: Bernard F6BVP <f6bvp@free.fr> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Acked-by: Ralf Baechle<ralf@linux-mips.org> > Cc: stable@kernel.org Applied, thanks! -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c index 9624cbf..fea7cb4 100644 --- a/drivers/net/hamradio/6pack.c +++ b/drivers/net/hamradio/6pack.c @@ -694,10 +694,10 @@ static void sixpack_close(struct tty_struct *tty) { struct sixpack *sp; - write_lock(&disc_data_lock); + write_lock_bh(&disc_data_lock); sp = tty->disc_data; tty->disc_data = NULL; - write_unlock(&disc_data_lock); + write_unlock_bh(&disc_data_lock); if (!sp) return; diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c index 9f84c83..324f7bf 100644 --- a/drivers/net/hamradio/mkiss.c +++ b/drivers/net/hamradio/mkiss.c @@ -813,10 +813,10 @@ static void mkiss_close(struct tty_struct *tty) { struct mkiss *ax; - write_lock(&disc_data_lock); + write_lock_bh(&disc_data_lock); ax = tty->disc_data; tty->disc_data = NULL; - write_unlock(&disc_data_lock); + write_unlock_bh(&disc_data_lock); if (!ax) return;