diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2011-07-01 17:30:00 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-07-13 05:29:25 +0200 |
| commit | 06ce414d4a0811a979a82cddc3e429e6bd704c98 (patch) | |
| tree | 9ff0ef50bf725b2668d164fa713910f3e3d8bdc6 | |
| parent | d2c7e885624f03cdbba80f124096e5073156969e (diff) | |
6pack,mkiss: fix lock inconsistency
commit 6e4e2f811bade330126d4029c88c831784a7efd9 upstream.
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/net/hamradio/6pack.c | 4 | ||||
| -rw-r--r-- | drivers/net/hamradio/mkiss.c | 4 |
2 files changed, 4 insertions, 4 deletions
diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c index fb588301a05d..0e5b54b2b4d7 100644 --- a/drivers/net/hamradio/6pack.c +++ b/drivers/net/hamradio/6pack.c @@ -690,10 +690,10 @@ 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 db4b7f1603f6..6cfc2b484911 100644 --- a/drivers/net/hamradio/mkiss.c +++ b/drivers/net/hamradio/mkiss.c @@ -811,10 +811,10 @@ 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; |