diff options
| author | Dan Carpenter <error27@gmail.com> | 2010-05-25 11:37:17 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-06-04 13:37:17 -0700 |
| commit | 328be395a396b1333b56e04571365dc614c96e46 (patch) | |
| tree | e4266351b4641c44f43747e776964d6321f10d3d /drivers/char/n_gsm.c | |
| parent | e59e2bd9e85604ad601ec7dd056baffcd6ad56a0 (diff) | |
| download | lwn-328be395a396b1333b56e04571365dc614c96e46.tar.gz lwn-328be395a396b1333b56e04571365dc614c96e46.zip | |
TTY/n_gsm: potential double lock
In gsm_dlci_data_kick() we call gsm_dlci_data_sweep() with the
"gsm->tx_lock" held so we can't lock it again inside
gsm_dlci_data_sweep(). I removed that lock from and added one to
gsmld_write_wakeup() instead. The sweep function is only called from
those two places.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/char/n_gsm.c')
| -rw-r--r-- | drivers/char/n_gsm.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/char/n_gsm.c b/drivers/char/n_gsm.c index c4161d5e053d..e4089c432f15 100644 --- a/drivers/char/n_gsm.c +++ b/drivers/char/n_gsm.c @@ -904,9 +904,7 @@ static void gsm_dlci_data_sweep(struct gsm_mux *gsm) int len; /* Priority ordering: We should do priority with RR of the groups */ int i = 1; - unsigned long flags; - spin_lock_irqsave(&gsm->tx_lock, flags); while (i < NUM_DLCI) { struct gsm_dlci *dlci; @@ -927,7 +925,6 @@ static void gsm_dlci_data_sweep(struct gsm_mux *gsm) if (len == 0) i++; } - spin_unlock_irqrestore(&gsm->tx_lock, flags); } /** @@ -2230,12 +2227,16 @@ static int gsmld_open(struct tty_struct *tty) static void gsmld_write_wakeup(struct tty_struct *tty) { struct gsm_mux *gsm = tty->disc_data; + unsigned long flags; /* Queue poll */ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); gsm_data_kick(gsm); - if (gsm->tx_bytes < TX_THRESH_LO) + if (gsm->tx_bytes < TX_THRESH_LO) { + spin_lock_irqsave(&gsm->tx_lock, flags); gsm_dlci_data_sweep(gsm); + spin_unlock_irqrestore(&gsm->tx_lock, flags); + } } /** |