diff options
| author | Alexey Khoroshilov <khoroshilov@ispras.ru> | 2015-09-12 00:34:48 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-09-12 02:18:33 +0300 |
| commit | e8684c88774c0ddfeefdbed0aa469b25b9962f3e (patch) | |
| tree | e88c7b91bd30df72be335b9577d30126a4851523 | |
| parent | 38c089d1d8d058f5dff018a811568aa8e8bc47fc (diff) | |
| download | linux-e8684c88774c0ddfeefdbed0aa469b25b9962f3e.tar.xz | |
irda: ali-ircc: Fix deadlock in ali_ircc_sir_change_speed()
ali_ircc_sir_change_speed() is always called with self->lock held,
so acquiring the lock inside it leads to unavoidable deadlock.
Call graph:
ali_ircc_sir_change_speed() is called from ali_ircc_change_speed()
ali_ircc_fir_hard_xmit() under spin_lock_irqsave(&self->lock, flags);
ali_ircc_sir_hard_xmit() under spin_lock_irqsave(&self->lock, flags);
ali_ircc_net_ioctl() under spin_lock_irqsave(&self->lock, flags);
ali_ircc_dma_xmit_complete()
ali_ircc_fir_interrupt()
ali_ircc_interrupt() under spin_lock(&self->lock);
ali_ircc_sir_write_wakeup()
ali_ircc_sir_interrupt()
ali_ircc_interrupt() under spin_lock(&self->lock);
The patch removes spin_lock/unlock from ali_ircc_sir_change_speed().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/irda/ali-ircc.c | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/drivers/net/irda/ali-ircc.c b/drivers/net/irda/ali-ircc.c index 58ae11a14bb6..64bb44d5d867 100644 --- a/drivers/net/irda/ali-ircc.c +++ b/drivers/net/irda/ali-ircc.c @@ -1031,7 +1031,6 @@ static void ali_ircc_fir_change_speed(struct ali_ircc_cb *priv, __u32 baud) static void ali_ircc_sir_change_speed(struct ali_ircc_cb *priv, __u32 speed) { struct ali_ircc_cb *self = priv; - unsigned long flags; int iobase; int fcr; /* FIFO control reg */ int lcr; /* Line control reg */ @@ -1061,8 +1060,6 @@ static void ali_ircc_sir_change_speed(struct ali_ircc_cb *priv, __u32 speed) /* Update accounting for new speed */ self->io.speed = speed; - spin_lock_irqsave(&self->lock, flags); - divisor = 115200/speed; fcr = UART_FCR_ENABLE_FIFO; @@ -1089,9 +1086,6 @@ static void ali_ircc_sir_change_speed(struct ali_ircc_cb *priv, __u32 speed) /* without this, the connection will be broken after come back from FIR speed, but with this, the SIR connection is harder to established */ outb((UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2), iobase+UART_MCR); - - spin_unlock_irqrestore(&self->lock, flags); - } static void ali_ircc_change_dongle_speed(struct ali_ircc_cb *priv, int speed) |