diff options
| author | Felipe Balbi <balbi@ti.com> | 2014-04-23 09:58:26 -0500 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-07-11 13:33:33 +0100 |
| commit | 87520218746b8d973670e37237666f174590898c (patch) | |
| tree | 47d80c86cb14fc43d58d6b697f718c80541a960c | |
| parent | 0efda016ac2fb3db57ee19f5df746eca4250955d (diff) | |
bluetooth: hci_ldisc: fix deadlock condition
commit da64c27d3c93ee9f89956b9de86c4127eb244494 upstream.
LDISCs shouldn't call tty->ops->write() from within
->write_wakeup().
->write_wakeup() is called with port lock taken and
IRQs disabled, tty->ops->write() will try to acquire
the same port lock and we will deadlock.
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Reported-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Tested-by: Andreas Bießmann <andreas@biessmann.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/bluetooth/hci_ldisc.c | 25 | ||||
| -rw-r--r-- | drivers/bluetooth/hci_uart.h | 2 |
2 files changed, 22 insertions, 5 deletions
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index 8f3d6dbeb1226..08bbc48c43f68 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -120,10 +120,6 @@ static inline struct sk_buff *hci_uart_dequeue(struct hci_uart *hu) int hci_uart_tx_wakeup(struct hci_uart *hu) { - struct tty_struct *tty = hu->tty; - struct hci_dev *hdev = hu->hdev; - struct sk_buff *skb; - if (test_and_set_bit(HCI_UART_SENDING, &hu->tx_state)) { set_bit(HCI_UART_TX_WAKEUP, &hu->tx_state); return 0; @@ -131,6 +127,22 @@ int hci_uart_tx_wakeup(struct hci_uart *hu) BT_DBG(""); + schedule_work(&hu->write_work); + + return 0; +} + +static void hci_uart_write_work(struct work_struct *work) +{ + struct hci_uart *hu = container_of(work, struct hci_uart, write_work); + struct tty_struct *tty = hu->tty; + struct hci_dev *hdev = hu->hdev; + struct sk_buff *skb; + + /* REVISIT: should we cope with bad skbs or ->write() returning + * and error value ? + */ + restart: clear_bit(HCI_UART_TX_WAKEUP, &hu->tx_state); @@ -155,7 +167,6 @@ restart: goto restart; clear_bit(HCI_UART_SENDING, &hu->tx_state); - return 0; } /* ------- Interface to HCI layer ------ */ @@ -274,6 +285,8 @@ static int hci_uart_tty_open(struct tty_struct *tty) hu->tty = tty; tty->receive_room = 65536; + INIT_WORK(&hu->write_work, hci_uart_write_work); + spin_lock_init(&hu->rx_lock); /* Flush any pending characters in the driver and line discipline. */ @@ -308,6 +321,8 @@ static void hci_uart_tty_close(struct tty_struct *tty) if (hdev) hci_uart_close(hdev); + cancel_work_sync(&hu->write_work); + if (test_and_clear_bit(HCI_UART_PROTO_SET, &hu->flags)) { if (hdev) { hci_unregister_dev(hdev); diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h index 99fb35239d1fe..ff404007609a1 100644 --- a/drivers/bluetooth/hci_uart.h +++ b/drivers/bluetooth/hci_uart.h @@ -64,6 +64,8 @@ struct hci_uart { unsigned long flags; unsigned long hdev_flags; + struct work_struct write_work; + struct hci_uart_proto *proto; void *priv; |