This is a note to let you know that I've just added the patch titled bluetooth: hci_ldisc: fix deadlock condition to the 3.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bluetooth-hci_ldisc-fix-deadlock-condition.patch and it can be found in the queue-3.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From da64c27d3c93ee9f89956b9de86c4127eb244494 Mon Sep 17 00:00:00 2001 From: Felipe Balbi <balbi@xxxxxx> Date: Wed, 23 Apr 2014 09:58:26 -0500 Subject: bluetooth: hci_ldisc: fix deadlock condition MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Felipe Balbi <balbi@xxxxxx> 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@xxxxxxxxxxxx> Reviewed-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> Reported-by: Huang Shijie <b32955@xxxxxxxxxxxxx> Signed-off-by: Felipe Balbi <balbi@xxxxxx> Tested-by: Andreas Bießmann <andreas@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/bluetooth/hci_ldisc.c | 24 +++++++++++++++++++----- drivers/bluetooth/hci_uart.h | 1 + 2 files changed, 20 insertions(+), 5 deletions(-) --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -118,10 +118,6 @@ static inline struct sk_buff *hci_uart_d 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; @@ -129,6 +125,22 @@ int hci_uart_tx_wakeup(struct hci_uart * 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); @@ -153,7 +165,6 @@ restart: goto restart; clear_bit(HCI_UART_SENDING, &hu->tx_state); - return 0; } static void hci_uart_init_work(struct work_struct *work) @@ -282,6 +293,7 @@ static int hci_uart_tty_open(struct tty_ tty->receive_room = 65536; INIT_WORK(&hu->init_ready, hci_uart_init_work); + INIT_WORK(&hu->write_work, hci_uart_write_work); spin_lock_init(&hu->rx_lock); @@ -319,6 +331,8 @@ static void hci_uart_tty_close(struct tt 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) { if (test_bit(HCI_UART_REGISTERED, &hu->flags)) --- a/drivers/bluetooth/hci_uart.h +++ b/drivers/bluetooth/hci_uart.h @@ -68,6 +68,7 @@ struct hci_uart { unsigned long hdev_flags; struct work_struct init_ready; + struct work_struct write_work; struct hci_uart_proto *proto; void *priv; Patches currently in stable-queue which might be from balbi@xxxxxx are queue-3.15/usb-dwc3-gadget-clear-stall-when-disabling-endpoint.patch queue-3.15/bluetooth-hci_ldisc-fix-deadlock-condition.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html