This is a note to let you know that I've just added the patch titled
bluetooth: hci_ldisc: fix deadlock condition
to the 3.10-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-3.10 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)
@@ -289,6 +300,7 @@ 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);
@@ -326,6 +338,8 @@ 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-3.10/usb-dwc3-gadget-clear-stall-when-disabling-endpoint.patch
queue-3.10/bluetooth-hci_ldisc-fix-deadlock-condition.patch
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