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  1. 30 4月, 2017 3 次提交
    • D
      Bluetooth: hci_ldisc: Add protocol check to hci_uart_tx_wakeup() · 2d6f1da1
      由 Dean Jenkins 提交于 
      Before attempting to schedule a work-item onto hu->write_work in
hci_uart_tx_wakeup(), check that the Data Link protocol layer is
still bound to the HCI UART driver.

Failure to perform this protocol check causes a race condition between
the work queue hu->write_work running hci_uart_write_work() and the
Data Link protocol layer being unbound (closed) in hci_uart_tty_close().

Note hci_uart_tty_close() does have a "cancel_work_sync(&hu->write_work)"
but it is ineffective because it cannot prevent work-items being added
to hu->write_work after cancel_work_sync() has run.

Therefore, add a check for HCI_UART_PROTO_READY into hci_uart_tx_wakeup()
which prevents scheduling of the work queue when HCI_UART_PROTO_READY
is in the clear state. However, note a small race condition remains
because the hci_uart_tx_wakeup() thread can run in parallel with the
hci_uart_tty_close() thread so it is possible that a schedule of
hu->write_work can occur when HCI_UART_PROTO_READY is cleared. A complete
solution needs locking of the threads which is implemented in a future
commit.
Signed-off-by: NDean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
      2d6f1da1
    • D
      Bluetooth: hci_ldisc: Add protocol check to hci_uart_dequeue() · 048e1bd3
      由 Dean Jenkins 提交于 
      Before attempting to dequeue a Data Link protocol encapsulated message,
check that the Data Link protocol is still bound to the HCI UART driver.
This makes the code consistent with the usage of the other proto
function pointers.

Therefore, add a check for HCI_UART_PROTO_READY into hci_uart_dequeue()
and return NULL if the Data Link protocol is not bound.

This is needed for robustness as there is a scheduling race condition.
hci_uart_write_work() is scheduled to run via work queue hu->write_work
from hci_uart_tx_wakeup(). Therefore, there is a delay between
scheduling hci_uart_write_work() to run and hci_uart_dequeue() running
whereby the Data Link protocol layer could become unbound during the
scheduling delay. In this case, without the check, the call to the
unbound Data Link protocol layer dequeue function can crash.

It is noted that hci_uart_tty_close() has a
"cancel_work_sync(&hu->write_work)" statement but this only reduces
the window of the race condition because it is possible for a new
work-item to be added to work queue hu->write_work after the call to
cancel_work_sync(). For example, Data Link layer retransmissions can
be added to the work queue after the cancel_work_sync() has finished.
Signed-off-by: NDean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
      048e1bd3
    • D
      Bluetooth: hci_ldisc: Add protocol check to hci_uart_send_frame() · ab00f89f
      由 Dean Jenkins 提交于 
      Before attempting to send a HCI message, check that the Data Link
protocol is still bound to the HCI UART driver. This makes the code
consistent with the usage of the other proto function pointers.

Therefore, add a check for HCI_UART_PROTO_READY into hci_uart_send_frame()
and return -EUNATCH if the Data Link protocol is not bound.

This also allows hci_send_frame() to report the error of an unbound
Data Link protocol layer. Therefore, it assists with diagnostics into
why HCI messages are being sent when the Data Link protocol is not
bound and avoids potential crashes.
Signed-off-by: NDean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
      ab00f89f
  3. 22 4月, 2017 3 次提交
  5. 14 4月, 2017 1 次提交
  7. 13 4月, 2017 2 次提交
  9. 24 9月, 2016 1 次提交
  11. 20 9月, 2016 1 次提交
  13. 10 7月, 2016 1 次提交
    • M
      Bluetooth: Rename HCI_BREDR into HCI_PRIMARY · ca8bee5d
      由 Marcel Holtmann 提交于 
      The HCI_BREDR naming is confusing since it actually stands for Primary
Bluetooth Controller. Which is a term that has been used in the latest
standard. However from a legacy point of view there only really have
been Basic Rate (BR) and Enhanced Data Rate (EDR). Recent versions of
Bluetooth introduced Low Energy (LE) and made this terminology a little
bit confused since Dual Mode Controllers include BR/EDR and LE. To
simplify this the name HCI_PRIMARY stands for the Primary Controller
which can be a single mode or dual mode controller.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
      ca8bee5d
  15. 09 4月, 2016 1 次提交
  17. 24 2月, 2016 1 次提交
  19. 10 12月, 2015 1 次提交
  21. 20 11月, 2015 1 次提交
  23. 21 10月, 2015 1 次提交
  25. 05 10月, 2015 2 次提交
  27. 24 9月, 2015 1 次提交
    • F
      Bluetooth: Remove useless rx_lock spinlock · 7649faff
      由 Frederic Danis 提交于 
      rx_lock spinlock is only used in hci_uart_tty_receive() which is the
receive_buf ldisc callback.

hci_uart_tty_receive() is protected from re-entrance by its only
caller (flush_to_ldisc() in drivers/tty/tty_buffer.c) which held a
mutex (buf->lock) for this section.
This lock allows "safe use of the line discipline's receive_buf()
method by excluding the buffer work and any pending flush from using
the flip buffer." (comments from tty_buffer_lock_exclusive() in
drivers/tty/tty_buffer.c)

So, no need to double protect this resource with rx_lock.
Signed-off-by: NFrederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
      7649faff
  29. 11 8月, 2015 1 次提交
  31. 27 7月, 2015 1 次提交
  33. 23 7月, 2015 1 次提交
  35. 18 6月, 2015 2 次提交
  37. 06 6月, 2015 2 次提交
  39. 08 4月, 2015 12 次提交
  41. 02 4月, 2015 1 次提交