Messages in this thread | | | Date | Tue, 30 Aug 2016 19:08:47 +0200 | From | Boris Brezillon <> | Subject | Re: [PATCH 1/4] Bluetooth: hci_ldisc: fix a race in the hdev closing path |
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On Tue, 30 Aug 2016 09:53:59 -0700 Marcel Holtmann <marcel@holtmann.org> wrote:
> Hi Boris, > > > hci_uart_tty_close() is cancelling any pending write work, but some > > hci_uart_proto implementations might re-schedule this work after its > > cancellation (by calling hci_uart_tx_wakeup()). > > > > Make sure the write work is not re-scheduled in our back while we're > > closing the device. > > > > We also cancel any pending init work and prevent the active one (if > > any) from registering the hdev if the line discipline is being closed. > > > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > > --- > > drivers/bluetooth/hci_ldisc.c | 15 ++++++++++++++- > > drivers/bluetooth/hci_uart.h | 1 + > > 2 files changed, 15 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c > > index dda97398c59a..de7f7f1f995c 100644 > > --- a/drivers/bluetooth/hci_ldisc.c > > +++ b/drivers/bluetooth/hci_ldisc.c > > @@ -130,7 +130,9 @@ int hci_uart_tx_wakeup(struct hci_uart *hu) > > > > BT_DBG(""); > > > > - schedule_work(&hu->write_work); > > + /* Don't schedule the work if the device is being closed. */ > > + if (!test_bit(HCI_UART_CLOSING, &hu->flags)) > > + schedule_work(&hu->write_work); > > > > return 0; > > } > > @@ -180,6 +182,11 @@ static void hci_uart_init_work(struct work_struct *work) > > if (!test_and_clear_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags)) > > return; > > > > + if (test_bit(HCI_UART_CLOSING, &hu->flags)) { > > + BT_DBG("HCI device is being closed, don't register it."); > > + return; > > + } > > + > > err = hci_register_dev(hu->hdev); > > if (err < 0) { > > BT_ERR("Can't register HCI device"); > > @@ -490,7 +497,13 @@ static void hci_uart_tty_close(struct tty_struct *tty) > > if (hdev) > > hci_uart_close(hdev); > > > > + /* > > + * Set the closing bit to make sure nobody re-schedules the write work > > + * in our back. > > + */ > > please use the network subsystem comment style here.
Sure, I'll comply to the net subsystem coding style in my v2.
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