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Diffstat (limited to 'net/bluetooth/rfcomm/tty.c')
-rw-r--r--net/bluetooth/rfcomm/tty.c271
1 files changed, 126 insertions, 145 deletions
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index b6e44ad6cca6..6d126faf145f 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -58,7 +58,6 @@ struct rfcomm_dev {
uint modem_status;
struct rfcomm_dlc *dlc;
- wait_queue_head_t wait;
struct device *tty_dev;
@@ -76,13 +75,6 @@ static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);
/* ---- Device functions ---- */
-/*
- * The reason this isn't actually a race, as you no doubt have a little voice
- * screaming at you in your head, is that the refcount should never actually
- * reach zero unless the device has already been taken off the list, in
- * rfcomm_dev_del(). And if that's not true, we'll hit the BUG() in
- * rfcomm_dev_destruct() anyway.
- */
static void rfcomm_dev_destruct(struct tty_port *port)
{
struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
@@ -90,10 +82,9 @@ static void rfcomm_dev_destruct(struct tty_port *port)
BT_DBG("dev %p dlc %p", dev, dlc);
- /* Refcount should only hit zero when called from rfcomm_dev_del()
- which will have taken us off the list. Everything else are
- refcounting bugs. */
- BUG_ON(!list_empty(&dev->list));
+ spin_lock(&rfcomm_dev_lock);
+ list_del(&dev->list);
+ spin_unlock(&rfcomm_dev_lock);
rfcomm_dlc_lock(dlc);
/* Detach DLC if it's owned by this dev */
@@ -112,8 +103,39 @@ static void rfcomm_dev_destruct(struct tty_port *port)
module_put(THIS_MODULE);
}
+/* device-specific initialization: open the dlc */
+static int rfcomm_dev_activate(struct tty_port *port, struct tty_struct *tty)
+{
+ struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
+
+ return rfcomm_dlc_open(dev->dlc, &dev->src, &dev->dst, dev->channel);
+}
+
+/* we block the open until the dlc->state becomes BT_CONNECTED */
+static int rfcomm_dev_carrier_raised(struct tty_port *port)
+{
+ struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
+
+ return (dev->dlc->state == BT_CONNECTED);
+}
+
+/* device-specific cleanup: close the dlc */
+static void rfcomm_dev_shutdown(struct tty_port *port)
+{
+ struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
+
+ if (dev->tty_dev->parent)
+ device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);
+
+ /* close the dlc */
+ rfcomm_dlc_close(dev->dlc, 0);
+}
+
static const struct tty_port_operations rfcomm_port_ops = {
.destruct = rfcomm_dev_destruct,
+ .activate = rfcomm_dev_activate,
+ .shutdown = rfcomm_dev_shutdown,
+ .carrier_raised = rfcomm_dev_carrier_raised,
};
static struct rfcomm_dev *__rfcomm_dev_get(int id)
@@ -236,7 +258,6 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
tty_port_init(&dev->port);
dev->port.ops = &rfcomm_port_ops;
- init_waitqueue_head(&dev->wait);
skb_queue_head_init(&dev->pending);
@@ -282,7 +303,9 @@ out:
dev->id, NULL);
if (IS_ERR(dev->tty_dev)) {
err = PTR_ERR(dev->tty_dev);
+ spin_lock(&rfcomm_dev_lock);
list_del(&dev->list);
+ spin_unlock(&rfcomm_dev_lock);
goto free;
}
@@ -301,27 +324,6 @@ free:
return err;
}
-static void rfcomm_dev_del(struct rfcomm_dev *dev)
-{
- unsigned long flags;
- BT_DBG("dev %p", dev);
-
- BUG_ON(test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags));
-
- spin_lock_irqsave(&dev->port.lock, flags);
- if (dev->port.count > 0) {
- spin_unlock_irqrestore(&dev->port.lock, flags);
- return;
- }
- spin_unlock_irqrestore(&dev->port.lock, flags);
-
- spin_lock(&rfcomm_dev_lock);
- list_del_init(&dev->list);
- spin_unlock(&rfcomm_dev_lock);
-
- tty_port_put(&dev->port);
-}
-
/* ---- Send buffer ---- */
static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc)
{
@@ -333,10 +335,9 @@ static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc)
static void rfcomm_wfree(struct sk_buff *skb)
{
struct rfcomm_dev *dev = (void *) skb->sk;
- struct tty_struct *tty = dev->port.tty;
atomic_sub(skb->truesize, &dev->wmem_alloc);
- if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags) && tty)
- tty_wakeup(tty);
+ if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags))
+ tty_port_tty_wakeup(&dev->port);
tty_port_put(&dev->port);
}
@@ -410,6 +411,7 @@ static int rfcomm_release_dev(void __user *arg)
{
struct rfcomm_dev_req req;
struct rfcomm_dev *dev;
+ struct tty_struct *tty;
if (copy_from_user(&req, arg, sizeof(req)))
return -EFAULT;
@@ -429,11 +431,15 @@ static int rfcomm_release_dev(void __user *arg)
rfcomm_dlc_close(dev->dlc, 0);
/* Shut down TTY synchronously before freeing rfcomm_dev */
- if (dev->port.tty)
- tty_vhangup(dev->port.tty);
+ tty = tty_port_tty_get(&dev->port);
+ if (tty) {
+ tty_vhangup(tty);
+ tty_kref_put(tty);
+ }
+
+ if (!test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags))
+ tty_port_put(&dev->port);
- if (!test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags))
- rfcomm_dev_del(dev);
tty_port_put(&dev->port);
return 0;
}
@@ -563,16 +569,21 @@ static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
{
struct rfcomm_dev *dev = dlc->owner;
+ struct tty_struct *tty;
if (!dev)
return;
BT_DBG("dlc %p dev %p err %d", dlc, dev, err);
dev->err = err;
- wake_up_interruptible(&dev->wait);
+ if (dlc->state == BT_CONNECTED) {
+ device_move(dev->tty_dev, rfcomm_get_device(dev),
+ DPM_ORDER_DEV_AFTER_PARENT);
- if (dlc->state == BT_CLOSED) {
- if (!dev->port.tty) {
+ wake_up_interruptible(&dev->port.open_wait);
+ } else if (dlc->state == BT_CLOSED) {
+ tty = tty_port_tty_get(&dev->port);
+ if (!tty) {
if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
/* Drop DLC lock here to avoid deadlock
* 1. rfcomm_dev_get will take rfcomm_dev_lock
@@ -580,6 +591,9 @@ static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
* rfcomm_dev_lock -> dlc lock
* 2. tty_port_put will deadlock if it's
* the last reference
+ *
+ * FIXME: when we release the lock anything
+ * could happen to dev, even its destruction
*/
rfcomm_dlc_unlock(dlc);
if (rfcomm_dev_get(dev->id) == NULL) {
@@ -587,12 +601,17 @@ static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
return;
}
- rfcomm_dev_del(dev);
+ if (!test_and_set_bit(RFCOMM_TTY_RELEASED,
+ &dev->flags))
+ tty_port_put(&dev->port);
+
tty_port_put(&dev->port);
rfcomm_dlc_lock(dlc);
}
- } else
- tty_hangup(dev->port.tty);
+ } else {
+ tty_hangup(tty);
+ tty_kref_put(tty);
+ }
}
}
@@ -604,10 +623,8 @@ static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
BT_DBG("dlc %p dev %p v24_sig 0x%02x", dlc, dev, v24_sig);
- if ((dev->modem_status & TIOCM_CD) && !(v24_sig & RFCOMM_V24_DV)) {
- if (dev->port.tty && !C_CLOCAL(dev->port.tty))
- tty_hangup(dev->port.tty);
- }
+ if ((dev->modem_status & TIOCM_CD) && !(v24_sig & RFCOMM_V24_DV))
+ tty_port_tty_hangup(&dev->port, true);
dev->modem_status =
((v24_sig & RFCOMM_V24_RTC) ? (TIOCM_DSR | TIOCM_DTR) : 0) |
@@ -638,124 +655,92 @@ static void rfcomm_tty_copy_pending(struct rfcomm_dev *dev)
tty_flip_buffer_push(&dev->port);
}
-static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
+/* do the reverse of install, clearing the tty fields and releasing the
+ * reference to tty_port
+ */
+static void rfcomm_tty_cleanup(struct tty_struct *tty)
{
- DECLARE_WAITQUEUE(wait, current);
- struct rfcomm_dev *dev;
- struct rfcomm_dlc *dlc;
- unsigned long flags;
- int err, id;
+ struct rfcomm_dev *dev = tty->driver_data;
- id = tty->index;
+ clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
- BT_DBG("tty %p id %d", tty, id);
+ rfcomm_dlc_lock(dev->dlc);
+ tty->driver_data = NULL;
+ rfcomm_dlc_unlock(dev->dlc);
- /* We don't leak this refcount. For reasons which are not entirely
- clear, the TTY layer will call our ->close() method even if the
- open fails. We decrease the refcount there, and decreasing it
- here too would cause breakage. */
- dev = rfcomm_dev_get(id);
- if (!dev)
- return -ENODEV;
+ /*
+ * purge the dlc->tx_queue to avoid circular dependencies
+ * between dev and dlc
+ */
+ skb_queue_purge(&dev->dlc->tx_queue);
- BT_DBG("dev %p dst %pMR channel %d opened %d", dev, &dev->dst,
- dev->channel, dev->port.count);
+ tty_port_put(&dev->port);
+}
- spin_lock_irqsave(&dev->port.lock, flags);
- if (++dev->port.count > 1) {
- spin_unlock_irqrestore(&dev->port.lock, flags);
- return 0;
- }
- spin_unlock_irqrestore(&dev->port.lock, flags);
+/* we acquire the tty_port reference since it's here the tty is first used
+ * by setting the termios. We also populate the driver_data field and install
+ * the tty port
+ */
+static int rfcomm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+ struct rfcomm_dev *dev;
+ struct rfcomm_dlc *dlc;
+ int err;
+
+ dev = rfcomm_dev_get(tty->index);
+ if (!dev)
+ return -ENODEV;
dlc = dev->dlc;
/* Attach TTY and open DLC */
-
rfcomm_dlc_lock(dlc);
tty->driver_data = dev;
- dev->port.tty = tty;
rfcomm_dlc_unlock(dlc);
set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
- err = rfcomm_dlc_open(dlc, &dev->src, &dev->dst, dev->channel);
- if (err < 0)
- return err;
-
- /* Wait for DLC to connect */
- add_wait_queue(&dev->wait, &wait);
- while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
+ /* install the tty_port */
+ err = tty_port_install(&dev->port, driver, tty);
+ if (err)
+ rfcomm_tty_cleanup(tty);
- if (dlc->state == BT_CLOSED) {
- err = -dev->err;
- break;
- }
+ return err;
+}
- if (dlc->state == BT_CONNECTED)
- break;
+static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
+{
+ struct rfcomm_dev *dev = tty->driver_data;
+ int err;
- if (signal_pending(current)) {
- err = -EINTR;
- break;
- }
+ BT_DBG("tty %p id %d", tty, tty->index);
- tty_unlock(tty);
- schedule();
- tty_lock(tty);
- }
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&dev->wait, &wait);
+ BT_DBG("dev %p dst %pMR channel %d opened %d", dev, &dev->dst,
+ dev->channel, dev->port.count);
- if (err == 0)
- device_move(dev->tty_dev, rfcomm_get_device(dev),
- DPM_ORDER_DEV_AFTER_PARENT);
+ err = tty_port_open(&dev->port, tty, filp);
+ if (err)
+ return err;
+ /*
+ * FIXME: rfcomm should use proper flow control for
+ * received data. This hack will be unnecessary and can
+ * be removed when that's implemented
+ */
rfcomm_tty_copy_pending(dev);
rfcomm_dlc_unthrottle(dev->dlc);
- return err;
+ return 0;
}
static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
{
struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
- unsigned long flags;
-
- if (!dev)
- return;
BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc,
dev->port.count);
- spin_lock_irqsave(&dev->port.lock, flags);
- if (!--dev->port.count) {
- spin_unlock_irqrestore(&dev->port.lock, flags);
- if (dev->tty_dev->parent)
- device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);
-
- /* Close DLC and dettach TTY */
- rfcomm_dlc_close(dev->dlc, 0);
-
- clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
-
- rfcomm_dlc_lock(dev->dlc);
- tty->driver_data = NULL;
- dev->port.tty = NULL;
- rfcomm_dlc_unlock(dev->dlc);
-
- if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags)) {
- spin_lock(&rfcomm_dev_lock);
- list_del_init(&dev->list);
- spin_unlock(&rfcomm_dev_lock);
-
- tty_port_put(&dev->port);
- }
- } else
- spin_unlock_irqrestore(&dev->port.lock, flags);
-
- tty_port_put(&dev->port);
+ tty_port_close(&dev->port, tty, filp);
}
static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
@@ -1055,17 +1040,11 @@ static void rfcomm_tty_hangup(struct tty_struct *tty)
BT_DBG("tty %p dev %p", tty, dev);
- if (!dev)
- return;
-
- rfcomm_tty_flush_buffer(tty);
+ tty_port_hangup(&dev->port);
- if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
- if (rfcomm_dev_get(dev->id) == NULL)
- return;
- rfcomm_dev_del(dev);
+ if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags) &&
+ !test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags))
tty_port_put(&dev->port);
- }
}
static int rfcomm_tty_tiocmget(struct tty_struct *tty)
@@ -1128,6 +1107,8 @@ static const struct tty_operations rfcomm_ops = {
.wait_until_sent = rfcomm_tty_wait_until_sent,
.tiocmget = rfcomm_tty_tiocmget,
.tiocmset = rfcomm_tty_tiocmset,
+ .install = rfcomm_tty_install,
+ .cleanup = rfcomm_tty_cleanup,
};
int __init rfcomm_init_ttys(void)
@@ -1146,7 +1127,7 @@ int __init rfcomm_init_ttys(void)
rfcomm_tty_driver->subtype = SERIAL_TYPE_NORMAL;
rfcomm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
rfcomm_tty_driver->init_termios = tty_std_termios;
- rfcomm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+ rfcomm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
rfcomm_tty_driver->init_termios.c_lflag &= ~ICANON;
tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);