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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-22 16:12:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-22 16:12:24 -0700
commit94b5aff4c6f72fee6b0f49d49e4fa8b204e8ded9 (patch)
tree39197121b6ef8cddaa0f4057fe24b4ced58e8982 /net
parent5d4e2d08e7fdf7339f84a1c670d296a77e02f881 (diff)
parent59bd234b72fc29887839d792b7d6c7e8d2a577a6 (diff)
Merge tag 'tty-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull TTY updates from Greg Kroah-Hartman: "Here's the big TTY/serial driver pull request for the 3.5-rc1 merge window. Nothing major in here, just lots of incremental changes from Alan and Jiri reworking some tty core things to behave better and to get a more solid grasp on some of the nasty tty locking issues. There are a few tty and serial driver updates in here as well. All of this has been in the linux-next releases for a while with no problems. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'tty-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (115 commits) serial: bfin_uart: Make MMR access compatible with 32 bits bf609 style controller. serial: bfin_uart: RTS and CTS MMRs can be either 16-bit width or 32-bit width. serial: bfin_uart: narrow the reboot condition in DMA tx interrupt serial: bfin_uart: Adapt bf5xx serial driver to bf60x serial4 controller. Revert "serial_core: Update buffer overrun statistics." tty: hvc_xen: NULL dereference on allocation failure tty: Fix LED error return tty: Allow uart_register/unregister/register tty: move global ldisc idle waitqueue to the individual ldisc serial8250-em: Add DT support serial8250-em: clk_get() IS_ERR() error handling fix serial_core: Update buffer overrun statistics. tty: drop the pty lock during hangup cris: fix missing tty arg in wait_event_interruptible_tty call tty/amiserial: Add missing argument for tty_unlock() tty_lock: Localise the lock pty: Lock the devpts bits privately tty_lock: undo the old tty_lock use on the ctty serial8250-em: Emma Mobile UART driver V2 Add missing call to uart_update_timeout() ...
Diffstat (limited to 'net')
-rw-r--r--net/bluetooth/rfcomm/tty.c137
1 files changed, 64 insertions, 73 deletions
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index 4bf54b377255..aa5d73b786ac 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -48,13 +48,12 @@
static struct tty_driver *rfcomm_tty_driver;
struct rfcomm_dev {
+ struct tty_port port;
struct list_head list;
- atomic_t refcnt;
char name[12];
int id;
unsigned long flags;
- atomic_t opened;
int err;
bdaddr_t src;
@@ -64,9 +63,7 @@ struct rfcomm_dev {
uint modem_status;
struct rfcomm_dlc *dlc;
- struct tty_struct *tty;
wait_queue_head_t wait;
- struct work_struct wakeup_task;
struct device *tty_dev;
@@ -82,11 +79,18 @@ 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);
static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);
-static void rfcomm_tty_wakeup(struct work_struct *work);
-
/* ---- Device functions ---- */
-static void rfcomm_dev_destruct(struct rfcomm_dev *dev)
+
+/*
+ * 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);
struct rfcomm_dlc *dlc = dev->dlc;
BT_DBG("dev %p dlc %p", dev, dlc);
@@ -113,23 +117,9 @@ static void rfcomm_dev_destruct(struct rfcomm_dev *dev)
module_put(THIS_MODULE);
}
-static inline void rfcomm_dev_hold(struct rfcomm_dev *dev)
-{
- atomic_inc(&dev->refcnt);
-}
-
-static inline void rfcomm_dev_put(struct rfcomm_dev *dev)
-{
- /* 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. */
- if (atomic_dec_and_test(&dev->refcnt))
- rfcomm_dev_destruct(dev);
-}
+static const struct tty_port_operations rfcomm_port_ops = {
+ .destruct = rfcomm_dev_destruct,
+};
static struct rfcomm_dev *__rfcomm_dev_get(int id)
{
@@ -154,7 +144,7 @@ static inline struct rfcomm_dev *rfcomm_dev_get(int id)
if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
dev = NULL;
else
- rfcomm_dev_hold(dev);
+ tty_port_get(&dev->port);
}
spin_unlock(&rfcomm_dev_lock);
@@ -241,7 +231,6 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
sprintf(dev->name, "rfcomm%d", dev->id);
list_add(&dev->list, head);
- atomic_set(&dev->refcnt, 1);
bacpy(&dev->src, &req->src);
bacpy(&dev->dst, &req->dst);
@@ -250,10 +239,9 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
dev->flags = req->flags &
((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC));
- atomic_set(&dev->opened, 0);
-
+ tty_port_init(&dev->port);
+ dev->port.ops = &rfcomm_port_ops;
init_waitqueue_head(&dev->wait);
- INIT_WORK(&dev->wakeup_task, rfcomm_tty_wakeup);
skb_queue_head_init(&dev->pending);
@@ -320,18 +308,23 @@ free:
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));
- if (atomic_read(&dev->opened) > 0)
+ 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);
- rfcomm_dev_put(dev);
+ tty_port_put(&dev->port);
}
/* ---- Send buffer ---- */
@@ -345,15 +338,16 @@ 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))
- queue_work(system_nrt_wq, &dev->wakeup_task);
- rfcomm_dev_put(dev);
+ if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags) && tty)
+ tty_wakeup(tty);
+ tty_port_put(&dev->port);
}
static inline void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev)
{
- rfcomm_dev_hold(dev);
+ tty_port_get(&dev->port);
atomic_add(skb->truesize, &dev->wmem_alloc);
skb->sk = (void *) dev;
skb->destructor = rfcomm_wfree;
@@ -432,7 +426,7 @@ static int rfcomm_release_dev(void __user *arg)
return -ENODEV;
if (dev->flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) {
- rfcomm_dev_put(dev);
+ tty_port_put(&dev->port);
return -EPERM;
}
@@ -440,12 +434,12 @@ static int rfcomm_release_dev(void __user *arg)
rfcomm_dlc_close(dev->dlc, 0);
/* Shut down TTY synchronously before freeing rfcomm_dev */
- if (dev->tty)
- tty_vhangup(dev->tty);
+ if (dev->port.tty)
+ tty_vhangup(dev->port.tty);
if (!test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags))
rfcomm_dev_del(dev);
- rfcomm_dev_put(dev);
+ tty_port_put(&dev->port);
return 0;
}
@@ -523,7 +517,7 @@ static int rfcomm_get_dev_info(void __user *arg)
if (copy_to_user(arg, &di, sizeof(di)))
err = -EFAULT;
- rfcomm_dev_put(dev);
+ tty_port_put(&dev->port);
return err;
}
@@ -559,7 +553,7 @@ static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
return;
}
- tty = dev->tty;
+ tty = dev->port.tty;
if (!tty || !skb_queue_empty(&dev->pending)) {
skb_queue_tail(&dev->pending, skb);
return;
@@ -585,13 +579,13 @@ static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
wake_up_interruptible(&dev->wait);
if (dlc->state == BT_CLOSED) {
- if (!dev->tty) {
+ if (!dev->port.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
* but in rfcomm_dev_add there's lock order:
* rfcomm_dev_lock -> dlc lock
- * 2. rfcomm_dev_put will deadlock if it's
+ * 2. tty_port_put will deadlock if it's
* the last reference
*/
rfcomm_dlc_unlock(dlc);
@@ -601,11 +595,11 @@ static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
}
rfcomm_dev_del(dev);
- rfcomm_dev_put(dev);
+ tty_port_put(&dev->port);
rfcomm_dlc_lock(dlc);
}
} else
- tty_hangup(dev->tty);
+ tty_hangup(dev->port.tty);
}
}
@@ -618,8 +612,8 @@ 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->tty && !C_CLOCAL(dev->tty))
- tty_hangup(dev->tty);
+ if (dev->port.tty && !C_CLOCAL(dev->port.tty))
+ tty_hangup(dev->port.tty);
}
dev->modem_status =
@@ -630,21 +624,9 @@ static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
}
/* ---- TTY functions ---- */
-static void rfcomm_tty_wakeup(struct work_struct *work)
-{
- struct rfcomm_dev *dev = container_of(work, struct rfcomm_dev,
- wakeup_task);
- struct tty_struct *tty = dev->tty;
- if (!tty)
- return;
-
- BT_DBG("dev %p tty %p", dev, tty);
- tty_wakeup(tty);
-}
-
static void rfcomm_tty_copy_pending(struct rfcomm_dev *dev)
{
- struct tty_struct *tty = dev->tty;
+ struct tty_struct *tty = dev->port.tty;
struct sk_buff *skb;
int inserted = 0;
@@ -671,6 +653,7 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
DECLARE_WAITQUEUE(wait, current);
struct rfcomm_dev *dev;
struct rfcomm_dlc *dlc;
+ unsigned long flags;
int err, id;
id = tty->index;
@@ -686,10 +669,14 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
return -ENODEV;
BT_DBG("dev %p dst %s channel %d opened %d", dev, batostr(&dev->dst),
- dev->channel, atomic_read(&dev->opened));
+ dev->channel, dev->port.count);
- if (atomic_inc_return(&dev->opened) > 1)
+ 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);
dlc = dev->dlc;
@@ -697,7 +684,7 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
rfcomm_dlc_lock(dlc);
tty->driver_data = dev;
- dev->tty = tty;
+ dev->port.tty = tty;
rfcomm_dlc_unlock(dlc);
set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
@@ -723,9 +710,9 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
break;
}
- tty_unlock();
+ tty_unlock(tty);
schedule();
- tty_lock();
+ tty_lock(tty);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&dev->wait, &wait);
@@ -744,13 +731,17 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
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,
- atomic_read(&dev->opened));
+ dev->port.count);
- if (atomic_dec_and_test(&dev->opened)) {
+ 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);
@@ -758,11 +749,10 @@ static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
rfcomm_dlc_close(dev->dlc, 0);
clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
- cancel_work_sync(&dev->wakeup_task);
rfcomm_dlc_lock(dev->dlc);
tty->driver_data = NULL;
- dev->tty = NULL;
+ dev->port.tty = NULL;
rfcomm_dlc_unlock(dev->dlc);
if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags)) {
@@ -770,11 +760,12 @@ static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
list_del_init(&dev->list);
spin_unlock(&rfcomm_dev_lock);
- rfcomm_dev_put(dev);
+ tty_port_put(&dev->port);
}
- }
+ } else
+ spin_unlock_irqrestore(&dev->port.lock, flags);
- rfcomm_dev_put(dev);
+ tty_port_put(&dev->port);
}
static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
@@ -1083,7 +1074,7 @@ static void rfcomm_tty_hangup(struct tty_struct *tty)
if (rfcomm_dev_get(dev->id) == NULL)
return;
rfcomm_dev_del(dev);
- rfcomm_dev_put(dev);
+ tty_port_put(&dev->port);
}
}