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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-22 16:12:24 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-22 16:12:24 -0700 |
commit | 94b5aff4c6f72fee6b0f49d49e4fa8b204e8ded9 (patch) | |
tree | 39197121b6ef8cddaa0f4057fe24b4ced58e8982 /net | |
parent | 5d4e2d08e7fdf7339f84a1c670d296a77e02f881 (diff) | |
parent | 59bd234b72fc29887839d792b7d6c7e8d2a577a6 (diff) | |
download | linux-3.10-94b5aff4c6f72fee6b0f49d49e4fa8b204e8ded9.tar.gz linux-3.10-94b5aff4c6f72fee6b0f49d49e4fa8b204e8ded9.tar.bz2 linux-3.10-94b5aff4c6f72fee6b0f49d49e4fa8b204e8ded9.zip |
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.c | 137 |
1 files changed, 64 insertions, 73 deletions
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c index 4bf54b37725..aa5d73b786a 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); } } |