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| author | Gianluca Anzolin <gianluca@sottospazio.it> | 2014-01-06 21:23:50 +0100 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2014-01-06 13:51:45 -0800 |
| commit | 5b899241874dcc1a2b932a668731c80a3a869575 (patch) | |
| tree | a138c1ce7fb63a0a966fc64e86a26d80b3f80f6d /net | |
| parent | cb6ca8e1ed922082bacc6e5e5ee040491a443ea2 (diff) | |
| download | linux-5b899241874dcc1a2b932a668731c80a3a869575.tar.bz2 | |
Bluetooth: Release RFCOMM port when the last user closes the TTY
This patch fixes a userspace regression introduced by the commit
29cd718b.
If the rfcomm device was created with the flag RFCOMM_RELEASE_ONHUP the
user space expects that the tty_port is released as soon as the last
process closes the tty.
The current code attempts to release the port in the function
rfcomm_dev_state_change(). However it won't get a reference to the
relevant tty to send a HUP: at that point the tty is already destroyed
and therefore NULL.
This patch fixes the regression by taking over the tty refcount in the
tty install method(). This way the tty_port is automatically released as
soon as the tty is destroyed.
As a consequence the check for RFCOMM_RELEASE_ONHUP flag in the hangup()
method is now redundant. Instead we have to be careful with the reference
counting in the rfcomm_release_dev() function.
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
Reported-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bluetooth/rfcomm/tty.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c index 84fcf9fff3ea..a535ef148ef6 100644 --- a/net/bluetooth/rfcomm/tty.c +++ b/net/bluetooth/rfcomm/tty.c @@ -437,7 +437,8 @@ static int rfcomm_release_dev(void __user *arg) tty_kref_put(tty); } - if (!test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags)) + if (!test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags) && + !test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags)) tty_port_put(&dev->port); tty_port_put(&dev->port); @@ -670,10 +671,20 @@ static int rfcomm_tty_install(struct tty_driver *driver, struct tty_struct *tty) /* install the tty_port */ err = tty_port_install(&dev->port, driver, tty); - if (err) + if (err) { rfcomm_tty_cleanup(tty); + return err; + } - return err; + /* take over the tty_port reference if the port was created with the + * flag RFCOMM_RELEASE_ONHUP. This will force the release of the port + * when the last process closes the tty. The behaviour is expected by + * userspace. + */ + if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) + tty_port_put(&dev->port); + + return 0; } static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp) @@ -1010,10 +1021,6 @@ static void rfcomm_tty_hangup(struct tty_struct *tty) BT_DBG("tty %p dev %p", tty, dev); tty_port_hangup(&dev->port); - - 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) |