diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2016-01-09 21:13:44 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-01-26 23:17:54 -0800 |
| commit | 0bfd464d3fdd5bb322f9cace4cc47f1796545cf7 (patch) | |
| tree | 39464f856fd4dc6b58c31e2cfbbbb882ce3b7ec1 | |
| parent | 92e963f50fc74041b5e9e744c330dca48e04f08d (diff) | |
tty: Wait interruptibly for tty lock on reopen
Allow a signal to interrupt the wait for a tty reopen; eg., if
the tty has starting final close and is waiting for the device to
drain.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org> # 4.4
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/tty_io.c | 8 | ||||
| -rw-r--r-- | drivers/tty/tty_mutex.c | 8 | ||||
| -rw-r--r-- | include/linux/tty.h | 1 |
3 files changed, 16 insertions, 1 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 892c92354745..765935b144d6 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2065,7 +2065,12 @@ retry_open: if (tty) { mutex_unlock(&tty_mutex); - tty_lock(tty); + retval = tty_lock_interruptible(tty); + if (retval) { + if (retval == -EINTR) + retval = -ERESTARTSYS; + goto err_unref; + } /* safe to drop the kref from tty_driver_lookup_tty() */ tty_kref_put(tty); retval = tty_reopen(tty); @@ -2152,6 +2157,7 @@ retry_open: return 0; err_unlock: mutex_unlock(&tty_mutex); +err_unref: /* after locks to avoid deadlock */ if (!IS_ERR_OR_NULL(driver)) tty_driver_kref_put(driver); diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c index 77703a391207..d2f3c4cd697f 100644 --- a/drivers/tty/tty_mutex.c +++ b/drivers/tty/tty_mutex.c @@ -19,6 +19,14 @@ void __lockfunc tty_lock(struct tty_struct *tty) } EXPORT_SYMBOL(tty_lock); +int tty_lock_interruptible(struct tty_struct *tty) +{ + if (WARN(tty->magic != TTY_MAGIC, "L Bad %p\n", tty)) + return -EIO; + tty_kref_get(tty); + return mutex_lock_interruptible(&tty->legacy_mutex); +} + void __lockfunc tty_unlock(struct tty_struct *tty) { if (WARN(tty->magic != TTY_MAGIC, "U Bad %p\n", tty)) diff --git a/include/linux/tty.h b/include/linux/tty.h index 2fd8708ea888..d9fb4b043f56 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -649,6 +649,7 @@ extern long vt_compat_ioctl(struct tty_struct *tty, /* tty_mutex.c */ /* functions for preparation of BKL removal */ extern void __lockfunc tty_lock(struct tty_struct *tty); +extern int tty_lock_interruptible(struct tty_struct *tty); extern void __lockfunc tty_unlock(struct tty_struct *tty); extern void __lockfunc tty_lock_slave(struct tty_struct *tty); extern void __lockfunc tty_unlock_slave(struct tty_struct *tty); |