tty: Revert the tty locking series, it needs more work

This reverts the tty layer change to use per-tty locking, because it's
not correct yet, and fixing it will require some more deep surgery.

The main revert is d29f3ef39be4 ("tty_lock: Localise the lock"), but
there are several smaller commits that built upon it, they also get
reverted here. The list of reverted commits is:

  fde86d310886 - tty: add lockdep annotations
  8f6576ad476b - tty: fix ldisc lock inversion trace
  d3ca8b64b97e - pty: Fix lock inversion
  b1d679afd766 - tty: drop the pty lock during hangup
  abcefe5fc357 - tty/amiserial: Add missing argument for tty_unlock()
  fd11b42e3598 - cris: fix missing tty arg in wait_event_interruptible_tty call
  d29f3ef39be4 - tty_lock: Localise the lock

The revert had a trivial conflict in the 68360serial.c staging driver
that got removed in the meantime.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 6 deletions

diff --git a/drivers/tty/n_r3964.c b/drivers/tty/n_r3964.c
index 656ad93bbc96..5c6c31459a2f 100644
--- a/drivers/tty/n_r3964.c
+++ b/drivers/tty/n_r3964.c
@@ -1065,8 +1065,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
 
 	TRACE_L("read()");
 
-	/* FIXME: should use a private lock */
-	tty_lock(tty);
+	tty_lock();
 
 	pClient = findClient(pInfo, task_pid(current));
 	if (pClient) {
@@ -1078,7 +1077,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
 				goto unlock;
 			}
 			/* block until there is a message: */
-			wait_event_interruptible_tty(tty, pInfo->read_wait,
+			wait_event_interruptible_tty(pInfo->read_wait,
 					(pMsg = remove_msg(pInfo, pClient)));
 		}
 
@@ -1108,7 +1107,7 @@ static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
 	}
 	ret = -EPERM;
 unlock:
-	tty_unlock(tty);
+	tty_unlock();
 	return ret;
 }
 
@@ -1157,7 +1156,7 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
 	pHeader->locks = 0;
 	pHeader->owner = NULL;
 
-	tty_lock(tty);
+	tty_lock();
 
 	pClient = findClient(pInfo, task_pid(current));
 	if (pClient) {
@@ -1176,7 +1175,7 @@ static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
 	add_tx_queue(pInfo, pHeader);
 	trigger_transmit(pInfo);
 
-	tty_unlock(tty);
+	tty_unlock();
 
 	return 0;
 }