1 files changed, 21 insertions, 96 deletions

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index b280abaad91b..fb76a7d80e7e 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -113,8 +113,6 @@ struct n_tty_data {
 	DECLARE_BITMAP(read_flags, N_TTY_BUF_SIZE);
 	unsigned char echo_buf[N_TTY_BUF_SIZE];
 
-	int minimum_to_wake;
-
 	/* consumer-published */
 	size_t read_tail;
 	size_t line_start;
@@ -153,15 +151,6 @@ static inline unsigned char *echo_buf_addr(struct n_tty_data *ldata, size_t i)
 	return &ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)];
 }
 
-static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
-			       unsigned char __user *ptr)
-{
-	struct n_tty_data *ldata = tty->disc_data;
-
-	tty_audit_add_data(tty, &x, 1, ldata->icanon);
-	return put_user(x, ptr);
-}
-
 static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
 			    size_t tail, size_t n)
 {
@@ -171,7 +160,7 @@ static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
 	int uncopied;
 
 	if (n > size) {
-		tty_audit_add_data(tty, from, size, ldata->icanon);
+		tty_audit_add_data(tty, from, size);
 		uncopied = copy_to_user(to, from, size);
 		if (uncopied)
 			return uncopied;
@@ -180,7 +169,7 @@ static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
 		from = ldata->read_buf;
 	}
 
-	tty_audit_add_data(tty, from, n, ldata->icanon);
+	tty_audit_add_data(tty, from, n);
 	return copy_to_user(to, from, n);
 }
 
@@ -239,8 +228,8 @@ static ssize_t chars_in_buffer(struct tty_struct *tty)
 
 static void n_tty_write_wakeup(struct tty_struct *tty)
 {
-	if (tty->fasync && test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags))
-		kill_fasync(&tty->fasync, SIGIO, POLL_OUT);
+	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	kill_fasync(&tty->fasync, SIGIO, POLL_OUT);
 }
 
 static void n_tty_check_throttle(struct tty_struct *tty)
@@ -272,8 +261,6 @@ static void n_tty_check_unthrottle(struct tty_struct *tty)
 	if (tty->driver->type == TTY_DRIVER_TYPE_PTY) {
 		if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
 			return;
-		if (!tty->count)
-			return;
 		n_tty_kick_worker(tty);
 		tty_wakeup(tty->link);
 		return;
@@ -292,8 +279,6 @@ static void n_tty_check_unthrottle(struct tty_struct *tty)
 		tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE);
 		if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
 			break;
-		if (!tty->count)
-			break;
 		n_tty_kick_worker(tty);
 		unthrottled = tty_unthrottle_safe(tty);
 		if (!unthrottled)
@@ -381,28 +366,6 @@ static void n_tty_flush_buffer(struct tty_struct *tty)
 }
 
 /**
- *	n_tty_chars_in_buffer	-	report available bytes
- *	@tty: tty device
- *
- *	Report the number of characters buffered to be delivered to user
- *	at this instant in time.
- *
- *	Locking: exclusive termios_rwsem
- */
-
-static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
-{
-	ssize_t n;
-
-	WARN_ONCE(1, "%s is deprecated and scheduled for removal.", __func__);
-
-	down_write(&tty->termios_rwsem);
-	n = chars_in_buffer(tty);
-	up_write(&tty->termios_rwsem);
-	return n;
-}
-
-/**
  *	is_utf8_continuation	-	utf8 multibyte check
  *	@c: byte to check
  *
@@ -1561,8 +1524,6 @@ n_tty_receive_buf_closing(struct tty_struct *tty, const unsigned char *cp,
 			flag = *fp++;
 		if (likely(flag == TTY_NORMAL))
 			n_tty_receive_char_closing(tty, *cp++);
-		else
-			n_tty_receive_char_flagged(tty, *cp++, flag);
 	}
 }
 
@@ -1664,7 +1625,7 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
 	/* publish read_head to consumer */
 	smp_store_release(&ldata->commit_head, ldata->read_head);
 
-	if ((read_cnt(ldata) >= ldata->minimum_to_wake) || L_EXTPROC(tty)) {
+	if (read_cnt(ldata)) {
 		kill_fasync(&tty->fasync, SIGIO, POLL_IN);
 		wake_up_interruptible_poll(&tty->read_wait, POLLIN);
 	}
@@ -1785,12 +1746,6 @@ static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
 	return n_tty_receive_buf_common(tty, cp, fp, count, 1);
 }
 
-int is_ignored(int sig)
-{
-	return (sigismember(&current->blocked, sig) ||
-		current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
-}
-
 /**
  *	n_tty_set_termios	-	termios data changed
  *	@tty: terminal
@@ -1937,7 +1892,6 @@ static int n_tty_open(struct tty_struct *tty)
 	reset_buffer_flags(tty->disc_data);
 	ldata->column = 0;
 	ldata->canon_column = 0;
-	ldata->minimum_to_wake = 1;
 	ldata->num_overrun = 0;
 	ldata->no_room = 0;
 	ldata->lnext = 0;
@@ -2015,7 +1969,7 @@ static int copy_from_read_buf(struct tty_struct *tty,
 		retval = copy_to_user(*b, from, n);
 		n -= retval;
 		is_eof = n == 1 && *from == EOF_CHAR(tty);
-		tty_audit_add_data(tty, from, n, ldata->icanon);
+		tty_audit_add_data(tty, from, n);
 		smp_store_release(&ldata->read_tail, ldata->read_tail + n);
 		/* Turn single EOF into zero-length read */
 		if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
@@ -2109,7 +2063,7 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
 			ldata->line_start = ldata->read_tail;
 		else
 			ldata->push = 0;
-		tty_audit_push(tty);
+		tty_audit_push();
 	}
 	return 0;
 }
@@ -2200,14 +2154,9 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 		minimum = MIN_CHAR(tty);
 		if (minimum) {
 			time = (HZ / 10) * TIME_CHAR(tty);
-			if (time)
-				ldata->minimum_to_wake = 1;
-			else if (!waitqueue_active(&tty->read_wait) ||
-				 (ldata->minimum_to_wake > minimum))
-				ldata->minimum_to_wake = minimum;
 		} else {
 			timeout = (HZ / 10) * TIME_CHAR(tty);
-			ldata->minimum_to_wake = minimum = 1;
+			minimum = 1;
 		}
 	}
 
@@ -2225,19 +2174,15 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 			cs = tty->link->ctrl_status;
 			tty->link->ctrl_status = 0;
 			spin_unlock_irq(&tty->link->ctrl_lock);
-			if (tty_put_user(tty, cs, b++)) {
+			if (put_user(cs, b)) {
 				retval = -EFAULT;
-				b--;
 				break;
 			}
+			b++;
 			nr--;
 			break;
 		}
 
-		if (((minimum - (b - buf)) < ldata->minimum_to_wake) &&
-		    ((minimum - (b - buf)) >= 1))
-			ldata->minimum_to_wake = (minimum - (b - buf));
-
 		done = check_other_done(tty);
 
 		if (!input_available_p(tty, 0)) {
@@ -2275,11 +2220,11 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 
 			/* Deal with packet mode. */
 			if (packet && b == buf) {
-				if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
+				if (put_user(TIOCPKT_DATA, b)) {
 					retval = -EFAULT;
-					b--;
 					break;
 				}
+				b++;
 				nr--;
 			}
 
@@ -2303,9 +2248,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 	up_read(&tty->termios_rwsem);
 
 	remove_wait_queue(&tty->read_wait, &wait);
-	if (!waitqueue_active(&tty->read_wait))
-		ldata->minimum_to_wake = minimum;
-
 	mutex_unlock(&ldata->atomic_read_lock);
 
 	if (b - buf)
@@ -2417,7 +2359,7 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
 	}
 break_out:
 	remove_wait_queue(&tty->write_wait, &wait);
-	if (b - buf != nr && tty->fasync)
+	if (nr && tty->fasync)
 		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 	up_read(&tty->termios_rwsem);
 	return (b - buf) ? b - buf : retval;
@@ -2440,7 +2382,6 @@ break_out:
 static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
 							poll_table *wait)
 {
-	struct n_tty_data *ldata = tty->disc_data;
 	unsigned int mask = 0;
 
 	poll_wait(file, &tty->read_wait, wait);
@@ -2453,12 +2394,6 @@ static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
 		mask |= POLLPRI | POLLIN | POLLRDNORM;
 	if (tty_hung_up_p(file))
 		mask |= POLLHUP;
-	if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) {
-		if (MIN_CHAR(tty) && !TIME_CHAR(tty))
-			ldata->minimum_to_wake = MIN_CHAR(tty);
-		else
-			ldata->minimum_to_wake = 1;
-	}
 	if (tty->ops->write && !tty_is_writelocked(tty) &&
 			tty_chars_in_buffer(tty) < WAKEUP_CHARS &&
 			tty_write_room(tty) > 0)
@@ -2507,25 +2442,12 @@ static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
 	}
 }
 
-static void n_tty_fasync(struct tty_struct *tty, int on)
-{
-	struct n_tty_data *ldata = tty->disc_data;
-
-	if (!waitqueue_active(&tty->read_wait)) {
-		if (on)
-			ldata->minimum_to_wake = 1;
-		else if (!tty->fasync)
-			ldata->minimum_to_wake = N_TTY_BUF_SIZE;
-	}
-}
-
-struct tty_ldisc_ops tty_ldisc_N_TTY = {
+static struct tty_ldisc_ops n_tty_ops = {
 	.magic           = TTY_LDISC_MAGIC,
 	.name            = "n_tty",
 	.open            = n_tty_open,
 	.close           = n_tty_close,
 	.flush_buffer    = n_tty_flush_buffer,
-	.chars_in_buffer = n_tty_chars_in_buffer,
 	.read            = n_tty_read,
 	.write           = n_tty_write,
 	.ioctl           = n_tty_ioctl,
@@ -2533,7 +2455,6 @@ struct tty_ldisc_ops tty_ldisc_N_TTY = {
 	.poll            = n_tty_poll,
 	.receive_buf     = n_tty_receive_buf,
 	.write_wakeup    = n_tty_write_wakeup,
-	.fasync		 = n_tty_fasync,
 	.receive_buf2	 = n_tty_receive_buf2,
 };
 
@@ -2541,14 +2462,18 @@ struct tty_ldisc_ops tty_ldisc_N_TTY = {
  *	n_tty_inherit_ops	-	inherit N_TTY methods
  *	@ops: struct tty_ldisc_ops where to save N_TTY methods
  *
- *	Enables a 'subclass' line discipline to 'inherit' N_TTY
- *	methods.
+ *	Enables a 'subclass' line discipline to 'inherit' N_TTY methods.
  */
 
 void n_tty_inherit_ops(struct tty_ldisc_ops *ops)
 {
-	*ops = tty_ldisc_N_TTY;
+	*ops = n_tty_ops;
 	ops->owner = NULL;
 	ops->refcount = ops->flags = 0;
 }
 EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
+
+void __init n_tty_init(void)
+{
+	tty_register_ldisc(N_TTY, &n_tty_ops);
+}