1 files changed, 22 insertions, 54 deletions

diff --git a/kernel/drivers/tty/n_tty.c b/kernel/drivers/tty/n_tty.c
index 16ed0b6c7..cf000b331 100644
--- a/kernel/drivers/tty/n_tty.c
+++ b/kernel/drivers/tty/n_tty.c
@@ -169,7 +169,7 @@ static inline int tty_copy_to_user(struct tty_struct *tty,
 {
 	struct n_tty_data *ldata = tty->disc_data;
 
-	tty_audit_add_data(tty, to, n, ldata->icanon);
+	tty_audit_add_data(tty, from, n, ldata->icanon);
 	return copy_to_user(to, from, n);
 }
 
@@ -201,7 +201,7 @@ static void n_tty_kick_worker(struct tty_struct *tty)
 		 */
 		WARN_RATELIMIT(test_bit(TTY_LDISC_HALTED, &tty->flags),
 			       "scheduling buffer work for halted ldisc\n");
-		queue_work(system_unbound_wq, &tty->port->buf.work);
+		tty_buffer_restart_work(tty->port);
 	}
 }
 
@@ -258,16 +258,13 @@ static void n_tty_check_throttle(struct tty_struct *tty)
 
 static void n_tty_check_unthrottle(struct tty_struct *tty)
 {
-	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
-	    tty->link->ldisc->ops->write_wakeup == n_tty_write_wakeup) {
+	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);
-		n_tty_write_wakeup(tty->link);
-		if (waitqueue_active(&tty->link->write_wait))
-			wake_up_interruptible_poll(&tty->link->write_wait, POLLOUT);
+		tty_wakeup(tty->link);
 		return;
 	}
 
@@ -343,8 +340,7 @@ static void n_tty_packet_mode_flush(struct tty_struct *tty)
 		spin_lock_irqsave(&tty->ctrl_lock, flags);
 		tty->ctrl_status |= TIOCPKT_FLUSHREAD;
 		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
-		if (waitqueue_active(&tty->link->read_wait))
-			wake_up_interruptible(&tty->link->read_wait);
+		wake_up_interruptible(&tty->link->read_wait);
 	}
 }
 
@@ -1180,8 +1176,6 @@ static void n_tty_receive_break(struct tty_struct *tty)
 		put_tty_queue('\0', ldata);
 	}
 	put_tty_queue('\0', ldata);
-	if (waitqueue_active(&tty->read_wait))
-		wake_up_interruptible_poll(&tty->read_wait, POLLIN);
 }
 
 /**
@@ -1200,13 +1194,12 @@ static void n_tty_receive_break(struct tty_struct *tty)
 static void n_tty_receive_overrun(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
-	char buf[64];
 
 	ldata->num_overrun++;
 	if (time_after(jiffies, ldata->overrun_time + HZ) ||
 			time_after(ldata->overrun_time, jiffies)) {
 		printk(KERN_WARNING "%s: %d input overrun(s)\n",
-			tty_name(tty, buf),
+			tty_name(tty),
 			ldata->num_overrun);
 		ldata->overrun_time = jiffies;
 		ldata->num_overrun = 0;
@@ -1239,8 +1232,6 @@ static void n_tty_receive_parity_error(struct tty_struct *tty, unsigned char c)
 			put_tty_queue('\0', ldata);
 	} else
 		put_tty_queue(c, ldata);
-	if (waitqueue_active(&tty->read_wait))
-		wake_up_interruptible_poll(&tty->read_wait, POLLIN);
 }
 
 static void
@@ -1383,8 +1374,7 @@ handle_newline:
 			put_tty_queue(c, ldata);
 			smp_store_release(&ldata->canon_head, ldata->read_head);
 			kill_fasync(&tty->fasync, SIGIO, POLL_IN);
-			if (waitqueue_active(&tty->read_wait))
-				wake_up_interruptible_poll(&tty->read_wait, POLLIN);
+			wake_up_interruptible_poll(&tty->read_wait, POLLIN);
 			return 0;
 		}
 	}
@@ -1481,8 +1471,6 @@ static void n_tty_receive_char_closing(struct tty_struct *tty, unsigned char c)
 static void
 n_tty_receive_char_flagged(struct tty_struct *tty, unsigned char c, char flag)
 {
-	char buf[64];
-
 	switch (flag) {
 	case TTY_BREAK:
 		n_tty_receive_break(tty);
@@ -1496,7 +1484,7 @@ n_tty_receive_char_flagged(struct tty_struct *tty, unsigned char c, char flag)
 		break;
 	default:
 		printk(KERN_ERR "%s: unknown flag %d\n",
-		       tty_name(tty, buf), flag);
+		       tty_name(tty), flag);
 		break;
 	}
 }
@@ -1670,8 +1658,7 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
 
 	if ((read_cnt(ldata) >= ldata->minimum_to_wake) || L_EXTPROC(tty)) {
 		kill_fasync(&tty->fasync, SIGIO, POLL_IN);
-		if (waitqueue_active(&tty->read_wait))
-			wake_up_interruptible_poll(&tty->read_wait, POLLIN);
+		wake_up_interruptible_poll(&tty->read_wait, POLLIN);
 	}
 }
 
@@ -1890,10 +1877,8 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 	}
 
 	/* The termios change make the tty ready for I/O */
-	if (waitqueue_active(&tty->write_wait))
-		wake_up_interruptible(&tty->write_wait);
-	if (waitqueue_active(&tty->read_wait))
-		wake_up_interruptible(&tty->read_wait);
+	wake_up_interruptible(&tty->write_wait);
+	wake_up_interruptible(&tty->read_wait);
 }
 
 /**
@@ -2066,13 +2051,13 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
 	size_t eol;
 	size_t tail;
 	int ret, found = 0;
-	bool eof_push = 0;
 
 	/* N.B. avoid overrun if nr == 0 */
-	n = min(*nr, smp_load_acquire(&ldata->canon_head) - ldata->read_tail);
-	if (!n)
+	if (!*nr)
 		return 0;
 
+	n = min(*nr + 1, smp_load_acquire(&ldata->canon_head) - ldata->read_tail);
+
 	tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);
 	size = min_t(size_t, tail + n, N_TTY_BUF_SIZE);
 
@@ -2093,12 +2078,11 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
 	n = eol - tail;
 	if (n > N_TTY_BUF_SIZE)
 		n += N_TTY_BUF_SIZE;
-	n += found;
-	c = n;
+	c = n + found;
 
-	if (found && !ldata->push && read_buf(ldata, eol) == __DISABLED_CHAR) {
-		n--;
-		eof_push = !n && ldata->read_tail != ldata->line_start;
+	if (!found || read_buf(ldata, eol) != __DISABLED_CHAR) {
+		c = min(*nr, c);
+		n = c;
 	}
 
 	n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu size:%zu more:%zu\n",
@@ -2128,7 +2112,7 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
 			ldata->push = 0;
 		tty_audit_push(tty);
 	}
-	return eof_push ? -EAGAIN : 0;
+	return 0;
 }
 
 extern ssize_t redirected_tty_write(struct file *, const char __user *,
@@ -2155,23 +2139,10 @@ static int job_control(struct tty_struct *tty, struct file *file)
 	/* NOTE: not yet done after every sleep pending a thorough
 	   check of the logic of this change. -- jlc */
 	/* don't stop on /dev/console */
-	if (file->f_op->write == redirected_tty_write ||
-	    current->signal->tty != tty)
+	if (file->f_op->write == redirected_tty_write)
 		return 0;
 
-	spin_lock_irq(&tty->ctrl_lock);
-	if (!tty->pgrp)
-		printk(KERN_ERR "n_tty_read: no tty->pgrp!\n");
-	else if (task_pgrp(current) != tty->pgrp) {
-		spin_unlock_irq(&tty->ctrl_lock);
-		if (is_ignored(SIGTTIN) || is_current_pgrp_orphaned())
-			return -EIO;
-		kill_pgrp(task_pgrp(current), SIGTTIN, 1);
-		set_thread_flag(TIF_SIGPENDING);
-		return -ERESTARTSYS;
-	}
-	spin_unlock_irq(&tty->ctrl_lock);
-	return 0;
+	return __tty_check_change(tty, SIGTTIN);
 }
 
 
@@ -2298,10 +2269,7 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 
 		if (ldata->icanon && !L_EXTPROC(tty)) {
 			retval = canon_copy_from_read_buf(tty, &b, &nr);
-			if (retval == -EAGAIN) {
-				retval = 0;
-				continue;
-			} else if (retval)
+			if (retval)
 				break;
 		} else {
 			int uncopied;