3 files changed, 47 insertions, 9 deletions

diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index bdae832..428f4fe 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -1102,6 +1102,11 @@ static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
 	if (I_IUCLC(tty) && L_IEXTEN(tty))
 		c = tolower(c);
 
+	if (L_EXTPROC(tty)) {
+		put_tty_queue(c, tty);
+		return;
+	}
+
 	if (tty->stopped && !tty->flow_stopped && I_IXON(tty) &&
 	    I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty) &&
 	    c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && c != SUSP_CHAR(tty)) {
@@ -1409,7 +1414,8 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 
 	n_tty_set_room(tty);
 
-	if (!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) {
+	if ((!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) ||
+		L_EXTPROC(tty)) {
 		kill_fasync(&tty->fasync, SIGIO, POLL_IN);
 		if (waitqueue_active(&tty->read_wait))
 			wake_up_interruptible(&tty->read_wait);
@@ -1585,7 +1591,7 @@ static int n_tty_open(struct tty_struct *tty)
 static inline int input_available_p(struct tty_struct *tty, int amt)
 {
 	tty_flush_to_ldisc(tty);
-	if (tty->icanon) {
+	if (tty->icanon && !L_EXTPROC(tty)) {
 		if (tty->canon_data)
 			return 1;
 	} else if (tty->read_cnt >= (amt ? amt : 1))
@@ -1632,6 +1638,11 @@ static int copy_from_read_buf(struct tty_struct *tty,
 		spin_lock_irqsave(&tty->read_lock, flags);
 		tty->read_tail = (tty->read_tail + n) & (N_TTY_BUF_SIZE-1);
 		tty->read_cnt -= n;
+		/* Turn single EOF into zero-length read */
+		if (L_EXTPROC(tty) && tty->icanon && n == 1) {
+			if (!tty->read_cnt && (*b)[n-1] == EOF_CHAR(tty))
+				n--;
+		}
 		spin_unlock_irqrestore(&tty->read_lock, flags);
 		*b += n;
 		*nr -= n;
@@ -1812,7 +1823,7 @@ do_it_again:
 			nr--;
 		}
 
-		if (tty->icanon) {
+		if (tty->icanon && !L_EXTPROC(tty)) {
 			/* N.B. avoid overrun if nr == 0 */
 			while (nr && tty->read_cnt) {
 				int eol;
diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index d83a431..b640ef2 100644
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -171,6 +171,23 @@ static int pty_set_lock(struct tty_struct *tty, int __user *arg)
 	return 0;
 }
 
+/* Send a signal to the slave */
+static int pty_signal(struct tty_struct *tty, int sig)
+{
+	unsigned long flags;
+	struct pid *pgrp;
+
+	if (tty->link) {
+		spin_lock_irqsave(&tty->link->ctrl_lock, flags);
+		pgrp = get_pid(tty->link->pgrp);
+		spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
+
+		kill_pgrp(pgrp, sig, 1);
+		put_pid(pgrp);
+	}
+	return 0;
+}
+
 static void pty_flush_buffer(struct tty_struct *tty)
 {
 	struct tty_struct *to = tty->link;
@@ -321,6 +338,8 @@ static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file,
 	switch (cmd) {
 	case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
 		return pty_set_lock(tty, (int __user *) arg);
+	case TIOCSIG:    /* Send signal to other side of pty */
+		return pty_signal(tty, (int) arg);
 	}
 	return -ENOIOCTLCMD;
 }
@@ -476,6 +495,8 @@ static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
 		return pty_set_lock(tty, (int __user *)arg);
 	case TIOCGPTN: /* Get PT Number */
 		return put_user(tty->index, (unsigned int __user *)arg);
+	case TIOCSIG:    /* Send signal to other side of pty */
+		return pty_signal(tty, (int) arg);
 	}
 
 	return -ENOIOCTLCMD;
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index 6bd5f88..0c18899 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -517,19 +517,25 @@ static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
 
 	/* See if packet mode change of state. */
 	if (tty->link && tty->link->packet) {
+		int extproc = (old_termios.c_lflag & EXTPROC) |
+				(tty->termios->c_lflag & EXTPROC);
 		int old_flow = ((old_termios.c_iflag & IXON) &&
 				(old_termios.c_cc[VSTOP] == '\023') &&
 				(old_termios.c_cc[VSTART] == '\021'));
 		int new_flow = (I_IXON(tty) &&
 				STOP_CHAR(tty) == '\023' &&
 				START_CHAR(tty) == '\021');
-		if (old_flow != new_flow) {
+		if ((old_flow != new_flow) || extproc) {
 			spin_lock_irqsave(&tty->ctrl_lock, flags);
-			tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
-			if (new_flow)
-				tty->ctrl_status |= TIOCPKT_DOSTOP;
-			else
-				tty->ctrl_status |= TIOCPKT_NOSTOP;
+			if (old_flow != new_flow) {
+				tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
+				if (new_flow)
+					tty->ctrl_status |= TIOCPKT_DOSTOP;
+				else
+					tty->ctrl_status |= TIOCPKT_NOSTOP;
+			}
+			if (extproc)
+				tty->ctrl_status |= TIOCPKT_IOCTL;
 			spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 			wake_up_interruptible(&tty->link->read_wait);
 		}