3 files changed, 47 insertions, 9 deletions

diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index bdae8327143c..428f4fe0b5f7 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 d83a43130df4..b640ef29be1c 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 6bd5f8866c74..0c1889971459 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);
                 }