X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=drivers%2Ftty%2Fpty.c;h=7a1a53819e22ca5f7ec29bb6c52db8a7fe8e61fd;hb=4ed60fc257185dbb0daea7cd3e4289d1658b11f6;hp=7c4447a5c0f4c07a9b552aa5229db29f57bf0d76;hpb=bf10fa857f0604865006d9705e63415b9d4e0d62;p=firefly-linux-kernel-4.4.55.git

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 7c4447a5c0f4..7a1a53819e22 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -47,7 +47,9 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
 	set_bit(TTY_IO_ERROR, &tty->flags);
 	wake_up_interruptible(&tty->read_wait);
 	wake_up_interruptible(&tty->write_wait);
+	spin_lock_irq(&tty->ctrl_lock);
 	tty->packet = 0;
+	spin_unlock_irq(&tty->ctrl_lock);
 	/* Review - krefs on tty_link ?? */
 	if (!tty->link)
 		return;
@@ -178,21 +180,21 @@ static int pty_get_lock(struct tty_struct *tty, int __user *arg)
 /* Set the packet mode on a pty */
 static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)
 {
-	unsigned long flags;
 	int pktmode;
 
 	if (get_user(pktmode, arg))
 		return -EFAULT;
 
-	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	spin_lock_irq(&tty->ctrl_lock);
 	if (pktmode) {
 		if (!tty->packet) {
-			tty->packet = 1;
 			tty->link->ctrl_status = 0;
+			smp_mb();
+			tty->packet = 1;
 		}
 	} else
 		tty->packet = 0;
-	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	spin_unlock_irq(&tty->ctrl_lock);
 
 	return 0;
 }
@@ -207,15 +209,12 @@ static int pty_get_pktmode(struct tty_struct *tty, int __user *arg)
 /* 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);
+		pgrp = tty_get_pgrp(tty->link);
+		if (pgrp)
+			kill_pgrp(pgrp, sig, 1);
 		put_pid(pgrp);
 	}
 	return 0;
@@ -224,16 +223,15 @@ static int pty_signal(struct tty_struct *tty, int sig)
 static void pty_flush_buffer(struct tty_struct *tty)
 {
 	struct tty_struct *to = tty->link;
-	unsigned long flags;
 
 	if (!to)
 		return;
 	/* tty_buffer_flush(to); FIXME */
 	if (to->packet) {
-		spin_lock_irqsave(&tty->ctrl_lock, flags);
+		spin_lock_irq(&tty->ctrl_lock);
 		tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
 		wake_up_interruptible(&to->read_wait);
-		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+		spin_unlock_irq(&tty->ctrl_lock);
 	}
 }
 
@@ -262,6 +260,32 @@ out:
 static void pty_set_termios(struct tty_struct *tty,
 					struct ktermios *old_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) || extproc) {
+			spin_lock_irq(&tty->ctrl_lock);
+			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_irq(&tty->ctrl_lock);
+			wake_up_interruptible(&tty->link->read_wait);
+		}
+	}
+
 	tty->termios.c_cflag &= ~(CSIZE | PARENB);
 	tty->termios.c_cflag |= (CS8 | CREAD);
 }
@@ -278,7 +302,6 @@ static void pty_set_termios(struct tty_struct *tty,
 static int pty_resize(struct tty_struct *tty,  struct winsize *ws)
 {
 	struct pid *pgrp, *rpgrp;
-	unsigned long flags;
 	struct tty_struct *pty = tty->link;
 
 	/* For a PTY we need to lock the tty side */
@@ -286,17 +309,9 @@ static int pty_resize(struct tty_struct *tty,  struct winsize *ws)
 	if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
 		goto done;
 
-	/* Get the PID values and reference them so we can
-	   avoid holding the tty ctrl lock while sending signals.
-	   We need to lock these individually however. */
-
-	spin_lock_irqsave(&tty->ctrl_lock, flags);
-	pgrp = get_pid(tty->pgrp);
-	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
-
-	spin_lock_irqsave(&pty->ctrl_lock, flags);
-	rpgrp = get_pid(pty->pgrp);
-	spin_unlock_irqrestore(&pty->ctrl_lock, flags);
+	/* Signal the foreground process group of both ptys */
+	pgrp = tty_get_pgrp(tty);
+	rpgrp = tty_get_pgrp(pty);
 
 	if (pgrp)
 		kill_pgrp(pgrp, SIGWINCH, 1);
@@ -327,26 +342,26 @@ static void pty_start(struct tty_struct *tty)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&tty->ctrl_lock, flags);
 	if (tty->link && tty->link->packet) {
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
 		tty->ctrl_status &= ~TIOCPKT_STOP;
 		tty->ctrl_status |= TIOCPKT_START;
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 		wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
 	}
-	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 }
 
 static void pty_stop(struct tty_struct *tty)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&tty->ctrl_lock, flags);
 	if (tty->link && tty->link->packet) {
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
 		tty->ctrl_status &= ~TIOCPKT_START;
 		tty->ctrl_status |= TIOCPKT_STOP;
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 		wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
 	}
-	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 }
 
 /**
@@ -489,7 +504,6 @@ static const struct tty_operations master_pty_ops_bsd = {
 	.flush_buffer = pty_flush_buffer,
 	.chars_in_buffer = pty_chars_in_buffer,
 	.unthrottle = pty_unthrottle,
-	.set_termios = pty_set_termios,
 	.ioctl = pty_bsd_ioctl,
 	.cleanup = pty_cleanup,
 	.resize = pty_resize,
@@ -666,7 +680,6 @@ static const struct tty_operations ptm_unix98_ops = {
 	.flush_buffer = pty_flush_buffer,
 	.chars_in_buffer = pty_chars_in_buffer,
 	.unthrottle = pty_unthrottle,
-	.set_termios = pty_set_termios,
 	.ioctl = pty_unix98_ioctl,
 	.resize = pty_resize,
 	.shutdown = pty_unix98_shutdown,