From b4b7ff4b08e691656c9d77c758fc355833128ac0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 20 Jan 2016 14:01:31 -0300
Subject: Linux-libre 4.4-gnu

---
 drivers/tty/tty_io.c | 59 ++++++++++++++++++++++++++--------------------------
 1 file changed, 29 insertions(+), 30 deletions(-)

(limited to 'drivers/tty/tty_io.c')

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index f435977de..bcc8e1e8b 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -390,10 +390,10 @@ EXPORT_SYMBOL_GPL(tty_find_polling_driver);
  *	Locking: ctrl_lock
  */
 
-int tty_check_change(struct tty_struct *tty)
+int __tty_check_change(struct tty_struct *tty, int sig)
 {
 	unsigned long flags;
-	struct pid *pgrp;
+	struct pid *pgrp, *tty_pgrp;
 	int ret = 0;
 
 	if (current->signal->tty != tty)
@@ -403,33 +403,35 @@ int tty_check_change(struct tty_struct *tty)
 	pgrp = task_pgrp(current);
 
 	spin_lock_irqsave(&tty->ctrl_lock, flags);
-
-	if (!tty->pgrp) {
-		printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n");
-		goto out_unlock;
-	}
-	if (pgrp == tty->pgrp)
-		goto out_unlock;
+	tty_pgrp = tty->pgrp;
 	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 
-	if (is_ignored(SIGTTOU))
-		goto out_rcuunlock;
-	if (is_current_pgrp_orphaned()) {
-		ret = -EIO;
-		goto out_rcuunlock;
+	if (tty_pgrp && pgrp != tty->pgrp) {
+		if (is_ignored(sig)) {
+			if (sig == SIGTTIN)
+				ret = -EIO;
+		} else if (is_current_pgrp_orphaned())
+			ret = -EIO;
+		else {
+			kill_pgrp(pgrp, sig, 1);
+			set_thread_flag(TIF_SIGPENDING);
+			ret = -ERESTARTSYS;
+		}
 	}
-	kill_pgrp(pgrp, SIGTTOU, 1);
-	rcu_read_unlock();
-	set_thread_flag(TIF_SIGPENDING);
-	ret = -ERESTARTSYS;
-	return ret;
-out_unlock:
-	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
-out_rcuunlock:
 	rcu_read_unlock();
+
+	if (!tty_pgrp) {
+		pr_warn("%s: tty_check_change: sig=%d, tty->pgrp == NULL!\n",
+			tty_name(tty), sig);
+	}
+
 	return ret;
 }
 
+int tty_check_change(struct tty_struct *tty)
+{
+	return __tty_check_change(tty, SIGTTOU);
+}
 EXPORT_SYMBOL(tty_check_change);
 
 static ssize_t hung_up_tty_read(struct file *file, char __user *buf,
@@ -1198,11 +1200,9 @@ void tty_write_message(struct tty_struct *tty, char *msg)
 	if (tty) {
 		mutex_lock(&tty->atomic_write_lock);
 		tty_lock(tty);
-		if (tty->ops->write && tty->count > 0) {
-			tty_unlock(tty);
+		if (tty->ops->write && tty->count > 0)
 			tty->ops->write(tty, msg, strlen(msg));
-		} else
-			tty_unlock(tty);
+		tty_unlock(tty);
 		tty_write_unlock(tty);
 	}
 	return;
@@ -1693,7 +1693,7 @@ static void release_tty(struct tty_struct *tty, int idx)
 	tty->port->itty = NULL;
 	if (tty->link)
 		tty->link->port->itty = NULL;
-	cancel_work_sync(&tty->port->buf.work);
+	tty_buffer_cancel_work(tty->port);
 
 	tty_kref_put(tty->link);
 	tty_kref_put(tty);
@@ -2573,7 +2573,6 @@ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
 	struct pid *pgrp;
 	pid_t pgrp_nr;
 	int retval = tty_check_change(real_tty);
-	unsigned long flags;
 
 	if (retval == -EIO)
 		return -ENOTTY;
@@ -2596,10 +2595,10 @@ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
 	if (session_of_pgrp(pgrp) != task_session(current))
 		goto out_unlock;
 	retval = 0;
-	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	spin_lock_irq(&tty->ctrl_lock);
 	put_pid(real_tty->pgrp);
 	real_tty->pgrp = get_pid(pgrp);
-	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	spin_unlock_irq(&tty->ctrl_lock);
 out_unlock:
 	rcu_read_unlock();
 	return retval;
-- 
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