From 633caba8932d9ba2f79bbcb7573e58eae3fdac68 Mon Sep 17 00:00:00 2001
From: Peter Hurley <peter@hurleysoftware.com>
Date: Wed, 5 Nov 2014 12:40:03 -0500
Subject: [PATCH] tty: Move tty hung up check from port->lock critical section
The port->lock does not protect the filp->f_op field; move
the tty_hung_up_p() test outside the port->lock critical section
in tty_port_close_start().
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/tty/tty_port.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 1b9335796da4..3b641d115fd2 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -473,12 +473,10 @@ int tty_port_close_start(struct tty_port *port,
{
unsigned long flags;
- spin_lock_irqsave(&port->lock, flags);
- if (tty_hung_up_p(filp)) {
- spin_unlock_irqrestore(&port->lock, flags);
+ if (tty_hung_up_p(filp))
return 0;
- }
+ spin_lock_irqsave(&port->lock, flags);
if (tty->count == 1 && port->count != 1) {
printk(KERN_WARNING
"tty_port_close_start: tty->count = 1 port count = %d.\n",
--
2.20.1