diff mbox

[1/4] net/irda: Fix port open counts

Message ID 1362499747-4262-2-git-send-email-peter@hurleysoftware.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Peter Hurley March 5, 2013, 4:09 p.m. UTC 
Saving the port count bump is unsafe. If the tty is hung up while
this open was blocking, the port count is zeroed.

Explicitly check if the tty was hung up while blocking, and correct
the port count if not.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
---
 net/irda/ircomm/ircomm_tty.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)
diff mbox

Patch

diff --git a/net/irda/ircomm/ircomm_tty.c b/net/irda/ircomm/ircomm_tty.c
index 9a5fd3c..1721dc7 100644
--- a/net/irda/ircomm/ircomm_tty.c
+++ b/net/irda/ircomm/ircomm_tty.c
@@ -280,7 +280,7 @@  static int ircomm_tty_block_til_ready(struct ircomm_tty_cb *self,
 	struct tty_port *port = &self->port;
 	DECLARE_WAITQUEUE(wait, current);
 	int		retval;
-	int		do_clocal = 0, extra_count = 0;
+	int		do_clocal = 0;
 	unsigned long	flags;
 
 	IRDA_DEBUG(2, "%s()\n", __func__ );
@@ -315,10 +315,8 @@  static int ircomm_tty_block_til_ready(struct ircomm_tty_cb *self,
 	      __FILE__, __LINE__, tty->driver->name, port->count);
 
 	spin_lock_irqsave(&port->lock, flags);
-	if (!tty_hung_up_p(filp)) {
-		extra_count = 1;
+	if (!tty_hung_up_p(filp))
 		port->count--;
-	}
 	spin_unlock_irqrestore(&port->lock, flags);
 	port->blocked_open++;
 
@@ -361,12 +359,10 @@  static int ircomm_tty_block_til_ready(struct ircomm_tty_cb *self,
 	__set_current_state(TASK_RUNNING);
 	remove_wait_queue(&port->open_wait, &wait);
 
-	if (extra_count) {
-		/* ++ is not atomic, so this should be protected - Jean II */
-		spin_lock_irqsave(&port->lock, flags);
+	spin_lock_irqsave(&port->lock, flags);
+	if (!tty_hung_up_p(filp))
 		port->count++;
-		spin_unlock_irqrestore(&port->lock, flags);
-	}
+	spin_unlock_irqrestore(&port->lock, flags);
 	port->blocked_open--;
 
 	IRDA_DEBUG(1, "%s(%d):block_til_ready after blocking on %s open_count=%d\n",