net/irda: Fix port open counts
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 @@
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 @@
__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 @@
__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",