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authorPeter Hurley <peter@hurleysoftware.com>2013-03-05 06:09:04 +0000
committerDavid S. Miller <davem@davemloft.net>2013-03-06 02:47:04 -0500
commita4ed2e737cb73e4405a3649f8aef7619b99fecae (patch)
tree6cc188dc7dd206790023fb360af4b1a886611855
parent0305d0689efd35b4c9f88bb560c104ed118d2277 (diff)
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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>
-rw-r--r--net/irda/ircomm/ircomm_tty.c14
1 files changed, 5 insertions, 9 deletions
diff --git a/net/irda/ircomm/ircomm_tty.c b/net/irda/ircomm/ircomm_tty.c
index 9a5fd3c3e53..1721dc7e431 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",