summaryrefslogtreecommitdiff
path: root/drivers/tty/hvc/hvc_console.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/tty/hvc/hvc_console.c')
-rw-r--r--drivers/tty/hvc/hvc_console.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
index acf6d143c753..81f23af8beca 100644
--- a/drivers/tty/hvc/hvc_console.c
+++ b/drivers/tty/hvc/hvc_console.c
@@ -89,6 +89,8 @@ static LIST_HEAD(hvc_structs);
*/
static DEFINE_SPINLOCK(hvc_structs_lock);
+/* Mutex to serialize hvc_open */
+static DEFINE_MUTEX(hvc_open_mutex);
/*
* This value is used to assign a tty->index value to a hvc_struct based
* upon order of exposure via hvc_probe(), when we can not match it to
@@ -333,16 +335,24 @@ static int hvc_install(struct tty_driver *driver, struct tty_struct *tty)
*/
static int hvc_open(struct tty_struct *tty, struct file * filp)
{
- struct hvc_struct *hp = tty->driver_data;
+ struct hvc_struct *hp;
unsigned long flags;
int rc = 0;
+ mutex_lock(&hvc_open_mutex);
+
+ hp = tty->driver_data;
+ if (!hp) {
+ rc = -EIO;
+ goto out;
+ }
+
spin_lock_irqsave(&hp->port.lock, flags);
/* Check and then increment for fast path open. */
if (hp->port.count++ > 0) {
spin_unlock_irqrestore(&hp->port.lock, flags);
hvc_kick();
- return 0;
+ goto out;
} /* else count == 0 */
spin_unlock_irqrestore(&hp->port.lock, flags);
@@ -371,6 +381,8 @@ static int hvc_open(struct tty_struct *tty, struct file * filp)
/* Force wakeup of the polling thread */
hvc_kick();
+out:
+ mutex_unlock(&hvc_open_mutex);
return rc;
}