summaryrefslogtreecommitdiff
path: root/drivers/tty
diff options
context:
space:
mode:
authorTyrel Datwyler <tyreld@linux.ibm.com>2020-08-21 02:46:38 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-09-04 19:09:44 +0300
commit63ffcbdad738e3d1c857027789a2273df3337624 (patch)
treeacf9c5aaae4a49c87a70c56d07b58392318f13f1 /drivers/tty
parentdb332356222d9429731ab9395c89cca403828460 (diff)
downloadlinux-63ffcbdad738e3d1c857027789a2273df3337624.tar.xz
tty: hvcs: Don't NULL tty->driver_data until hvcs_cleanup()
The code currently NULLs tty->driver_data in hvcs_close() with the intent of informing the next call to hvcs_open() that device needs to be reconfigured. However, when hvcs_cleanup() is called we copy hvcsd from tty->driver_data which was previoulsy NULLed by hvcs_close() and our call to tty_port_put(&hvcsd->port) doesn't actually do anything since &hvcsd->port ends up translating to NULL by chance. This has the side effect that when hvcs_remove() is called we have one too many port references preventing hvcs_destuct_port() from ever being called. This also prevents us from reusing the /dev/hvcsX node in a future hvcs_probe() and we can eventually run out of /dev/hvcsX devices. Fix this by waiting to NULL tty->driver_data in hvcs_cleanup(). Fixes: 27bf7c43a19c ("TTY: hvcs, add tty install") Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com> Link: https://lore.kernel.org/r/20200820234643.70412-1-tyreld@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/hvc/hvcs.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index 55105ac38f89..509d1042825a 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -1216,13 +1216,6 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
tty_wait_until_sent(tty, HVCS_CLOSE_WAIT);
- /*
- * This line is important because it tells hvcs_open that this
- * device needs to be re-configured the next time hvcs_open is
- * called.
- */
- tty->driver_data = NULL;
-
free_irq(irq, hvcsd);
return;
} else if (hvcsd->port.count < 0) {
@@ -1237,6 +1230,13 @@ static void hvcs_cleanup(struct tty_struct * tty)
{
struct hvcs_struct *hvcsd = tty->driver_data;
+ /*
+ * This line is important because it tells hvcs_open that this
+ * device needs to be re-configured the next time hvcs_open is
+ * called.
+ */
+ tty->driver_data = NULL;
+
tty_port_put(&hvcsd->port);
}