ipack/devices/ipoctal: fix kernel bug when using pppd
Trying to setup the pppd server to use ipoctal's serial ports, it says the ports
are busy the first time. If the operation is repeated, a kernel bug due to a
dereference of a NULL pointer appears.
Removing the one-access-only setup from the driver, removes this kernel bug.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/ipack/devices/ipoctal.c b/drivers/ipack/devices/ipoctal.c
index a33a849..8d0a866 100644
--- a/drivers/ipack/devices/ipoctal.c
+++ b/drivers/ipack/devices/ipoctal.c
@@ -38,7 +38,6 @@
spinlock_t lock;
unsigned int pointer_read;
unsigned int pointer_write;
- atomic_t open;
struct tty_port tty_port;
union scc2698_channel __iomem *regs;
union scc2698_block __iomem *block_regs;
@@ -70,22 +69,12 @@
static int ipoctal_open(struct tty_struct *tty, struct file *file)
{
- int res;
struct ipoctal_channel *channel;
channel = dev_get_drvdata(tty->dev);
-
- if (atomic_read(&channel->open))
- return -EBUSY;
-
tty->driver_data = channel;
- res = tty_port_open(&channel->tty_port, tty, file);
- if (res)
- return res;
-
- atomic_inc(&channel->open);
- return 0;
+ return tty_port_open(&channel->tty_port, tty, file);
}
static void ipoctal_reset_stats(struct ipoctal_stats *stats)
@@ -111,9 +100,7 @@
struct ipoctal_channel *channel = tty->driver_data;
tty_port_close(&channel->tty_port, tty, filp);
-
- if (atomic_dec_and_test(&channel->open))
- ipoctal_free_channel(channel);
+ ipoctal_free_channel(channel);
}
static int ipoctal_get_icount(struct tty_struct *tty,
@@ -205,10 +192,6 @@
u8 isr, sr;
struct tty_struct *tty;
- /* If there is no client, skip the check */
- if (!atomic_read(&channel->open))
- return;
-
tty = tty_port_tty_get(&channel->tty_port);
if (!tty)
return;