The riscom8 board uses lock_kernel to protect bits of the port setting
ioctl logic. We can use the port mutex for this as the logic is internal
and will also lock set versus open (a locking property that has been lost
somewhere along the way)

Signed-off-by: Alan Cox <alan@linux.intel.com>
---

 drivers/char/riscom8.c |   14 ++++++++------
 1 files changed, 8 insertions(+), 6 deletions(-)


diff --git a/drivers/char/riscom8.c b/drivers/char/riscom8.c
index 0a8d1e5..9c00b7d 100644
--- a/drivers/char/riscom8.c
+++ b/drivers/char/riscom8.c
@@ -47,7 +47,6 @@
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/tty_flip.h>
-#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 #include <linux/device.h>
 
@@ -1183,6 +1182,7 @@ static int rc_set_serial_info(struct tty_struct *tty, struct riscom_port *port,
 	if (copy_from_user(&tmp, newinfo, sizeof(tmp)))
 		return -EFAULT;
 
+	mutex_lock(&port->port.mutex);
 	change_speed = ((port->port.flags & ASYNC_SPD_MASK) !=
 			(tmp.flags & ASYNC_SPD_MASK));
 
@@ -1190,8 +1190,10 @@ static int rc_set_serial_info(struct tty_struct *tty, struct riscom_port *port,
 		if ((tmp.close_delay != port->port.close_delay) ||
 		    (tmp.closing_wait != port->port.closing_wait) ||
 		    ((tmp.flags & ~ASYNC_USR_MASK) !=
-		     (port->port.flags & ~ASYNC_USR_MASK)))
+		     (port->port.flags & ~ASYNC_USR_MASK))) {
+			mutex_unlock(&port->port.mutex);
 			return -EPERM;
+		}
 		port->port.flags = ((port->port.flags & ~ASYNC_USR_MASK) |
 			       (tmp.flags & ASYNC_USR_MASK));
 	} else  {
@@ -1207,6 +1209,7 @@ static int rc_set_serial_info(struct tty_struct *tty, struct riscom_port *port,
 		rc_change_speed(tty, bp, port);
 		spin_unlock_irqrestore(&riscom_lock, flags);
 	}
+	mutex_unlock(&port->port.mutex);
 	return 0;
 }
 
@@ -1219,12 +1222,15 @@ static int rc_get_serial_info(struct riscom_port *port,
 	memset(&tmp, 0, sizeof(tmp));
 	tmp.type = PORT_CIRRUS;
 	tmp.line = port - rc_port;
+
+	mutex_lock(&port->port.mutex);
 	tmp.port = bp->base;
 	tmp.irq  = bp->irq;
 	tmp.flags = port->port.flags;
 	tmp.baud_base = (RC_OSCFREQ + CD180_TPC/2) / CD180_TPC;
 	tmp.close_delay = port->port.close_delay * HZ/100;
 	tmp.closing_wait = port->port.closing_wait * HZ/100;
+	mutex_unlock(&port->port.mutex);
 	tmp.xmit_fifo_size = CD180_NFIFO;
 	return copy_to_user(retinfo, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }
@@ -1241,14 +1247,10 @@ static int rc_ioctl(struct tty_struct *tty, struct file *filp,
 
 	switch (cmd) {
 	case TIOCGSERIAL:
-		lock_kernel();
 		retval = rc_get_serial_info(port, argp);
-		unlock_kernel();
 		break;
 	case TIOCSSERIAL:
-		lock_kernel();
 		retval = rc_set_serial_info(tty, port, argp);
-		unlock_kernel();
 		break;
 	default:
 		retval = -ENOIOCTLCMD;

--
unsubscribe notice
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/