1 files changed, 46 insertions, 2 deletions

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 0c4881d18cd5..8bc8337c99c4 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -30,6 +30,7 @@
 #include <linux/list.h>
 #include <linux/smp_lock.h>
 #include <asm/uaccess.h>
+#include <asm/semaphore.h>
 #include <linux/usb.h>
 #include "usb-serial.h"
 #include "pl2303.h"
@@ -42,10 +43,10 @@
 
 /* Driver structure we register with the USB core */
 static struct usb_driver usb_serial_driver = {
-        .owner =        THIS_MODULE,
         .name =         "usbserial",
         .probe =        usb_serial_probe,
         .disconnect =   usb_serial_disconnect,
+        .no_dynamic_id =        1,
 };
 
 /* There is no MODULE_DEVICE_TABLE for usbserial.c.  Instead
@@ -188,6 +189,11 @@ static int serial_open (struct tty_struct *tty, struct file * filp)
 
         portNumber = tty->index - serial->minor;
         port = serial->port[portNumber];
+        if (!port)
+                return -ENODEV;
+
+        if (down_interruptible(&port->sem))
+                return -ERESTARTSYS;
          
         ++port->open_count;
 
@@ -213,6 +219,7 @@ static int serial_open (struct tty_struct *tty, struct file * filp)
                         goto bailout_module_put;
         }
 
+        up(&port->sem);
         return 0;
 
 bailout_module_put:
@@ -220,6 +227,7 @@ bailout_module_put:
 bailout_kref_put:
         kref_put(&serial->kref, destroy_serial);
         port->open_count = 0;
+        up(&port->sem);
         return retval;
 }
 
@@ -232,8 +240,10 @@ static void serial_close(struct tty_struct *tty, struct file * filp)
 
         dbg("%s - port %d", __FUNCTION__, port->number);
 
+        down(&port->sem);
+
         if (port->open_count == 0)
-                return;
+                goto out;
 
         --port->open_count;
         if (port->open_count == 0) {
@@ -251,6 +261,9 @@ static void serial_close(struct tty_struct *tty, struct file * filp)
         }
 
         kref_put(&port->serial->kref, destroy_serial);
+
+out:
+        up(&port->sem);
 }
 
 static int serial_write (struct tty_struct * tty, const unsigned char *buf, int count)
@@ -258,6 +271,9 @@ static int serial_write (struct tty_struct * tty, const unsigned char *buf, int
         struct usb_serial_port *port = tty->driver_data;
         int retval = -EINVAL;
 
+        if (!port)
+                goto exit;
+
         dbg("%s - port %d, %d byte(s)", __FUNCTION__, port->number, count);
 
         if (!port->open_count) {
@@ -277,6 +293,9 @@ static int serial_write_room (struct tty_struct *tty)
         struct usb_serial_port *port = tty->driver_data;
         int retval = -EINVAL;
 
+        if (!port)
+                goto exit;
+
         dbg("%s - port %d", __FUNCTION__, port->number);
 
         if (!port->open_count) {
@@ -296,6 +315,9 @@ static int serial_chars_in_buffer (struct tty_struct *tty)
         struct usb_serial_port *port = tty->driver_data;
         int retval = -EINVAL;
 
+        if (!port)
+                goto exit;
+
         dbg("%s = port %d", __FUNCTION__, port->number);
 
         if (!port->open_count) {
@@ -314,6 +336,9 @@ static void serial_throttle (struct tty_struct * tty)
 {
         struct usb_serial_port *port = tty->driver_data;
 
+        if (!port)
+                return;
+
         dbg("%s - port %d", __FUNCTION__, port->number);
 
         if (!port->open_count) {
@@ -330,6 +355,9 @@ static void serial_unthrottle (struct tty_struct * tty)
 {
         struct usb_serial_port *port = tty->driver_data;
 
+        if (!port)
+                return;
+
         dbg("%s - port %d", __FUNCTION__, port->number);
 
         if (!port->open_count) {
@@ -347,6 +375,9 @@ static int serial_ioctl (struct tty_struct *tty, struct file * file, unsigned in
         struct usb_serial_port *port = tty->driver_data;
         int retval = -ENODEV;
 
+        if (!port)
+                goto exit;
+
         dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
 
         if (!port->open_count) {
@@ -368,6 +399,9 @@ static void serial_set_termios (struct tty_struct *tty, struct termios * old)
 {
         struct usb_serial_port *port = tty->driver_data;
 
+        if (!port)
+                return;
+
         dbg("%s - port %d", __FUNCTION__, port->number);
 
         if (!port->open_count) {
@@ -384,6 +418,9 @@ static void serial_break (struct tty_struct *tty, int break_state)
 {
         struct usb_serial_port *port = tty->driver_data;
 
+        if (!port)
+                return;
+
         dbg("%s - port %d", __FUNCTION__, port->number);
 
         if (!port->open_count) {
@@ -445,6 +482,9 @@ static int serial_tiocmget (struct tty_struct *tty, struct file *file)
 {
         struct usb_serial_port *port = tty->driver_data;
 
+        if (!port)
+                goto exit;
+
         dbg("%s - port %d", __FUNCTION__, port->number);
 
         if (!port->open_count) {
@@ -464,6 +504,9 @@ static int serial_tiocmset (struct tty_struct *tty, struct file *file,
 {
         struct usb_serial_port *port = tty->driver_data;
 
+        if (!port)
+                goto exit;
+
         dbg("%s - port %d", __FUNCTION__, port->number);
 
         if (!port->open_count) {
@@ -742,6 +785,7 @@ int usb_serial_probe(struct usb_interface *interface,
                 port->number = i + serial->minor;
                 port->serial = serial;
                 spin_lock_init(&port->lock);
+                sema_init(&port->sem, 1);
                 INIT_WORK(&port->work, usb_serial_port_softint, port);
                 serial->port[i] = port;
         }