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path: root/drivers/usb/serial/usb-serial.c
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Diffstat (limited to 'drivers/usb/serial/usb-serial.c')
-rw-r--r--drivers/usb/serial/usb-serial.c48
1 files changed, 46 insertions, 2 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 0c4881d18cd..8bc8337c99c 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;
}