USB: serial: fix race between probe and open

[linux-flexiantxendom0.git] / drivers / usb / serial / usb-serial.c

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 2a982e6..38d7ebd 100644 (file)
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -21,7 +21,6 @@
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
 #include <linux/tty.h>
 #include <linux/tty_driver.h>
 #include <linux/tty_flip.h>
@@ -52,6 +51,7 @@ static struct usb_driver usb_serial_driver = {
        .suspend =      usb_serial_suspend,
        .resume =       usb_serial_resume,
        .no_dynamic_id =        1,
+       .supports_autosuspend = 1,
 };
 
 /* There is no MODULE_DEVICE_TABLE for usbserial.c.  Instead
@@ -406,7 +406,7 @@ static void serial_unthrottle(struct tty_struct *tty)
                port->serial->type->unthrottle(tty);
 }
 
-static int serial_ioctl(struct tty_struct *tty, struct file *file,
+static int serial_ioctl(struct tty_struct *tty,
                                        unsigned int cmd, unsigned long arg)
 {
        struct usb_serial_port *port = tty->driver_data;
@@ -417,7 +417,7 @@ static int serial_ioctl(struct tty_struct *tty, struct file *file,
        /* pass on to the driver specific version of this function
           if it is available */
        if (port->serial->type->ioctl) {
-               retval = port->serial->type->ioctl(tty, file, cmd, arg);
+               retval = port->serial->type->ioctl(tty, cmd, arg);
        } else
                retval = -ENOIOCTLCMD;
        return retval;
@@ -496,18 +496,18 @@ static const struct file_operations serial_proc_fops = {
        .release        = single_release,
 };
 
-static int serial_tiocmget(struct tty_struct *tty, struct file *file)
+static int serial_tiocmget(struct tty_struct *tty)
 {
        struct usb_serial_port *port = tty->driver_data;
 
        dbg("%s - port %d", __func__, port->number);
 
        if (port->serial->type->tiocmget)
-               return port->serial->type->tiocmget(tty, file);
+               return port->serial->type->tiocmget(tty);
        return -EINVAL;
 }
 
-static int serial_tiocmset(struct tty_struct *tty, struct file *file,
+static int serial_tiocmset(struct tty_struct *tty,
                            unsigned int set, unsigned int clear)
 {
        struct usb_serial_port *port = tty->driver_data;
@@ -515,7 +515,19 @@ static int serial_tiocmset(struct tty_struct *tty, struct file *file,
        dbg("%s - port %d", __func__, port->number);
 
        if (port->serial->type->tiocmset)
-               return port->serial->type->tiocmset(tty, file, set, clear);
+               return port->serial->type->tiocmset(tty, set, clear);
+       return -EINVAL;
+}
+
+static int serial_get_icount(struct tty_struct *tty,
+                               struct serial_icounter_struct *icount)
+{
+       struct usb_serial_port *port = tty->driver_data;
+
+       dbg("%s - port %d", __func__, port->number);
+
+       if (port->serial->type->get_icount)
+               return port->serial->type->get_icount(tty, icount);
        return -EINVAL;
 }
 
@@ -736,6 +748,7 @@ int usb_serial_probe(struct usb_interface *interface,
 
        serial = create_serial(dev, interface, type);
        if (!serial) {
+               module_put(type->driver.owner);
                dev_err(&interface->dev, "%s - out of memory\n", __func__);
                return -ENOMEM;
        }
@@ -746,11 +759,11 @@ int usb_serial_probe(struct usb_interface *interface,
 
                id = get_iface_id(type, interface);
                retval = type->probe(serial, id);
-               module_put(type->driver.owner);
 
                if (retval) {
                        dbg("sub driver rejected device");
                        kfree(serial);
+                       module_put(type->driver.owner);
                        return retval;
                }
        }
@@ -822,6 +835,7 @@ int usb_serial_probe(struct usb_interface *interface,
                if (num_bulk_in == 0 || num_bulk_out == 0) {
                        dev_info(&interface->dev, "PL-2303 hack: descriptors matched but endpoints did not\n");
                        kfree(serial);
+                       module_put(type->driver.owner);
                        return -ENODEV;
                }
        }
@@ -835,22 +849,15 @@ int usb_serial_probe(struct usb_interface *interface,
                        dev_err(&interface->dev,
                            "Generic device with no bulk out, not allowed.\n");
                        kfree(serial);
+                       module_put(type->driver.owner);
                        return -EIO;
                }
        }
 #endif
        if (!num_ports) {
                /* if this device type has a calc_num_ports function, call it */
-               if (type->calc_num_ports) {
-                       if (!try_module_get(type->driver.owner)) {
-                               dev_err(&interface->dev,
-                                       "module get failed, exiting\n");
-                               kfree(serial);
-                               return -EIO;
-                       }
+               if (type->calc_num_ports)
                        num_ports = type->calc_num_ports(serial);
-                       module_put(type->driver.owner);
-               }
                if (!num_ports)
                        num_ports = type->num_ports;
        }
@@ -904,9 +911,8 @@ int usb_serial_probe(struct usb_interface *interface,
                        dev_err(&interface->dev, "No free urbs available\n");
                        goto probe_error;
                }
-               buffer_size = serial->type->bulk_in_size;
-               if (!buffer_size)
-                       buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
+               buffer_size = max_t(int, serial->type->bulk_in_size,
+                               usb_endpoint_maxp(endpoint));
                port->bulk_in_size = buffer_size;
                port->bulk_in_endpointAddress = endpoint->bEndpointAddress;
                port->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
@@ -936,7 +942,7 @@ int usb_serial_probe(struct usb_interface *interface,
                        goto probe_error;
                buffer_size = serial->type->bulk_out_size;
                if (!buffer_size)
-                       buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
+                       buffer_size = usb_endpoint_maxp(endpoint);
                port->bulk_out_size = buffer_size;
                port->bulk_out_endpointAddress = endpoint->bEndpointAddress;
                port->bulk_out_buffer = kmalloc(buffer_size, GFP_KERNEL);
@@ -984,7 +990,7 @@ int usb_serial_probe(struct usb_interface *interface,
                                                "No free urbs available\n");
                                goto probe_error;
                        }
-                       buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
+                       buffer_size = usb_endpoint_maxp(endpoint);
                        port->interrupt_in_endpointAddress =
                                                endpoint->bEndpointAddress;
                        port->interrupt_in_buffer = kmalloc(buffer_size,
@@ -1015,7 +1021,7 @@ int usb_serial_probe(struct usb_interface *interface,
                                                "No free urbs available\n");
                                goto probe_error;
                        }
-                       buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
+                       buffer_size = usb_endpoint_maxp(endpoint);
                        port->interrupt_out_size = buffer_size;
                        port->interrupt_out_endpointAddress =
                                                endpoint->bEndpointAddress;
@@ -1039,13 +1045,7 @@ int usb_serial_probe(struct usb_interface *interface,
 
        /* if this device type has an attach function, call it */
        if (type->attach) {
-               if (!try_module_get(type->driver.owner)) {
-                       dev_err(&interface->dev,
-                                       "module get failed, exiting\n");
-                       goto probe_error;
-               }
                retval = type->attach(serial);
-               module_put(type->driver.owner);
                if (retval < 0)
                        goto probe_error;
                serial->attached = 1;
@@ -1059,6 +1059,12 @@ int usb_serial_probe(struct usb_interface *interface,
                serial->attached = 1;
        }
 
+       /* Avoid race with tty_open and serial_install by setting the
+        * disconnected flag and not clearing it until all ports have been
+        * registered.
+        */
+       serial->disconnected = 1;
+
        if (get_free_serial(serial, num_ports, &minor) == NULL) {
                dev_err(&interface->dev, "No more free serial devices\n");
                goto probe_error;
@@ -1083,15 +1089,19 @@ int usb_serial_probe(struct usb_interface *interface,
                }
        }
 
+       serial->disconnected = 0;
+
        usb_serial_console_init(debug, minor);
 
 exit:
        /* success */
        usb_set_intfdata(interface, serial);
+       module_put(type->driver.owner);
        return 0;
 
 probe_error:
        usb_serial_put(serial);
+       module_put(type->driver.owner);
        return -EIO;
 }
 EXPORT_SYMBOL_GPL(usb_serial_probe);
@@ -1204,6 +1214,7 @@ static const struct tty_operations serial_ops = {
        .chars_in_buffer =      serial_chars_in_buffer,
        .tiocmget =             serial_tiocmget,
        .tiocmset =             serial_tiocmset,
+       .get_icount =           serial_get_icount,
        .cleanup =              serial_cleanup,
        .install =              serial_install,
        .proc_fops =            &serial_proc_fops,
@@ -1343,6 +1354,12 @@ int usb_serial_register(struct usb_serial_driver *driver)
 
        if (!driver->description)
                driver->description = driver->driver.name;
+       if (!driver->usb_driver) {
+               WARN(1, "Serial driver %s has no usb_driver\n",
+                               driver->description);
+               return -EINVAL;
+       }
+       driver->usb_driver->supports_autosuspend = 1;
 
        /* Add this device to our list of devices */
        mutex_lock(&table_lock);