[DRIVER MODEL] Fix macsonic

Release code in driver modules is a potential cause of oopsen.
The device may be in use by a userspace process, which will keep
a reference to the device.  If the module is unloaded, the module
text will be freed.  Subsequently, when the last reference is
dropped, the release code will be called, which no longer exists.

Use generic platform device allocation/release code in modules.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/macsonic.c b/drivers/net/macsonic.c
index e9c999d..9ef4592 100644 (file)
--- a/drivers/net/macsonic.c
+++ b/drivers/net/macsonic.c
@@ -599,18 +599,8 @@ static struct device_driver mac_sonic_driver = {
        .remove = __devexit_p(mac_sonic_device_remove),
 };
 
-static void mac_sonic_platform_release(struct device *device)
-{
-       struct platform_device *pldev;
-
-       /* free device */
-       pldev = to_platform_device (device);
-       kfree (pldev);
-}
-
 static int __init mac_sonic_init_module(void)
 {
-       struct platform_device *pldev;
        int err;
 
        if ((err = driver_register(&mac_sonic_driver))) {
@@ -618,27 +608,20 @@ static int __init mac_sonic_init_module(void)
                return err;
        }
 
-       mac_sonic_device = NULL;
-
-       if (!(pldev = kmalloc (sizeof (*pldev), GFP_KERNEL))) {
+       mac_sonic_device = platform_device_alloc(mac_sonic_string, 0);
+       if (!mac_sonic_device) {
                goto out_unregister;
        }
 
-       memset(pldev, 0, sizeof (*pldev));
-       pldev->name             = mac_sonic_string;
-       pldev->id               = 0;
-       pldev->dev.release      = mac_sonic_platform_release;
-       mac_sonic_device        = pldev;
-
-       if (platform_device_register (pldev)) {
-               kfree(pldev);
+       if (platform_device_add(mac_sonic_device)) {
+               platform_device_put(mac_sonic_device);
                mac_sonic_device = NULL;
        }
 
        return 0;
 
 out_unregister:
-       platform_device_unregister(pldev);
+       driver_unregister(&mac_sonic_driver);
 
        return -ENOMEM;
 }