usb/dummy_hcd: don't probe for udc if hcd failed

the_controller is allocated in dummy_hcd_probe() and is NULL if the
allocation failed. The probe function of the udc driver is dereferencing
this pointer and fault.
Alan Stern suggested to abort the dummy_hcd driver probing so the module
is not loaded. The is abort-on-error has been also added to the udc
driver.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/gadget/dummy_hcd.c b/drivers/usb/gadget/dummy_hcd.c
index 3214ca375d640536ab871b05a76b3e9b8924ad62..61ff927928ab9620231eddce21056a4160488e5f 100644 (file)
--- a/drivers/usb/gadget/dummy_hcd.c
+++ b/drivers/usb/gadget/dummy_hcd.c
@@ -892,10 +892,11 @@ static int dummy_udc_probe (struct platform_device *pdev)
                return rc;
        }
 
-       platform_set_drvdata (pdev, dum);
        rc = device_create_file (&dum->gadget.dev, &dev_attr_function);
        if (rc < 0)
                device_unregister (&dum->gadget.dev);
+       else
+               platform_set_drvdata(pdev, dum);
        return rc;
 }
 
@@ -1995,11 +1996,29 @@ static int __init init (void)
        retval = platform_device_add(the_hcd_pdev);
        if (retval < 0)
                goto err_add_hcd;
+       if (!the_controller) {
+               /*
+                * The hcd was added successfully but its probe function failed
+                * for some reason.
+                */
+               retval = -EINVAL;
+               goto err_add_udc;
+       }
        retval = platform_device_add(the_udc_pdev);
        if (retval < 0)
                goto err_add_udc;
+       if (!platform_get_drvdata(the_udc_pdev)) {
+               /*
+                * The udc was added successfully but its probe function failed
+                * for some reason.
+                */
+               retval = -EINVAL;
+               goto err_probe_udc;
+       }
        return retval;
 
+err_probe_udc:
+       platform_device_del(the_udc_pdev);
 err_add_udc:
        platform_device_del(the_hcd_pdev);
 err_add_hcd: