ACPI / hotplug / PCI: Rework the handling of eject requests

Hello Rafael J. Wysocki,

The patch dd2151be28b9: "ACPI / hotplug / PCI: Rework the handling of eject requests" from Feb 4, 2014, leads to the following static checker warning:

	drivers/acpi/scan.c:479 acpi_generic_hotplug_event()
	error: we previously assumed 'adev->handler' could be null (see line 473)

drivers/acpi/scan.c
464 static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type) 465 {
466 switch (type) {
467 case ACPI_NOTIFY_BUS_CHECK:
468 return acpi_scan_bus_check(adev);
469 case ACPI_NOTIFY_DEVICE_CHECK:
470 return acpi_scan_device_check(adev);
471 case ACPI_NOTIFY_EJECT_REQUEST:
472 case ACPI_OST_EC_OSPM_EJECT:

   473                  if (adev->handler && !adev->handler->hotplug.enabled) {
                            ^^^^^^^^^^^^^

Patch adds new check.

   474                          dev_info(&adev->dev, "Eject disabled\n");
   475                          return -EPERM;
   476                  }
   477                  acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
   478                                    ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
   479                  return acpi_scan_hot_remove(adev);

"adev->handler" is dereferenced without checking inside the call to acpi_scan_hot_remove().

480 }
481 return -EINVAL;
482 }

regards,
dan carpenter