Commit 0998d063 authored May 23, 2012 by Hans de Goede Committed by Greg Kroah-Hartman Jun 13, 2012

device-core: Ensure drvdata = NULL when no driver is bound



1) drvdata is for a driver to store a pointer to driver specific data
2) If no driver is bound, there is no driver specific data associated with
   the device
3) Thus logically drvdata should be NULL if no driver is bound.

But many drivers don't clear drvdata on device_release, or set drvdata
early on in probe and leave it set on probe error. Both of which results
in a dangling pointer in drvdata.

This patch enforce for drvdata to be NULL after device_release or on probe
failure.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent b02f8bed

drivers/base/dd.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -283,6 +283,7 @@ probe_failed:
		devres_release_all(dev);
		driver_sysfs_remove(dev);
		dev->driver = NULL;
		dev_set_drvdata(dev, NULL);

		if (ret == -EPROBE_DEFER) {
		/* Driver requested deferred probing */
		@@ -487,6 +488,7 @@ static void __device_release_driver(struct device *dev)
		drv->remove(dev);
		devres_release_all(dev);
		dev->driver = NULL;
		dev_set_drvdata(dev, NULL);
		klist_remove(&dev->p->knode_driver);
		if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,

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