dev_printk() is now GPL-only

[Matthew Wilcox <matthew@wil.cx>]

Does dev_driver_string() really need to be GPL-only?  Up to this point,
proprietary modules have been entitled to call dev_printk(), but now:

#define dev_printk(level, dev, format, arg...)  \
        printk(level "%s %s: " format , dev_driver_string(dev) , (dev)->bus_id , ## arg)

with

EXPORT_SYMBOL_GPL(dev_driver_string);

means that they're not allowed to.

On a related note, one might wonder if

        return dev->driver ? dev->driver->name :
	                        (dev->bus ? dev->bus->name : "");

really qualifies for the full weight of copyright enforcement, and query
whether using it makes your driver a derived work.  Particularly since
all one is doing is asking the kernel for a nice printk prefix and know
nothing about the innards of the device model.