Re: [PATCH v6 3/8] firmware_loader: Move module refcounts to allow unloading

[Dan Williams]

Russ Weight wrote:
[..]
> Clearly this would be an unexpected/unusual case. Someone with root
> access would have to remove the device driver. I'm not sure how much
> effort should be expended in preventing it - but this is the reasoning
> behind the incrementing/decrementing of the module reference counts.

The module reference needs to be held only if the producer of those
symbols can be removed without triggering some coordinated removal with
action consumer. A driver that fails to call
firmware_upload_unregister() in its module removal path is simply a driver
with a memory-leak and use-after-free bug, not something the firmware
upload core needs to worry about.

So, the prevention mechanism is "thou shalt use
firmware_upload_unregister() correctly", and when that is in place
explicit module references are not only redundant, but trying to
implement them causes circular dependency loops.