Re: [PATCH] gpio: omap: do not register driver in probe()

["Danilo Krummrich" <dakr@kernel.org>]

On Fri Jan 23, 2026 at 4:23 PM CET, Greg KH wrote:
> On Fri, Jan 23, 2026 at 03:25:43PM +0100, Danilo Krummrich wrote:
>> On Fri Jan 23, 2026 at 3:19 PM CET, Greg KH wrote:
>> > But there are no platform resources for this at all, shouldn't this be a
>> > faux device instead?
>> 
>> Probably, but that's for another patch, since this one may potentially be
>> backported beyond the existence of the faux bus.
>> 
>> > That being said, ignoring the return value of platform_device_register()
>> > is probably not something we want to keep around.
>> 
>> Yes, as mentioned below the commit message, there are a couple of things that
>> need to be followed up on here.
>> 
>> With this patch I only intend to fix the deadlock condition and otherwise keep
>> all the existing semantics as it is.
>> 
>> I.e. maybe it is intentional and this driver should not abort probing if this
>> can't be registered for some reason.
>
> Ok, fair enough, fixing this immediate bug is good enough for me.
>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Just for the record, the things that should still be addressed:

  (1) Potential UAF on module unload: The device is declared as global static
      (should use a dynamic allocation instead); device is never unregistered.

  (2) Handle return value of *_device_register().

  (3) Use faux bus; maybe not directly suitable as omap_mpuio_driver only uses
      struct dev_pm_ops callbacks. Though, we could extend struct
      faux_device_ops accordingly.

- Danilo