Re: [PATCH] x86: mcheck: call put_device on device_register failure

[Levente Kurusa <levex@linux.com>]

2013-11-30 12:12, Borislav Petkov:
> On Sat, Nov 30, 2013 at 08:30:33AM +0100, Levente Kurusa wrote:
>> No, if the call to put_device gives up the last reference to the
>> device, then device_release gets called which in turn frees the memory
>> associated with it. In this case, mce_device_release() will get
>> called, which is just a simple kfree call.
> 
> Aah, that's that delayed freeing the driver core does, right. Now you
> made me go and look into detail:
> 
> device_unregister
> |->put_device
>   |->kobject_put
>      |->kref_put(&kobj->kref, kobject_release)
> 	|->kref_sub(kref, 1, release)
> 	   |->release
> 	   |->kobject_release
> 	      |->kobject_cleanup
> 	         |->t->release
> 		 |->device_release
> 		    |->mce_device_release
> 
Now this tree makes me wonder if there are devices where
the author forgot to set a device_release or when the put_device
is not called. I will take a look into this.
> 
> Ok, I see it now. :-) :-)
> 
> Thanks, I'll take your patch as-is.
> 
Awesome, thanks! :-)


-- 
Regards,
Levente Kurusa