linux-kernel - Re: [PATCH] x86: mcheck: call put_device on device

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Message-ID: <20131130111214.GB4323@pd.tnic>
Date:	Sat, 30 Nov 2013 12:12:14 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Levente Kurusa <levex@...ux.com>
Cc:	Ingo Molnar <mingo@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Tony Luck <tony.luck@...el.com>,
	"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
	EDAC <linux-edac@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86: mcheck: call put_device on device_register failure

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


Ok, I see it now. :-) :-)

Thanks, I'll take your patch as-is.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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