Messages in this thread | | | Date | Mon, 2 Dec 2013 21:23:30 -0500 | From | "Chen, Gong" <> | Subject | Re: [PATCH] x86: mcheck: call put_device on device_register failure |
| |
On Sat, Nov 30, 2013 at 12:12:14PM +0100, Borislav Petkov wrote: > Date: Sat, 30 Nov 2013 12:12:14 +0100 > From: Borislav Petkov <bp@alien8.de> > To: Levente Kurusa <levex@linux.com> > Cc: Ingo Molnar <mingo@kernel.org>, Thomas Gleixner <tglx@linutronix.de>, > Tony Luck <tony.luck@intel.com>, "H. Peter Anvin" <hpa@zytor.com>, > x86@kernel.org, EDAC <linux-edac@vger.kernel.org>, LKML > <linux-kernel@vger.kernel.org> > Subject: Re: [PATCH] x86: mcheck: call put_device on device_register failure > User-Agent: Mutt/1.5.21 (2010-09-15) > > 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. >
I have some concerns about it. if device_register is failed, it will backtraces all kinds of conditions automatically, including put_device definately. So do we really need an extra put_device when it returns failure? [unhandled content-type:application/pgp-signature] | |