RE: [PATCH] Drivers: hv: vmbus: incorrect device name is printedwhen child device is unregistered

From: KY Srinivasan
Date: Fri Jun 14 2013 - 17:37:00 EST




> -----Original Message-----
> From: Greg KH (gregkh@xxxxxxxxxxxxxxxxxxx)
> [mailto:gregkh@xxxxxxxxxxxxxxxxxxx]
> Sent: Friday, June 14, 2013 12:23 PM
> To: KY Srinivasan
> Cc: Fernando Soto; linux-kernel@xxxxxxxxxxxxxxx; Haiyang Zhang
> Subject: Re: [PATCH] Drivers: hv: vmbus: incorrect device name is printed when
> child device is unregistered
>
> On Fri, Jun 14, 2013 at 02:13:44AM +0000, KY Srinivasan wrote:
> >
> >
> > > -----Original Message-----
> > > From: Fernando Soto [mailto:fsoto@xxxxxxxxxxxxxxxxxxx]
> > > Sent: Thursday, June 13, 2013 8:11 PM
> > > To: linux-kernel@xxxxxxxxxxxxxxx
> > > Cc: KY Srinivasan; Haiyang Zhang
> > > Subject: [PATCH] Drivers: hv: vmbus: incorrect device name is printed when
> child
> > > device is unregistered
> > >
> > > From: Fernando Soto <fsoto@xxxxxxxxxxxxxxxxxxx>
> > > Please CC me, I am not subscribed to the list.
> > >
> > > Whenever a device is unregistered in vmbus_device_unregister
> > > (drivers/hv/vmbus_drv.c), the device name in the log message may contain
> > > garbage as the memory has already been freed by the time pr_info is called.
> Log
> > > example:
> > > [ 3149.170475] hv_vmbus: child device àõsèè0_5 unregistered
> > >
> > > By logging the message just before calling device_unregister, the correct
> device
> > > name is printed:
> > > [ 3145.034652] hv_vmbus: child device vmbus_0_5 unregistered
> > >
> > > Signed-off-by: Fernando M Soto <fsoto@xxxxxxxxxxxxxxxxxxx>
> > Acked-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
> >
> > > --- linux-3.10-rc5/drivers/hv/vmbus_drv.c.orig 2013-06-13
> 19:20:55.359511352 -
> > > 0400
> > > +++ linux-3.10-rc5/drivers/hv/vmbus_drv.c 2013-06-13 19:21:39.299511695 -
> > > 0400
> > > @@ -698,14 +698,14 @@ int vmbus_device_register(struct hv_devi
> > > */
> > > void vmbus_device_unregister(struct hv_device *device_obj)
> > > {
> > > + pr_info("child device %s unregistered\n",
> > > + dev_name(&device_obj->device));
> > > +
> > > /*
> > > * Kick off the process of unregistering the device.
> > > * This will call vmbus_remove() and eventually vmbus_device_release()
> > > */
> > > device_unregister(&device_obj->device);
> > > -
> > > - pr_info("child device %s unregistered\n",
> > > - dev_name(&device_obj->device));
>
> No, please just remove these entirely, or make them pr_debug(), you
> shouldn't clutter up the kernel log for stuff like this.

Agreed. Fernando, do you want to submit a patch as suggested by Greg.

K. Y
>
> thanks,
>
> greg k-h
>


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