Re: [PATCH 3/9] Thermal: Add APIs to bind cdev to new zone structure

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Jan 09, 2013 at 09:21:23AM +0000, R, Durgadoss wrote:
> > -----Original Message-----
> > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > Sent: Tuesday, January 08, 2013 12:56 AM
> > To: R, Durgadoss
> > Cc: Zhang, Rui; linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org;
> > eduardo.valentin@ti.com; hongbo.zhang@linaro.org; wni@nvidia.com
> > Subject: Re: [PATCH 3/9] Thermal: Add APIs to bind cdev to new zone
> > structure
> > 
> > On Mon, Jan 07, 2013 at 12:43:20PM +0530, Durgadoss R wrote:
> > > +struct thermal_cooling_device *get_cdev_by_name(const char *name)
> > > +{
> > > +	struct thermal_cooling_device *pos;
> > > +	struct thermal_cooling_device *cdev = NULL;
> > > +
> > > +	mutex_lock(&cdev_list_lock);
> > > +	for_each_cdev(pos) {
> > > +		if (!strnicmp(pos->type, name, THERMAL_NAME_LENGTH)) {
> > > +			cdev = pos;
> > > +			break;
> > > +		}
> > > +	}
> > > +	mutex_unlock(&cdev_list_lock);
> > > +	return cdev;
> > > +}
> > > +EXPORT_SYMBOL(get_cdev_by_name);
> > 
> > EXPORT_SYMBOL_GPL?
> 
> We have all other exports as EXPORT_SYMBOL in this file(thermal_sys.c)
> If _GPL is required, the we will do a single patch changing all of them to
> EXPORT_SYMBOL_GPL.

Fair enough.

> > You also forgot to increment the reference count, which is required for
> > all reference counted objects.
> 
> Sorry, I could not get what you are saying here.

You are doing a "get" call, yet you are failing to increment a reference
count on the object.  That isn't allowed and can cause bad problems.
Please use proper reference counting for your structures.

greg k-h