Re: [PATCH 08/18] iommu: Introduce cache_invalidate API

[Andriy Shevchenko]

On Tue, Apr 09, 2019 at 09:43:28AM -0700, Jacob Pan wrote:
> On Tue, 9 Apr 2019 13:07:18 +0300
> Andriy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> > On Mon, Apr 08, 2019 at 04:59:23PM -0700, Jacob Pan wrote:

> > > +int iommu_cache_invalidate(struct iommu_domain *domain, struct
> > > device *dev,
> > > +			   struct iommu_cache_invalidate_info
> > > *inv_info) +{
> > > +	int ret = 0;  
> > 
> > Redundant assignment.
> > 
> I am not a security expert but initialization of local variable can be
> more secure.
> I was looking at this talk.
> https://outflux.net/slides/2018/lss/danger.pdf
> https://cwe.mitre.org/data/definitions/457.html

I hardly see any of these applied to your case here.
Care to show what I'm missing?

> > > +	if (unlikely(!domain->ops->cache_invalidate))
> > > +		return -ENODEV;
> > > +
> > > +	ret = domain->ops->cache_invalidate(domain, dev, inv_info);
> > > +
> > > +	return ret;
> > > +}  

-- 
With Best Regards,
Andy Shevchenko