Re: [PATCH] vfio powerpc: implemented IOMMU driver for VFIO

[Alexey Kardashevskiy]

On 08/12/12 04:01, Alex Williamson wrote:
> > +	case VFIO_IOMMU_MAP_DMA: {
> > +		vfio_iommu_spapr_tce_dma_map param;
> > +		struct iommu_table *tbl = container->tbl;
> > +		enum dma_data_direction direction;
> > +		unsigned long locked, lock_limit;
> > +
> > +		if (WARN_ON(!tbl))
> > +			return -ENXIO;
> > +
> > +		minsz = offsetofend(vfio_iommu_spapr_tce_dma_map, size);
> > +
> > +		if (copy_from_user(&param, (void __user *)arg, minsz))
> > +			return -EFAULT;
> > +
> > +		if (param.argsz < minsz)
> > +			return -EINVAL;
> > +
> > +		if ((param.flags & VFIO_DMA_MAP_FLAG_READ) &&
> > +				(param.flags & VFIO_DMA_MAP_FLAG_WRITE))
> > +			direction = DMA_BIDIRECTIONAL;
> > +		else if (param.flags & VFIO_DMA_MAP_FLAG_READ)
> > +			direction = DMA_TO_DEVICE;
> > +		else if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
> > +			direction = DMA_FROM_DEVICE;
> > +		else
> > +			return -EINVAL;
>
> flags needs to be sanitized too.  Return EINVAL if any unknown bit is
> set or else sloppy users may make it very difficult to make use of those
> flag bits later.


It already returns -EINVAL on any bit set except READ/WRITE, no?


--
Alexey
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