Re: [PATCH v4 3/5] iommu/uapi: Use named union for user data

Jacob Pan
2020-07-08T15:12:45Z

On Wed, 8 Jul 2020 10:17:57 +0800
Lu Baolu <baolu.lu@linux.intel.com> wrote:

> Hi Jacob,
>
> On 7/8/20 7:43 AM, Jacob Pan wrote:
> > IOMMU UAPI data size is filled by the user space which must be
> > validated by ther kernel. To ensure backward compatibility, user
> > data can only be extended by either re-purpose padding bytes or
> > extend the variable sized union at the end. No size change is
> > allowed before the union. Therefore, the minimum size is the offset
> > of the union.
> >
> > To use offsetof() on the union, we must make it named.
> >
> > Link:https://lkml.org/lkml/2020/6/11/834
>
> Please use lore.kernel.org links.
>
OK. will do.

> Best regards,
> baolu

[Jacob Pan]