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.
Best regards,
baolu