On Mon, Jan 04, 2021 at 01:26:41AM +1100, Daurnimator wrote:

On Fri, 28 Aug 2020 at 00:59, Stefano Garzarella [off-list ref] wrote:

quoted

+               __u8 register_op; /* IORING_RESTRICTION_REGISTER_OP */

Can you confirm that this intentionally limited the future range of
IORING_REGISTER opcodes to 0-255?

It was based on io_uring_probe, so we used u8 for opcodes, but we have 
room to extend it in the future.

So, for now, this allow to register restrictions up to 255 
IORING_REGISTER opcode.