On Thu, 2021-03-18 at 12:16 +0100, Johannes Berg wrote: > > Yeah, that's a dilemma. An oft-seen trick is to add more bytes for > > the future use, e.g. extend to 16 bytes and fill 0 for the remaining. > > Yeah, I guess I could stick a reserved[15] there, it's small enough.
Actually, that doesn't really help anything either. If today I require that the reserved bytes are sent as 0 by userspace, then any potential expansion that requires userspace to set it will break when userspace does it and runs on an old kernel. If I don't require the reserved bytes to be set to 0 then somebody will invariably get it wrong and send garbage, and then we again cannot extend it. So ... that all seems pointless. I guess I'll send the patch as it is now. johannes
