On Mon, Jun 29, 2026 at 03:29:50PM -0700, Dave Hansen wrote: > But, really, if ENTER is so evil and nobody uses it, shouldn't we just > have an MSR bit somewhere to tell the CPU to #UD for it rather than > playing these stack games?
For supervisor mode only, I suppose. We can't ever get rid of userspace ENTER because legacy I suppose. But we can make sure the kernel is clean. So yeah, having a knob to make supervisor-ENTER trap would be useful I suppose.
