Dev Blogs
Mapping them to concepts from C# and the now-defunct C++/CX.
Not always.
ud0 and ud1 have parameters? How undefined were they?
They weren't defined, not even as undefined.
ud2 and sometimes int 3 for code that shouldn’t execute?
It shouldn't execute, but for different reasons.
Hot-patching is for Windows, not for you.
They either predate hot-patching or never needed it.
Once again, the benefit of fixed-length instructions.
Fixed-length instructions makes it a much easier task.
Swearing is also poor form.
Only on first execution.