[jcranmer]

What you need is some kind of handle with the ability to do system calls on behalf of another process via that handle. CreateProcess would return this handle, whereas StartProcess would actually use that handle to start execution.

Windows and Fuchsia are two handle-based OSes, and Fuchsia does in fact spawn processes in this manner (Windows just has a family of CreateProcess methods that do both).

[tsimionescu]

This would probably be a cleaner approach, that doesn't duplicate all process functionality between syscalls and the Process struct I was thinking of, and it also is far easier to keep backwards compatible.

[the8472]

If you can do syscalls on behalf of another process, sure. But that's more than "just" CreateProcess.