[nrdvana]

The problem is that you end up with two syscalls for every setting. e.g. chroot to change your own root, then newproc_chroot to change the root of a newly spawned process. Start making a list of all the ways you can change process state and you'll realize there are probably hundreds, here. Now imagine being the kernel author and having to duplicate all that code.

Having used both, I can easily say that CreateProcess is deficient, and fork/exec is kind of genius in how many things it makes possible. Could Windows fix CreateProcess with more API? Sure, but they didn't, probably because nobody wanted to spend the effort duplicating all their kernel code.

[jcranmer]

> The problem is that you end up with two syscalls for every setting. e.g. chroot to change your own root, then newproc_chroot to change the root of a newly spawned process.

Or you add just one syscall to get the handle for the current process and then make all of the syscalls like chroot a userspace alias for proc_chroot(curprocess(), new_root).