It really isn't; the program just needs to be able to declare what it expects it should be able to do, and what it expects its children should be able to do. The latter doesn't need to be a subset of the former.

▲

dcrazy 2 hours ago | parent | next [-]

That “just” is doing a LOT of work.

▲

0c3ca83 2 hours ago | parent [-]

It's already done on OpenBSD, and linux has the pieces to do it, though it's far more fragile and complicated. I'm not speaking hypothetically here, I've implemented code that works this way.

	▲	dcrazy 2 hours ago \| parent [-]
		You are minimizing the difference in scope between the audience and applications of OpenBSD and those of macOS. macOS has had a capabilities model for over a decade called App Sandboxing. It would be entirely impractical to expect app authors to correctly declare their permissions up front and for users to audit them. Hence the permissions granted to sandboxed apps are pre-determined by the OS, and can be extended through explicit user interaction.

▲

saagarjha 3 hours ago | parent | prev [-]

This is really hard to do in general

	▲	eviks an hour ago \| parent \| next [-]
		Indeed, is only the OS mastermind had billions and years to fix the foundation...
	▲	0c3ca83 2 hours ago \| parent \| prev [-]
		It's done on the majority of the OpenBSD base system, as well as important ports like Chrome and Firefox. Linux also has the parts to do this, though it's more fragile and complicated.