Ubuntu on Windows

Posted Mar 30, 2016 21:07 UTC (Wed) by Karellen (subscriber, #67644)
Parent article: Ubuntu on Windows

As mentioned elsewhere, are we sure this wasn't accidentally posted a couple of days early?

Still, I wonder - the article mentions that Windows has effectively re-implemented the Linux syscall interface. Does anyone know if that means that they're also running the stock Ubuntu glibc? Actually, thinking about it, the syscall ABI is probably easier to reimplement than the outward-facing libc ABI, or than messing around with some hybrid of the two.

Second, the Ubuntu filesystem appears to be installed per-user?!? Does that seem odd to anyone? Although... the screenshots make it look like the Ubuntu "system" is running as root. Does anyone know if the Linux subsystem supports users? Or does everything think it's running as Linux UID 0, even when running as a non-privileged Windows user? (Are the Ubuntu packages OK with that? I thought some packages would probably have postinst errors if they couldn't set permissions to some non-root UID) I guess some kind of PAM module would be the best way of creating a better mapping between Linux subsystem users and real Windows accounts? Could you even get sudo working if that were the case?

Ubuntu on Windows

Posted Mar 31, 2016 3:12 UTC (Thu) by jdub (guest, #27) [Link] (2 responses)

Yes, it's the stock Ubuntu user land, including glibc. Exactly the same bits you'd expect to find after installing Ubuntu, or booting a VM, minus the kernel and related utilities.

Yes, it's an implementation of the Linux kernel ABI (syscalls, special file systems, etc).

Yes, the rootfs is installed per-user, under AppData. The combination of all of the above means it's not just restricted to Ubuntu, and different users can run different flavours. Seems there can only be one flavour per user, though.

Yes, in the first public beta release, everything runs as root, but that will be fixed soon. Ultimately "root" on WinLS has the same permissions as the executing NT user, so it doesn't mean very much (but the safety and semantics of uid awareness will be good).

Based on what I've seen so far (particularly the per-user rootfs), I doubt there'll be any mapping between different Windows users within the Linux subsystem. It's theoretically doable, but way too much to bite off to start with.

Ubuntu on Windows

Posted Mar 31, 2016 4:57 UTC (Thu) by joey (guest, #328) [Link] (1 responses)

Hey jdub, do you know if this allows a Linux process to exec() a .EXE?

And does it support inotify?

These would be my likely pain points for dropping git-annex's windows port in favor of this. Fingers crossed.

Ubuntu on Windows

Posted Mar 31, 2016 7:15 UTC (Thu) by jdub (guest, #27) [Link]

I don't have any inside info, but I suspect "no" on the former (but not outside the realms of possibility), and "not yet" on the latter (but I reckon *notify will land because lots of dev tools use it to watch for code changes).