[OE-core] pseudo: host user contamination

[Seebs]

On Mon, 26 Mar 2018 20:49:30 +0200
Andreas Müller <schnitzeltony at gmail.com> wrote:

> Interesting background: mv/renameat2 change seemed so important for
> Fedora that they backported the changes into 8.27.

It looks like the reason for this is the RENAME_NOREPLACE flag, which
avoids a possible race condition.

FWIW, I've traded a couple of emails with the coreutils people, and I
think at this point I'm going to try a custom wrapper for syscall that
just yields ENOTSUPP, because any attempt to do something fancier
seems like it's going to be potentially error-prone.

Since the man page gave the ia64 example, I went and checked, and it
is indeed the case that calls other than syscall(2) will clobber r10
after system calls, so it's actually not possible for a C wrapper to
do what we want on an intercepted syscall.

Luckily for everyone, no one actually cares about ia64, aka Itanic.

-s