Spectre v3, aka Meltdown — CVE-2017-5754

KPTI is the approach adopted by every major operating system, but not everyone implemented it at the same time.

Linux, being included in the embargo, had a mitigation since at least December 2017.

The 4^th and 5^th of January, DragonflyBSD added a KTPI-like, via 1 2 3 4.

The 7^th of January 2018, NetBSD did the same, and the so did FreeBSD on the 19^th

In February 2018, Philip Guenther and Mike Larkin implemented an equivalent of KTPI in OpenBSD for AMD64. Although, to be fair, support for ARM64 was added the 10^th of January.