OpenBSD 6.3 Released With Spectre/Meltdown Mitigation, ARM64 SMP Support
OpenBSD 6.3 is the project's first release with mitigation for the Meltdown CPU vulnerability as well as Spectre. Kernel Page Table Isolation (KPTI) is used for mitigating Meltdown, similar to on Linux. For Spectre V2 they are flushing the branch target buffer on ARM processors. Intel CPUs also now have their microcode updates automatically applied by fw_update with OpenBSD 6.3.
This is also the project's first update since OpenBSD 6.2 debuted last October, so overall it's quite a big update. On the 64-bit ARM side, it's their first release to support SMP (Symmetric Multi-Processing). Additionally, for ARMv7 platforms, OpenBSD is finally providing VFP and NEON support. There are also many ARM driver updates too with this release as well as support for the Rockchip RK3328/RK3288 SoCs, Allwinner SoC support additions, and much more.
On the x86 side, bring-up of Intel Cannonlake and Icelake processors has begun with there now being Ethernet support, among other hardware support improvements.
OpenBSD 6.3 also has wireless driver improvements, a variety of general networking subsystem enhancements, a variety of security improvements, and is shipping with OpenSSH 7.7 and LibreSSL 2.7.2.
More details on the massive set of changes for OpenBSD 6.3 can be found via today's release notes.