Spectre V1 Mitigation & Other Spectre/Meltdown Updates For 64-bit ARM On Linux 4.16

Last week was the updates providing initial Spectre Variant Two and Meltdown mitigation for 64-bit ARM hardware on the Linux 4.16 kernel. This week as the Linux 4.16 merge window nears the end, Spectre Variant One mitigation has come for ARM64 as well as other Spectre V2 / Meltdown updates.

Today's code called up for pulling into Linux 4.16 provide initial mitigation for Spectre Variant One "Bounds Check Bypass" in the kernel. There are also updates for Variant Two of dealing with newer firmware interfaces and additional branch predictor hardening. On the Meltdown side is an update for Cavium Thunder X hardware that is not affected but hardware erratum has some conflicts with getting KPTI disabled.

The complete list of these latest Meltdown/Spectre improvements for AArch64 hardware can be found from this pull request.