32-bit ARM Finally Gets Mitigated For Spectre V1/V2 With Linux 4.18
While 64-bit ARM (AArch64) has been mitigated for months with the mainline Linux kernel against Spectre Variant One and Two, with the upcoming Linux 4.18 kernel is finally Spectre V1/V2 treatment for 32-bit ARM.
Landing today in the Linux kernel Git code is the initial Spectre variant one and two fixes for 32-bit ARM devices.This includes firmware-based hardening for Spectre V2, speculation barrier macros for Spectre V1 to prevent against speculation with arrays, etc.
Back in the day when building a 12-core 32-bit ARM cluster was special.
It will be interesting to see the performance impact of Spectre V1/V2 handling for 32-bit ARM, especially considering those were the days when ARM performance was much slower... Also included with today's Linux ARM updates are Clang compiler support improvements for trying to build the ARM Linux kernel with this GCC alternative.