Arm Has Many Changes On Tap For Linux 5.6 From Spectre/Meltdown Bits To New RNG

While the Linux 5.5 kernel isn't even released yet, it's ideally coming out on Sunday should there not be a one week delay. But in any event Arm's Will Deacon has already sent in the pull request of the ARM architecture changes for Linux 5.6.

Among the ARM architecture feature work for Linux 5.6 includes:

- Support for ARMv8.5 RNG instructions for high bandwidth, secure hardware random number generation.

- ARMv8.5 EOPD as a feature allowing page table isolation (KPTI) to be disabled on CPUs not impacted by Meltdown even if KASLR (Kernel Address Space Layout Randomization) is enabled.

- Whitelisting more ARM CPUs that are unaffected by Spectre Variant Two.

- Advertising various new ARM instructions to user-space.

- A workaround for Cortex-A55 erratum.

- LLVM Clang compiler fixes for the kernel.

- Continued work on the path to migrating more Assembly entry code to C.

The complete list via the pull request. Of course, outside of the architectural changes is all of the SoC/platform changes and that separate pull request will be sent in after the Linux 5.6 merge window is open.