Linux 4.8 Bringing Intel MPX Enhancements, Work Towards Virtually Mapped Kernel Stacks

Ingo Molnar sent in his pull requests on Monday for the Linux 4.8 kernel. Among the interesting material this cycle were the x86/mm changes with some notable commits.

The x86 memory management work for Linux 4.8 includes prep work for supporting virtually mapped kernel stacks, a workaround for erratum of Intel's Knights Landing hardware, Intel MPX (Memory Protection Extensions) enhancements, and other fixes and clean-ups.

Virtually mapped kernel stacks would allow the kernel stacks to no longer be physically contiguous plus other improvements around the design of kernel stacks, such as reliable faults when the stack overflows. With Linux 4.8 the virtually mapped kernel stacks support hasn't landed in full, but the prep work is there, so maybe we'll see it for Linux 4.9.

More details on the x86/mm changes that made it for Linux 4.8 can be found via this pull request.