Submitted on Monday by Peter Anvin for the Linux 3.14 merge window is the basic infrastructure work for Memory Protection Extensions, a feature coming to Intel CPUs beginning with next year's Skylake -- not to be confused with the Broadwell CPUs shipping in a few months.
MPX is a new x86 instruction extension and set of registers that bring greater security through checking pointer references for fending off buffer overflows.
Intel MPX isn't just implemented as a kernel feature but also requires changes to the compiler and run-time libraries.
For those not familiar with Intel Memory Protection Extensions I had written about MPX support still baking for Linux earlier this month.
The initial MPX kernel work was part of the x86/cpufeature pull request and introduces the basic kernel infrastructure for this feature. This pull request doesn't provide MPX support itself but just the basic support. This early support was landed for the KVM support for MPX that is expected to land later in the 3.14 merge window.
More details on this early kernel work for Intel MPX can be found via this pull request.