kernel: x86: exceptions are not cleared in AMD FXSAVE workaround

The restorefpuchecking function in arch/x86/include/asm/fpu-internal.h in the Linux kernel before 3.12.8 on the AMD K7 and K8 platforms does not clear pending exceptions before proceeding to an EMMS instruction, which allows local users to cause a denial of service task kill or possibly gain...