[PATCH 0/5] x86, microcode, AMD: Size checking fixes

[Borislav Petkov <bp@amd64.org>]

From: Borislav Petkov <borislav.petkov@amd.com>

Hi all,

this is a patchset that reworks and fixes ucode size checking. The meat
of it is contained in 3/5 which reworks the code to iterate over the
patches in the microcode binary image _without_ vmalloc-ing space for
every patch in succession in order to look at it and go on to the next,
if it doesn't fit.

In any case, we end up loading at most one patch so before we copy it
in local storage we do all possible checks on it now, and copy it only
then, if all checks are passed.

Also, for simplicity, we alloc a single 4K page as a buffer for it which
we keep per CPU as long as the ucode module is loaded and free upon
exit. This simplifies all allocations/cleanup paths significantly.

Suggestions are welcome,
thanks.