On Fri, Dec 15, 2017 at 2:20 AM Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > This reverts commit 87e2bd898d3a79a8c609f183180adac47879a2a4 which is > commit edc3b9129cecd0f0857112136f5b8b1bc1d45918 upstream. > > Turns there was too many other issues with this patch to make it viable > for the stable tree. This was sort of a long time ago, but does anyone remember why this needed to be reverted from 4.4? The reason I ask is that without this, commit 02ff2769edbc / "x86/mm/pat: Make set_memory_np() L1TF safe" in 4.4.148 is broken. That patch has - set_pud(pud, __pud(cpa->pfn | _PAGE_PSE | - massage_pgprot(pud_pgprot))); + set_pud(pud, pud_mkhuge(pfn_pud(cpa->pfn, + canon_pgprot(pud_pgprot)))); (and similarly for pmds) but pfn_pud() is operating on page frame numbers and __pud(cpa->pfn... in the old code is operating on physical addresses. This is bad enough that 4.4.148 and all newer 4.4.y crash early in boot on some EFI systems that I have. For now I am re-applying the "ensure cpa->pfn only contains page frame numbers" patch, ported on top of 4.4.151. - R.
