On Wed, 2018-08-22 at 17:48 -0700, Roland Dreier wrote: > 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? See <https://lore.kernel.org/lkml/1512686629.18523.217.camel@xxxxxxxxxxxxxxx/T/#u>. Ben. > 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. > -- Ben Hutchings, Software Developer Codethink Ltd https://www.codethink.co.uk/ Dale House, 35 Dale Street Manchester, M1 2HF, United Kingdom
