Messages in this thread | | | From | Pavel Tatashin <> | Date | Fri, 12 Jan 2018 08:52:47 -0500 | Subject | Re: [4.4] broken conversion from efi to kernel page table |
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Hi Jiri,
This patch solves a different problem than _PAGE_NX. The problem it solves is similar to + efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);, Where after applying PTI mask CR3 can point to invalid page table. But, this patch is specific to stable 4.4.110 since it uses trampoline_pgd from realmode, instead of allocating its own page table as 4.6 and later do.
Thank you, Pavel
On Fri, Jan 12, 2018 at 5:04 AM, Jiri Kosina <jikos@kernel.org> wrote: > On Thu, 11 Jan 2018, Pavel Tatashin wrote: > >> This fixes boot panics, hangs which I reported in this thread: > > Are you using EFI old_memmap? > > If so, then > > https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=x86/pti&id=de53c3786a3ce162a1c815d0c04c766c23ec9c0a > > ("x86/pti: Unbreak EFI old_memmap") should be the cure. > > If not, you might be missing this in in arch/x86/platform/efi/efi_64.c > > - efi_pgd = (pgd_t *)__get_free_page(gfp_mask); > + efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER); > > Could you please let me know if either of this fixes your problem? > > Thanks, > > -- > Jiri Kosina > SUSE Labs >
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