Open-coded page table entry checks don't work correctly when we fold the page table level at runtime.

pgd_present() on 4-level paging machine always returns true, but open-coded version of the check may return false-negative result and we silently skip the rest of the loop body in efi_call_phys_epilog().

Replace open-coded checks with proper helpers.

Signed-off-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Fixes: 94133e46a0f5 ("x86/efi: Correct EFI identity mapping under 'efi=old_map' when KASLR is enabled") Cc: stable@vger.kernel.org # 4.12+ Cc: Baoquan He bhe@redhat.com Cc: Matt Fleming matt@codeblueprint.co.uk Cc: Andrey Ryabinin aryabinin@virtuozzo.com --- arch/x86/platform/efi/efi_64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index e01f7ceb9e7a..77873ce700ae 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -166,14 +166,14 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd) pgd = pgd_offset_k(pgd_idx * PGDIR_SIZE); set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);

- if (!(pgd_val(*pgd) & _PAGE_PRESENT)) + if (!pgd_present(*pgd)) continue;

for (i = 0; i < PTRS_PER_P4D; i++) { p4d = p4d_offset(pgd, pgd_idx * PGDIR_SIZE + i * P4D_SIZE);

- if (!(p4d_val(*p4d) & _PAGE_PRESENT)) + if (!p4d_present(*p4d)) continue;

pud = (pud_t *)p4d_page_vaddr(*p4d);