Merge tag 'x86_urgent_for_v6.5_rc6' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-2.6-microblaze.git] / mm / pagewalk.c

diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 6443710..2022333 100644 (file)
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -48,8 +48,11 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
        if (walk->no_vma) {
                /*
                 * pte_offset_map() might apply user-specific validation.
+                * Indeed, on x86_64 the pmd entries set up by init_espfix_ap()
+                * fit its pmd_bad() check (_PAGE_NX set and _PAGE_RW clear),
+                * and CONFIG_EFI_PGT_DUMP efi_mm goes so far as to walk them.
                 */
-               if (walk->mm == &init_mm)
+               if (walk->mm == &init_mm || addr >= TASK_SIZE)
                        pte = pte_offset_kernel(pmd, addr);
                else
                        pte = pte_offset_map(pmd, addr);