gup_can_follow_protnone
if (pmd_protnone(*pmd) && !gup_can_follow_protnone(vma, flags))
if (pte_protnone(pte) && !gup_can_follow_protnone(vma, flags))
if (pmd_protnone(pmdval) && !gup_can_follow_protnone(vma, flags))