diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 461ea3bbd8d9..5f9f01532e67 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -744,7 +744,8 @@ struct folio *folio_walk_start(struct folio_walk *fw, pud = pudp_get(pudp); if (pud_none(pud)) goto not_found; - if (IS_ENABLED(CONFIG_PGTABLE_HAS_HUGE_LEAVES) && pud_leaf(pud)) { + if (IS_ENABLED(CONFIG_PGTABLE_HAS_HUGE_LEAVES) && + (!pud_present(pud) || pud_leaf(pud))) { ptl = pud_lock(vma->vm_mm, pudp); pud = pudp_get(pudp); @@ -753,6 +754,10 @@ struct folio *folio_walk_start(struct folio_walk *fw, fw->pudp = pudp; fw->pud = pud; + /* + * TODO: FW_MIGRATION support for PUD migration entries + * once there are relevant users. + */ if (!pud_present(pud) || pud_devmap(pud) || pud_special(pud)) { spin_unlock(ptl); goto not_found; @@ -769,12 +774,13 @@ struct folio *folio_walk_start(struct folio_walk *fw, } pmd_table: - VM_WARN_ON_ONCE(pud_leaf(*pudp)); + VM_WARN_ON_ONCE(!pud_present(pud) || pud_leaf(pud)); pmdp = pmd_offset(pudp, addr); pmd = pmdp_get_lockless(pmdp); if (pmd_none(pmd)) goto not_found; - if (IS_ENABLED(CONFIG_PGTABLE_HAS_HUGE_LEAVES) && pmd_leaf(pmd)) { + if (IS_ENABLED(CONFIG_PGTABLE_HAS_HUGE_LEAVES) && + (!pmd_present(pmd) || pmd_leaf(pmd))) { ptl = pmd_lock(vma->vm_mm, pmdp); pmd = pmdp_get(pmdp); @@ -786,7 +792,7 @@ struct folio *folio_walk_start(struct folio_walk *fw, if (pmd_none(pmd)) { spin_unlock(ptl); goto not_found; - } else if (!pmd_leaf(pmd)) { + } else if (pmd_present(pmd) && !pmd_leaf(pmd)) { spin_unlock(ptl); goto pte_table; } else if (pmd_present(pmd)) { @@ -812,7 +818,7 @@ struct folio *folio_walk_start(struct folio_walk *fw, } pte_table: - VM_WARN_ON_ONCE(pmd_leaf(pmdp_get_lockless(pmdp))); + VM_WARN_ON_ONCE(!pmd_present(pmd) || pmd_leaf(pmd)); ptep = pte_offset_map_lock(vma->vm_mm, pmdp, addr, &ptl); if (!ptep) goto not_found;