diff options
| -rw-r--r-- | include/linux/pagewalk.h | 5 | ||||
| -rw-r--r-- | mm/pagewalk.c | 40 |
2 files changed, 37 insertions, 8 deletions
diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h index aa6a0b63964e..d5d07f7a9c14 100644 --- a/include/linux/pagewalk.h +++ b/include/linux/pagewalk.h @@ -73,6 +73,7 @@ enum page_walk_action { * @mm: mm_struct representing the target process of page table walk * @vma: vma currently walked (NULL if walking outside vmas) * @action: next action to perform (see enum page_walk_action) + * @no_vma: walk ignoring vmas (vma will always be NULL) * @private: private data for callbacks' usage * * (see the comment on walk_page_range() for more details) @@ -82,12 +83,16 @@ struct mm_walk { struct mm_struct *mm; struct vm_area_struct *vma; enum page_walk_action action; + bool no_vma; void *private; }; int walk_page_range(struct mm_struct *mm, unsigned long start, unsigned long end, const struct mm_walk_ops *ops, void *private); +int walk_page_range_novma(struct mm_struct *mm, unsigned long start, + unsigned long end, const struct mm_walk_ops *ops, + void *private); int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, void *private); int walk_page_mapping(struct address_space *mapping, pgoff_t first_index, diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 690af44609e2..d5773465f6da 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -39,7 +39,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, do { again: next = pmd_addr_end(addr, end); - if (pmd_none(*pmd) || !walk->vma) { + if (pmd_none(*pmd) || (!walk->vma && !walk->no_vma)) { if (ops->pte_hole) err = ops->pte_hole(addr, next, walk); if (err) @@ -65,13 +65,16 @@ again: * Check this here so we only break down trans_huge * pages when we _need_ to */ - if (walk->action == ACTION_CONTINUE || + if ((!walk->vma && (pmd_leaf(*pmd) || !pmd_present(*pmd))) || + walk->action == ACTION_CONTINUE || !(ops->pte_entry)) continue; - split_huge_pmd(walk->vma, pmd, addr); - if (pmd_trans_unstable(pmd)) - goto again; + if (walk->vma) { + split_huge_pmd(walk->vma, pmd, addr); + if (pmd_trans_unstable(pmd)) + goto again; + } err = walk_pte_range(pmd, addr, next, walk); if (err) @@ -93,7 +96,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, do { again: next = pud_addr_end(addr, end); - if (pud_none(*pud) || !walk->vma) { + if (pud_none(*pud) || (!walk->vma && !walk->no_vma)) { if (ops->pte_hole) err = ops->pte_hole(addr, next, walk); if (err) @@ -111,11 +114,13 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, if (walk->action == ACTION_AGAIN) goto again; - if (walk->action == ACTION_CONTINUE || + if ((!walk->vma && (pud_leaf(*pud) || !pud_present(*pud))) || + walk->action == ACTION_CONTINUE || !(ops->pmd_entry || ops->pte_entry)) continue; - split_huge_pud(walk->vma, pud, addr); + if (walk->vma) + split_huge_pud(walk->vma, pud, addr); if (pud_none(*pud)) goto again; @@ -389,6 +394,25 @@ int walk_page_range(struct mm_struct *mm, unsigned long start, return err; } +int walk_page_range_novma(struct mm_struct *mm, unsigned long start, + unsigned long end, const struct mm_walk_ops *ops, + void *private) +{ + struct mm_walk walk = { + .ops = ops, + .mm = mm, + .private = private, + .no_vma = true + }; + + if (start >= end || !walk.mm) + return -EINVAL; + + lockdep_assert_held(&walk.mm->mmap_sem); + + return __walk_page_range(start, end, &walk); +} + int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, void *private) { |