diff options
| -rw-r--r-- | mm/rmap.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 0f00570d1b9e..b1ba1236ffba 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1955,7 +1955,14 @@ static inline unsigned int folio_unmap_pte_batch(struct folio *folio, if (userfaultfd_wp(vma)) return 1; - return folio_pte_batch(folio, pvmw->pte, pte, max_nr); + /* + * If unmap fails, we need to restore the ptes. To avoid accidentally + * upgrading write permissions for ptes that were not originally + * writable, and to avoid losing the soft-dirty bit, use the + * appropriate FPB flags. + */ + return folio_pte_batch_flags(folio, vma, pvmw->pte, &pte, max_nr, + FPB_RESPECT_WRITE | FPB_RESPECT_SOFT_DIRTY); } /* |