diff options
Diffstat (limited to 'mm/mremap.c')
| -rw-r--r-- | mm/mremap.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index 6ccecc03f56a..30d7d2482eea 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -149,14 +149,18 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, if (pte_none(*old_pte)) continue; + pte = ptep_get_and_clear(mm, old_addr, old_pte); /* - * We are remapping a dirty PTE, make sure to - * flush TLB before we drop the PTL for the + * If we are remapping a dirty PTE, make sure + * to flush TLB before we drop the PTL for the * old PTE or we may race with page_mkclean(). + * + * This check has to be done after we removed the + * old PTE from page tables or another thread may + * dirty it after the check and before the removal. */ - if (pte_present(*old_pte) && pte_dirty(*old_pte)) + if (pte_present(pte) && pte_dirty(pte)) force_flush = true; - pte = ptep_get_and_clear(mm, old_addr, old_pte); pte = move_pte(pte, new_vma->vm_page_prot, old_addr, new_addr); pte = move_soft_dirty_pte(pte); set_pte_at(mm, new_addr, new_pte, pte); |