diff options
Diffstat (limited to 'mm/mremap.c')
| -rw-r--r-- | mm/mremap.c | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index da22ad2a5678..30d7d2482eea 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -104,11 +104,13 @@ static pte_t move_soft_dirty_pte(pte_t pte) static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, unsigned long old_addr, unsigned long old_end, struct vm_area_struct *new_vma, pmd_t *new_pmd, - unsigned long new_addr, bool need_rmap_locks) + unsigned long new_addr, bool need_rmap_locks, bool *need_flush) { struct mm_struct *mm = vma->vm_mm; pte_t *old_pte, *new_pte, pte; spinlock_t *old_ptl, *new_ptl; + bool force_flush = false; + unsigned long len = old_end - old_addr; /* * When need_rmap_locks is true, we take the i_mmap_rwsem and anon_vma @@ -146,7 +148,19 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, new_pte++, new_addr += PAGE_SIZE) { if (pte_none(*old_pte)) continue; + pte = ptep_get_and_clear(mm, old_addr, old_pte); + /* + * 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(pte) && pte_dirty(pte)) + force_flush = true; 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); @@ -156,6 +170,10 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, if (new_ptl != old_ptl) spin_unlock(new_ptl); pte_unmap(new_pte - 1); + if (force_flush) + flush_tlb_range(vma, old_end - len, old_end); + else + *need_flush = true; pte_unmap_unlock(old_pte - 1, old_ptl); if (need_rmap_locks) drop_rmap_locks(vma); @@ -201,13 +219,12 @@ unsigned long move_page_tables(struct vm_area_struct *vma, if (need_rmap_locks) take_rmap_locks(vma); moved = move_huge_pmd(vma, old_addr, new_addr, - old_end, old_pmd, new_pmd); + old_end, old_pmd, new_pmd, + &need_flush); if (need_rmap_locks) drop_rmap_locks(vma); - if (moved) { - need_flush = true; + if (moved) continue; - } } split_huge_pmd(vma, old_pmd, old_addr); if (pmd_trans_unstable(old_pmd)) @@ -220,11 +237,10 @@ unsigned long move_page_tables(struct vm_area_struct *vma, extent = next - new_addr; if (extent > LATENCY_LIMIT) extent = LATENCY_LIMIT; - move_ptes(vma, old_pmd, old_addr, old_addr + extent, - new_vma, new_pmd, new_addr, need_rmap_locks); - need_flush = true; + move_ptes(vma, old_pmd, old_addr, old_addr + extent, new_vma, + new_pmd, new_addr, need_rmap_locks, &need_flush); } - if (likely(need_flush)) + if (need_flush) flush_tlb_range(vma, old_end-len, old_addr); mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start, mmun_end); |