diff options
Diffstat (limited to 'mm/userfaultfd.c')
| -rw-r--r-- | mm/userfaultfd.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index ce13c4062647..60a0be33766f 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -251,7 +251,7 @@ static int mfill_atomic_pte_copy(pmd_t *dst_pmd, if (!*foliop) { ret = -ENOMEM; folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, dst_vma, - dst_addr, false); + dst_addr); if (!folio) goto out; @@ -1135,7 +1135,7 @@ static int move_pages_pte(struct mm_struct *mm, pmd_t *dst_pmd, pmd_t *src_pmd, spinlock_t *src_ptl, *dst_ptl; pte_t *src_pte = NULL; pte_t *dst_pte = NULL; - + pmd_t dummy_pmdval; struct folio *src_folio = NULL; struct anon_vma *src_anon_vma = NULL; struct mmu_notifier_range range; @@ -1146,7 +1146,14 @@ static int move_pages_pte(struct mm_struct *mm, pmd_t *dst_pmd, pmd_t *src_pmd, src_addr, src_addr + PAGE_SIZE); mmu_notifier_invalidate_range_start(&range); retry: - dst_pte = pte_offset_map_nolock(mm, dst_pmd, dst_addr, &dst_ptl); + /* + * Use the maywrite version to indicate that dst_pte will be modified, + * but since we will use pte_same() to detect the change of the pte + * entry, there is no need to get pmdval, so just pass a dummy variable + * to it. + */ + dst_pte = pte_offset_map_rw_nolock(mm, dst_pmd, dst_addr, &dummy_pmdval, + &dst_ptl); /* Retry if a huge pmd materialized from under us */ if (unlikely(!dst_pte)) { @@ -1154,7 +1161,9 @@ retry: goto out; } - src_pte = pte_offset_map_nolock(mm, src_pmd, src_addr, &src_ptl); + /* same as dst_pte */ + src_pte = pte_offset_map_rw_nolock(mm, src_pmd, src_addr, &dummy_pmdval, + &src_ptl); /* * We held the mmap_lock for reading so MADV_DONTNEED |