summaryrefslogtreecommitdiff
path: root/mm/userfaultfd.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/userfaultfd.c')
-rw-r--r--mm/userfaultfd.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 7d5d709cc838..e0db855c89b4 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -1064,8 +1064,13 @@ static int move_present_pte(struct mm_struct *mm,
src_folio->index = linear_page_index(dst_vma, dst_addr);
orig_dst_pte = mk_pte(&src_folio->page, dst_vma->vm_page_prot);
- /* Follow mremap() behavior and treat the entry dirty after the move */
- orig_dst_pte = pte_mkwrite(pte_mkdirty(orig_dst_pte), dst_vma);
+ /* Set soft dirty bit so userspace can notice the pte was moved */
+#ifdef CONFIG_MEM_SOFT_DIRTY
+ orig_dst_pte = pte_mksoft_dirty(orig_dst_pte);
+#endif
+ if (pte_dirty(orig_src_pte))
+ orig_dst_pte = pte_mkdirty(orig_dst_pte);
+ orig_dst_pte = pte_mkwrite(orig_dst_pte, dst_vma);
set_pte_at(mm, dst_addr, dst_pte, orig_dst_pte);
out:
@@ -1100,6 +1105,9 @@ static int move_swap_pte(struct mm_struct *mm, struct vm_area_struct *dst_vma,
}
orig_src_pte = ptep_get_and_clear(mm, src_addr, src_pte);
+#ifdef CONFIG_MEM_SOFT_DIRTY
+ orig_src_pte = pte_swp_mksoft_dirty(orig_src_pte);
+#endif
set_pte_at(mm, dst_addr, dst_pte, orig_src_pte);
double_pt_unlock(dst_ptl, src_ptl);