3 files changed, 20 insertions, 7 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index fbdb9d40847f..f223ac26b5d9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -596,7 +596,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
 }
 
 void do_set_pte(struct vm_area_struct *vma, unsigned long address,
-                struct page *page, pte_t *pte, bool write, bool anon);
+                struct page *page, pte_t *pte, bool write, bool anon, bool old);
 #endif
 
 /*
diff --git a/mm/filemap.c b/mm/filemap.c
index 8f4859989f1b..b418405903bc 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2191,7 +2191,7 @@ repeat:
                 if (file->f_ra.mmap_miss > 0)
                         file->f_ra.mmap_miss--;
                 addr = address + (page->index - vmf->pgoff) * PAGE_SIZE;
-                do_set_pte(vma, addr, page, pte, false, false);
+                do_set_pte(vma, addr, page, pte, false, false, true);
                 unlock_page(page);
                 goto next;
 unlock:
diff --git a/mm/memory.c b/mm/memory.c
index 007c72ad03f6..f29e5ab0342d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2876,7 +2876,7 @@ static int __do_fault(struct vm_area_struct *vma, unsigned long address,
  * vm_ops->map_pages.
  */
 void do_set_pte(struct vm_area_struct *vma, unsigned long address,
-                struct page *page, pte_t *pte, bool write, bool anon)
+                struct page *page, pte_t *pte, bool write, bool anon, bool old)
 {
         pte_t entry;
 
@@ -2884,6 +2884,8 @@ void do_set_pte(struct vm_area_struct *vma, unsigned long address,
         entry = mk_pte(page, vma->vm_page_prot);
         if (write)
                 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+        if (old)
+                entry = pte_mkold(entry);
         if (anon) {
                 inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES);
                 page_add_new_anon_rmap(page, vma, address, false);
@@ -3021,9 +3023,20 @@ static int do_read_fault(struct mm_struct *mm, struct vm_area_struct *vma,
          */
         if (vma->vm_ops->map_pages && fault_around_bytes >> PAGE_SHIFT > 1) {
                 pte = pte_offset_map_lock(mm, pmd, address, &ptl);
-                do_fault_around(vma, address, pte, pgoff, flags);
                 if (!pte_same(*pte, orig_pte))
                         goto unlock_out;
+                do_fault_around(vma, address, pte, pgoff, flags);
+                /* Check if the fault is handled by faultaround */
+                if (!pte_same(*pte, orig_pte)) {
+                        /*
+                         * Faultaround produce old pte, but the pte we've
+                         * handler fault for should be young.
+                         */
+                        pte_t entry = pte_mkyoung(*pte);
+                        if (ptep_set_access_flags(vma, address, pte, entry, 0))
+                                update_mmu_cache(vma, address, pte);
+                        goto unlock_out;
+                }
                 pte_unmap_unlock(pte, ptl);
         }
 
@@ -3038,7 +3051,7 @@ static int do_read_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                 put_page(fault_page);
                 return ret;
         }
-        do_set_pte(vma, address, fault_page, pte, false, false);
+        do_set_pte(vma, address, fault_page, pte, false, false, false);
         unlock_page(fault_page);
 unlock_out:
         pte_unmap_unlock(pte, ptl);
@@ -3090,7 +3103,7 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                 }
                 goto uncharge_out;
         }
-        do_set_pte(vma, address, new_page, pte, true, true);
+        do_set_pte(vma, address, new_page, pte, true, true, false);
         mem_cgroup_commit_charge(new_page, memcg, false, false);
         lru_cache_add_active_or_unevictable(new_page, vma);
         pte_unmap_unlock(pte, ptl);
@@ -3147,7 +3160,7 @@ static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                 put_page(fault_page);
                 return ret;
         }
-        do_set_pte(vma, address, fault_page, pte, true, false);
+        do_set_pte(vma, address, fault_page, pte, true, false, false);
         pte_unmap_unlock(pte, ptl);
 
         if (set_page_dirty(fault_page))