+ /*
+ * If it's a COW mapping, write protect it both
+ * in the parent and the child
+ */
+ if ((vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE) {
+ ptep_set_wrprotect(src_pte);
+ pte = *src_pte;
+ }
+
+ /*
+ * If it's a shared mapping, mark it clean in
+ * the child
+ */
+ if (vm_flags & VM_SHARED)
+ pte = pte_mkclean(pte);
+ pte = pte_mkold(pte);
+ get_page(page);
+ // dst_mm->rss++;
+ vx_rsspages_inc(dst_mm);
+ if (PageAnon(page))
+ // dst_mm->anon_rss++;
+ vx_anonpages_inc(dst_mm);
+ set_pte(dst_pte, pte);
+ page_dup_rmap(page);
+}
+
+static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+ pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end)
+{
+ pte_t *src_pte, *dst_pte;
+ pte_t *s, *d;
+ unsigned long vm_flags = vma->vm_flags;
+
+ d = dst_pte = pte_alloc_map(dst_mm, dst_pmd, addr);
+ if (!dst_pte)
+ return -ENOMEM;
+
+ spin_lock(&src_mm->page_table_lock);
+ s = src_pte = pte_offset_map_nested(src_pmd, addr);
+ for (; addr < end; addr += PAGE_SIZE, s++, d++) {
+ if (pte_none(*s))
+ continue;
+ copy_one_pte(dst_mm, src_mm, d, s, vm_flags, addr);
+ }
+ pte_unmap_nested(src_pte);
+ pte_unmap(dst_pte);
+ spin_unlock(&src_mm->page_table_lock);
+ cond_resched_lock(&dst_mm->page_table_lock);
+ return 0;
+}
+
+static int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+ pud_t *dst_pud, pud_t *src_pud, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long end)
+{
+ pmd_t *src_pmd, *dst_pmd;
+ int err = 0;
+ unsigned long next;
+
+ src_pmd = pmd_offset(src_pud, addr);
+ dst_pmd = pmd_alloc(dst_mm, dst_pud, addr);
+ if (!dst_pmd)
+ return -ENOMEM;
+
+ for (; addr < end; addr = next, src_pmd++, dst_pmd++) {
+ next = (addr + PMD_SIZE) & PMD_MASK;
+ if (next > end || next <= addr)
+ next = end;
+ if (pmd_none(*src_pmd))
+ continue;
+ if (pmd_bad(*src_pmd)) {
+ pmd_ERROR(*src_pmd);
+ pmd_clear(src_pmd);