- fault_pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
- return __gup_device_huge(fault_pfn, addr, end, pages, nr);
+ fault_pfn = pud_pfn(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
+ if (!__gup_device_huge(fault_pfn, addr, end, pages, nr))
+ return 0;
+
+ if (unlikely(pud_val(orig) != pud_val(*pudp))) {
+ undo_dev_pagemap(nr, nr_start, pages);
+ return 0;
+ }
+ return 1;