--- a/mm/gup.c~mm-gupc-fix-the-comment-of-return-value-for-populate_vma_page_range +++ a/mm/gup.c @@ -1404,7 +1404,8 @@ retry: * * This takes care of mlocking the pages too if VM_LOCKED is set. * - * return 0 on success, negative error code on error. + * Return either number of pages pinned in the vma, or a negative error + * code on error. * * vma->vm_mm->mmap_lock must be held. *