On 08/15/2018 08:49 PM, Yang Shi wrote:
> + start_vma = munmap_lookup_vma(mm, start, end);
> + if (!start_vma)
> + goto out;
> + if (IS_ERR(start_vma)) {
> + ret = PTR_ERR(start_vma);
> + goto out;
> + }
> +
> + prev = start_vma->vm_prev;
> +
> + if (unlikely(uf)) {
> + ret = userfaultfd_unmap_prep(start_vma, start, end, uf);
> + if (ret)
> + goto out;
> + }
> +
You sure it's ok to redo this in case of goto regular path? The
preparations have some side-effects... I would rather move this after
the regular path check?
