Re: [PATCH 03/16] mm: simplify gup_fast_permitted

[Linus Torvalds]

On Mon, Jun 3, 2019 at 12:41 AM Christoph Hellwig <hch@xxxxxx> wrote:
>
> I only removed a duplicate of it.

I don't see any remaining cases.

> The full (old) code in get_user_pages_fast() looks like this:
>
>         if (nr_pages <= 0)
>                 return 0;
>
>         if (unlikely(!access_ok((void __user *)start, len)))
>                 return -EFAULT;
>
>         if (gup_fast_permitted(start, nr_pages)) {

Yes, and that code was correct.

The new code has no test at all for "nr_pages == 0", afaik.

                 Linus