Re: [syzbot] WARNING in get_vaddr_frames

[Linus Torvalds]

On Sat, Jan 21, 2023 at 12:03 AM syzbot
<syzbot+59a71007ccac79e8bb69@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> syzbot has bisected this issue to:
>
> commit 6647e76ab623b2b3fb2efe03a86e9c9046c52c33
> Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Date:   Thu Dec 1 00:10:52 2022 +0000
>
>     v4l2: don't fall back to follow_pfn() if pin_user_pages_fast() fails

Yeah, that warning is kind of expected.

> Reported-by: syzbot+59a71007ccac79e8bb69@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 6647e76ab623 ("v4l2: don't fall back to follow_pfn() if pin_user_pages_fast() fails")

Is there a way to tell syzbot to ignore one particular warning?

Because we could certainly turn it into a pr_warn_once(), but
honestly, if a real use case sees this, I'd rather have the bigger
splat for a while yet.

Then we can remove it entirely (maybe in six months or something?)

                Linus