Re: [REGRESSION] Re: [PATCH v8 15/19] mm: don't allow huge faults for files with pre content watches

Linus Torvalds
2025-02-02T00:58:47Z

On Sat, 1 Feb 2025 at 06:38, Christian Brauner <brauner@kernel.org> wrote:
>
> Ok, but those "device fds" aren't really device fds in the sense that
> they are character fds. They are regular files afaict from:
>
> vfio_device_open_file(struct vfio_device *device)
>
> (Well, it's actually worse as anon_inode_getfile() files don't have any
> mode at all but that's beside the point.)?
>
> In any case, I think you're right that such files would (accidently?)
> qualify for content watches afaict. So at least that should probably get
> FMODE_NONOTIFY.

Hmm. Can we just make all anon_inodes do that? I don't think you can
sanely have pre-content watches on anon-inodes, since you can't really
have access to them to _set_ the content watch from outside anyway..

In fact, maybe do it in alloc_file_pseudo()?

Amir / Josef?

Linus