Re: GUP guarantees wrt to userspace mappings redesign

[Oleg Nesterov]

I am sure I missed the problem, but...

On 05/02, Kirill A. Shutemov wrote:
>
> Quick look around:
>
>  - I don't see any check page_count() around __replace_page() in uprobes,
>    so it can easily replace pinned page.

Why it should? even if it races with get_user_pages_fast()... this doesn't
differ from the case when an application writes to MAP_PRIVATE non-anonymous
region, no?

Oleg.