Re: [PATCH RFC] mm: add MAP_EXCLUSIVE to create exclusive user mappings

[Kirill A. Shutemov]

On Sun, Oct 27, 2019 at 12:17:32PM +0200, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> 
> The mappings created with MAP_EXCLUSIVE are visible only in the context of
> the owning process and can be used by applications to store secret
> information that will not be visible not only to other processes but to the
> kernel as well.
> 
> The pages in these mappings are removed from the kernel direct map and
> marked with PG_user_exclusive flag. When the exclusive area is unmapped,
> the pages are mapped back into the direct map.

I probably blind, but I don't see where you manipulate direct map...

-- 
 Kirill A. Shutemov