Re: [PATCH v17 08/10] PM: hibernate: disable when there are active secretmem users

[David Hildenbrand]

On 08.02.21 11:18, Michal Hocko wrote:
> On Mon 08-02-21 10:49:18, Mike Rapoport wrote:
> > From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> >
> > It is unsafe to allow saving of secretmem areas to the hibernation
> > snapshot as they would be visible after the resume and this essentially
> > will defeat the purpose of secret memory mappings.
> >
> > Prevent hibernation whenever there are active secret memory users.
>
> Does this feature need any special handling? As it is effectivelly
> unevictable memory then it should behave the same as other mlock, ramfs
> which should already disable hibernation as those cannot be swapped out,
> no?

Why should unevictable memory not go to swap when hibernating? We're 
merely dumping all of our system RAM (including any unmovable 
allocations) to swap storage and the system is essentially completely 
halted.

--
Thanks,

David / dhildenb