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

Matthew Garrett
2021-02-22T18:29:13Z

On Mon, Feb 22, 2021 at 12:23:59PM +0200, Mike Rapoport wrote:
> On Mon, Feb 22, 2021 at 07:34:52AM +0000, Matthew Garrett wrote:
> > On Mon, Feb 08, 2021 at 10:49:18AM +0200, Mike Rapoport wrote:
> >
> > > 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.
> >
> > Sorry for being a bit late to this - from the point of view of running
> > processes (and even the kernel once resume is complete), hibernation is
> > effectively equivalent to suspend to RAM. Why do they need to be handled
> > differently here?
>
> Hibernation leaves a copy of the data on the disk which we want to prevent.

Who are you worried about seeing it, and at what points in time?