Re: [PATCH v2 3/3] dm-crypt: Adds support for wiping key when doing suspend/hibernation

From: Pali RohÃr
Date: Tue Jul 28 2015 - 10:48:23 EST


On Tuesday 28 July 2015 16:44:19 Pavel Machek wrote:
> On Sun 2015-06-21 13:20:34, Pali RohÃr wrote:
> > This patch adds dm message commands and option strings to optionally wipe key
> > from dm-crypt device before entering suspend or hibernate state.
> >
> > Before key is wiped dm device must be suspended. To prevent race conditions with
> > I/O and userspace processes, wiping action must be called after processes are
> > freezed. Otherwise userspace processes could start reading/writing to disk after
> > dm device is suspened and freezing processes before suspend/hibernate action
> > will fail.
>
> Are you sure this is enough?
>
> We still may need to allocate memory after userspace is frozen, and
> that could mean writing dirty buffers out to make some memory free...
>
> Pavel
>

Hm... good question. Maybe it is needed to also flush all buffers?

--
Pali RohÃr
pali.rohar@xxxxxxxxx
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