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Date:   Mon, 22 Feb 2021 12:23:59 +0200
From:   Mike Rapoport <rppt@kernel.org>
To:     Matthew Garrett <mjg59@srcf.ucam.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Andy Lutomirski <luto@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>, Borislav Petkov <bp@alien8.de>,
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Subject: Re: [PATCH v17 08/10] PM: hibernate: disable when there are active
 secretmem users
Message-ID: <20210222102359.GE1447004@kernel.org>
References: <20210208084920.2884-1-rppt@kernel.org>
 <20210208084920.2884-9-rppt@kernel.org>
 <20210222073452.GA30403@codon.org.uk>
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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.

-- 
Sincerely yours,
Mike.