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Date:   Mon, 8 Feb 2021 23:28:51 +0200
From:   Mike Rapoport <rppt@kernel.org>
To:     Michal Hocko <mhocko@suse.com>
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>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Christopher Lameter <cl@linux.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        David Hildenbrand <david@redhat.com>,
        Elena Reshetova <elena.reshetova@intel.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
        James Bottomley <jejb@linux.ibm.com>,
        "Kirill A. Shutemov" <kirill@shutemov.name>,
        Matthew Wilcox <willy@infradead.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Mike Rapoport <rppt@linux.ibm.com>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
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        Palmer Dabbelt <palmerdabbelt@google.com>
Subject: Re: [PATCH v17 08/10] PM: hibernate: disable when there are active
 secretmem users
Message-ID: <20210208212851.GY242749@kernel.org>
References: <20210208084920.2884-1-rppt@kernel.org>
 <20210208084920.2884-9-rppt@kernel.org>
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On Mon, Feb 08, 2021 at 11:18:37AM +0100, Michal Hocko wrote:
> On Mon 08-02-21 10:49:18, Mike Rapoport wrote:
> > From: Mike Rapoport <rppt@linux.ibm.com>
> > 
> > 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?

As David already said, hibernation does not care about mlocked memory, so
this feature requires a special handling.

-- 
Sincerely yours,
Mike.