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Date:   Thu, 16 May 2019 17:29:46 +0100
From:   Aaron Tomlin <atomlin@redhat.com>
To:     Jann Horn <jannh@google.com>
Cc:     Oleksandr Natalenko <oleksandr@redhat.com>,
        kernel list <linux-kernel@vger.kernel.org>,
        Kirill Tkhai <ktkhai@virtuozzo.com>,
        Hugh Dickins <hughd@google.com>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Michal Hocko <mhocko@suse.com>,
        Matthew Wilcox <willy@infradead.org>,
        Pavel Tatashin <pasha.tatashin@soleen.com>,
        Greg KH <greg@kroah.com>,
        Suren Baghdasaryan <surenb@google.com>,
        Minchan Kim <minchan@kernel.org>,
        Timofey Titovets <nefelim4ag@gmail.com>,
        Grzegorz Halat <ghalat@redhat.com>,
        Linux-MM <linux-mm@kvack.org>,
        Linux API <linux-api@vger.kernel.org>
Subject: Re: [PATCH RFC 4/5] mm/ksm, proc: introduce remote merge
Message-ID: <20190516162946.zwzhxkft342b25pd@atomlin.usersys.com>
References: <20190516094234.9116-1-oleksandr@redhat.com>
 <20190516094234.9116-5-oleksandr@redhat.com>
 <CAG48ez2yXw_PJXO-mS=Qw5rkLpG6zDPd0saMhhGk09-du2bpaA@mail.gmail.com>
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On Thu 2019-05-16 12:00 +0200, Jann Horn wrote:
> On Thu, May 16, 2019 at 11:43 AM Oleksandr Natalenko
> <oleksandr@redhat.com> wrote:
[ ... ]
> > +       }
> > +
> > +       down_write(&mm->mmap_sem);
> 
> Should a check for mmget_still_valid(mm) be inserted here? See commit
> 04f5866e41fb70690e28397487d8bd8eea7d712a.

Yes - I'd say this is required here.

Thanks,

-- 
Aaron Tomlin