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Date:   Tue, 30 Apr 2019 12:38:08 +0300
From:   Cyrill Gorcunov <gorcunov@gmail.com>
To:     Kirill Tkhai <ktkhai@virtuozzo.com>
Cc:     Michal =?iso-8859-1?Q?Koutn=FD?= <mkoutny@suse.com>,
        akpm@linux-foundation.org, arunks@codeaurora.org, brgl@bgdev.pl,
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        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        mguzik@redhat.com, mhocko@kernel.org, rppt@linux.ibm.com,
        vbabka@suse.cz
Subject: Re: [PATCH 1/3] mm: get_cmdline use arg_lock instead of mmap_sem
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On Tue, Apr 30, 2019 at 12:09:57PM +0300, Kirill Tkhai wrote:
> 
> This looks OK for me.
> 
> But speaking about existing code it's a secret for me, why we ignore arg_lock
> in binfmt code, e.g. in load_elf_binary().

Well, strictly speaking we probably should but you know setup of
the @arg_start by kernel's elf loader doesn't cause any side
effects as far as I can tell (its been working this lockless
way for years, mmap_sem is taken later in the loader code).
Though for consistency sake we probably should set it up
under the spinlock.