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Date:   Tue, 13 Nov 2018 12:43:05 -0800
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Oleg Nesterov <oleg@redhat.com>
Cc:     Ben Woodard <woodard@redhat.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Kees Cook <keescook@chromium.org>,
        Michal Hocko <mhocko@suse.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] exec: increase BINPRM_BUF_SIZE to 256
Message-Id: <20181113124305.73b8ac9e5a2ef9b18d3444b2@linux-foundation.org>
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        <20181112160956.GA28472@redhat.com>
        <20181112155248.4dde2613979f4c176565629e@linux-foundation.org>
        <20181113165557.GG30990@redhat.com>
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On Tue, 13 Nov 2018 17:55:58 +0100 Oleg Nesterov <oleg@redhat.com> wrote:

> > However it would be basically cost-free to increase
> > BINPRM_BUF_SIZE up to the point where sizeof(struct linux_binprm) ==
> > PAGE_SIZE?
> 
> I don't think we should take sizeof(struct linux_binprm) into account, the
> new members can come at any time and we can never decrease BINPRM_BUF_SIZE.

My main point is..  why not make BINPRM_BUF_SIZE a lot larger than 256?