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From:   Matteo Croce <mcroce@redhat.com>
Date:   Tue, 30 Apr 2019 12:46:31 +0200
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Subject: Re: [PATCH v4] proc/sysctl: add shared variables for range check
To:     LKML <linux-kernel@vger.kernel.org>, linux-fsdevel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Kees Cook <keescook@chromium.org>,
        Matthew Wilcox <willy@infradead.org>
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On Tue, Apr 30, 2019 at 12:26 AM Matteo Croce <mcroce@redhat.com> wrote:
>
> Add a const int array containing the most commonly used values,
> some macros to refer more easily to the correct array member,
> and use them instead of creating a local one for every object file.
>

Ok it seems that this simply can't be done, because there are at least
two points where extra1,2 are set to a non const struct:
in ip_vs_control_net_init_sysctl() it's assigned to struct netns_ipvs,
while in mpls_dev_sysctl_register() it's assigned to a struct mpls_dev
and a struct net.

So, sadly making extra1,2 const is a no-go :(

Andrew, I'm thinking to add the "sad and lame" cast in the macro, to
have a single point where hide it


Regards,
--
Matteo Croce
per aspera ad upstream