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Date:   Sat, 9 May 2020 15:39:41 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Stephen Kitt <steve@sk2.org>
Cc:     "David S . Miller" <davem@davemloft.net>,
        Joe Perches <joe@perches.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] net: Protect INET_ADDR_COOKIE on 32-bit
 architectures
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On Sat, 9 May 2020 22:49:28 +0200 Stephen Kitt wrote:
> On Sat, 9 May 2020 21:05:48 +0200, Stephen Kitt <steve@sk2.org> wrote:
> > On Sat, 9 May 2020 10:59:14 -0700, Jakub Kicinski <kuba@kernel.org> wro=
te: =20
> > > What if we went back to your original proposal of an empty struct but
> > > added in an extern in front? That way we should get linker error on
> > > pointer references.   =20
> >=20
> > That silently fails to fail if any other link object provides a definit=
ion
> > for the symbol, even if the type doesn=E2=80=99t match... =20
>=20
> And it breaks the build if INET_ADDR_COOKIE is used twice in the same uni=
t,
> e.g. in inet_hashtables.c.

Ah, so we'd have to use a valid type like, say, char.