From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72568C47255 for ; Sat, 9 May 2020 22:39:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36D1421582 for ; Sat, 9 May 2020 22:39:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589063985; bh=SwQUS2Nt2C8FBvN11lGb6nzUbV64QKYF4/J0HiSqlRU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=oKCW9aImZJtfUH8IJsygs8UyCneqGh6ar27fZ1FjozH5/N7OsRMMTQfNPm+mvfvVU N3dI1nxCYOYDpxTrHpQH2+3Irs4HvD15J6h0aP94r1OtNKJZfY1CLGgi/EktQZw3IH H7IfrPCT1jX8eEKkF+QHr8WxyxYijeV39diBBCR0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728682AbgEIWjo (ORCPT ); Sat, 9 May 2020 18:39:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:46752 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726771AbgEIWjn (ORCPT ); Sat, 9 May 2020 18:39:43 -0400 Received: from kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com (unknown [163.114.132.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3643821473; Sat, 9 May 2020 22:39:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589063983; bh=SwQUS2Nt2C8FBvN11lGb6nzUbV64QKYF4/J0HiSqlRU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=CVNbL4ksp91+dUs+vz47oyZ7p/mbQA1Iby6izWutLBGFbm4+7KM3jeamMIbqGi5In 7OSkwBp3Dfny+nbscPdTYVHvP9MBH8lNGT9w58UB2ftCdRXhswFYYZJcd3hTOo2d/g U4DYV/bRr1GGnf0MMA9xoL/wR00BVb0fdVgVx1ws= Date: Sat, 9 May 2020 15:39:41 -0700 From: Jakub Kicinski To: Stephen Kitt Cc: "David S . Miller" , Joe Perches , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] net: Protect INET_ADDR_COOKIE on 32-bit architectures Message-ID: <20200509153941.03088923@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <20200509224928.26d44ac4@heffalump.sk2.org> References: <20200508120457.29422-1-steve@sk2.org> <20200508205025.3207a54e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20200509101322.12651ba0@heffalump.sk2.org> <20200509105914.04fd19c8@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20200509210548.116c7385@heffalump.sk2.org> <20200509224928.26d44ac4@heffalump.sk2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 9 May 2020 22:49:28 +0200 Stephen Kitt wrote: > On Sat, 9 May 2020 21:05:48 +0200, Stephen Kitt wrote: > > On Sat, 9 May 2020 10:59:14 -0700, Jakub Kicinski 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.