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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1CBE3C83F12 for ; Tue, 29 Aug 2023 14:20:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8C621280017; Tue, 29 Aug 2023 10:20:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 875758E001A; Tue, 29 Aug 2023 10:20:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 78BC1280017; Tue, 29 Aug 2023 10:20:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 694D78E001A for ; Tue, 29 Aug 2023 10:20:50 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 41171801A8 for ; Tue, 29 Aug 2023 14:20:50 +0000 (UTC) X-FDA: 81177353460.12.B634228 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf27.hostedemail.com (Postfix) with ESMTP id 6282740026 for ; Tue, 29 Aug 2023 14:20:48 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=m00QA0Ga; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf27.hostedemail.com: domain of alx@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=alx@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1693318848; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=PxeXUOnD7PYEciy0dvhsLqCmeqzwQiENRFdPjI/FXxA=; b=tsHi1RYH6tXQPONYqHIhVRSsFYJdHtmGMfEWKxKtBleWDH6AemAT7QimgPWs8IisIgtkF7 AdsKME7/3C28pYlVSidaOFyh9BO8mUOsyEqtOlGIF2xWDKNUvxn2ZUYbul+33IcQFsL4zt CxhJR5Ev2GJELEMFTdy+sOmRpeK2zQg= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=m00QA0Ga; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf27.hostedemail.com: domain of alx@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=alx@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1693318848; a=rsa-sha256; cv=none; b=8VGKq0dar0VL1YluQV56nyWdXAfV+nzA4HzvnRcNc3ZMJXknZ+Hwm1gRdtAEAJvwnz0LT2 BClC1PJWkjULd91yzNJl0HMmAxLi6VyCIBy6TWDIJWZtFtqiBP5AxtTn60pQRd+nswiWtJ ke2Dj0dHJ9V10UJg3fggyzmYvEVb+f8= Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7111062462; Tue, 29 Aug 2023 14:20:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DFC9EC433CB; Tue, 29 Aug 2023 14:20:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1693318846; bh=jh5Pdm8IhvHQhNDOAydUSnj3OBHPBtf/CvgDegn5pgw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=m00QA0Ga9n5ebiqd+zRmFqG+wDIjY7iVrxzvYov7jUs3u4U68gFbHCTEDHzPQV5F8 QtTpgHrvnEigk97FcctU2Tgis7sQrEsHn1MG3cDU+yfKzFyRRsGXa06659kcN9yM4j bR6qkwiB2a4G/oOCZOCivED8n2cxlNLrUuEQ5NRFkpETXco+51iDh+qHshi7BVWjm1 qYDx3Kyd0NLKRWlsXDJ6XhLzkZHVLGDYs6UzPWcJ4ApHiNvYLPkO+J/q1GG6U6eD7R vw6/6DidNU3D31dUDv1+BF6KM/lyOVypNL/ZDwEp0Kk1gru6Zvdx/ZDUzwY86cxXbR xPtZDgjqQr6Fw== Message-ID: <8a7df4fd-9cf6-9a2e-feec-1c70197ed5fa@kernel.org> Date: Tue, 29 Aug 2023 16:20:42 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.1 Subject: Re: 'struct dynamic': struct tag leak in UAPI headers Content-Language: en-US To: Matthew Wilcox Cc: David Howells , Eric Biederman , Kees Cook , linux-mm@kvack.org, Rolf Eike Beer , Arnd Bergmann , Thomas Gleixner , "Paul E. McKenney" , Dave Jones References: <926f8e5c-40bd-dae0-2492-f6e6dbd6c96e@kernel.org> From: Alejandro Colomar Organization: Linux In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------5b5eQfwVjc7jAAJEJUh9IbXr" X-Rspamd-Queue-Id: 6282740026 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: 5tdwownzd3o4p1gwn3fuu1gacd6eqw7e X-HE-Tag: 1693318848-516153 X-HE-Meta: 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 GWsRdHbw 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --------------5b5eQfwVjc7jAAJEJUh9IbXr Content-Type: multipart/mixed; boundary="------------qUiT45GW8DqJPTbSmWbBjMtW"; protected-headers="v1" From: Alejandro Colomar To: Matthew Wilcox Cc: David Howells , Eric Biederman , Kees Cook , linux-mm@kvack.org, Rolf Eike Beer , Arnd Bergmann , Thomas Gleixner , "Paul E. McKenney" , Dave Jones Message-ID: <8a7df4fd-9cf6-9a2e-feec-1c70197ed5fa@kernel.org> Subject: Re: 'struct dynamic': struct tag leak in UAPI headers References: <926f8e5c-40bd-dae0-2492-f6e6dbd6c96e@kernel.org> In-Reply-To: --------------qUiT45GW8DqJPTbSmWbBjMtW Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 2023-08-29 16:17, Matthew Wilcox wrote: > Ooh, story time! Long, long ago, we did not separate "Linux headers" > from "libc headers". It used to be somebody's job to take the files > in /usr/src/linux/include/linux and copy them to /usr/include/linux. > Bold people used a symlink. People who cared about things like "Well, > POSIX says that" would edit the files after copying them to remove thin= gs > that POSIX said shouldn't be there or put _GNU_SOURCE markers around th= em. >=20 > At some point, we decided to split the headers to create the uapi heade= rs > to make this job easier. Refinements are, of course, possible, and now= > easier than ever, but I think it's fair to say that anybody who include= d > at any time in history got given a struct dynamic. Thanks for the story! :-) > Well, it's a compile-time failure either way. Code that depended on it= > is compiling happily today, and the code that would want to use it > doesn't exist yet, so I'd rather err on the side of keeping code writte= n > in the last 30 years working. Fair enough. Cheers, Alex --=20 GPG key fingerprint: A9348594CE31283A826FBDD8D57633D441E25BB5 --------------qUiT45GW8DqJPTbSmWbBjMtW-- --------------5b5eQfwVjc7jAAJEJUh9IbXr Content-Type: application/pgp-signature; name="OpenPGP_signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="OpenPGP_signature" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE6jqH8KTroDDkXfJAnowa+77/2zIFAmTt/roACgkQnowa+77/ 2zIiDhAAkU7S41pdaNKwByTz0XuVDzwE/uX/UunC86jNaxZJNCMKz6aYYDE71eKt uQ+PTT+UPIlaZkXzrdHF+jKrRBIgQQXFsaawHZlU9f3ebqtduZxTzprsQ1hX/NNE 3v8ZLRY3C5P9sE2Y9xrjt/rZuTZWkVHSie/vzuajDHEy/wYAxWhKjEw0bsxVjYNe Nxi0O3EfjbrqVbrpY55T0XgfFoElyFvVPNQuFEYJWEF/PaTks/RmXCoQBuE6OsLy ROCl1zP//YZBMbunhr8XSgUF/W2FvTdTBvdblh5b81s6+NvJpoWdikRdauYb3MRU 69qkSGvFSjiUx/kHke/21+4N1WcUWPC2serFYC+SjCdO0pMuo2xwR9ilvSGkCrfC uOzUlOZg5ls1OuiptUGeOqKoJuY8zBVR75mCxurAJEU16DY3U8wzZo6Z6KUUShCV +Nim3hAfss521civgcZkQeoqKapc+NVg/C/Pv4AaYDmTstT3+TNXts9hKo5G7tj3 mx5iYgoalKxZlT1vhUpd8+wmBUZI6y4w2ungk3jd5RSqKO+tEfe/Ul/5Cu88O9ou dhLMfRa6tfpkqPq9WLQcnQnb4sMTjF9EisYqauKm5kpRq1Q0v/cYz2UkgbeOii31 V5552kd7CAtaCc1Qb3pH1gOEseAUeHGR7TMwymFxoPIFxOn4LiI= =qgP2 -----END PGP SIGNATURE----- --------------5b5eQfwVjc7jAAJEJUh9IbXr--