Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754415AbaAUKgd (ORCPT ); Tue, 21 Jan 2014 05:36:33 -0500 Received: from multi.imgtec.com ([194.200.65.239]:30793 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754091AbaAUKgb (ORCPT ); Tue, 21 Jan 2014 05:36:31 -0500 Message-ID: <52DE4DA3.7090301@imgtec.com> Date: Tue, 21 Jan 2014 10:36:19 +0000 From: James Hogan User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Dan Carpenter CC: Chen Gang , , , Greg KH , , "linux-kernel@vger.kernel.org" , , , , Subject: Re: [PATCH] drivers: staging: lustre: lustre: include: add "__attribute__((packed))" for the related union References: <52DA4E6A.1000308@gmail.com> <20140118100547.GS7444@mwanda> <52DA56C2.5010802@gmail.com> <20140118142404.GT7444@mwanda> <52DBA3D4.3090308@gmail.com> <52DD0EFF.2010305@imgtec.com> <20140120123045.GV7444@mwanda> <52DD18A5.1090308@imgtec.com> <20140120125603.GD4815@mwanda> <20140120211356.GG4815@mwanda> In-Reply-To: <20140120211356.GG4815@mwanda> X-Enigmail-Version: 1.5.2 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="FU3XnrEtioXfThSukdsKvdelQ5i32u6un" X-Originating-IP: [192.168.154.65] X-SEF-Processed: 7_3_0_01192__2014_01_21_10_36_26 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --FU3XnrEtioXfThSukdsKvdelQ5i32u6un Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Dan, On 20/01/14 21:13, Dan Carpenter wrote: > I made a quick and dirty sparse patch to check for this. I don't think= > I will bother trying to send it to sparse upstream, but you can if you > want to. >=20 > It found 289 unions which might need a __packed added. The lustre > unions were not in my allmodconfig so they're not listed. Thanks a lot for this, it seems to be useful. I'm adapting it to reduce false negatives (e.g. omitting the check if the struct/union is already packed), and I imagine it could be made to only warn about padded unpacked structs/unions which are used as nested members of packed structs/unions. It wouldn't catch everything but would probably catch a lot of cases that are most likely to be genuine since they would have been packed at the outer level for a reason. > Perhaps there could be a command line option or a pragma so that unions= > will work in the kernel. We don't care about linking to outside > libraries. We still interact with userland via structs and unions, so it would probably have to exclude anything in uapi/. Cheers James --FU3XnrEtioXfThSukdsKvdelQ5i32u6un Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) iQIcBAEBAgAGBQJS3k2pAAoJEKHZs+irPybfPJkP/Rz2wG7DQZiN5MIMRGYxOzMr H4s6CrJ8H5BKtOWdmRsDtLbuHVtzotxecYS2hpxPsiPKYdwxhQM7s9nEV1p0mdk7 dFgs/e7zZslWtZ2Hmn8kErXWfGBXkk7sRBH7A5L0laaJA6jqdsnIzP+aXhwVm29r HVR79LBRpY3o8ygEaNmDvbkJBJfGhhBlQOdsvx96mb89a4r2xnfpcPvWEz8bJ0NG fdHw01pXeIfTs/7cWFqO77qAJAFXn7cbOkvGLem0elS4syNQd0hj09t+8nX9KPCV mhpmgAeE9wam8eyAqAqSixFik1+48q5u8bnGt/oZHYGIyxJWnKnbueTirslnZ1z9 qJQgw+QoLqEv7gS/RLsEW+4sn8k98ITSiSkolEwPI6dhuIiUVrQXmmc9/o+wi27P QF2QftBtGbeK1K+GN+4ua/Yfnh4Gx+WS5RbhnoSmZmRYxmnTYFHgCbDGcEOT0snp +cdDUPHt0pxWEVoDyxgNd2l5Dx9t44mFhqTOS/BMjcbAruKZfvBt9OmTtJlvIefP FVlbD65Yy2tFAXbdkKbcwKIw2vutLPEfmVV+zxx/oaQmQvSGhGP20+ALS+vsusAB rMdfZt0dzTpkoJIsddrduS3wKE3i4b9HyriDUJ8Bl8D/RR4r6R7+Mna8riO6GJVV vCi8jprxvhomCTMTO4Oa =Mti+ -----END PGP SIGNATURE----- --FU3XnrEtioXfThSukdsKvdelQ5i32u6un-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/