From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752523AbdFNPsG (ORCPT ); Wed, 14 Jun 2017 11:48:06 -0400 Received: from vmicros1.altlinux.org ([194.107.17.57]:42632 "EHLO vmicros1.altlinux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752451AbdFNPsE (ORCPT ); Wed, 14 Jun 2017 11:48:04 -0400 Date: Wed, 14 Jun 2017 18:48:03 +0300 From: "Dmitry V. Levin" To: Greg Kroah-Hartman Cc: Gleb Fotengauer-Malinovskiy , Laura Abbott , linux-kernel@vger.kernel.org, Sumit Semwal , Arve =?utf-8?B?SGrDuG5uZXbDpWc=?= , Riley Andrews , devel@driverdev.osuosl.org Subject: Re: [PATCH] staging: android: uapi: drop definitions of removed ION_IOC_{FREE,SHARE} ioctls Message-ID: <20170614154802.GA28592@altlinux.org> Mail-Followup-To: Greg Kroah-Hartman , Gleb Fotengauer-Malinovskiy , Laura Abbott , linux-kernel@vger.kernel.org, Sumit Semwal , Arve =?utf-8?B?SGrDuG5uZXbDpWc=?= , Riley Andrews , devel@driverdev.osuosl.org References: <20170530141128.GA1469@glebfm.cloud.tilaa.com> <3725e052-5e57-3455-01e2-76ee33eeb15b@redhat.com> <20170613181704.GD2828@glebfm.cloud.tilaa.com> <20170614050839.GB11953@kroah.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="VS++wcV0S1rZb1Fb" Content-Disposition: inline In-Reply-To: <20170614050839.GB11953@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --VS++wcV0S1rZb1Fb Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jun 14, 2017 at 07:08:39AM +0200, Greg Kroah-Hartman wrote: > On Tue, Jun 13, 2017 at 09:17:05PM +0300, Gleb Fotengauer-Malinovskiy wro= te: > > On Tue, May 30, 2017 at 04:33:57PM -0700, Laura Abbott wrote: > > > On 05/30/2017 07:11 AM, Gleb Fotengauer-Malinovskiy wrote: > > > > This problem was found by strace ioctl list generator. > > > >=20 > > > > Fixes: 15c6098cfec5 ("staging: android: ion: Remove ion_handle and = ion_client") > >=20 > > As this commit fixes a regression, please apply it to the tree which wi= ll > > be merged before 4.12 release, too. >=20 > What "regression" is there? The fact that a staging driver has a few > spare ioctls floating around in a header file? How is that bad? I thought it was pretty obvious. OK, here is a bit more detailed explanation. There is an uapi header that after commit 15c6098cfec5 provides definitions of ioctl macros that do not compile when used. Imagine a userspace code that does something as harmless as #ifdef ION_IOC_FREE use(ION_IOC_FREE); #endif This simple code is broken by commit 15c6098cfec5. The regression is not a pure virtual one, there is a quite real userspace (strace ioctl list generator) broken by the change. --=20 ldv --VS++wcV0S1rZb1Fb Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBCAAGBQJZQVqyAAoJEAVFT+BVnCUIa9gP/0P3gTvIVVj6nGchPuFCGSco 4F/LQ2Jmbt3sBM55YIyECRR+NTOAFAeG9xA0zLOJgzCBJKKWG4ZjByjECi+p9KIK 7dNE1zsKCGOBFGKFpNWTCnK4BS85auH7qErIw4Vq+4OFLabCQ4XGYEh13X7N4DuD FeBpXEWCQTIzZU2DcBwYlRoapk/Or0iq4LRUwjAbgsJXkfJAvOnI0ZLKy5jyaXxx MxK8GXPL9M1pIZUNwVcOTfzpoXFCwldOWNifKknIeSAQ3vFna+79RT1ywuTnqoyi GsAU3Ve63/+7viMTmWxlQD/G6PF6GkA/dNPT9bz4BWxHxwv1ZpWAtdkgIUNxvFia gUXF5eB6HUIsjg9NUupIEDEAgJ9yc2kurjpIAGUU6of6f7Tsm7Z2wvl0Z3z0HaNA cYeaje3Zj012wE8iqPVCm/FCyDZxj/fpYQJcatU673lREmABpPIgkO2RIg3ckzpS Tj2J2MntRJ74Fgu3Vd8qXSXLFXPATjFjzdlAKL5jj9Hy8KDa54iqcOkCYw7e5xKl UjrEFE0xWifntAn9ywXoulyJfFIQHcf/T+4P1GZdg6xZY3KetHjmZU1SZ3fFfeGb K0qVBKjHbfPKARdpIODL9FjGu9oRU/Z5XzKIm7gvdIrtHxNtefag5Zwz1Lc/4gqH E4j+o/iFOtBwMpf/w8Be =0wR+ -----END PGP SIGNATURE----- --VS++wcV0S1rZb1Fb--