From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753425AbdBUOzO (ORCPT ); Tue, 21 Feb 2017 09:55:14 -0500 Received: from mailout2.w1.samsung.com ([210.118.77.12]:13925 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752429AbdBUOzH (ORCPT ); Tue, 21 Feb 2017 09:55:07 -0500 MIME-version: 1.0 Content-type: text/plain; charset=utf-8; format=flowed X-AuditID: cbfec7f5-f79d06d000004445-de-58ac54c7b798 Subject: Re: [PATCH] dma-buf: add support for compat ioctl To: =?UTF-8?Q?Christian_K=c3=b6nig?= , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, Bartlomiej Zolnierkiewicz From: Marek Szyprowski Message-id: Date: Tue, 21 Feb 2017 15:55:02 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 In-reply-to: Content-transfer-encoding: 8bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupmleLIzCtJLcpLzFFi42LZduzned3jIWsiDO7uVrHYOGM9q8X51RMY La58fc9m8eXKQyaLy7vmsFn0bNjK6sDmcb/7OJPH7X+PmT36tqxi9Pi8Sc6j494l1gDWKC6b lNSczLLUIn27BK6MtfPOMxf8YK+4f6GftYFxCVsXIyeHhICJxNRd71ggbDGJC/fWA8W5OIQE ljJK/Ll0kRnC+cwosa5rMSNMx5m3q1kgEssYJRb+PQvWzisgKPFj8j0wm1nASuLZv1ZWiKLn jBIn3p9nB0kIAyWmnzkLtltEoE5i8r0ORoiGCokF0+aA2WwChhJdb7vYIIbaSczctpsVxGYR UJU4NG8x2BxRgRiJ3k3TmEFsTgF7iUPT30HNkZc4eOU52HUSAvPYJXb/XAnUzAHkyEpsOsAM YbpInPvrCfGMsMSr41vYIWwZic6Og0wQdj+jRFOrNoQ9g1Hi3FteCNta4vDxi6wQq/gkJm2b DjWSV6KjTQiixEOibX8nNKwcJZqaVkGDoZVJov3pNrYJjPKzkIJrFlJwzULywQJG5lWMIqml xbnpqcWmesWJucWleel6yfm5mxiBSeT0v+NfdzAuPWZ1iFGAg1GJh7fDdU2EEGtiWXFl7iFG CQ5mJRHet0ZAId6UxMqq1KL8+KLSnNTiQ4zSHCxK4rx7FlwJFxJITyxJzU5NLUgtgskycXBK NTDmsHInZS6RMfo5fSe7wHkBrvdLrig5NaukBWXo6tg2G68Ll2ic3+SUsHGCa32R7RebiBcb Q1KDZ/9ksFsv7aRhZczyrEPF9WLzt4Mcr5cy80fpuwgn86s7/1QRlbZwFeCavSOjs/iW66MF Xp+f7E13fv7TyDPQuXfnpVM66RoX91edmvlbVImlOCPRUIu5qDgRANDZBYkeAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrDIsWRmVeSWpSXmKPExsVy+t/xq7rSoWsiDHY+NrXYOGM9q8X51RMY La58fc9m8eXKQyaLy7vmsFn0bNjK6sDmcb/7OJPH7X+PmT36tqxi9Pi8Sc6j494l1gDWKDeb jNTElNQihdS85PyUzLx0W6XQEDddCyWFvMTcVFulCF3fkCAlhbLEnFIgz8gADTg4B7gHK+nb JbhlrJ13nrngB3vF/Qv9rA2MS9i6GDk5JARMJM68Xc0CYYtJXLi3HijOxSEksIRRYuPp84wg CV4BQYkfk++BFTELmEl8eXmYFaLoOaPEq0VTmEASwgJWEtPPnAXq5uAQEaiTOLU3E6KmnUni y+bjzBDNFRINz0+BDWITMJToetvFBrHATmLmtt2sIDaLgKrEoXmL2UFsUYEYib3998HmcwrY Sxya/o4RYo68xMErz1kmMArMQnLfLCT3zUJStoCReRWjSGppcW56brGhXnFibnFpXrpecn7u JkZgTG079nPzDsZLG4MPMQpwMCrx8D5wXxMhxJpYVlyZe4hRgoNZSYT3rRFQiDclsbIqtSg/ vqg0J7X4EKMp0LETmaVEk/OB8Z5XEm9oYmhuaWhkbGFhbmSkJM5b8uFKuJBAemJJanZqakFq EUwfEwenVAOjSFmLW967f90BT17ZWj/LDvERnP78t0qoeWH/j+8zvHzTH+65PMN0+9sbtxuy lDKdHlRWdm+8+u/7gg7NuyJ2mgnbeDcenneGJ4jlW5hbsc+WgwEXX2zpk2I5ZyvIdOSuxMM7 QUl6glf/fdUIeX4+/8t2t3qW1PMWWwKnHfvIN7tLUy6NOTdZiaU4I9FQi7moOBEA3eVWa78C AAA= X-MTR: 20000000000000000@CPGS X-CMS-MailID: 20170221145503eucas1p27fd3debe24e755ddf035e6bf57ef2c79 X-Msg-Generator: CA X-Sender-IP: 182.198.249.179 X-Local-Sender: =?UTF-8?B?TWFyZWsgU3p5cHJvd3NraRtTUlBPTC1LZXJuZWwgKFRQKRs=?= =?UTF-8?B?7IK87ISx7KCE7J6QG1NlbmlvciBTb2Z0d2FyZSBFbmdpbmVlcg==?= X-Global-Sender: =?UTF-8?B?TWFyZWsgU3p5cHJvd3NraRtTUlBPTC1LZXJuZWwgKFRQKRtT?= =?UTF-8?B?YW1zdW5nIEVsZWN0cm9uaWNzG1NlbmlvciBTb2Z0d2FyZSBFbmdpbmVlcg==?= X-Sender-Code: =?UTF-8?B?QzEwG0VIURtDMTBDRDAyQ0QwMjczOTI=?= CMS-TYPE: 201P X-HopCount: 7 X-CMS-RootMailID: 20170221132114eucas1p2e527d5b5516494ba54aa91f48b3e227f X-RootMTR: 20170221132114eucas1p2e527d5b5516494ba54aa91f48b3e227f References: <1487683261-2655-1-git-send-email-m.szyprowski@samsung.com> <917aff70-64f7-7224-a015-0e77951bbc1d@vodafone.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dear All, On 2017-02-21 15:37, Marek Szyprowski wrote: > Hi Christian, > > On 2017-02-21 14:59, Christian König wrote: >> Am 21.02.2017 um 14:21 schrieb Marek Szyprowski: >>> Add compat ioctl support to dma-buf. This lets one to use >>> DMA_BUF_IOCTL_SYNC >>> ioctl from 32bit application on 64bit kernel. Data structures for >>> both 32 >>> and 64bit modes are same, so there is no need for additional >>> translation >>> layer. >> >> Well I might be wrong, but IIRC compat_ioctl was just optional and if >> not specified unlocked_ioctl was called instead. >> >> If that is true your patch wouldn't have any effect at all. > > Well, then why I got -ENOTTY in the 32bit test app for this ioctl on > 64bit ARM64 kernel without this patch? > I've checked in fs/compat_ioctl.c, I see no fallback in COMPAT_SYSCALL_DEFINE3, so one has to provide compat_ioctl callback to have ioctl working with 32bit apps. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland