From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:13368 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387852AbfGaKuw (ORCPT ); Wed, 31 Jul 2019 06:50:52 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x6VAnuss013471 for ; Wed, 31 Jul 2019 06:50:52 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2u39k4818t-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 31 Jul 2019 06:50:51 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 31 Jul 2019 11:50:47 +0100 Date: Wed, 31 Jul 2019 12:50:39 +0200 From: Heiko Carstens Subject: Re: [PATCH v5 15/29] compat_ioctl: move tape handling into drivers References: <20190730192552.4014288-1-arnd@arndb.de> <20190730195819.901457-1-arnd@arndb.de> <20190730195819.901457-3-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190730195819.901457-3-arnd@arndb.de> Message-Id: <20190731105039.GB3488@osiris> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Arnd Bergmann Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "David S. Miller" , Vasily Gorbik , Christian Borntraeger , Kai =?iso-8859-1?Q?M=E4kisara?= , "James E.J. Bottomley" , "Martin K. Petersen" , linux-ide@vger.kernel.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org On Tue, Jul 30, 2019 at 09:55:31PM +0200, Arnd Bergmann wrote: > MTIOCPOS and MTIOCGET are incompatible between 32-bit and 64-bit user > space, and traditionally have been translated in fs/compat_ioctl.c. > > To get rid of that translation handler, move a corresponding > implementation into each of the four drivers implementing those commands. > > The interesting part of that is now in a new linux/mtio.h header that > wraps the existing uapi/linux/mtio.h header and provides an abstraction > to let drivers handle both cases easily. Using an in_compat_syscall() > check, the caller does not have to keep track of whether this was > called through .unlocked_ioctl() or .compat_ioctl(). > > Signed-off-by: Arnd Bergmann Besides the two minor things below Acked-by: Heiko Carstens > diff --git a/include/linux/mtio.h b/include/linux/mtio.h > new file mode 100644 > index 000000000000..fa2783fd37d1 > --- /dev/null > +++ b/include/linux/mtio.h > @@ -0,0 +1,59 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef _LINUX_MTIO_COMPAT_H > +#define _LINUX_MTIO_COMPAT_H > + > +#include > +#include > +#include > + > +/* > + * helper functions for implementing compat ioctls on the four tape > + * drivers: we define the 32-bit layout of each incompatible strucucture, typo: structure > + * plus a wrapper function to copy it to user space in either format. > + */ > + > +struct mtget32 { > + s32 mt_type; > + s32 mt_resid; > + s32 mt_dsreg; > + s32 mt_gstat; > + s32 mt_erreg; > + s32 mt_fileno; > + s32 mt_blkno; > +}; > +#define MTIOCGET32 _IOR('m', 2, struct mtget32) > + > +struct mtpos32 { > + s32 mt_blkno; > +}; > +#define MTIOCPOS32 _IOR('m', 3, struct mtpos32) > + > +static inline int put_user_mtget(void __user *u, struct mtget *k) > +{ > + struct mtget32 k32 = { > + .mt_type = k->mt_type, > + .mt_resid = k->mt_resid, > + .mt_dsreg = k->mt_dsreg, > + .mt_gstat = k->mt_gstat, > + .mt_fileno = k->mt_fileno, > + .mt_blkno = k->mt_blkno, > + }; mt_erreg is missing here.