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 X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIM_SIGNED, MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C107BC46469 for ; Wed, 12 Sep 2018 16:02:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52F8320833 for ; Wed, 12 Sep 2018 16:02:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="sNirJhDp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 52F8320833 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728003AbeILVHH (ORCPT ); Wed, 12 Sep 2018 17:07:07 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:33196 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726677AbeILVHG (ORCPT ); Wed, 12 Sep 2018 17:07:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To: From:Date:Sender:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=DC8VCz/nDf7DRYDASPGB5gU41kIWFZRCMSM++6l7RxY=; b=sNirJhDpzDuTLj0z9vgzgrdyV WhCR3ugHc/TG9p4uyMr2j5vKWb9cXd76dhmC54+EAdw8Pxp8V1E7KgtIYRyS4oojVmlOr1iO85UTg s+w/Qh8dsTcDEXbYGrWJNBxagU1La/8SeukhOi9e3M+C9xbj8ufuVYgj8dXX0GtPZ5ZAS4u44/lSC yY3f7ftRzqV6gioXw0L+HJgmGkHDDTrlYZPnErU5dszFoIXn/khOYBRjE2/1ik66TGN2KJa/Pf8uT zhuSVineaJkbHygfCL2nM2qK0X6n9W4qtS0n7jwo0H0Mi2u/w8faYsVAElLvrbE05mowIpF7V9q1A fb2UeM8UA==; Received: from [177.97.26.110] (helo=coco.lan) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1g07aG-0003YR-Ed; Wed, 12 Sep 2018 16:01:40 +0000 Date: Wed, 12 Sep 2018 13:01:31 -0300 From: Mauro Carvalho Chehab To: Arnd Bergmann Cc: viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, Greg Kroah-Hartman , "David S. Miller" , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, qat-linux@intel.com, linux-crypto@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, linux-input@vger.kernel.org, linux-iio@vger.kernel.org, linux-rdma@vger.kernel.org, linux-nvdimm@lists.01.org, linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-remoteproc@vger.kernel.org, sparclinux@vger.kernel.org, linux-scsi@vger.kernel.org, linux-usb@vger.kernel.org, linux-fbdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-btrfs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH v2 05/17] compat_ioctl: move more drivers to generic_compat_ioctl_ptrarg Message-ID: <20180912130131.2c6581d5@coco.lan> In-Reply-To: <20180912151134.436719-1-arnd@arndb.de> References: <20180912150142.157913-1-arnd@arndb.de> <20180912151134.436719-1-arnd@arndb.de> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Wed, 12 Sep 2018 17:08:52 +0200 Arnd Bergmann escreveu: > The .ioctl and .compat_ioctl file operations have the same prototype so > they can both point to the same function, which works great almost all > the time when all the commands are compatible. >=20 > One exception is the s390 architecture, where a compat pointer is only > 31 bit wide, and converting it into a 64-bit pointer requires calling > compat_ptr(). Most drivers here will ever run in s390, but since we now > have a generic helper for it, it's easy enough to use it consistently. >=20 > I double-checked all these drivers to ensure that all ioctl arguments > are used as pointers or are ignored, but are not interpreted as integer > values. >=20 > Signed-off-by: Arnd Bergmann > --- > drivers/media/rc/lirc_dev.c | 4 +--- > diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c > index f862f1b7f996..077209f414ed 100644 > --- a/drivers/media/rc/lirc_dev.c > +++ b/drivers/media/rc/lirc_dev.c > @@ -730,9 +730,7 @@ static const struct file_operations lirc_fops =3D { > .owner =3D THIS_MODULE, > .write =3D ir_lirc_transmit_ir, > .unlocked_ioctl =3D ir_lirc_ioctl, > -#ifdef CONFIG_COMPAT > - .compat_ioctl =3D ir_lirc_ioctl, > -#endif > + .compat_ioctl =3D generic_compat_ioctl_ptrarg, > .read =3D ir_lirc_read, > .poll =3D ir_lirc_poll, > .open =3D ir_lirc_open, Adding an infrared remote controller to a s390 mainframe sounds fun :-) I suspect that one could implement it on a s390 platform=20 using gpio-ir-recv and/or gpio-ir-tx drivers. Perhaps one possible practical usage would be to let the mainframe to send remote controller codes to adjust the air conditioning system ;-) =46rom lirc driver's PoV, there's nothing that really prevents one to do that and use lirc API, and the driver is generic enough to work on any hardware platform. I didn't check the implementation of generic_compat_ioctl_ptrarg(), but assuming it is ok, Acked-by: Mauro Carvalho Chehab Thanks, Mauro