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=-8.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 6BED7C432C0 for ; Mon, 2 Dec 2019 01:23:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 273EC20881 for ; Mon, 2 Dec 2019 01:23:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JbwPnDI8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727279AbfLBBXL (ORCPT ); Sun, 1 Dec 2019 20:23:11 -0500 Received: from mail-pg1-f193.google.com ([209.85.215.193]:33913 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727266AbfLBBXL (ORCPT ); Sun, 1 Dec 2019 20:23:11 -0500 Received: by mail-pg1-f193.google.com with SMTP id r11so528481pgf.1; Sun, 01 Dec 2019 17:23:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=dMdDU7QPfqkfhU93NmKAKuY/iBXJ4ghiOz+NSAn8CiY=; b=JbwPnDI8OxxpXKPY1ygxBWujZyN2RpsTQ4WphYMfy+RsO5+9/B5KEYI7tvMiPmvRoh K8rM/5WWnjy0S9xHOyDt850wsZw4agJ1RSiKyK++A/Fe2X8dazhB32XSD2hZvZNPbsf7 tmQNwmYpr9cAECsTS0eYRa0I8edk9D8n9Jas3PVNV8OTGGzy25YtMfKcBrLFUyr5wy0X 5YcgUqAWgcXICJ8hfgDnj9FTYud0UYfbx5LGYAAXUfYbiFtE/CLOxlQgxmzVBDm52whl x4auD4RoWMU3c6Bx8QinYLzkP94/kUPuqU7F5hQ23XTOYLPtgbrNSD5qJMXCNPt6es8z AVQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=dMdDU7QPfqkfhU93NmKAKuY/iBXJ4ghiOz+NSAn8CiY=; b=IMML6iTX5BmlS6NAbXrSV1QRu8GaviA1Jwo93zMxx3CT308wFz2E/sx640iSMI594s HCLe1hJINYh78hSXzlRuEILrrODiQ2mFw9vm4hjXngaWAX7JkNPIOYgQC9fAmDH1tZU7 Rgb7rLKKLJxeonLH9OthzrQOH7jbWFbzpRIHqKBjeobunm47oSsJr9GNYoCXKzyXujf0 re8rEZSX/KAm7OkFdm+Rv/K5En2PnEg65vgiVdZ0PPvIc0303Twg+FuXUXcnLIiFH8I3 MuBvpzOr8y0EMX7XmJ6qenI+gi2rnpfQKsidFoMuscLHo/oe0Xge4wcyn2BO0Qr5rBpr 5VMA== X-Gm-Message-State: APjAAAXZUy6NV9OpX7BVPzr/MGSwaTpwWzM/ZJMiqaanlQbxP7iswwxd ex0xUOAHWbqFSynBt1+LzMk= X-Google-Smtp-Source: APXvYqwxTVM2SJdf0fAcJ9eL46EQoaRI/xaWiLcdiJWwmOu/TEFvTCc4nbiWPVWt3IL/a9UwEwuJsQ== X-Received: by 2002:a63:1b1b:: with SMTP id b27mr26614665pgb.402.1575249788764; Sun, 01 Dec 2019 17:23:08 -0800 (PST) Received: from dtor-ws ([2620:15c:202:201:3adc:b08c:7acc:b325]) by smtp.gmail.com with ESMTPSA id y3sm10277577pfe.183.2019.12.01.17.23.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 01 Dec 2019 17:23:08 -0800 (PST) Date: Sun, 1 Dec 2019 17:23:05 -0800 From: Dmitry Torokhov To: Pali =?iso-8859-1?Q?Roh=E1r?= Cc: Abhishek Pandit-Subedi , linux-input@vger.kernel.org, linux-bluetooth@vger.kernel.org, Luiz Augusto von Dentz , Enric Balletbo i Serra , linux-kernel@vger.kernel.org, Thomas Gleixner , Logan Gunthorpe , Andrey Smirnov , Kirill Smelkov Subject: Re: [PATCH] Input: uinput - Add UI_SET_UNIQ ioctl handler Message-ID: <20191202012305.GQ248138@dtor-ws> References: <20191127185139.65048-1-abhishekpandit@chromium.org> <20191201145357.ybq5gfty4ulnfasq@pali> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20191201145357.ybq5gfty4ulnfasq@pali> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Hi Pali, On Sun, Dec 01, 2019 at 03:53:57PM +0100, Pali Rohár wrote: > Hello! > > On Wednesday 27 November 2019 10:51:39 Abhishek Pandit-Subedi wrote: > > Support setting the uniq attribute of the input device. The uniq > > attribute is used as a unique identifier for the connected device. > > > > For example, uinput devices created by BlueZ will store the address of > > the connected device as the uniq property. > > > > Signed-off-by: Abhishek Pandit-Subedi > > ... > > > diff --git a/include/uapi/linux/uinput.h b/include/uapi/linux/uinput.h > > index c9e677e3af1d..d5b7767c1b02 100644 > > --- a/include/uapi/linux/uinput.h > > +++ b/include/uapi/linux/uinput.h > > @@ -145,6 +145,7 @@ struct uinput_abs_setup { > > #define UI_SET_PHYS _IOW(UINPUT_IOCTL_BASE, 108, char*) > > #define UI_SET_SWBIT _IOW(UINPUT_IOCTL_BASE, 109, int) > > #define UI_SET_PROPBIT _IOW(UINPUT_IOCTL_BASE, 110, int) > > +#define UI_SET_UNIQ _IOW(UINPUT_IOCTL_BASE, 111, char*) > > I think that usage of char* as type in _IOW would cause compatibility > problems like it is for UI_SET_PHYS (there is UI_SET_PHYS_COMPAT). Size > of char* pointer depends on userspace (32 vs 64bit), so 32bit process on > 64bit kernel would not be able to call this new UI_SET_UNIQ ioctl. > > I would suggest to define this ioctl as e.g.: > > #define UI_SET_UNIQ _IOW(_IOC_WRITE, UINPUT_IOCTL_BASE, 111, 0) > > And then in uinput.c code handle it as: > > case UI_SET_UNIQ & ~IOCSIZE_MASK: > > as part of section /* Now check variable-length commands */ If we did not have UI_SET_PHYS in its current form, I'd agree with you, but I think there is benefit in having UI_SET_UNIQ be similar to UI_SET_PHYS. But you are absolutely correct that in current form the patch is deficient on 64/32 systems, and the compat handling needs to be added before it can be accepted. Thanks. -- Dmitry