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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 08109C2D0DB for ; Tue, 21 Jan 2020 07:56:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D89D822522 for ; Tue, 21 Jan 2020 07:56:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728205AbgAUH45 (ORCPT ); Tue, 21 Jan 2020 02:56:57 -0500 Received: from mout.kundenserver.de ([212.227.126.130]:34765 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725789AbgAUH44 (ORCPT ); Tue, 21 Jan 2020 02:56:56 -0500 Received: from mail-qk1-f176.google.com ([209.85.222.176]) by mrelayeu.kundenserver.de (mreue009 [212.227.15.129]) with ESMTPSA (Nemesis) id 1MrQN5-1jN4gy1L1j-00oVpR for ; Tue, 21 Jan 2020 08:56:55 +0100 Received: by mail-qk1-f176.google.com with SMTP id x129so1804996qke.8 for ; Mon, 20 Jan 2020 23:56:55 -0800 (PST) X-Gm-Message-State: APjAAAWtYuRWYftvoxM0Q9pnIOkIRr9Ox23ymBFxDj78bM6AN/2YTdda LypIvFKlPKgKKU7e6kYtqNzrk4vg/2DelfsWAT8= X-Google-Smtp-Source: APXvYqz4tiDJoI2migNnImA2omna2zj+7OgcgTO5jqY48X4PjHVty245HTtfMAVLuNHgqnoCcyHNuiGdUN5ZOP4kl94= X-Received: by 2002:a37:2f02:: with SMTP id v2mr3229598qkh.3.1579593414178; Mon, 20 Jan 2020 23:56:54 -0800 (PST) MIME-Version: 1.0 References: <20200120221323.GJ15860@mit.edu> In-Reply-To: <20200120221323.GJ15860@mit.edu> From: Arnd Bergmann Date: Tue, 21 Jan 2020 08:56:37 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Question about dynamic minor number of misc device To: "Theodore Y. Ts'o" Cc: Zhenzhong Duan , Greg Kroah-Hartman , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:UcYfFRlinOqwCjCCYDRzvoYlDPafztP3ta4y9slIdqm2BtQ8Mtk Lhp5V7Ve2x7fahWEBguMbjl9B9tSfOSdfq1dxkh0DnzO/CKQSJAvccm//s5yKKSjWK+cxfW uv41vNAKiGTzcZ7J7nAtkFKPx1A9lKxeajsssmEOv99iCjjkrD4VN8FHP1wmPyfyzaMbKIB ezgRLlhqUezCfF9f4juSg== X-UI-Out-Filterresults: notjunk:1;V03:K0:tmR6Eac6mUY=:ej3nGrtUr/oiI8d3CFxebz 08Mm+FUmhHmaCjg7Rb53ecpIDQe1vYQr8W/Hc2g3Ryb7JSyu5teN20jxl8Syt5tb4GmynWhBG hpd7KFiCsPM9Dx5GaMbwKXXySZqEI8dBgeB0wAhRadgD3HmXt4E8N9okFOvxRtfVUwEH08fse GoxdoxfCOmqax/RGdTGEDGM6TvXlH63aEwIKLt/RzsP2TYGkoDX/lAwc5DuEaZ9D75W8uVf6K fCzF27QQn73lmYeVp9NY6a2jH0w/TSTiJyIyleaU79EL5TgLwcUE0wWM0NThl17MP60rx0Akd 6HjU46KUTQVekFIqVKtVfaTmxipZfyH7YqJ5v3hVqZrB63vwezl+G6/kKPAmRcDJBn4xjkj7T qquSO+YkxO+a99GUZocIiZ7fdyxzv3+tUwYZU5mlX9dghDMVxg3DYGSRYaDSy1ib31phyWjpS 1wKi4427kF1wOTQYyVfHfVSuwQyo5PmTY4g/XTEVREsp3CtPzzMd+pw/qLgwqE1OMyuNJyhdW F1pRaR8JllHBPO1neLg5y+7G2p26T35ITC6eIrzBWWS3+CBaqIUfyF6dHYMtfkcCAD3g3ajdF SYiKy0zXE9z/PsR9CoxUjrSbRfbRejgrUP7N3xxjbQzHHTieGFl0Y3yQsnEvVQqjis8CtC/I8 I7nrfWY4UuBm/ROOjNwJiebNPDefnkT8keNhyh86HXXJsRkTH+VzpHO667Dor/Dhdd9vs5oHF UMRafpjwX7B3u00DbUuSjgl0+SKgRPNdhE9y1B2pkdoEWC+j14VlqFEkM6SClyA1PVbc6FtgH X1R6axf4nCP5AC+QDf2dYhhbwBuwcuHhizqx7/SVUAk+kg8wiAZvp8HSNyiv5kzPDtPDIMkie v6yIlgyvTGu3RLWH+XOA== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 20, 2020 at 11:13 PM Theodore Y. Ts'o wrote: > > On Mon, Jan 20, 2020 at 11:59:32AM +0100, Arnd Bergmann wrote: > > On Mon, Jan 20, 2020 at 11:26 AM Zhenzhong Duan > > wrote: > > > On Mon, Jan 20, 2020 at 6:03 PM Arnd Bergmann wrote: > > > > On Mon, Jan 20, 2020 at 9:33 AM Zhenzhong Duan wrote: > > > > On a related note, I checked for drivers that call misc_register() > > > > with a minor number that is not defined in include/linux/misc.h > > > > and found a bunch, including some that have conflicting numbers, > > > > conflicting names or numbers from the dynamic range: > > > > > > > > drivers/staging/speakup/devsynth.c:#define SYNTH_MINOR 25 > > > > drivers/staging/speakup/speakup_soft.c:#define SOFTSYNTH_MINOR 26 /* > > > > drivers/staging/speakup/speakup_soft.c:#define SOFTSYNTHU_MINOR 27 /* > > > > drivers/macintosh/via-pmu.c:#define PMU_MINOR 154 > > > > drivers/macintosh/ans-lcd.h:#define ANSLCD_MINOR 156 > > > > drivers/auxdisplay/charlcd.c:#define LCD_MINOR 156 > > > > drivers/char/applicom.c:#define AC_MINOR 157 > > > > drivers/char/nwbutton.h:#define BUTTON_MINOR 158 > > > > arch/arm/include/asm/nwflash.h:#define FLASH_MINOR 160 > > > > drivers/sbus/char/envctrl.c:#define ENVCTRL_MINOR 162 > > > > drivers/sbus/char/flash.c:#define FLASH_MINOR 152 > > > > drivers/sbus/char/uctrl.c:#define UCTRL_MINOR 174 > > > > drivers/char/toshiba.c:#define TOSH_MINOR_DEV 181 > > > > arch/um/drivers/random.c:#define RNG_MISCDEV_MINOR > > > > drivers/auxdisplay/panel.c:#define KEYPAD_MINOR 185 > > > > drivers/video/fbdev/pxa3xx-gcu.c:#define MISCDEV_MINOR 197 > > > > kernel/power/user.c:#define SNAPSHOT_MINOR 231 > > > > drivers/parisc/eisa_eeprom.c:#define EISA_EEPROM_MINOR 241 > > > > > > > > If you would like to help clean that up, you are definitely welcome > > > > to send patches. > > > > > > Ok, should that be a patch for all drivers or seperate patch for each driver? > > > > I think one patch to move the ones with unique names would be fine, > > but then separate patches for > > > > - FLASH_MINOR move and rename to avoid conflict > > - change speakup to dynamic minors > > - support for high dynamic minor numbers if you are really motivated > > (probably nobody needs these) > > Are we sure that reassigning minor device number conflits isn't going > to break systems? Especially those on random, older, architectures > they might not be using udev. To clarify: the only numbers that I think should be changed to dynamic allocation are for drivers/staging/speakup. While this is a fairly old subsystem, I would expect that it being staging means we can be a little more progressive with the changes. Arnd