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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 35CE6ECE560 for ; Sat, 15 Sep 2018 18:51:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D32142083A for ; Sat, 15 Sep 2018 18:51:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D32142083A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.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 S1727805AbeIPALN (ORCPT ); Sat, 15 Sep 2018 20:11:13 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:38234 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727302AbeIPALN (ORCPT ); Sat, 15 Sep 2018 20:11:13 -0400 Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 844CDC97; Sat, 15 Sep 2018 18:51:14 +0000 (UTC) Date: Sat, 15 Sep 2018 20:51:11 +0200 From: gregkh To: Arnd Bergmann Cc: Al Viro , Linux Kernel Mailing List Subject: Re: [PATCH 02/50] move compat handling of tty ioctls to tty_compat_ioctl() Message-ID: <20180915185111.GC25288@kroah.com> References: <20180913023119.GQ19965@ZenIV.linux.org.uk> <20180913024049.24567-1-viro@ZenIV.linux.org.uk> <20180913024049.24567-2-viro@ZenIV.linux.org.uk> <20180914181656.GB20521@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 14, 2018 at 09:38:52PM +0200, Arnd Bergmann wrote: > On Fri, Sep 14, 2018 at 8:17 PM gregkh wrote: > > > > On Fri, Sep 14, 2018 at 05:15:52PM +0200, Arnd Bergmann wrote: > > > On Thu, Sep 13, 2018 at 4:40 AM Al Viro wrote: > > > > + case TCSETX: > > > + case TCSETXF: > > > + case TCSETXW: > > > + case TIOCGETC: > > > + case TIOCGETP: > > > + case TIOCGPTPEER: > > > + case TIOCSERCONFIG: > > > + case TIOCSETC: > > > + case TIOCSETN: > > > + case TIOCSETP: > > > + case TIOCVHANGUP: > > > > > > Should these all be added in a stable backport patch? > > > > Why? What is being "fixed" here that anyone has noticed before that is > > causing problems in those old kernels? If no one has complained about > > the lack of compat fixups, well... :) > > Most of the individual ones don't matter: > > TCSETX/TCSETXF/TCSETXW/TCGETX never did anything, > we don't care about them. > > TIOCSERCONFIG has always been broken in compat mode, > not sure who calls it in practice. This is 'setserial autoconfig'. > > TIOCGETC/TIOCGETP/TIOCSETC/TIOCSETN/TIOCSETP > are only defined on alpha, mips, powerpc and sparc to start > with. They seem to only be there for compatibility with some > Unix version for those architectures but were never part of > the normal Linux API or the compat set, so I guess they > also don't matter. > > The two that I think we may care about are: > > TIOCGPTPEER is a fairly recent regression from commit > 311fc65c9fb9 ("pty: Repair TIOCGPTPEER") in 4.14 after it was > added in 4.13. > > TIOCVHANGUP was introduced to be used by systemd in > commit 3c95c985fa91 ("tty: add TIOCVHANGUP to allow clean tty > shutdown of all ttys"). > https://raspberrypi.stackexchange.com/questions/54143 > has a bug report noting a problem with Raspbian systemd > that was related to TIOCVHANGUP. I don't think it's the > missing compat line that caused it, but the same system > would try to run TIOCVHANGUP in compat mode on > Raspberry Pi3 when using a 64-bit kernel with raspbian, > so there are definitely callers. Ah, ok, that makes sense, I forgot about the new ioctls and didn't realize it was a regression. greg k-h