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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 08F5CC00454 for ; Mon, 9 Dec 2019 15:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D22B520836 for ; Mon, 9 Dec 2019 15:41:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575906068; bh=xchqQrFdZC9lF1bCvucvR91oCh8m2y80Hp0P0ydGrDk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=mwyFJuNt28+6gkXk8VUVqfn30vgacVxYrzlf/dcLJ36+q1Sz5mCt4dvpdrvINdI+l lai1SuHkp5sd29ydLhte6VRZQgps55cXknigAscwtmX1IYVA7rC6LxNQBm8yJEylUG L9TMmMYBY9fGy4NdchebfhvuyMmDKtB/eMOKaVfc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726484AbfLIPlF (ORCPT ); Mon, 9 Dec 2019 10:41:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:40724 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726080AbfLIPlF (ORCPT ); Mon, 9 Dec 2019 10:41:05 -0500 Received: from localhost (unknown [89.205.132.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E023C2073D; Mon, 9 Dec 2019 15:41:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575906064; bh=xchqQrFdZC9lF1bCvucvR91oCh8m2y80Hp0P0ydGrDk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=T6ptTT5Dvl7Ke0t4vlq8m8f4XwnvIcTx03hZ7ubXpADtuyaQreXvuWT/F3tAUw0iO nv0m8FLvmrHqSej/FKphn7MbmX/ckC1wKOZ9PaDgJOXkqAH1c+1QVOtZrqdxcZIKLV S5/fZKB6PwdMdpgk8HQYC1Tf4PzP6toHs+047CQY= Date: Mon, 9 Dec 2019 16:41:01 +0100 From: Greg Kroah-Hartman To: Arnd Bergmann Cc: "David S. Miller" , Krzysztof Halasa , devel@driverdev.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Eric Biggers , Andrew Hendry , linux-x25@vger.kernel.org, Kevin Curtis , "R.J.Dunlop" , Zhao Qiang , syzbot+429c200ffc8772bfe070@syzkaller.appspotmail.com, syzbot+eec0c87f31a7c3b66f7b@syzkaller.appspotmail.com Subject: Re: [PATCH 4/4] [RFC] staging/net: move AF_X25 into drivers/staging Message-ID: <20191209154101.GB1284708@kroah.com> References: <20191209151256.2497534-1-arnd@arndb.de> <20191209151256.2497534-4-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191209151256.2497534-4-arnd@arndb.de> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Dec 09, 2019 at 04:12:56PM +0100, Arnd Bergmann wrote: > syzbot keeps finding issues in the X.25 implementation that nobody is > interested in fixing. Given that all the x25 patches of the past years > that are not global cleanups tend to fix user-triggered oopses, is it > time to just retire the subsystem? > > I looked a bit closer and found: > > - we used to support x25 hardware in linux, but with WAN_ROUTER > removed in linux-3.9 and isdn4linux removed in 5.3, there is only hdlc, > ethernet and the N_X25 tty ldisc left. Out of these, only HDLC_X25 made > it beyond the experimental stage, so this is probably what everyone > uses if there are users at all. > > - The most common hdlc hardware that people seem to be using are > the "farsync" PCIe and USB adapters. Linux only has drivers for the > older PCI devices from that series, but no hardware that works on > modern systems. > > - The manufacturer still updates their own kernel drivers and provides > support, but ships that with a fork or rewrite of the subsystem > code now. Kevin Curtis is also listed as maintainer, but appears to > have given up in 2013 after [1]. > > - The most popular software implementation appears to be X25 over TCP > (XOT), which is supported by Farsite and other out-of-tree stacks but > never had an implementation in mainline. > > - Most other supported HDLC hardware that we supoprt is for the ISA or > PCI buses. There are newer PCIe or USB devices, but those all require > a custom device driver and often a custom subsystem, none of which got > submitted for mainline inclusion. This includes hardware from Microgate > (SyncLink), Comtrol (RocketPort Express) and Sealevel (SeaMAC). > > - The X.25 subsystem is listed as "odd fixes", but the last reply on > the netdev mailing list from the maintainer was also in 2013[2]. > > - The HDLC subsystem itself is listed as maintained by Krzysztof Halasa, > and there were new drivers merged for SoC based devices as late as > 2016 by Zhao Qiang: Freescale/NXP QUICC Engine and Maxim ds26522. > There has not been much work on HDLC or drivers/net/wan recently, > but both developers are still responsive on the mailing list and > work on other parts of the kernel. > > Based on the above, I would conclude that X.25 can probably get moved > to staging as keeping it in the kernel seems to do more harm than good, > but HDLC below it should probably stay as there it seems there are still > users of a small subset of the mainline drivers. > > Move all of X.25 into drivers/staging for now, with a projected removal > date set for Linux-5.8. > > Cc: Eric Biggers > Cc: Andrew Hendry > Cc: linux-x25@vger.kernel.org > Cc: Kevin Curtis > Cc: "R.J.Dunlop" > Cc: Zhao Qiang > Cc: Krzysztof Halasa > Reported-by: syzbot+429c200ffc8772bfe070@syzkaller.appspotmail.com > Reported-by: syzbot+eec0c87f31a7c3b66f7b@syzkaller.appspotmail.com > Link: https://syzkaller.appspot.com/bug?id=5b0ecf0386f56be7fe7210a14d0f62df765c0c39 > Signed-off-by: Arnd Bergmann > ---- > > If anyone has different views or additional information, let us know. > > If you agree with the above, please Ack. ACK! Acked-by: Greg Kroah-Hartman