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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, URIBL_RED autolearn=unavailable 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 8E2D8C433DB for ; Thu, 7 Jan 2021 16:54:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 63F6923433 for ; Thu, 7 Jan 2021 16:54:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728830AbhAGQyW (ORCPT ); Thu, 7 Jan 2021 11:54:22 -0500 Received: from mx2.suse.de ([195.135.220.15]:41484 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727453AbhAGQyV (ORCPT ); Thu, 7 Jan 2021 11:54:21 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1610038414; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Pdu2Y4stVeDASDk2LXn54SiG/OCAKS17/WRR19PCG6Y=; b=cZuxRQKeKcDjNzXo7fVYNuoJ3UVoKSS96AVmLCsQ1k7CUVUsHTEjb3eVBCQruNqjgcA4SF XTW/TX7L5bmq4qoit3VZD2jqBoAaWd4p77/hZHyKwJmu0wtiLvLCPUxORUQFRF4Jf91RAg rfRyAGUqr9+x7h/xKF1c0RUE+ms606U= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 13BB9AD26; Thu, 7 Jan 2021 16:53:34 +0000 (UTC) Date: Thu, 7 Jan 2021 17:53:33 +0100 From: Petr Mladek To: David Gow Cc: Shuah Khan , Andy Shevchenko , Brendan Higgins , Senozhatsky , Sergey Senozhatsky , "open list:KERNEL SELFTEST FRAMEWORK" , KUnit Development , Linux Kernel Mailing List Subject: Re: [PATCH] kunit: tool: Force the use of the 'tty' console for UML Message-ID: References: <20201222073900.3490607-1-davidgow@google.com> <20201222111102.GC4077@smile.fi.intel.com> <4ae7779c-15c5-0474-5840-44531dcf1d94@linuxfoundation.org> <3828c7ee-52b0-42f9-5771-74ef9386756c@linuxfoundation.org> <20210105185731.GT4077@smile.fi.intel.com> <918b2d05-f51b-0866-89b3-19a016abdaa3@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 2021-01-06 12:29:12, David Gow wrote: > On Wed, Jan 6, 2021 at 3:52 AM Shuah Khan wrote: > > > > On 1/5/21 11:57 AM, Andy Shevchenko wrote: > > > On Tue, Jan 05, 2021 at 09:34:33AM -0700, Shuah Khan wrote: > > >> On 1/5/21 9:21 AM, Petr Mladek wrote: > > >>> On Mon 2021-01-04 09:23:57, Shuah Khan wrote: > > >>>> On 12/22/20 4:11 AM, Andy Shevchenko wrote: > > >>>>> On Mon, Dec 21, 2020 at 11:39:00PM -0800, David Gow wrote: > > >>>>>> kunit_tool relies on the UML console outputting printk() output to the > > >>>>>> tty in order to get results. Since the default console driver could > > >>>>>> change, pass 'console=tty' to the kernel. > > >>>>>> > > >>>>>> This is triggered by a change[1] to use ttynull as a fallback console > > >>>>>> driver which -- by chance or by design -- seems to have changed the > > >>>>>> default console output on UML, breaking kunit_tool. While this may be > > >>>>>> fixed, we should be less fragile to such changes in the default. > > >>>>>> > > >>>>>> [1]: > > >>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=757055ae8dedf5333af17b3b5b4b70ba9bc9da4e > > >>>>> > > >>>>> Reported-by: Andy Shevchenko > > >>>>> Tested-by: Andy Shevchenko > > >>>>> > > >>>> > > >>>> Thank you all. Now in linux-kselftest kunit-fixes branch. > > >>>> > > >>>> Will send this up for rc3. > > >>>> > > >>>> Sorry for the delay - have been away from the keyboard for a > > >>>> bit. > > >>> > > >>> JFYI, I am not sure that this is the right solution. I am > > >>> looking into it, see > > >>> https://lore.kernel.org/linux-kselftest/X%2FSRA1P8t+ONZFKb@alley/ > > >>> for more details. > > >>> > > >> > > >> Thanks Petr. I will hold off on sending the patch up to Linus and > > >> let you find a the right solution. > > > > > > Please. leave it in Linux Next at least. Otherwise kunit will be broken for a > > > long time which is not good. > > > > > > > > > > Yes. That is the plan. It will be in there until real fix comes in. The real fix would be too complicated for 5.11-rc3. Instead, I proposed to revert the problematic commit, see https://lore.kernel.org/lkml/20210107164400.17904-2-pmladek@suse.com/ I would like to push it for 5.11-rc3. > Personally, I think that this patch makes some sense to keep even if > the underlying issue with ttynull is resolved. Given that kunit.py > requires the console output, explicitly stating we want console=tty > set is probably worth doing rather than relying on it being the > default. I agree that the patch makes sense on its own. kunit depends on the particular console. Note that "tty" is actually the UML-specific stdio console implemented in arch/um/drivers/stdio_console.c. Best Regards, Petr