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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 61A1BC3A5A3 for ; Tue, 27 Aug 2019 22:00:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D0AA20828 for ; Tue, 27 Aug 2019 22:00:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566943259; bh=PS/QwP4Xax9g527ItgaFxeFjQ7qAcrtvuXy5R4KNyhw=; h=Subject:To:Cc:References:From:Date:In-Reply-To:List-ID:From; b=bfN5cr6mhdHh/2ZPmd3+71QJCVSil/+gf3gI0Jt8e8jSNLX1NOedf7UX5B7ZK84o/ phIPbxi43cPnlCWjcSVZnml9VGUR1gwqst1DNxGI5yg431RcG47uYSTktN6aAABM1D FQzXFOnvc6VF1xLiA344CGS0sDUhv1Yfm2mAflKo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726289AbfH0WA6 (ORCPT ); Tue, 27 Aug 2019 18:00:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:52752 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725976AbfH0WA5 (ORCPT ); Tue, 27 Aug 2019 18:00:57 -0400 Received: from [192.168.1.112] (c-24-9-64-241.hsd1.co.comcast.net [24.9.64.241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 077D32070B; Tue, 27 Aug 2019 22:00:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566943256; bh=PS/QwP4Xax9g527ItgaFxeFjQ7qAcrtvuXy5R4KNyhw=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=bi2IrWWe/7PtGt1+NJhcsHsNOSc4/7KQ4HaHP2+ovZn1/EcUZdvDbZ8fWztRml/Nn NPf/qENpTXyyPtKXsdeWUiF/Sfl85SerhYGHl9scCqEuHi/XPaYN3pdpV+Vj9W+p5D PGAEAV/1D3H6aiDR35ymNCUmRRt+aNhY2L3F1/e0= Subject: Re: [PATCH v1] kunit: fix failure to build without printk To: Brendan Higgins Cc: kunit-dev@googlegroups.com, Linux Kernel Mailing List , "open list:KERNEL SELFTEST FRAMEWORK" , Frank Rowand , Stephen Boyd , Randy Dunlap , Stephen Rothwell , shuah References: <20190827174932.44177-1-brendanhiggins@google.com> From: shuah Message-ID: <10b44374-829d-0daa-8fb0-4450582cb40c@kernel.org> Date: Tue, 27 Aug 2019 16:00:55 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/27/19 3:36 PM, Brendan Higgins wrote: > On Tue, Aug 27, 2019 at 2:09 PM Brendan Higgins > wrote: >> >> On Tue, Aug 27, 2019 at 2:03 PM Brendan Higgins >> wrote: >>> >>> On Tue, Aug 27, 2019 at 1:21 PM shuah wrote: >>>> >>>> On 8/27/19 11:49 AM, Brendan Higgins wrote: >>>>> Previously KUnit assumed that printk would always be present, which is >>>>> not a valid assumption to make. Fix that by ifdefing out functions which >>>>> directly depend on printk core functions similar to what dev_printk >>>>> does. >>>>> >>>>> Reported-by: Randy Dunlap >>>>> Link: https://lore.kernel.org/linux-kselftest/0352fae9-564f-4a97-715a-fabe016259df@kernel.org/T/#t >>>>> Cc: Stephen Rothwell >>>>> Signed-off-by: Brendan Higgins >>>>> --- >>>>> include/kunit/test.h | 7 +++++++ >>>>> kunit/test.c | 41 ++++++++++++++++++++++++----------------- >>>>> 2 files changed, 31 insertions(+), 17 deletions(-) >>>>> >>>>> diff --git a/include/kunit/test.h b/include/kunit/test.h >>>>> index 8b7eb03d4971..339af5f95c4a 100644 >>>>> --- a/include/kunit/test.h >>>>> +++ b/include/kunit/test.h >>>>> @@ -339,9 +339,16 @@ static inline void *kunit_kzalloc(struct kunit *test, size_t size, gfp_t gfp) >>> [...] >>>> Okay after reviewing this, I am not sure why you need to do all >>>> this. >>>> >>>> Why can't you just change the root function that throws the warn: >>>> >>>> static int kunit_vprintk_emit(int level, const char *fmt, va_list args) >>>> { >>>> return vprintk_emit(0, level, NULL, 0, fmt, args); >>>> } >>>> >>>> You aren'r really doing anything extra here, other than calling >>>> vprintk_emit() >>> >>> Yeah, I did that a while ago. I think it was a combination of trying >>> to avoid an extra layer of adding and then removing the log level, and >>> that's what dev_printk and friends did. >>> >>> But I think you are probably right. It's a lot of maintenance overhead >>> to get rid of that. Probably best to just use what the printk people >>> have. >>> >>>> Unless I am missing something, can't you solve this problem by including >>>> printk.h and let it handle the !CONFIG_PRINTK case? >>> >>> Randy, I hope you don't mind, but I am going to ask you to re-ack my >>> next revision since it basically addresses the problem in a totally >>> different way. >> >> Actually, scratch that. Checkpatch doesn't like me calling printk >> without using a KERN_. >> >> Now that I am thinking back to when I wrote this. I think it also >> might not like using a dynamic KERN_ either (printk("%s my >> message", KERN_INFO)). >> >> I am going to have to do some more investigation. > > Alright, I am pretty sure it is safe to do printk("%smessage", KERN_); > > Looking at the printk implementation, it appears to do the format > before it checks the log level: > > https://elixir.bootlin.com/linux/v5.2.10/source/kernel/printk/printk.c#L1907 > > So I am pretty sure we can do it either with the vprintk_emit or with printk. Let me see if we are on the same page first. I am asking if you can just include printk.h for vprintk_emit() define for both CONFIG_PRINTK and !CONFIG_PRINTK cases. I am not asking you to use printk() in place of vprintk_emit(). It is perfectly fine to use vprintk_emit() > > So it appears that we have to weigh the following trade-offs: > > Using vprintk_emit: > > Pros: > - That's what dev_printk uses. Not sure what you mean by this. I am suggesting if you can just call vprintk_emit() and include printk.h and not have to ifdef around all the other callers of kunit_vprintk_emit() Yes. There is the other issue of why do you need the complexity of having kunit_vprintk_emit() at all. thanks, -- Shuah