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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C507C636D4 for ; Wed, 1 Feb 2023 11:41:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9912E6B0071; Wed, 1 Feb 2023 06:41:43 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 940946B0072; Wed, 1 Feb 2023 06:41:43 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7E1816B0074; Wed, 1 Feb 2023 06:41:43 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 6DEFD6B0071 for ; Wed, 1 Feb 2023 06:41:43 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 3EE434012D for ; Wed, 1 Feb 2023 11:41:43 +0000 (UTC) X-FDA: 80418533286.01.A645C85 Received: from mail-pj1-f50.google.com (mail-pj1-f50.google.com [209.85.216.50]) by imf24.hostedemail.com (Postfix) with ESMTP id 5ACA218000A for ; Wed, 1 Feb 2023 11:41:41 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=T3X2hrM0; spf=pass (imf24.hostedemail.com: domain of hn.min.lee@gmail.com designates 209.85.216.50 as permitted sender) smtp.mailfrom=hn.min.lee@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1675251701; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5bXvsgoiR+l3eWpgXtRlq4Hbq0hyNkL1nv2x5YPzs4o=; b=smet3g2VUZ0O4NKn6Ev25lXuLsxwOfgegfVbM53N7LPW5HWSJFjqjW8hYCRHokT8XI6cAW svnTGwqbKGIhuJc2+dDZYC/uBexZN3TkdcA9qCvCfOphoZEZpLpLpJU9GFvbw+YoupWZL/ ww6yZS76N6JSI8NE/ye56OfyqjTO6bw= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=T3X2hrM0; spf=pass (imf24.hostedemail.com: domain of hn.min.lee@gmail.com designates 209.85.216.50 as permitted sender) smtp.mailfrom=hn.min.lee@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1675251701; a=rsa-sha256; cv=none; b=CbASUEyDWaL7+9vVTuU+WfEsHeAfYY4vn0546xvZLqLaeCe3MidyWcEzPaspElBaF95ZCR 7LuCcbO2p9ikmngvEFIN2sqOaX/PJALBwzp7v5BibLSs8Ds6+lWelZa/hRi3dxeAZ6SIez fQsL0ZO1lfcm3bwPCbIvaDQhhRXqtTY= Received: by mail-pj1-f50.google.com with SMTP id nm12-20020a17090b19cc00b0022c2155cc0bso1706716pjb.4 for ; Wed, 01 Feb 2023 03:41:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=5bXvsgoiR+l3eWpgXtRlq4Hbq0hyNkL1nv2x5YPzs4o=; b=T3X2hrM0WKKoWJ6KGYHnf0BQr7JyLhIQDVWxq9npfd8Jhsz05Es81zwx3TIatEp+/f 9dUbTZKL9Dz3QQ7ckwYcbsjJgA1pvVDqFoi+4R71yEtafoawRnlsX56lMTnbJt0dzKPb CblfL85QAG+GiWIsWpoGImzHp6E0sKC+QK4mPEKg5YySGbzPKQijLSeFnC34WR0LD6sH 5kfK5kfP+6h08UsUlW6X3pDhqc7lFtJveKKTIB3mcMtM5402ZvURzAjREEGdfZvQROUA UE/yU4x82yUhahakcHKjlHkt0jUnC+OgGwgWFKzN01PPF174MAPTGprDOLAkQr4Cae+0 6Uuw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=5bXvsgoiR+l3eWpgXtRlq4Hbq0hyNkL1nv2x5YPzs4o=; b=xKkpMAQ8fEMFTWsssOOunBNTHiJx3al0HePx40M47mI0P4A2rg4DB4spXb1642zVe0 rlL4LVC2ItF0rrt/T/UwZPIyaCfsivjMq0fhgYJtuPjYzjdixGKBYu08IG3Q2uB7EcGk awC8gpbGM2B6BWCnA3FTKNxQC5XJes1I5SuUqU28c07byDI+v1q3dQ7fzVge7CDnHmVZ 0/i97hBg3pAkFwiHEfJHiSbgVea1MgH6ogfZ7PjYQXCr7AaKOwLAmQTqv7WM0m0oZ3wY 7gg84PJZQAo7C67/bHa+T6eRk6hUSzOYTTasmUHE6lFbtzEBHYYShtELQFWsQ4nSfdlj uqeQ== X-Gm-Message-State: AO0yUKVqSQ1kqUbt/0EM/xVXZ/X2nvULtYguSiIOm2sVwWLl9gC9DHlQ qVj3bwCcnPBFrG0Cfx6kLjc= X-Google-Smtp-Source: AK7set94acvRQfUPbtBsFbvSUn3Lw6SO1V5JWqbdMVT2dTr90tfbsG7QXf7bNN5/G4ePIBhaDW9u0g== X-Received: by 2002:a17:902:c943:b0:196:5787:d73a with SMTP id i3-20020a170902c94300b001965787d73amr2848104pla.53.1675251700015; Wed, 01 Feb 2023 03:41:40 -0800 (PST) Received: from min-iamroot ([210.91.70.133]) by smtp.gmail.com with ESMTPSA id ay2-20020a1709028b8200b0019468fe44d3sm11476329plb.25.2023.02.01.03.41.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Feb 2023 03:41:39 -0800 (PST) Date: Wed, 1 Feb 2023 20:41:34 +0900 From: Hyunmin Lee To: Christophe Leroy Cc: Andrew Morton , Uladzislau Rezki , Christoph Hellwig , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Gwan-gyeong Mun , Jeungwoo Yoo , Sangyun Kim , Hyeonggon Yoo <42.hyeyoo@gmail.com> Subject: Re: [PATCH v3] mm/vmalloc: replace BUG_ON to a simple if statement Message-ID: <20230201114134.GA6060@min-iamroot> References: <20230201101152.GA5535@min-iamroot> <9f507a28-bbe3-7ebd-6e32-b5dc046c310d@csgroup.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9f507a28-bbe3-7ebd-6e32-b5dc046c310d@csgroup.eu> X-Rspamd-Queue-Id: 5ACA218000A X-Stat-Signature: f8nszocktae4gz6y4ng1oci9qnmmga45 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1675251701-303218 X-HE-Meta: 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 SwMGUKcc 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000056, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Feb 01, 2023 at 10:37:19AM +0000, Christophe Leroy wrote: > > > Le 01/02/2023 à 11:11, Hyunmin Lee a écrit : > > [Vous ne recevez pas souvent de courriers de hn.min.lee@gmail.com. D?couvrez pourquoi ceci est important ? https://aka.ms/LearnAboutSenderIdentification ] > > > > As per the coding standards, in the event of an abnormal condition that > > should not occur under normal circumstances, the kernel should attempt > > recovery and proceed with execution, rather than halting the machine. > > > > Specifically, in the alloc_vmap_area() function, use a simple if() > > instead of using BUG_ON() halting the machine. > > > > Co-Developed-by: Gwan-gyeong Mun > > Co-Developed-by: Jeungwoo Yoo > > Co-Developed-by: Sangyun Kim > > Signed-off-by: Hyunmin Lee > > Signed-off-by: Gwan-gyeong Mun > > Signed-off-by: Jeungwoo Yoo > > Signed-off-by: Sangyun Kim > > Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> > > --- > > v1->v2 : Add commit description > > v2->v3 : Change WARN_ON() to if() > > --- > > mm/vmalloc.c | 11 ++++++++--- > > 1 file changed, 8 insertions(+), 3 deletions(-) > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > index 74afa2208558..52a346bc02a1 100644 > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -1587,9 +1587,14 @@ static struct vmap_area *alloc_vmap_area(unsigned long size, > > int purged = 0; > > int ret; > > > > - BUG_ON(!size); > > - BUG_ON(offset_in_page(size)); > > - BUG_ON(!is_power_of_2(align)); > > + if (unlikely(!size)) > > + return ERR_PTR(-EINVAL); > > + > > + if (unlikely(offset_in_page(size))) > > + return ERR_PTR(-EINVAL); > > + > > + if (unlikely(!is_power_of_2(align))) > > + return ERR_PTR(-EINVAL); > > I would have written it more compact. When using BUG_ON or WARN_ON it is > interesting to have three separate lines because you get the line number > in the Oops message, but here you are just returning the exact same > error code, so it could be: > > if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align))) > return ERR_PTR(-EINVAL); > > > > > if (unlikely(!vmap_initialized)) > > return ERR_PTR(-EBUSY); > > -- > > 2.25.1 > > > > Hi Christophe, Thanks for your comment. I will send new patch. Best, Min