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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16429C4332F for ; Sun, 12 Nov 2023 20:18:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232269AbjKLUS1 (ORCPT ); Sun, 12 Nov 2023 15:18:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229664AbjKLUSZ (ORCPT ); Sun, 12 Nov 2023 15:18:25 -0500 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B1022116 for ; Sun, 12 Nov 2023 12:18:21 -0800 (PST) Received: by mail-pl1-x62a.google.com with SMTP id d9443c01a7336-1cc13149621so4523985ad.1 for ; Sun, 12 Nov 2023 12:18:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1699820301; x=1700425101; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=bgzcqveWGXZ8cELOepLq5XS/QVDQlGc8b6jyqXPEG4w=; b=FSY8MB8jSQ3f/PGgJ7koMwY/xS/LKqiMCCkGzB+gvUYwQAd5xC0NvA/A46CGom8PFn Ln+yNqQfT3iI7nGRMgoMzeiwqjL/i886eLHUll3/nr6CAilIZSpGqCItTEvo9hsvBw1O SqaYn2I7TihzlaBmI+50dwTBcCW2rQhryNysij8XLhxrLkBRPAn8CwrLPxu+XNHBLwAX SmRBn0pHSHkHUev6Uul99K3/hBM/EiP4oLloUwOAZRuTfmo13YmRDfKUlRAm3Kd1hSZ2 kn5YGVntDIlVdDXYlBOi2I8M65tj1mnqo7TGLBHdlWdZjLsoUAJ8U3Wvhv4b7WBi/eDM FoLw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699820301; x=1700425101; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=bgzcqveWGXZ8cELOepLq5XS/QVDQlGc8b6jyqXPEG4w=; b=jl13+RkSQU3pDwxd92zUfx+oR7gygxJcFuJIsexLf1uYo+KLHCsjFSx3dpS/mK1oWe kYe9fDqd7L8GTOeiV1G3buzIO8tcbqI8Q1iGZiXOMlGf2jZZhxOidfTMZ0dk6iZfm7vQ UvZ/Aa5FFL7Didv920iAc3zm2Bg4UOfN0Fj/0zyDkBZMCbwyFgu6T1Yji9X+s4hK9Zbi q4x8DOBuAiKqnk2fFd/CXLIi6ilqVlV7DHcLVpT2YebUUJgnqmYBjn1b/E5kjmHlFjk9 Zx4x1fIid+9wwBcBhRB+JOntjER8gWgfWlFvIRYL/9FNZDw1Pp+goT/CcDiDEx/d5t9i cTAg== X-Gm-Message-State: AOJu0YzHmcgC7QjVFOqOFeHxej7xehFSrM2iiWD7J9n7xcxFkmM4MXrG 9fQsiujZJJOThGdn86oLLsY= X-Google-Smtp-Source: AGHT+IGmKldSSZMid9qXjWh8w9COFO8BtH5jlrKeAvaY2WulTkeqttqsFpQntEaFr7AQ2udmWlR7pQ== X-Received: by 2002:a17:902:db0c:b0:1cc:277f:b4f6 with SMTP id m12-20020a170902db0c00b001cc277fb4f6mr6776508plx.6.1699820300880; Sun, 12 Nov 2023 12:18:20 -0800 (PST) Received: from [192.168.0.152] ([103.75.161.208]) by smtp.gmail.com with ESMTPSA id z4-20020a170902708400b001c739768214sm2880695plk.92.2023.11.12.12.18.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 12 Nov 2023 12:18:20 -0800 (PST) Message-ID: Date: Mon, 13 Nov 2023 01:48:14 +0530 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4] Fixing directly deferencing a __rcu pointer warning Content-Language: en-US To: Peter Zijlstra Cc: akpm@linux-foundation.org, brauner@kernel.org, surenb@google.com, mst@redhat.com, michael.christie@oracle.com, mjguzik@gmail.com, mathieu.desnoyers@efficios.com, npiggin@gmail.com, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org References: <202311031320.c3ebc782-oliver.sang@intel.com> <20231112193055.2072382-1-singhabhinav9051571833@gmail.com> <20231112195839.GA9987@noisy.programming.kicks-ass.net> From: Abhinav Singh In-Reply-To: <20231112195839.GA9987@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/13/23 01:28, Peter Zijlstra wrote: > On Mon, Nov 13, 2023 at 01:00:55AM +0530, Abhinav Singh wrote: >> This patch fixes the sparse warning with this message >> "dereference of noderef expression" , in this context >> it means about directly dereferencing a pointer tagged >> with __rcu annotation. > > Please, stop this madness. Just accept that sparse is a stupid tool and > the code is actually fine. Thank you for your tine maintainers. Okay I understood that this extra patch, is not required. Just one follow up question, in some driver code as well I see these warning, might be possible those are real issue. Can you suggest me like how do I know if a rcu related warning is really a issue or just a false positive warning. Thanks, Abhinav.