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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 EF448C3A5A1 for ; Wed, 28 Aug 2019 13:33:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC39922DA7 for ; Wed, 28 Aug 2019 13:33:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726548AbfH1Nd1 (ORCPT ); Wed, 28 Aug 2019 09:33:27 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:34168 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726368AbfH1Nd1 (ORCPT ); Wed, 28 Aug 2019 09:33:27 -0400 Received: by mail-wr1-f65.google.com with SMTP id s18so2560135wrn.1 for ; Wed, 28 Aug 2019 06:33:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Z/iwyChIHaytlF3nBMrrV8GH07zAorOvTXTDzjkWMC4=; b=mhLHONtENkVUYEfUmrEnjk8JxVjeeql6Q3rk8lvSJI42jqOuwHk6HVWtVUrR1oPYPy 0Lv5/g/tNMVPshdsnGZyjQZscUuFco1h+DQMCXGoxKrmXka9LxhWFwD4N0FrKGOVrhsp EAXqUVMs1e7LZeyc4U8xNGkTybqM+4M92IbWLVuW4q4ZFrEuMJbEtKOz3ZNgfEIO230u pEcAKnzNimPCrV5y/iSbULy2VYCLKhLwHpyyP5hx1iaEQlvXxsQ53xpOyisfdYBSornw gMJJ+jS/EiTD5dINcJZTx4ZaXb8cYRTNuQi+tfM06TjJ8x+qjL0HyLawPzg/Kk6C+0OB chOg== X-Gm-Message-State: APjAAAWUijSxB5cv/56HYoN5hJ+HySjJb74VracMoN5l1TK/ezUQAE7N rsZaAGv3ffHcwk+x80s+3Cs7G54I1Gc= X-Google-Smtp-Source: APXvYqz6NHrdtNukj5LtnpopGp/HDaj6j8Jqnf4sC0lzsqXu3EnDKYIjf7AtZ9r8d2aX1xdF1JdtcQ== X-Received: by 2002:adf:facc:: with SMTP id a12mr4728967wrs.205.1566999205347; Wed, 28 Aug 2019 06:33:25 -0700 (PDT) Received: from green.intra.ispras.ru (bran.ispras.ru. [83.149.199.196]) by smtp.googlemail.com with ESMTPSA id l62sm4848942wml.13.2019.08.28.06.33.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Aug 2019 06:33:24 -0700 (PDT) From: Denis Efremov To: Andy Whitcroft , Joe Perches Cc: Denis Efremov , Andrew Morton , linux-kernel@vger.kernel.org Subject: [PATCH v2] checkpatch: check for nested unlikely calls Date: Wed, 28 Aug 2019 16:32:56 +0300 Message-Id: <20190828133256.13630-1-efremov@linux.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190827165515.21668-1-efremov@linux.com> References: <20190827165515.21668-1-efremov@linux.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org IS_ERR, IS_ERR_OR_NULL, IS_ERR_VALUE already contain unlikely optimization internally. Thus, there is no point in calling these functions under likely/unlikely. This check is based on the coccinelle rule developed by Enrico Weigelt https://lore.kernel.org/lkml/1559767582-11081-1-git-send-email-info@metux.net/ Signed-off-by: Denis Efremov --- scripts/checkpatch.pl | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 93a7edfe0f05..55b90e1334d2 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -6480,6 +6480,12 @@ sub process { "Using $1 should generally have parentheses around the comparison\n" . $herecurr); } +# nested likely/unlikely calls + if ($line =~ /\b(?:(?:un)?likely)\s*\(!?\s*(IS_ERR(?:_OR_NULL|_VALUE)?)/) { + WARN("LIKELY_MISUSE", + "nested (un)?likely calls, unlikely already used in $1 internally\n" . $herecurr); + } + # whine mightly about in_atomic if ($line =~ /\bin_atomic\s*\(/) { if ($realfile =~ m@^drivers/@) { -- 2.21.0