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=-10.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 5D334C4727D for ; Mon, 5 Oct 2020 21:05:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 042BA207EA for ; Mon, 5 Oct 2020 21:05:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="i13avUSE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728956AbgJEVFQ (ORCPT ); Mon, 5 Oct 2020 17:05:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725861AbgJEVFP (ORCPT ); Mon, 5 Oct 2020 17:05:15 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54ACDC0613CE for ; Mon, 5 Oct 2020 14:05:14 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id 22so2816191pgv.6 for ; Mon, 05 Oct 2020 14:05:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=S28irEL+s00l76Xd6JezzJDnWUqPSi/xIcPO6jGVw0k=; b=i13avUSEFUfkzqcD46Nq22pgh7sreScxeo625UkqLK+daDX8lE4BFXwZCR+i0RWl4j kQm9H9aDflprfWtjdjMu/szcbm39wcJ2ojG/5XrIVT5i/zqP2JxIZQoZeRQA5IF5ZQ8c QofnFVvrTWOYSLWkSa8Di/OBLzw49kjy9yTGw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=S28irEL+s00l76Xd6JezzJDnWUqPSi/xIcPO6jGVw0k=; b=UvjhXFNaPlCt2JDcJ0rNNssuQtvltkt6G3usn7iqR0St5kDzas71KVjGyhcjtkvLuX 7UuHaQfsvEWVEQ8y6KimvQJmteMb7PhpEHGrQy7Gghp7LI5EjmT0BrAta9FBDjLjS8dF GaeWsbMeTi5tfXnoOWsA0AFZpS1PLvcey322uBx9Hdn0SPmimXV8/R8MVZJzmR3Yglet mdXF//lgvnXeYeTpGE2AauW5e2XVcPb4k9uar8gPjuHw+27FmhhUXT//E3SlsoPO117I dkLkfoj59IyKG8LmzxQByDZrqpglhTWTG7NuLuZdIP2SSy1YQ6Gu4EwWQPSqBuU0Iwy3 j9RQ== X-Gm-Message-State: AOAM531R1B7Ao3/1omkkbzd/HCgXMRpm0DpHMfYV4LfRUl3d73lSHFgT 60Ne36MzhrL6ANHsJyFymW0n3hwtSlUBkxFR X-Google-Smtp-Source: ABdhPJz/S0gfoJShrvVKOkjfbJx02Hws0BkXYZdBoTIGEHtSmorXowh1oXM2pwYvKWxA6ebn5AMJEw== X-Received: by 2002:a63:a510:: with SMTP id n16mr1283040pgf.256.1601931913748; Mon, 05 Oct 2020 14:05:13 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id q12sm478376pjd.16.2020.10.05.14.05.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Oct 2020 14:05:12 -0700 (PDT) Date: Mon, 5 Oct 2020 14:05:11 -0700 From: Kees Cook To: Sudip Mukherjee Cc: Luis Chamberlain , Iurii Zaikin , linux-kernel@vger.kernel.org, linux-safety@lists.elisa.tech, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] kernel/sysctl.c: drop unneeded assignment in proc_do_large_bitmap() Message-ID: <202010051404.CEE37CD617@keescook> References: <20201005203749.28083-1-sudipm.mukherjee@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201005203749.28083-1-sudipm.mukherjee@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Oct 05, 2020 at 09:37:49PM +0100, Sudip Mukherjee wrote: > The variable 'first' is assigned 0 inside the while loop in the if block > but it is not used in the if block and is only used in the else block. > So, remove the unneeded assignment. True, but in this case, please move the definition of "first" into the else block so it in only in scope there. Thanks! -Kees > > Signed-off-by: Sudip Mukherjee > --- > > The resultant binary stayed same after this change. Verified with > md5sum which remained same with and without this change. > > $ md5sum kernel/sysctl.o > e9e97adbfd3f0b32f83dd35d100c0e4e kernel/sysctl.o > > kernel/sysctl.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > index ce75c67572b9..b51ebfd1ba6e 100644 > --- a/kernel/sysctl.c > +++ b/kernel/sysctl.c > @@ -1508,7 +1508,6 @@ int proc_do_large_bitmap(struct ctl_table *table, int write, > } > > bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1); > - first = 0; > proc_skip_char(&p, &left, '\n'); > } > left += skipped; > -- > 2.11.0 > -- Kees Cook