From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f196.google.com (mail-pg1-f196.google.com [209.85.215.196]) by mx.groups.io with SMTP id smtpd.web10.124.1601931914242164868 for ; Mon, 05 Oct 2020 14:05:14 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@chromium.org header.s=google header.b=i13avUSE; spf=pass (domain: chromium.org, ip: 209.85.215.196, mailfrom: keescook@chromium.org) Received: by mail-pg1-f196.google.com with SMTP id m34so6754287pgl.9 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=Omp4VxeAlpaRUGPQQK8QW1UTgdG8NnK7e5xJz8OWwBoFiuUxheBK3DUObVlNRKVSn9 2vUhoAN2faOh0fN55q2KpwVqOu5nyut1/ghVcGjG9EksSA6VSH2YwC1JaWYQJv6qTaq9 5F2bqWlKMtBsxvj8Z2J+qrAA6uyIKkeftp5mRRihRTmgwOf3QFvvuK4H9lJ3MZQsOVYT xmjqnbirJC7NDBPUUiP/MrTc4DPmO06f50c8ZOprc5ABn8Uu5/VVYsbCke+3Mo7yjQHe c8nNXc/jJh5J/3MydUUbBd+4o1XbQ2xwHUmTIJjLXAke4wC6/3aj1qPjPCTZoDnTOf5S Mk4A== X-Gm-Message-State: AOAM53086MZmUOHA+nQ2MfaYeOJ9IQBS+8a6DCo0csUyLAdJFR/bKSOK qRLHSedntTctrc0HNG1pmZMH+A== 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) Return-Path: 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 In-Reply-To: <20201005203749.28083-1-sudipm.mukherjee@gmail.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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