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 8002AC4332F for ; Wed, 16 Nov 2022 22:43:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237845AbiKPWni (ORCPT ); Wed, 16 Nov 2022 17:43:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234495AbiKPWn2 (ORCPT ); Wed, 16 Nov 2022 17:43:28 -0500 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12F786BDCE for ; Wed, 16 Nov 2022 14:43:15 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id o7so18103pjj.1 for ; Wed, 16 Nov 2022 14:43:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Wf2gFJO0eZI55pjXm8OYjMYkGLte7QuRao7+IuvSaqE=; b=D2amVl9V9KQfzLW2zaIS23IBouuPji7hB+OAx+ZhW9BBCDB5OKBikMdNxb0VPTDxJj csClJ0YRCWBC/mBx5CM8cmRfxBeg4UGIi36VQSyP9C8PzSygpHTtXYMcx806fNdiiKsi DAssScFkYAwJ1pFNUcIn3ZWqN1hBHz6LpWnys= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to: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=Wf2gFJO0eZI55pjXm8OYjMYkGLte7QuRao7+IuvSaqE=; b=YcBUq3fLW/u8q4ci3Ek8lkfmQyw4cMM/8hUcvu5Y9MeSkwx8C2dmJyI0Gb64a82Psw Hmf5GPslDpt19VXvxXacurZ5bAtoHPKWWgukjpZMZEzwPWk9HN9gLalXhoCg3hcmSnYf dt44Jrvoo98FVVGgBysKhH38cwhwtwgqp2+gHI45I3WdrGtlfLhvF80c0qV/m6OUcqpQ or09ytxoE0u7RQfY3v84r1JSgxz59cdTMDel6PBF/YbMJmrsNA0yVxLmBPddHWCZQFM1 bH3wDEyrG0KXN9ZIbB6nz2GY2CR35jBBvDeMUnXSZof2Wv0D7t0M8X79rzxc1Evg6t2M 8gJg== X-Gm-Message-State: ANoB5pnqdsrcaQhuvQalz6VUP/4EJa0gep4/5xqE8MemoOIBa8W+JI+g J32UCmp4pU4m6br2cdqkIEJKSg== X-Google-Smtp-Source: AA0mqf5VxV4Cbn3MvfOzCKh9TKzLZskissYVmNmiO/kVOhEqnlwi5i8J4bomSjPXRjnnkIIEn4wz5w== X-Received: by 2002:a17:90b:3c42:b0:213:1ce7:d962 with SMTP id pm2-20020a17090b3c4200b002131ce7d962mr6007688pjb.63.1668638594628; Wed, 16 Nov 2022 14:43:14 -0800 (PST) Received: from www.outflux.net (198-0-35-241-static.hfc.comcastbusiness.net. [198.0.35.241]) by smtp.gmail.com with ESMTPSA id a9-20020a170902710900b00183c6784704sm12680746pll.291.2022.11.16.14.43.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Nov 2022 14:43:14 -0800 (PST) Date: Wed, 16 Nov 2022 14:43:13 -0800 From: Kees Cook To: "Jason A. Donenfeld" Cc: linux-kernel@vger.kernel.org, patches@lists.linux.dev, Greg Kroah-Hartman , Jakub Kicinski , Russell King , Catalin Marinas , Thomas Bogendoerfer , Heiko Carstens , Herbert Xu , Christoph =?iso-8859-1?Q?B=F6hmwalder?= , Jani Nikula , Jason Gunthorpe , Sakari Ailus , "Martin K . Petersen" , Theodore Ts'o , Andreas Dilger , Jaegeuk Kim , Richard Weinberger , "Darrick J . Wong" , SeongJae Park , Thomas Gleixner , Andrew Morton , Michael Ellerman , Helge Deller , netdev@vger.kernel.org, linux-crypto@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mmc@vger.kernel.org, linux-parisc@vger.kernel.org Subject: Re: [PATCH v2 3/3] treewide: use get_random_u32_between() when possible Message-ID: <202211161436.A45AD719A@keescook> References: <20221114164558.1180362-1-Jason@zx2c4.com> <20221114164558.1180362-4-Jason@zx2c4.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221114164558.1180362-4-Jason@zx2c4.com> Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Mon, Nov 14, 2022 at 05:45:58PM +0100, Jason A. Donenfeld wrote: > - (get_random_u32_below(1024) + 1) * PAGE_SIZE; > + get_random_u32_between(1, 1024 + 1) * PAGE_SIZE; I really don't like "between". Can't this be named "inclusive" (and avoid adding 1 everywhere, which seems ugly), or at least named something less ambiguous? > - n = get_random_u32_below(100) + 1; > + n = get_random_u32_between(1, 101); Because I find this much less readable. "Below 100" is clear: 0-99 inclusive, plus 1, so 1-100 inclusive. "Between 1 and 101" is not obvious to me to mean: 1-100 inclusive. These seem so much nicer: get_random_u32_inclusive(1, 1024) get_random_u32_inclusive(1, 100) -- Kees Cook