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=-5.7 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 1B76BC433E6 for ; Thu, 4 Feb 2021 11:01:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD11164E7B for ; Thu, 4 Feb 2021 11:01:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235558AbhBDLBf (ORCPT ); Thu, 4 Feb 2021 06:01:35 -0500 Received: from mail-ej1-f46.google.com ([209.85.218.46]:37745 "EHLO mail-ej1-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235378AbhBDLBO (ORCPT ); Thu, 4 Feb 2021 06:01:14 -0500 Received: by mail-ej1-f46.google.com with SMTP id jj19so4609866ejc.4; Thu, 04 Feb 2021 03:00:58 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=lYj7+T0uhcqQ91m5FLh+plxjvp8VVf54myAhRXHsJLg=; b=L1hhBRUkSVIkRnRcEHunMcIbB2gtTxEgpEaKlgMvSKKd7yzPIhuwqCQ8+2++Z6W3kI 4nQ6HG/pUcR9npUoYnBKt04DURAD4vRoDmYjj2vJeJ+e+qFysg+1Bl/clL79LB9Z9Z1y TtUTX6suaD2mlwyKH/kt74UNvYhA44aHTcwbqW48HzlOZC64HLBicKY2WNaTxi4OBpGG w1KLWyDWfEXJOeZzwdWClLaC0AsdkfkGADzWEp8svDviuxHr1lyvLOxkUWLqrtzn24rP Xi8ALtuh/vJuzbjwZ86x/738rDgBXAB52+SkG1Q/W++RJgmuD5+FKqlI6Sxe/4196o/c KZxw== X-Gm-Message-State: AOAM533Btxvh/coUnXJsQkdiD6YIXgAPLtuRwwbPgW8dGOlnRThQ87e1 TdhEjwtAlGXSuiOi1GdjwhQ= X-Google-Smtp-Source: ABdhPJwpkr/jHrKe8Ewv6L4nc2KPVwUXnxty6cATQegN+8BqxOyk20T+97wsJlpOdvLQppnrho4/kQ== X-Received: by 2002:a17:906:3e14:: with SMTP id k20mr7313111eji.42.1612436433117; Thu, 04 Feb 2021 03:00:33 -0800 (PST) Received: from ?IPv6:2a0b:e7c0:0:107::49? ([2a0b:e7c0:0:107::49]) by smtp.gmail.com with ESMTPSA id k9sm2273323edo.30.2021.02.04.03.00.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 04 Feb 2021 03:00:32 -0800 (PST) Subject: Re: Kernel version numbers after 4.9.255 and 4.4.255 To: Greg Kroah-Hartman Cc: Jari Ruusu , Sasha Levin , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" , "torvalds@linux-foundation.org" , masahiroy@kernel.org References: <7pR0YCctzN9phpuEChlL7_SS6auHOM80bZBcGBTZPuMkc6XjKw7HUXf9vZUPi-IaV2gTtsRVXgywQbja8xpzjGRDGWJsVYSGQN5sNuX1yaQ=@protonmail.com> <78ada91b-21ee-563f-9f75-3cbaeffafad4@kernel.org> From: Jiri Slaby Message-ID: Date: Thu, 4 Feb 2021 12:00:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=iso-8859-2; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04. 02. 21, 9:51, Greg Kroah-Hartman wrote: >> It might work somewhere, but there are a lot of (X * 65536 + Y * 256 + Z) >> assumptions all around the world. So this doesn't look like a good idea. > > Ok, so what happens if we "wrap"? What will break with that? At first > glance, I can't see anything as we keep the padding the same, and our > build scripts seem to pick the number up from the Makefile and treat it > like a string. > > It's only the crazy out-of-tree kernel stuff that wants to do minor > version checks that might go boom. And frankly, I'm not all that > concerned if they have problems :) Agreed. But currently, sublevel won't "wrap", it will "overflow" to patchlevel. And that might be a problem. So we might need to update the header generation using e.g. "sublevel & 0xff" (wrap around) or "sublevel > 255 : 255 : sublevel" (be monotonic and get stuck at 255). In both LINUX_VERSION_CODE generation and KERNEL_VERSION proper. thanks, -- js