From owner-freebsd-arch@freebsd.org Thu Dec 3 21:49:54 2015 Return-Path: Delivered-To: freebsd-arch@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C5C25A4006B for ; Thu, 3 Dec 2015 21:49:54 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: from mail-ig0-x229.google.com (mail-ig0-x229.google.com [IPv6:2607:f8b0:4001:c05::229]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 864E41CE6; Thu, 3 Dec 2015 21:49:54 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: by igvg19 with SMTP id g19so23041046igv.1; Thu, 03 Dec 2015 13:49:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc:content-type; bh=yWX4mgvJp7E9d7lUMkHrKOSLZ6wLcxU2oTQ2E7LCxuE=; b=VWlHpSRsXuz3ho9NBvGoScZzDrLFoeZvCstSycincsUNpRijf8alhCQaNpSypBNTv0 5Kf++iGJ9zWhlc8jrYPAX1LYa5P+aDJC6lCMYs/MYba5EnAMKcG1wc8h7lAgYlkyEDcI JSWzVy6WBZwvY1FoDBtRtW2bMMbjmqhbv47jK0gKwmwRb2fN3KD3FF5sxvp1WNeVgEg3 lwGoISawOVwUVkfLthwkFZ2hwy25DfFIG7iMFUb1uIAIwIabwvUtEHcoYrIvLYMjDJ3n xkMWAQp4lkz3wRU8KIfJijS4wEZaaRRVt5nq62YURoekkWsBhFMLA6BZ1QQKXjFWRGIN leRA== X-Received: by 10.50.43.234 with SMTP id z10mr955553igl.58.1449179393866; Thu, 03 Dec 2015 13:49:53 -0800 (PST) MIME-Version: 1.0 Sender: carpeddiem@gmail.com Received: by 10.107.169.85 with HTTP; Thu, 3 Dec 2015 13:49:34 -0800 (PST) In-Reply-To: References: <1449177325.6214.14.camel@freebsd.org> From: Ed Maste Date: Thu, 3 Dec 2015 21:49:34 +0000 X-Google-Sender-Auth: PFKC6SPood_iew-pf4vhPudvSRA Message-ID: Subject: Re: Removing build metadata, for reproducible kernel builds To: Justin Hibbits Cc: Ian Lepore , Warner Losh , "freebsd-arch@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Dec 2015 21:49:54 -0000 On 3 December 2015 at 21:35, Justin Hibbits wrote: > > svnversion resulting in a 'nnnnnnM'? Warner suggested this in the review also, and it might be a good way to choose a default. In any case it's clear that there's strong (and reasonable) objection to enabling this by default for all builds, so I'll not commit the change as-is. I believe there are three separate issues here: 1) It should be possible to build the kernel reproducibly. I hope this isn't contentious. 2) Control over enabling reproducible builds -- build knob or no, default to on/off, based on svnversion including 'M', forced on for release builds, etc. 3) Some tools rely on the current format / data, and will need to be fixed. I expect to make a change so that a reproducible build is possible, but not introduce a new knob or change anything by default. After that I'll work on the issues in #3 and once that's done we can start the bikeshed about whether there should be a knob, what the default should be etc. Thanks all for the feedback.