From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH 1/2] hvmloader: remove timestamp from smbios Date: Tue, 3 Feb 2015 16:23:31 +0000 Message-ID: <54D0F603.2000804@citrix.com> References: <1422978845-5908-1-git-send-email-olaf@aepfle.de> <1422978845-5908-2-git-send-email-olaf@aepfle.de> <54D0F121.70107@citrix.com> <54D10244020000780005C7EC@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <54D10244020000780005C7EC@mail.emea.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich , Olaf Hering , xen-devel@lists.xen.org Cc: Ian Jackson , Keir Fraser , Wei Liu , Ian Campbell , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org On 03/02/15 16:15, Jan Beulich wrote: >>>> On 03.02.15 at 17:02, wrote: >> On 03/02/15 15:54, Olaf Hering wrote: >>> Including a timestamp into the binary makes it impossible to get >>> reproducible binaries. Remove the timestamp because it carries no >>> valuable info. >> I agree with the sentiment, but this is not how to do it. >> >> A release date is part of the SMBIOS spec, and the change below results >> in a malformed smbios table (stale p->release_date_str = 3; pointer) >> >> A better approach would be to derive the date from the commit date of >> HEAD, which would be consistent across rebuilds. > Except that this information may not be available, and isn't really > relevant. Instead I'd suggest using the source time stamp of > smbios.c, as that's really the (almost) only thing controlling the > data presented to the guest. > > Or maybe - considering that git checkouts use the current time > for file timestamps rather than the last modification time - use > HEAD's if available, and fall back to smbios.c's otherwise. Both good points. That sounds like the best approach. ~Andrew