From: ludo@gnu.org (Ludovic Courtès)
To: Leo Famulari <leo@famulari.name>
Cc: guix-devel@gnu.org
Subject: Re: Meltdown / Spectre
Date: Tue, 16 Jan 2018 11:57:11 +0100 [thread overview]
Message-ID: <87po6a841k.fsf@gnu.org> (raw)
In-Reply-To: <20180110045930.GA29390@jasmine.lan> (Leo Famulari's message of "Tue, 9 Jan 2018 23:59:30 -0500")
Hello,
Leo Famulari <leo@famulari.name> skribis:
> On Wed, Jan 10, 2018 at 05:39:59AM +0800, Alex Vong wrote:
>> I have an idea. Should we add a news entry to Guix blog[0] summarizing
>> all the above? For example, we can advice users to install noscript and
>> turn off javascript by default and only enable it on trusted site when
>> necessary.
>
> I think it's a good idea to publish an advisory of some sort but I don't
> know if I'll have time in the next few days to write it.
It’s a good idea. I think the message you sent at the beginning of this
thread would be a good start. Not much more needs to be added at this
point, IMO.
>> About the "Retpoline" mitigation technique[1]. Right now only GCC 7.2.0
>> is patched, but our default gcc version is 5.4.0 in master and 5.5.0 in
>> core-updates. So I tried to apply the patches apply the patches to
>> 5.5.0. There are totally 17 commits/patches. The first 3 patch can be
>> modified to work while the 4th patch cannot be easily modified to work
>> because the function ``ix86_nopic_noplt_attribute_p'' is not present on
>> 5.5.0. Perhaps discarding the hunk would be fine, but we need to be
>> careful about it (maybe running tests make sure the fix really works).
>>
>> Do you think we should modify the patch to make it work on GCC 5 or
>> update core-updates to GCC 7 instead?
>
> So far I haven't had time to read about Retpoline, how it works, and the
> degree to which other mitigations work without it. So the following
> opinion is from a place of ignorance. I'm very interested to hear what
> everyone else thinks about your suggestion.
>
> Having said that, my opinion is that it's too late in this core-updates
> cycle to change the default GCC version, especially two major versions,
> from 5 to 7.
No doubt about it. :-)
> Something we can do very easily, even on the master branch, is to build
> specific packages with GCC 7, assuming the Retpoline technique would be
> effective in that context.
Yes, I see Alex submitted a patch already.
Thanks,
Ludo’.
next prev parent reply other threads:[~2018-01-16 10:57 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-06 13:20 What do Meltdown and Spectre mean for libreboot x200 user? Alex Vong
2018-01-06 17:23 ` Mark H Weaver
2018-01-06 17:43 ` Meltdown / Spectre Leo Famulari
2018-01-06 20:15 ` Mark H Weaver
2018-01-07 6:38 ` Mark H Weaver
2018-01-07 21:23 ` bug#30015: WebKitGTK nondeterministic build failures Mark H Weaver
2018-01-09 20:14 ` Efraim Flashner
2018-01-10 5:49 ` Leo Famulari
2020-03-22 20:40 ` Leo Famulari
2018-01-07 21:29 ` Meltdown / Spectre Mark H Weaver
2018-01-09 21:39 ` Alex Vong
2018-01-10 4:59 ` Leo Famulari
2018-01-16 10:57 ` Ludovic Courtès [this message]
2018-01-19 22:06 ` Mark H Weaver
2018-01-20 0:17 ` Leo Famulari
2018-01-21 16:26 ` Mark H Weaver
2018-01-24 14:23 ` Ludovic Courtès
2018-01-24 16:19 ` Mark H Weaver
2018-01-26 22:05 ` Mark H Weaver
2018-01-27 16:12 ` Ludovic Courtès
2018-01-10 15:00 ` ng0
2018-01-08 10:30 ` Ludovic Courtès
2018-01-10 5:27 ` Leo Famulari
2018-01-07 2:44 ` Chris Marusich
2018-01-08 17:22 ` Katherine Cox-Buday
2018-01-08 18:26 ` Marius Bakke
2018-01-08 21:51 ` Tobias Geerinckx-Rice
2018-01-08 22:01 ` Tobias Geerinckx-Rice
2018-01-09 20:13 ` Katherine Cox-Buday
2018-01-09 21:18 ` Tobias Geerinckx-Rice
2018-01-10 5:26 ` Leo Famulari
2018-01-11 19:45 ` Katherine Cox-Buday
2018-01-11 21:49 ` Adonay Felipe Nogueira
2018-01-10 10:46 ` Tobias Platen
2018-01-10 17:20 ` Leo Famulari
2018-01-10 6:43 ` Christopher Lemmer Webber
2018-01-10 18:41 ` Kei Kebreau
2018-01-16 3:58 ` Chris Marusich
2018-01-17 19:20 ` Gábor Boskovits
2018-01-14 15:11 ` Alex Vong
2018-01-09 23:10 ` Mark H Weaver
2018-01-10 5:04 ` Leo Famulari
2018-01-16 11:10 ` Ludovic Courtès
2018-01-17 2:38 ` Mike Gerwitz
2018-01-17 14:11 ` Ludovic Courtès
2018-01-10 9:36 ` Chris Marusich
2018-01-10 11:49 ` Adonay Felipe Nogueira
2018-01-10 12:35 ` Tobias Platen
2018-01-10 14:04 ` Gábor Boskovits
2018-01-12 0:25 ` Marius Bakke
2018-01-15 8:07 ` Pjotr Prins
2018-01-16 3:08 ` Mike Gerwitz
2018-01-16 10:04 ` Pjotr Prins
2018-01-12 7:39 ` Chris Marusich
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