git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / Atom feed
From: Jeff King <peff@peff.net>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: Thomas Braun <thomas.braun@virtuell-zuhause.de>,
	Duy Nguyen <pclouds@gmail.com>,
	Junio C Hamano <gitster@pobox.com>,
	Jeffrey Walton <noloader@gmail.com>,
	Todd Zullinger <tmz@pobox.com>, Git List <git@vger.kernel.org>,
	Marc Stevens <marc@marc-stevens.nl>
Subject: Re: disabling sha1dc unaligned access, was Re: One failed self test on Fedora 29
Date: Tue, 12 Mar 2019 17:01:25 -0400
Message-ID: <20190312210124.GA5025@sigill.intra.peff.net> (raw)
In-Reply-To: <87y35kb8ft.fsf@evledraar.gmail.com>

On Tue, Mar 12, 2019 at 01:09:42PM +0100, Ævar Arnfjörð Bjarmason wrote:

> > To be clear, I do sympathize with the notion that not pulling things
> > in-tree keeps our relationship with upstream more disciplined, and that
> > has value. I'm just not altogether clear how much it's really hurt us
> > overall to be undisciplined.
> 
> I agree that say the compat/regex divergence hasn't hurt us much if at
> all. Just that we have a few conflicting desires:
> 
>  A. Make sure you can "make" git by default without pulling down a bunch
>     of libraries, especially if they're not ubiquitous. Thus shipping
>     the likes of sha1dc.
> 
>  B. Being able to hotfix those libraries.
> 
>  C. Upstreaming those hotfixes when they happen.
> 
>  D. Updating the library we pulled in due to "A" from upstream.
> 
> In practice because we've wanted "A" we've felt the need to do "B", but
> then also not "C" without ever having the discussion that skipping that
> part was a good idea, and as a result "D" is hard.
> 
> Do we urgently need "D"? No. I'm just pointing out that in addition to
> optimzing for "B" being easy we should also weigh being good free
> software citizens and coordinate fixes with upstream, which also makes a
> future "D" easier.

Yeah, I think your mental model there makes some sense.

> Also, while I don't know of any bugs in compat/regex. I think it's a bit
> concerning that we're carrying 2010-era code for something like the
> regex engine that we expose e.g. over gitweb.

TBH, I think it's probably a bad idea to open any version of that code
to untrusted people, because it's easy to write a DoS regex against it.
There are libraries (like re2) that would be a better fit (I seem to
recall that there may be some DFA-only support in pcre, too, but I
haven't looked at it in a long time; if there is, it might be a sane
gitweb feature to only expose that engine).

-Peff

  reply	other threads:[~2019-03-12 21:01 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-08 10:48 Jeffrey Walton
2019-03-08 17:43 ` Todd Zullinger
2019-03-09 12:34   ` Jeffrey Walton
2019-03-09 13:12     ` Jeffrey Walton
2019-03-11  2:00       ` Junio C Hamano
2019-03-11  2:16         ` Jeffrey Walton
2019-03-11  3:37         ` disabling sha1dc unaligned access, was " Jeff King
2019-03-11 10:40           ` Jeffrey Walton
2019-03-11 18:19             ` Jeff King
2019-03-11 11:58           ` Duy Nguyen
2019-03-11 18:15             ` Thomas Braun
2019-03-11 18:23               ` Jeff King
2019-03-12  7:27                 ` Junio C Hamano
2019-03-12 10:51                   ` Jeff King
2019-03-13 11:47                     ` Thomas Braun
2019-03-13 15:39                       ` Jeff King
2019-03-13 16:00                         ` Ævar Arnfjörð Bjarmason
2019-03-12  8:53                 ` Ævar Arnfjörð Bjarmason
2019-03-12 11:05                   ` Jeff King
2019-03-12 12:09                     ` Ævar Arnfjörð Bjarmason
2019-03-12 21:01                       ` Jeff King [this message]
2019-03-12 21:06           ` [PATCH] Makefile: fix unaligned loads in sha1dc with UBSan Jeff King
2019-03-12 21:17             ` Ævar Arnfjörð Bjarmason
2019-03-12 21:19               ` Jeff King
2019-03-11  3:29     ` One failed self test on Fedora 29 Jeff King

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190312210124.GA5025@sigill.intra.peff.net \
    --to=peff@peff.net \
    --cc=avarab@gmail.com \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --cc=marc@marc-stevens.nl \
    --cc=noloader@gmail.com \
    --cc=pclouds@gmail.com \
    --cc=thomas.braun@virtuell-zuhause.de \
    --cc=tmz@pobox.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

git@vger.kernel.org list mirror (unofficial, one of many)

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://public-inbox.org/git
	git clone --mirror http://ou63pmih66umazou.onion/git
	git clone --mirror http://czquwvybam4bgbro.onion/git
	git clone --mirror http://hjrcffqmbrq6wope.onion/git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V1 git git/ https://public-inbox.org/git \
		git@vger.kernel.org
	public-inbox-index git

Example config snippet for mirrors.
Newsgroups are available over NNTP:
	nntp://news.public-inbox.org/inbox.comp.version-control.git
	nntp://ou63pmih66umazou.onion/inbox.comp.version-control.git
	nntp://czquwvybam4bgbro.onion/inbox.comp.version-control.git
	nntp://hjrcffqmbrq6wope.onion/inbox.comp.version-control.git
	nntp://news.gmane.io/gmane.comp.version-control.git
 note: .onion URLs require Tor: https://www.torproject.org/

code repositories for the project(s) associated with this inbox:

	https://80x24.org/mirrors/git.git

AGPL code for this site: git clone https://public-inbox.org/public-inbox.git