From: zimoun <zimon.toutoune@gmail.com>
To: "Ludovic Courtès" <ludo@gnu.org>
Cc: 41425@debbugs.gnu.org
Subject: [bug#41425] [PATCH 0/5] Have 'guix pull' protect against downgrade attacks
Date: Mon, 25 May 2020 16:36:52 +0200 [thread overview]
Message-ID: <CAJ3okZ3RrEUKE-iGxf_Z-0Ce_TS-ArKY0Vzq9ddeKaFBsqoybw@mail.gmail.com> (raw)
In-Reply-To: <87r1vc9iqb.fsf@gnu.org>
On Fri, 22 May 2020 at 15:56, Ludovic Courtès <ludo@gnu.org> wrote:
> > It is not easy -- nor impossible -- to evaluate such cost at the level
> > of "guix pull". And I failed to evaluate it using 'commit-relation'
> > with "guix repl" -- Segmentation fault with commit
> > c81457a5883ea43950eb2ecdcbb58a5b144bcd11 and
> > 4bdf4182fe080c3409f6ef9b410146b67cfa2595; probably because I did used
> > correctly the API.
Obviously, one had to read "probably I did *not* used correctly the API". :-)
> How can I reproduce the issue?
--8<---------------cut here---------------start------------->8---
(use-modules (guix git) (guix channels) (guix tests git) (git))
(define url-cache-directory (@@ (guix git) url-cache-directory))
(define dir (url-cache-directory (channel-url (car %default-channels))))
(define merge (with-repository dir repo (find-commit repo "Merge")))
merge
;; $1 = #<git-commit 4bdf4182fe080c3409f6ef9b410146b67cfa2595>
(define left (car (commit-parents merge)))
left
;; $2 = #<git-commit c81457a5883ea43950eb2ecdcbb58a5b144bcd11>
(commit-relation left merge)
Segmentation fault
--8<---------------cut here---------------end--------------->8---
Because of 'commit-closure'.
I do not know if it is the correct use of the API; and because I do
not know how to get easily a commit, I use 'find-commit' which is not
nice.
> > Well, what will be the timing impact of checking the "fast-fowardness"?
>
> I haven’t measured it, but it’s small compared to the cost of fetching
> the new revisions and performing the checkout. It’s roughly what ‘git
> pull’ does, although ‘git pull’ is probably faster because it’s in C and
> has been well optimized over the years.
My "worry" is about the complexity of the graph because
'commit-relation' walks somehow the graph of commits.
Cheers,
simon
next prev parent reply other threads:[~2020-05-25 14:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-20 21:38 [bug#41425] [PATCH 0/5] Have 'guix pull' protect against downgrade attacks Ludovic Courtès
2020-05-20 21:47 ` [bug#41425] [PATCH 1/5] git: Add 'commit-relation' Ludovic Courtès
2020-05-20 21:47 ` [bug#41425] [PATCH 2/5] channels: 'latest-channel-instances' doesn't leak internal state Ludovic Courtès
2020-05-20 21:47 ` [bug#41425] [PATCH 3/5] git: 'update-cached-checkout' returns the commit relation Ludovic Courtès
2020-05-20 21:47 ` [bug#41425] [PATCH 4/5] channels: 'latest-channel-instances' guards against non-forward updates Ludovic Courtès
2020-05-20 21:47 ` [bug#41425] [PATCH 5/5] pull: Protect against downgrade attacks Ludovic Courtès
2020-05-21 14:06 ` [bug#41425] [PATCH 0/5] Have 'guix pull' protect " zimoun
2020-05-22 13:55 ` Ludovic Courtès
2020-05-25 14:36 ` zimoun [this message]
2020-05-27 16:32 ` Ludovic Courtès
2020-05-28 8:06 ` zimoun
2020-05-24 22:02 ` bug#41425: " Ludovic Courtès
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