LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Willy Tarreau <w@1wt.eu>
To: Michal Kubecek <mkubecek@suse.cz>
Cc: linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	ojeda@kernel.org, Linus Torvalds <torvalds@linux-foundation.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	rust-for-linux@vger.kernel.org, linux-kbuild@vger.kernel.org,
	linux-doc@vger.kernel.org
Subject: Re: [PATCH 00/13] [RFC] Rust support
Date: Fri, 16 Apr 2021 11:29:44 +0200
Message-ID: <20210416092944.GB8790@1wt.eu> (raw)
In-Reply-To: <20210416081605.3m4apyornouf5p5s@lion.mk-sys.cz>

On Fri, Apr 16, 2021 at 10:16:05AM +0200, Michal Kubecek wrote:
> And I don't see how the two languages might coexist peacefully without
> rust toolchain being necessary for building any kernel useful in
> practice and anyone seriously involved in kernel development having to
> be proficient in both languages.

Two languages ? No, one is specified and multiple-implemented, the other
one is the defined as what its only compiler understands at the moment,
so it's not a language, it's a compiler's reference manual at best. I'm
waiting for the day you're force to write things which look wrong with a
big comment around saying "it's not a bug it's a workaround for a bug in
the unique compiler, waiting to be retrofitted into the spec to solve the
problem for every user". Already seen for at least another "language"
implemented by a single vendor 22 years ago.

> Neither of these looks appealing to me.
> 
> The dependency on rust toolchain was exactly what made me give up on
> building Firefox from mercurial snapshots few years ago. To be able to
> build them, one needed bleeding edge snapshots of rust toolchain which
> my distribution couldn't possibly provide and building them myself
> required way too much effort. This very discussion already revealed that
> rust kernel code would provide similar experience. I also have my doubts
> about the "optional" part; once there are some interesting drivers
> written in rust, even if only in the form of out of tree modules, there
> will be an enormous pressure on distributions, both community and
> enterprise, to enable rust support.

Yes this scarily looks like the usual "embrace and extend... and abandon
the corpse once it doesn't move anymore".

I've already faced situations where I couldn't compile a recent 5.x kernel
using my previous gcc-4.7 compiler and this really really really pissed me
off because I'd had it in a build farm for many architectures and I had to
give up. But I also know that updating to a newer version will take time,
will be durable and will be worth it for the long term (except for the fact
that gcc doubles the build time every two versions). But here having to use
*the* compiler of the day and being prepared to keep a collection of them
to work with different stable kernels, no!

Also, I'm a bit worried about long-term survival of the new
language-of-the-day-that-makes-you-look-cool-at-beer-events. I was once
told perl would replace C everywhere. Does someone use it outside of
checkpatch.pl anymore ? Then I was told that C was dead because PHP was
appearing everywhere. I've even seen (slow) log processors written with
it. Now PHP seems to only be a WAF-selling argument. Then Ruby was "safe"
and would rule them all. Safe as its tab[-1] which crashed the interpreter.
Anyone heard of it recently ? Then Python, whose 2.7 is still present on
a lot of systems because the forced transition to 3 broke tons of code.
Will there ever be a 4 after this sore experience ? Then JS, Rust, Go,
Zig and I don't know what. What I'm noting is that such languages appear,
serve a purpose well, have their moment of fame, last a decade and
disappear except at a few enthousiasts. C has been there for 50 years
and served as the basis of many newer languages so it's still well
understood. I'm sure about one thing, the C bugs we have today will be
fixable in 20 years. I'm not even sure the Rust code we'll merge today
will still be compilable in 10 years nor will support the relevant
architectures available by then, and probably this code will have to
be rewritten in C to become maintained again.

> The other problem is even worse. Once we have non-trivial amount of rust
> code around the tree, even if it's "just some drivers", you cannot
> completely ignore it. One example would be internal API changes. Today,
> if I want to touch e.g. ethtool_ops, I need to adjust all in tree NIC
> drivers providing the affected callback and adjust them. Usually most of
> the patch is generated by spatch but manual tweaks are often needed here
> and there. In the world of bilingual kernel with nontrivial number of
> NIC drivers written in rust, I don't see how I could do that without
> also being proficient in rust.

You'll simply change the code you're able to change and those in charge
of their driver will use your commit message as instruction to fix the
build on theirs. How do you want it to be otherwise ?

> Rust enthusiasts tell us they want to
> open kernel development to more people but the result could as well be
> exactly the opposite: it could restrict kernel development to people
> proficient in _both_ languages.

This has been my understanding from the very beginning. Language prophets
always want to conquier very visible targets as a gauge of their baby's
popularity.

> As Peter said, it's not an imminent problem but as it's obvious this is
> just the first step, we should have a clear idea what the plan is and
> what we can and should expect.

I think the experience could be... interesting. However, I do note that
I've read quite a few claims about better security yada yada due to a
stricter memory model. Except that I seem to have understood that a lot
of code will have to run in unsafe mode (which partially voids some of
the benefits), that we'll be at the mercy of the unique compiler's bugs,
and that in addition code auditing will be very hard and reviews of the
boundaries between the two languages almost inexistent. This is precisely
what will become the new playground of attackers, and I predict a
significant increase of vulnerabilities past this point. Time will tell,
hoping it's never too late to rollback if it gets crazy. As long as the
code remains readable, it could be rewritten in C to regain control...

> Michal

Willy

  reply index

Thread overview: 186+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-14 18:45 ojeda
2021-04-14 18:45 ` [PATCH 01/13] kallsyms: Support "big" kernel symbols (2-byte lengths) ojeda
2021-04-14 19:44   ` Matthew Wilcox
2021-04-14 19:59     ` Miguel Ojeda
2021-04-14 18:45 ` [PATCH 02/13] kallsyms: Increase maximum kernel symbol length to 512 ojeda
2021-04-14 23:48   ` Nick Desaulniers
2021-04-14 18:45 ` [PATCH 03/13] Makefile: Generate CLANG_FLAGS even in GCC builds ojeda
2021-04-14 18:59   ` Nathan Chancellor
2021-04-15 10:18     ` Miguel Ojeda
2021-04-14 23:46   ` Nick Desaulniers
2021-04-15  0:47     ` Miguel Ojeda
2021-04-14 18:45 ` [PATCH 04/13] Kbuild: Rust support ojeda
2021-04-14 23:19   ` Nick Desaulniers
2021-04-15  0:43     ` Miguel Ojeda
2021-04-15 18:03       ` Nick Desaulniers
2021-04-16 12:23         ` Miguel Ojeda
2021-04-17 19:35       ` Masahiro Yamada
2021-04-16 13:38   ` Peter Zijlstra
2021-04-16 17:05     ` Linus Torvalds
2021-04-16 17:47       ` Miguel Ojeda
2021-04-16 18:09         ` Al Viro
2021-04-16 18:57           ` Miguel Ojeda
2021-04-16 20:22             ` Willy Tarreau
2021-04-16 20:34               ` Connor Kuehl
2021-04-16 20:58                 ` Willy Tarreau
2021-04-16 21:39                   ` Miguel Ojeda
2021-04-16 22:04                     ` Willy Tarreau
2021-04-16 22:45                       ` Al Viro
2021-04-16 23:46                       ` Miguel Ojeda
2021-04-17  4:24                         ` Willy Tarreau
2021-04-17 15:38                           ` Miguel Ojeda
2021-04-16 21:19               ` Miguel Ojeda
2021-04-16 17:34     ` Miguel Ojeda
2021-04-19 19:58       ` David Sterba
2021-04-19 20:17         ` Matthew Wilcox
2021-04-19 21:03           ` Miguel Ojeda
2021-04-19 20:54         ` Miguel Ojeda
2021-04-14 18:45 ` [PATCH 05/13] Rust: Compiler builtins crate ojeda
2021-04-14 19:19   ` Linus Torvalds
2021-04-14 19:34     ` Miguel Ojeda
2021-04-14 18:45 ` [PATCH 06/13] Rust: Module crate ojeda
2021-04-14 18:45 ` [PATCH 07/13] Rust: Kernel crate ojeda
2021-04-14 19:31   ` Linus Torvalds
2021-04-14 19:50     ` Miguel Ojeda
2021-04-14 18:45 ` [PATCH 08/13] Rust: Export generated symbols ojeda
2021-04-14 18:46 ` [PATCH 09/13] Samples: Rust examples ojeda
2021-04-14 19:34   ` Linus Torvalds
2021-04-14 19:42     ` Miguel Ojeda
2021-04-14 19:49       ` Matthew Wilcox
2021-04-16 11:46       ` Andrej Shadura
2021-04-14 23:24     ` Nick Desaulniers
2021-04-15  7:10       ` Greg Kroah-Hartman
2021-04-15  7:39         ` Nick Desaulniers
2021-04-15 12:42         ` Miguel Ojeda
2021-04-16 13:07         ` Sven Van Asbroeck
2021-04-16 13:20           ` Greg Kroah-Hartman
2021-04-14 18:46 ` [PATCH 10/13] Documentation: Rust general information ojeda
2021-04-14 22:17   ` Nick Desaulniers
2021-04-14 23:34     ` Miguel Ojeda
2021-04-14 18:46 ` [PATCH 11/13] MAINTAINERS: Rust ojeda
2021-04-14 21:55   ` Nick Desaulniers
2021-04-14 22:02     ` Miguel Ojeda
2021-04-14 22:36   ` Nick Desaulniers
2021-04-14 18:46 ` [PATCH 12/13] Rust: add abstractions for Binder (WIP) ojeda
2021-04-14 18:46 ` [PATCH 13/13] Android: Binder IPC in Rust (WIP) ojeda
2021-04-14 19:44 ` [PATCH 00/13] [RFC] Rust support Linus Torvalds
2021-04-14 20:20   ` Miguel Ojeda
2021-04-15  1:38     ` Kees Cook
2021-04-15  8:26       ` David Laight
2021-04-15 18:08         ` Kees Cook
2021-04-15 12:39       ` Miguel Ojeda
2021-04-14 20:09 ` Matthew Wilcox
2021-04-14 20:21   ` Linus Torvalds
2021-04-14 20:35     ` Josh Triplett
2021-04-14 22:08     ` David Laight
2021-04-14 20:29   ` Miguel Ojeda
2021-04-18 15:31   ` Wedson Almeida Filho
2021-04-15  0:22 ` Nick Desaulniers
2021-04-15 10:05   ` Miguel Ojeda
2021-04-15 18:58 ` Peter Zijlstra
2021-04-16  2:22   ` Wedson Almeida Filho
2021-04-16  4:25     ` Al Viro
2021-04-16  5:02       ` Wedson Almeida Filho
2021-04-16  5:39         ` Paul Zimmerman
2021-04-16  7:46         ` Peter Zijlstra
2021-04-16  7:09     ` Peter Zijlstra
2021-04-17  5:23       ` comex
2021-04-17 12:46       ` David Laight
2021-04-17 14:51       ` Paolo Bonzini
2021-04-19  7:32         ` Peter Zijlstra
2021-04-19  7:53           ` Paolo Bonzini
2021-04-19  8:26             ` Peter Zijlstra
2021-04-19  8:35               ` Peter Zijlstra
2021-04-19  9:02               ` Paolo Bonzini
2021-04-19  9:36                 ` Peter Zijlstra
2021-04-19  9:40                   ` Paolo Bonzini
2021-04-19 11:01                     ` Will Deacon
2021-04-19 17:14                   ` Linus Torvalds
2021-04-19 18:38                     ` Paolo Bonzini
2021-04-19 18:50                       ` Linus Torvalds
2021-04-22 10:03     ` Linus Walleij
2021-04-22 14:09       ` David Laight
2021-04-22 15:24       ` Wedson Almeida Filho
2021-04-26  0:18         ` Linus Walleij
2021-04-26 14:26           ` Miguel Ojeda
2021-04-26 14:40           ` Wedson Almeida Filho
2021-04-26 16:03             ` Miguel Ojeda
2021-04-27 10:54             ` Linus Walleij
2021-04-27 11:13               ` Robin Randhawa
2021-04-29  1:52               ` Wedson Almeida Filho
2021-04-26 18:01           ` Miguel Ojeda
2021-04-22 21:28       ` Miguel Ojeda
2021-04-26  0:31         ` Linus Walleij
2021-04-26 18:18           ` Miguel Ojeda
2021-04-27 11:13             ` Linus Walleij
2021-04-28  2:51               ` Kyle Strand
2021-04-28  3:10               ` Miguel Ojeda
2021-05-04 21:21                 ` Linus Walleij
2021-05-04 23:30                   ` Miguel Ojeda
2021-05-05 11:34                     ` Linus Walleij
2021-05-05 14:17                       ` Miguel Ojeda
2021-05-05 15:13                         ` Enrico Weigelt, metux IT consult
2021-05-06 12:47                         ` Linus Walleij
2021-05-07 18:23                           ` Miguel Ojeda
2021-04-16  4:27   ` Boqun Feng
2021-04-16  6:04     ` Nick Desaulniers
2021-04-16 18:47       ` Paul E. McKenney
2021-04-19 20:35         ` Nick Desaulniers
2021-04-19 21:37           ` Paul E. McKenney
2021-04-19 22:03           ` Miguel Ojeda
2021-04-16 20:48     ` Josh Triplett
2021-04-16  8:16   ` Michal Kubecek
2021-04-16  9:29     ` Willy Tarreau [this message]
2021-04-16 11:24 ` Peter Zijlstra
2021-04-16 13:07   ` Wedson Almeida Filho
2021-04-16 14:19     ` Peter Zijlstra
2021-04-16 15:04       ` Miguel Ojeda
2021-04-16 15:43         ` Peter Zijlstra
2021-04-16 16:21           ` Miguel Ojeda
2021-04-16 15:33       ` Wedson Almeida Filho
2021-04-16 16:14         ` Willy Tarreau
2021-04-16 17:10           ` Miguel Ojeda
2021-04-16 17:18             ` Peter Zijlstra
2021-04-16 18:08               ` Matthew Wilcox
2021-04-17 11:17                 ` Peter Zijlstra
2021-04-17 11:46                   ` Willy Tarreau
2021-04-17 14:24                     ` Peter Zijlstra
2021-04-17 14:36                       ` Willy Tarreau
2021-04-17 13:46                   ` David Laight
2021-04-16 17:37             ` Willy Tarreau
2021-04-16 17:46               ` Connor Kuehl
2021-04-20  0:24               ` Nick Desaulniers
2021-04-20  3:47                 ` Willy Tarreau
2021-04-20  5:56                 ` Greg Kroah-Hartman
2021-04-20  6:16                   ` Willy Tarreau
2021-04-29 15:38                     ` peter enderborg
2021-04-17 13:53           ` Wedson Almeida Filho
2021-04-17 14:21             ` Willy Tarreau
2021-04-17 15:23               ` Miguel Ojeda
2021-04-18 15:51               ` Wedson Almeida Filho
2021-04-17 12:41       ` David Laight
2021-04-17 13:01         ` Wedson Almeida Filho
2021-04-16 15:03     ` Matthew Wilcox
2021-04-17 13:29       ` Wedson Almeida Filho
2021-04-16 15:58     ` Theodore Ts'o
2021-04-16 16:21       ` Wedson Almeida Filho
2021-04-17 15:11       ` Paolo Bonzini
2021-04-16 14:21   ` Miguel Ojeda
2021-04-17 20:42 ` Richard Weinberger
2021-04-28 18:34 ` Mariusz Ceier
2021-04-28 20:25   ` Nick Desaulniers
2021-04-28 21:21   ` David Laight
2021-04-29 11:14     ` Kajetan Puchalski
2021-04-29 11:25   ` Kajetan Puchalski
2021-04-29 14:06     ` Mariusz Ceier
2021-04-29 14:13       ` Sven Van Asbroeck
2021-04-29 14:26         ` Willy Tarreau
2021-04-29 15:06       ` Al Viro
2021-04-29 16:09         ` Mariusz Ceier
2021-04-30  6:39     ` Thomas Schoebel-Theuer
2021-04-30  8:30       ` David Laight
2021-05-05 13:58       ` Enrico Weigelt, metux IT consult
2021-05-05 14:41         ` Miguel Ojeda
2021-04-29  5:20 Mariusz Ceier
2021-04-29  5:21 Mariusz Ceier
2021-04-29  8:18 ` David Laight

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

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

  git send-email \
    --in-reply-to=20210416092944.GB8790@1wt.eu \
    --to=w@1wt.eu \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mkubecek@suse.cz \
    --cc=ojeda@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rust-for-linux@vger.kernel.org \
    --cc=torvalds@linux-foundation.org \
    /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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git
	git clone --mirror https://lore.kernel.org/lkml/10 lkml/git/10.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


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