From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Stephen Hemminger <stephen@networkplumber.org>,
Roland Dreier <roland@kernel.org>,
Linus Walleij <linus.walleij@linaro.org>,
Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
ksummit@lists.linux.dev
Subject: Re: [TECH TOPIC] Rust for Linux
Date: Thu, 8 Jul 2021 00:02:03 +0300 [thread overview]
Message-ID: <YOYWS+WFBrJt0cbf@pendragon.ideasonboard.com> (raw)
In-Reply-To: <22460501-fe09-f8e7-1051-b6b692500859@acm.org>
On Wed, Jul 07, 2021 at 01:32:36PM -0700, Bart Van Assche wrote:
> On 7/7/21 11:57 AM, Linus Torvalds wrote:
> > On Tue, Jul 6, 2021 at 7:41 PM Bart Van Assche <bvanassche@acm.org> wrote:
> >> As a sidenote, I'm surprised that C++ is not supported for Linux kernel
> >> code since C++ supports multiple mechanisms [..]
> >
> > You'd have to get rid of some of the complete garbage from C++ for it
> > to be usable.
> >
> > One of the trivial ones is "new" - not only is it a horribly stupid
> > namespace violation, but it depends on exception handling that isn't
> > viable for the kernel, so it's a namespace violation that has no
> > upsides, only downsides.
> >
> > Could we fix it with some kind of "-Dnew=New" trickery? Yes, but
> > considering all the other issues, it's just not worth the pain. C++ is
> > simply not a good language. It doesn't fix any of the fundamental
> > issues in C (ie no actual safety), and instead it introduces a lot of
> > new problems due to bad designs.
>
> Hi Linus,
>
> Thank you for having shared your opinion. You may want to know that
> every C++ project I have worked on so far enabled at least the following
> compiler flags: -fno-exceptions and -fno-rtti.
>
> What the C++ operator new does if not enough memory is available depends
> on the implementation of that operator. We could e.g. modify the
> behavior of operator new as follows:
Or we could forbid usage of new() and require different memory
allocation primitives. The kernel doesn't use malloc() either :-)
> - Add -fno-builtin-new to the compiler flags.
> - Define a custom version of operator new.
>
> An example (user space code):
>
> include <stdlib.h>
> #include <stdio.h>
>
> void *operator new(size_t size)
> {
> printf("%s\n", __func__);
> return malloc(size);
> }
>
> void operator delete(void *p)
> {
> printf("%s\n", __func__);
> free(p);
> }
>
> void operator delete(void *p, size_t size)
> {
> printf("%s\n", __func__);
> free(p);
> }
>
> void *operator new[](size_t size)
> {
> printf("%s\n", __func__);
> return malloc(size);
> }
>
> void operator delete[](void *p)
> {
> printf("%s\n", __func__);
> free(p);
> }
>
> void operator delete[](void *p, size_t size)
> {
> printf("%s\n", __func__);
> free(p);
> }
>
> int main(int, char **)
> {
> int *intp = new int;
> long *arrayp = new long[37];
> delete[] arrayp;
> delete intp;
> return 0;
> }
>
> The output of the above code:
>
> operator new
> operator new []
> operator delete []
> operator delete
--
Regards,
Laurent Pinchart
next prev parent reply other threads:[~2021-07-07 21:02 UTC|newest]
Thread overview: 201+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-25 22:09 [TECH TOPIC] Rust for Linux Miguel Ojeda
2021-07-05 23:51 ` Linus Walleij
2021-07-06 4:30 ` Leon Romanovsky
2021-07-06 9:55 ` Linus Walleij
2021-07-06 10:16 ` Geert Uytterhoeven
2021-07-06 17:59 ` Linus Walleij
2021-07-06 18:36 ` Miguel Ojeda
2021-07-06 19:12 ` Linus Walleij
2021-07-06 21:32 ` Miguel Ojeda
2021-07-07 14:10 ` Arnd Bergmann
2021-07-07 15:28 ` Miguel Ojeda
2021-07-07 15:50 ` Andrew Lunn
2021-07-07 16:34 ` Miguel Ojeda
2021-07-07 16:55 ` Arnd Bergmann
2021-07-07 17:54 ` Miguel Ojeda
2021-07-06 10:22 ` Leon Romanovsky
2021-07-06 14:30 ` Miguel Ojeda
2021-07-06 14:32 ` Miguel Ojeda
2021-07-06 15:03 ` Sasha Levin
2021-07-06 15:33 ` Miguel Ojeda
2021-07-06 15:42 ` Laurent Pinchart
2021-07-06 16:09 ` Mike Rapoport
2021-07-06 18:29 ` Miguel Ojeda
2021-07-06 18:38 ` Laurent Pinchart
2021-07-06 19:45 ` Steven Rostedt
2021-07-06 19:59 ` Miguel Ojeda
2021-07-06 18:53 ` Sasha Levin
2021-07-06 21:50 ` Miguel Ojeda
2021-07-07 4:57 ` Leon Romanovsky
2021-07-07 13:39 ` Alexandre Belloni
2021-07-07 13:50 ` Miguel Ojeda
2021-07-06 18:26 ` Linus Walleij
2021-07-06 19:11 ` Miguel Ojeda
2021-07-06 19:13 ` Johannes Berg
2021-07-06 19:43 ` Miguel Ojeda
2021-07-06 10:20 ` James Bottomley
2021-07-06 14:55 ` Miguel Ojeda
2021-07-06 15:01 ` Sasha Levin
2021-07-06 15:36 ` Miguel Ojeda
2021-07-09 10:02 ` Marco Elver
2021-07-09 16:02 ` Miguel Ojeda
2021-07-06 18:09 ` Linus Walleij
2021-07-06 14:24 ` Miguel Ojeda
2021-07-06 14:33 ` Laurent Pinchart
2021-07-06 14:56 ` Leon Romanovsky
2021-07-06 15:29 ` Miguel Ojeda
2021-07-07 4:38 ` Leon Romanovsky
2021-07-06 20:00 ` Roland Dreier
2021-07-06 20:36 ` Linus Walleij
2021-07-06 22:00 ` Laurent Pinchart
2021-07-07 7:27 ` Julia Lawall
2021-07-07 7:45 ` Greg KH
2021-07-07 7:52 ` James Bottomley
2021-07-07 13:49 ` Miguel Ojeda
2021-07-07 14:08 ` James Bottomley
2021-07-07 15:15 ` Miguel Ojeda
2021-07-07 15:44 ` Greg KH
2021-07-07 17:01 ` Wedson Almeida Filho
2021-07-07 17:20 ` Greg KH
2021-07-07 19:19 ` Wedson Almeida Filho
2021-07-07 20:38 ` Jan Kara
2021-07-07 23:09 ` Wedson Almeida Filho
2021-07-08 6:11 ` Greg KH
2021-07-08 13:36 ` Wedson Almeida Filho
2021-07-08 18:51 ` Greg KH
2021-07-08 19:31 ` Andy Lutomirski
2021-07-08 19:35 ` Geert Uytterhoeven
2021-07-08 21:56 ` Andy Lutomirski
2021-07-08 19:49 ` Linus Walleij
2021-07-08 20:34 ` Miguel Ojeda
2021-07-08 22:13 ` Linus Walleij
2021-07-09 7:24 ` Geert Uytterhoeven
2021-07-19 12:24 ` Wedson Almeida Filho
2021-07-19 13:15 ` Wedson Almeida Filho
2021-07-19 14:02 ` Arnd Bergmann
2021-07-19 14:13 ` Linus Walleij
2021-07-19 21:32 ` Arnd Bergmann
2021-07-19 21:33 ` Arnd Bergmann
2021-07-20 1:46 ` Miguel Ojeda
2021-07-20 6:43 ` Johannes Berg
2021-07-19 14:43 ` Geert Uytterhoeven
2021-07-19 18:24 ` Miguel Ojeda
2021-07-19 18:47 ` Steven Rostedt
2021-07-19 14:54 ` Miguel Ojeda
2021-07-19 17:32 ` Wedson Almeida Filho
2021-07-19 21:31 ` Arnd Bergmann
2021-07-19 17:37 ` Miguel Ojeda
2021-07-19 16:02 ` Vegard Nossum
2021-07-19 17:45 ` Miguel Ojeda
2021-07-19 17:54 ` Miguel Ojeda
2021-07-19 18:06 ` Wedson Almeida Filho
2021-07-19 19:37 ` Laurent Pinchart
2021-07-19 21:09 ` Wedson Almeida Filho
2021-07-20 23:54 ` Laurent Pinchart
2021-07-21 1:33 ` Andy Lutomirski
2021-07-21 1:42 ` Laurent Pinchart
2021-07-21 13:54 ` Linus Walleij
2021-07-21 14:13 ` Wedson Almeida Filho
2021-07-21 14:19 ` Linus Walleij
2021-07-22 11:33 ` Wedson Almeida Filho
2021-07-23 0:45 ` Linus Walleij
2021-07-21 4:39 ` Wedson Almeida Filho
2021-07-23 1:04 ` Laurent Pinchart
2021-07-21 4:23 ` Wedson Almeida Filho
2021-07-23 1:13 ` Laurent Pinchart
2021-07-19 22:57 ` Alexandre Belloni
2021-07-20 7:15 ` Miguel Ojeda
2021-07-20 9:39 ` Alexandre Belloni
2021-07-20 12:10 ` Miguel Ojeda
2021-07-19 13:53 ` Linus Walleij
2021-07-19 14:42 ` Wedson Almeida Filho
2021-07-19 22:16 ` Linus Walleij
2021-07-20 1:20 ` Wedson Almeida Filho
2021-07-20 13:21 ` Andrew Lunn
2021-07-20 13:38 ` Miguel Ojeda
2021-07-20 14:04 ` Andrew Lunn
2021-07-20 13:55 ` Greg KH
2021-07-20 1:21 ` Miguel Ojeda
2021-07-20 16:00 ` Mark Brown
2021-07-20 22:42 ` Linus Walleij
2021-07-19 14:43 ` Miguel Ojeda
2021-07-19 15:15 ` Andrew Lunn
2021-07-19 15:43 ` Miguel Ojeda
2021-07-09 7:03 ` Viresh Kumar
2021-07-09 17:06 ` Mark Brown
2021-07-09 17:43 ` Miguel Ojeda
2021-07-10 9:53 ` Jonathan Cameron
2021-07-10 20:09 ` Kees Cook
2021-07-08 13:55 ` Miguel Ojeda
2021-07-08 14:58 ` Greg KH
2021-07-08 15:02 ` Mark Brown
2021-07-08 16:38 ` Andy Lutomirski
2021-07-08 18:01 ` Greg KH
2021-07-08 18:00 ` Miguel Ojeda
2021-07-08 18:44 ` Greg KH
2021-07-08 23:09 ` Miguel Ojeda
2021-07-08 7:20 ` Geert Uytterhoeven
2021-07-08 13:41 ` Wedson Almeida Filho
2021-07-08 13:43 ` Geert Uytterhoeven
2021-07-08 13:54 ` Wedson Almeida Filho
2021-07-08 14:16 ` Geert Uytterhoeven
2021-07-08 14:24 ` Wedson Almeida Filho
2021-07-09 7:04 ` Jerome Glisse
2021-07-08 14:04 ` Miguel Ojeda
2021-07-08 14:18 ` Geert Uytterhoeven
2021-07-08 14:28 ` Miguel Ojeda
2021-07-08 14:33 ` Geert Uytterhoeven
2021-07-08 14:35 ` Miguel Ojeda
2021-07-09 11:55 ` Geert Uytterhoeven
2021-07-08 16:07 ` Andy Lutomirski
2021-07-07 20:58 ` Miguel Ojeda
2021-07-07 21:47 ` Laurent Pinchart
2021-07-07 22:44 ` Miguel Ojeda
2021-07-07 17:01 ` Miguel Ojeda
2021-07-07 10:50 ` Mark Brown
2021-07-07 10:56 ` Julia Lawall
2021-07-07 11:27 ` James Bottomley
2021-07-07 11:34 ` James Bottomley
2021-07-07 12:20 ` Greg KH
2021-07-07 12:38 ` James Bottomley
2021-07-07 12:45 ` Greg KH
2021-07-07 17:17 ` Laurent Pinchart
2021-07-08 6:49 ` cdev/devm_* issues (was Re: [TECH TOPIC] Rust for Linux) Greg KH
2021-07-08 8:23 ` Laurent Pinchart
2021-07-08 23:06 ` Linus Walleij
2021-07-09 0:02 ` Dan Williams
2021-07-09 16:53 ` Wedson Almeida Filho
2021-07-13 8:59 ` Linus Walleij
[not found] ` <CAHp75VfW7PxAyU=eYPNWFU_oUY=aStz-4W5gX87KSo402YhMXQ@mail.gmail.com>
2021-07-21 13:46 ` Linus Walleij
2021-07-21 15:49 ` Andy Shevchenko
2021-07-10 7:09 ` Dan Carpenter
2021-07-12 13:42 ` Jason Gunthorpe
2021-07-15 9:54 ` Daniel Vetter
2021-07-21 9:08 ` Dan Carpenter
2021-07-22 9:56 ` Daniel Vetter
2021-07-22 10:09 ` Dan Carpenter
2021-07-08 9:08 ` [TECH TOPIC] Rust for Linux Mauro Carvalho Chehab
2021-07-10 16:42 ` Laurent Pinchart
2021-07-10 17:18 ` Andy Lutomirski
2021-07-07 15:17 ` Mark Brown
2021-07-06 21:45 ` Bart Van Assche
2021-07-06 23:08 ` Stephen Hemminger
2021-07-07 2:41 ` Bart Van Assche
2021-07-07 18:57 ` Linus Torvalds
2021-07-07 20:32 ` Bart Van Assche
2021-07-07 20:39 ` Linus Torvalds
2021-07-07 21:40 ` Laurent Pinchart
2021-07-08 7:22 ` Geert Uytterhoeven
2021-07-07 21:02 ` Laurent Pinchart [this message]
2021-07-07 22:11 ` Miguel Ojeda
2021-07-07 22:43 ` Laurent Pinchart
2021-07-07 23:21 ` Miguel Ojeda
2021-07-07 23:40 ` Laurent Pinchart
2021-07-08 0:27 ` Miguel Ojeda
2021-07-08 0:56 ` Laurent Pinchart
2021-07-08 6:26 ` Alexey Dobriyan
2021-07-06 19:05 ` Bart Van Assche
2021-07-06 19:27 ` Miguel Ojeda
2021-07-07 15:48 ` Steven Rostedt
2021-07-07 16:44 ` Miguel Ojeda
2023-08-07 10:03 Miguel Ojeda
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=YOYWS+WFBrJt0cbf@pendragon.ideasonboard.com \
--to=laurent.pinchart@ideasonboard.com \
--cc=bvanassche@acm.org \
--cc=ksummit@lists.linux.dev \
--cc=linus.walleij@linaro.org \
--cc=miguel.ojeda.sandonis@gmail.com \
--cc=roland@kernel.org \
--cc=stephen@networkplumber.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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).