BPF Archive on lore.kernel.org
 help / color / Atom feed
From: Greg KH <gregkh@linuxfoundation.org>
To: "Alejandro Colomar (man-pages)" <alx.manpages@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
	"Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>,
	linux-man <linux-man@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	glibc <libc-alpha@sourceware.org>, GCC <gcc-patches@gcc.gnu.org>,
	bpf <bpf@vger.kernel.org>, David Laight <David.Laight@aculab.com>,
	Zack Weinberg <zackw@panix.com>,
	Joseph Myers <joseph@codesourcery.com>
Subject: Re: [RFC v2] bpf.2: Use standard types and attributes
Date: Tue, 4 May 2021 18:06:26 +0200
Message-ID: <YJFxArfp8wN3ILJb@kroah.com> (raw)
In-Reply-To: <69fb22e0-84bd-47fb-35b5-537a7d39c692@gmail.com>

On Tue, May 04, 2021 at 05:53:29PM +0200, Alejandro Colomar (man-pages) wrote:
> Hi Greg and Alexei,
> 
> > On Tue, May 04, 2021 at 07:12:01AM -0700, Alexei Starovoitov wrote:
> > > For the same reasons as explained earlier:
> > > Nacked-by: Alexei Starovoitov <ast@kernel.org>
> 
> Okay, I'll add that.
> 
> 
> On 5/4/21 4:24 PM, Greg KH wrote:> I agree, the two are not the same type at
> all, this change should not be
> > accepted.
> 
> I get that in the kernel you don't use the standard fixed-width types (with
> some exceptions), probably not to mess with code that relies on <stdint.h>
> not being included (I hope there's not much code that relies on this in
> 2021, but who knows).
> 
> But, there is zero difference between these types, from the point of view of
> the compiler.  There's 100% compatibility between those types, and you're
> able to mix'n'match them.  See some example below.
> 
> Could you please explain why the documentation, which supposedly only
> documents the API and not the internal implementation, should not use
> standard naming conventions?  The standard is much easier to read for
> userspace programmers, which might ignore why the kernel does some things in
> some specific ways.
> 
> BTW, just to clarify, bpf.2 is just a small sample to get reviews; the
> original intention was to replace __uNN by uintNN_t in all of the manual
> pages.

There's a very old post from Linus where he describes the difference
between things like __u32 and uint32_t.  They are not the same, they
live in different namespaces, and worlds, and can not always be swapped
out for each other on all arches.

Dig it up if you are curious, but for user/kernel apis you HAVE to use
the __uNN and can not use uintNN_t variants, so don't try to mix/match
them, it's good to just follow the kernel standard please.

So consider this my:

Nacked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

as well.

thanks,

greg k-h

  reply index

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210423230609.13519-1-alx.manpages@gmail.com>
2021-04-23 23:20 ` [RFC] " Alexei Starovoitov
2021-04-24 17:56   ` Alejandro Colomar (man-pages)
2021-04-25 16:52     ` Alexei Starovoitov
2021-04-25 19:12       ` Zack Weinberg
2021-04-24 20:43   ` David Laight
2021-04-25 19:16     ` Zack Weinberg
2021-04-25 21:09       ` David Laight
2021-05-04 11:05 ` [RFC v2] " Alejandro Colomar
2021-05-04 14:12   ` Alexei Starovoitov
2021-05-04 14:24     ` Greg KH
2021-05-04 15:53       ` Alejandro Colomar (man-pages)
2021-05-04 16:06         ` Greg KH [this message]
2021-05-04 18:37           ` Zack Weinberg
2021-05-04 18:54             ` Alejandro Colomar (man-pages)
2021-05-04 19:45               ` Florian Weimer
2021-05-04 19:59                 ` Alejandro Colomar (man-pages)
2021-05-05  8:23                 ` David Laight
2021-05-05 22:22                   ` Joseph Myers
2021-05-04 20:06               ` Daniel Borkmann
2021-05-04 20:16                 ` Alejandro Colomar (man-pages)
2021-05-04 20:33                 ` Zack Weinberg
2021-05-04 21:23                   ` Alexei Starovoitov
2021-05-15 19:01               ` [PATCH v3] " Alejandro Colomar
2021-05-16  9:16                 ` Alejandro Colomar (man-pages)
2021-05-17 18:56                   ` Daniel Borkmann
2021-05-21 11:12                     ` Alejandro Colomar
2021-05-04 16:08         ` [RFC v2] " Daniel Borkmann

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=YJFxArfp8wN3ILJb@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=David.Laight@aculab.com \
    --cc=alexei.starovoitov@gmail.com \
    --cc=alx.manpages@gmail.com \
    --cc=bpf@vger.kernel.org \
    --cc=gcc-patches@gcc.gnu.org \
    --cc=joseph@codesourcery.com \
    --cc=libc-alpha@sourceware.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-man@vger.kernel.org \
    --cc=mtk.manpages@gmail.com \
    --cc=zackw@panix.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

BPF Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/bpf/0 bpf/git/0.git

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

Example config snippet for mirrors

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


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