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From: dthaler1968@googlemail.com
To: "'Aoyang Fang \(SSE, 222010547\)'" <aoyangfang@link.cuhk.edu.cn>,
	<bpf@vger.kernel.org>, <bpf@ietf.org>
Cc: <void@manifault.com>
Subject: RE: [PATCH] update the consistency issue in documentation
Date: Thu, 4 Jan 2024 11:12:09 -0800	[thread overview]
Message-ID: <015701da3f41$eaab4d10$c001e730$@gmail.com> (raw)
In-Reply-To: <3A7D0A57-02EF-4ACB-A599-1029CFCA7E74@link.cuhk.edu.cn>

> -----Original Message-----
> From: Aoyang Fang (SSE, 222010547) <aoyangfang@link.cuhk.edu.cn>
> Sent: Wednesday, January 3, 2024 7:13 PM
> To: bpf@vger.kernel.org; bpf@ietf.org
> Cc: void@manifault.com
> Subject: [PATCH] update the consistency issue in documentation
> 
> From fa9f3f47ddeb3e9a615c17aea57d2ecd53a7d201 Mon Sep 17 00:00:00
> 2001
> From: lincyawer <53161583+Lincyaw@users.noreply.github.com>
> Date: Thu, 4 Jan 2024 10:51:36 +0800
> Subject: [PATCH] The original documentation of BPF_JMP instructions is
> somehow misleading. The code part of instruction, e.g., BPF_JEQ's value is
> noted as 0x1, however, in `include/uapi/linux/bpf.h`, the value of BPF_JEQ
is
> 0x10. At the same time, the description convention is inconsistent with
the
> BPF_ALU, whose code are also 4bit, but the value of BPF_ADD is 0x00

https://www.ietf.org/archive/id/draft-ietf-bpf-isa-00.html#section-3 says:
> ==============  ======  =================
> 4 bits (MSB)    1 bit   3 bits (LSB)
> ==============  ======  =================
> code            source  instruction class
> ==============  ======  =================

Hence the code field is 4 bits, and 0x10 cannot fit in a 4 bit field.
The documentation is already internally consistent, and this proposed
change would make the documentation incorrect.

Dave


WARNING: multiple messages have this Message-ID (diff)
From: dthaler1968=40googlemail.com@dmarc.ietf.org
To: "'Aoyang Fang \(SSE, 222010547\)'" <aoyangfang@link.cuhk.edu.cn>,
	<bpf@vger.kernel.org>, <bpf@ietf.org>
Cc: <void@manifault.com>
Subject: Re: [Bpf] [PATCH] update the consistency issue in documentation
Date: Thu, 4 Jan 2024 11:12:09 -0800	[thread overview]
Message-ID: <015701da3f41$eaab4d10$c001e730$@gmail.com> (raw)
Message-ID: <20240104191209.m8Oxd16wAN7CNKg2p7VXUc59X-ktEfR5hyZjnqP2EEM@z> (raw)
In-Reply-To: <3A7D0A57-02EF-4ACB-A599-1029CFCA7E74@link.cuhk.edu.cn>

> -----Original Message-----
> From: Aoyang Fang (SSE, 222010547) <aoyangfang@link.cuhk.edu.cn>
> Sent: Wednesday, January 3, 2024 7:13 PM
> To: bpf@vger.kernel.org; bpf@ietf.org
> Cc: void@manifault.com
> Subject: [PATCH] update the consistency issue in documentation
> 
> From fa9f3f47ddeb3e9a615c17aea57d2ecd53a7d201 Mon Sep 17 00:00:00
> 2001
> From: lincyawer <53161583+Lincyaw@users.noreply.github.com>
> Date: Thu, 4 Jan 2024 10:51:36 +0800
> Subject: [PATCH] The original documentation of BPF_JMP instructions is
> somehow misleading. The code part of instruction, e.g., BPF_JEQ's value is
> noted as 0x1, however, in `include/uapi/linux/bpf.h`, the value of BPF_JEQ
is
> 0x10. At the same time, the description convention is inconsistent with
the
> BPF_ALU, whose code are also 4bit, but the value of BPF_ADD is 0x00

https://www.ietf.org/archive/id/draft-ietf-bpf-isa-00.html#section-3 says:
> ==============  ======  =================
> 4 bits (MSB)    1 bit   3 bits (LSB)
> ==============  ======  =================
> code            source  instruction class
> ==============  ======  =================

Hence the code field is 4 bits, and 0x10 cannot fit in a 4 bit field.
The documentation is already internally consistent, and this proposed
change would make the documentation incorrect.

Dave

-- 
Bpf mailing list
Bpf@ietf.org
https://www.ietf.org/mailman/listinfo/bpf

  parent reply	other threads:[~2024-01-04 19:12 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-04  3:12 [PATCH] update the consistency issue in documentation Aoyang Fang (SSE, 222010547)
2024-01-04  3:12 ` [Bpf] " Aoyang Fang (SSE, 222010547)
2024-01-04 19:12 ` dthaler1968 [this message]
2024-01-04 19:12   ` dthaler1968=40googlemail.com
     [not found]   ` <20654405-C500-4A24-B09E-A28B25DF32AC@link.cuhk.edu.cn>
2024-01-05  1:31     ` dthaler1968
2024-01-05  1:31       ` [Bpf] " dthaler1968=40googlemail.com
     [not found] <F349E672-63EB-4DA3-84F8-45E360E02594@link.cuhk.edu.cn>
2024-01-04  3:39 ` David Vernet

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