netdev - Re: [RFC PATCH] ethtool: add FEC bins histogramm report

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <424e38be-127d-49d8-98bf-1b4a2075d710@linux.dev>
Date: Tue, 29 Jul 2025 19:07:59 +0100
From: Vadim Fedorenko <vadim.fedorenko@...ux.dev>
To: Andrew Lunn <andrew@...n.ch>
Cc: Michael Chan <michael.chan@...adcom.com>,
 Pavan Chebbi <pavan.chebbi@...adcom.com>, Tariq Toukan <tariqt@...dia.com>,
 Gal Pressman <gal@...dia.com>, intel-wired-lan@...ts.osuosl.org,
 Donald Hunter <donald.hunter@...il.com>, Jakub Kicinski <kuba@...nel.org>,
 Paolo Abeni <pabeni@...hat.com>, Simon Horman <horms@...nel.org>,
 netdev@...r.kernel.org
Subject: Re: [RFC PATCH] ethtool: add FEC bins histogramm report

On 29/07/2025 18:31, Andrew Lunn wrote:
>> The only one bin will have negative value is the one to signal the end
>> of the list of the bins, which is not actually put into netlink message.
>> It actually better to change spec to have unsigned values, I believe.
> 
> Can any of these NICs send runt packets? Can any send packets without
> an ethernet header and FCS?
> 
> Seems to me, the bin (0,0) is meaningless, so can could be considered
> the end marker. You then have unsigned everywhere, keeping it KISS.

I had to revisit the 802.3df-2024, and it looks like you are right:
"FEC_codeword_error_bin_i, where i=1 to 15, are optional 32-bit
counters. While align_status is true, for each codeword received with
exactly i correctable 10-bit symbols"

That means bin (0,0) doesn't exist according to standard, so we can use
it as a marker even though some vendors provide this bin as part of
histogram.

Thanks for the feedback!