linux-kernel - Re: [PATCH net] netdevsim: set the carrier when the device goes up

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] [day] [month] [year] [list]

Message-ID: <7e1d28c0-7276-448f-8d01-531b7e8bd195@lunn.ch>
Date: Mon, 13 Oct 2025 19:25:27 +0200
From: Andrew Lunn <andrew@...n.ch>
To: Breno Leitao <leitao@...ian.org>
Cc: Jakub Kicinski <kuba@...nel.org>, Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>,
	David Wei <dw@...idwei.uk>, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org, kernel-team@...a.com
Subject: Re: [PATCH net] netdevsim: set the carrier when the device goes up

On Mon, Oct 13, 2025 at 10:09:22AM -0700, Breno Leitao wrote:
> Bringing a linked netdevsim device down and then up causes communication
> failure because both interfaces lack carrier. Basically a ifdown/ifup on
> the interface make the link broken.
> 
> When a device is brought up, if it has a peer and this peer device is
> UP, set both carriers to on.
> 
> Signed-off-by: Breno Leitao <leitao@...ian.org>
> Fixes: 3762ec05a9fbda ("netdevsim: add NAPI support")

It was not obvious what adding NAPI has to do with carrier status.  I
had to go look at 3762ec05a9fbda to see that that was when nsim_stop()
started to change the carrier on stop. This patch makes nsim_open()
somewhat symmetrical. If you need a respin, maybe expand the commit
message to explain this.

Otherwise this looks O.K. to me.

Reviewed-by: Andrew Lunn <andrew@...n.ch>

    Andrew