From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.tipi-net.de (mail.tipi-net.de [194.13.80.246]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F5B52D7DD8; Wed, 14 Oct 2026 21:03:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.13.80.246 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792011791; cv=none; b=k6T8irF+ZeVWO5RLIa/hELT6fzuC+zNyJRZDNy0VIIIcChSpJ4gccaZOhRvAth+ysT+oVXCXcU6Dt0OZshoAx4YFHRnC+omxrQSkRWt6kBty7fVXI8fCjSQiPWgieNFPhsSXYMP6hjgtNim0asu1PXHkz9IEqnZw1t8betJ9Ado= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792011791; c=relaxed/simple; bh=SqjFtcMUiykXxYPVsn6NLogUDEnJnLN8ZRQiWX6Puok=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=KcwNDTAjWR6B/z2ckhSE4rDSLeOXdjSrEa2szqzCAO2N3j/rL/iZd7wmc9cyNBUmbkICX+CkyBWMlg7UZelgMwomtLBkZPAYvAVxO8aSxiD/3HXcoGpxCmeWyw9onpI8+UF2B7VB0WNMtJxyC4NWTuCl08Jtzuvgr8sRoXt1Eck= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tipi-net.de; spf=pass smtp.mailfrom=tipi-net.de; dkim=pass (2048-bit key) header.d=tipi-net.de header.i=@tipi-net.de header.b=yIkCqM8V; arc=none smtp.client-ip=194.13.80.246 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tipi-net.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tipi-net.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tipi-net.de header.i=@tipi-net.de header.b="yIkCqM8V" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id A5F15A158F; Wed, 14 Oct 2026 23:02:52 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tipi-net.de; s=dkim; t=1792011778; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=SqjFtcMUiykXxYPVsn6NLogUDEnJnLN8ZRQiWX6Puok=; b=yIkCqM8VXYULT4KSbksQvh0J7Tj15J46cr34YtosYI+MjN0Qk5769F9P5w48F1OB0hO8NY pNbnddSbAdW7N+NXrJnwhCD1yKwuI+R8VW88csJuiShpMYw7uFaeel2BUQH4vPdQOhYD28 yvTpcN52JWnyPulsJ+WwN9zZAtkZ4w+5OowTW6E+7A/S8UYV7yxAvT4LXOAh/L6aB8Vzl4 lbDcYE+Hmrw2M7T2zY3ZPtju8277v6m3C2XptLTMAwxS7uQIctI1WXhjCDTxrY+RhrjIPU yXH7MMdMrWrRib0sHpB8eTrNmO9wF+K5NQMpemE2L8DPo7STohPRaJl25S8bOA== Date: Wed, 14 Oct 2026 23:02:52 +0200 From: Nicolai Buchwitz To: Jakub Kicinski CC: "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Oleksij Rempel , Maxime Chevallier , Andrew Lunn , Maxime Coquelin , Alexandre Torgue , Jose Abreu , Saeed Mahameed , Tariq Toukan , Mark Bloch , Leon Romanovsky , Dragos Tatulea , Alexei Lazar , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-rdma@vger.kernel.org Subject: =?US-ASCII?Q?Re=3A_=5BPATCH_net-next_0/3=5D_net=3A_use_skb=5Fs?= =?US-ASCII?Q?hare=5Fcheck=28=29_in_loopback_selftest_hooks?= User-Agent: Thunderbird for Android In-Reply-To: <20261014130618.4c50f817@kernel.org> References: <20261007-nb-net-selftest-shared-net-v1-0-458369bfa1ba@tipi-net.de> <20261014130618.4c50f817@kernel.org> Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Last-TLS-Session-Version: TLSv1.3 Hi Jakub On October 14, 2026 10:06:18 PM GMT+02:00, Jakub Kicinski wrote: >On Wed, 07 Oct 2026 20:29:21 +0200 Nicolai Buchwitz wrote: >> The loopback selftest hooks can get a shared skb when another handler >> is bound to the device=2E Linearizing a non-linear frame then hits >> BUG_ON(skb_shared()) in pskb_expand_head()=2E >>=20 >> Stumbled over this on RPi CM4 (bcmgenet, with jumbo series applied + >> WIP selftest patches) with a packet socket open at the same time as >> running ethtool -t=2E >>=20 >> stmmac and mlx5 seem to have the same pattern, xgbe already handles >> shared skbs=2E Patches 2 and 3 are compile tested only=2E >>=20 >> As the impact is pretty limited and doesn't seem to bother anyone in >> the wild, I've chosen net-next, but kept the Fixes tags=2E That matches >> what Paolo suggested during the LPC track=2E > >Wonder if we should follow up and rename skb_unshare to skb_unclone_full >or some such? The "share" in the name is quite confusing for people who >haven't been around for 10+ years=2E=2E Makes sense=2E _unclone_full still sounds a bit clonky, but I can't think = of a better name right now=2E I will give it a thought and send a follow up= :) Regards, Nicolai