From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D5B5D32F759 for ; Wed, 4 Feb 2026 04:13:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770178437; cv=none; b=HK06QRkjOSZIS87vUnMNraJivujumEPmW26uCXcj5y6tCYgA8RPJcpjcKv0bs6KR5A0yxV55djgtStjvRskOtjpc2bd/jv0NBqqZwhrj4wkpXbWRZ9l5fCSX4VINcOnh8i9SWmmruu+78v8Bp9xbVhJO6wsWFmN4ngweX8wgjLg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770178437; c=relaxed/simple; bh=KKxKic9bFydxriupw9qy85sFhl9TNgXLirXtszfLGTo=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=oljU2pKkbXgl5+MX82E4P87ZrWVAwE/enK7foeubB9nuFs67QYDXjYxy4h7G2Yet7GY/kxJeQVd17XQ72ceV+G6FCSOF66eyMnV3jNc0ILdWDjQoLoQYZOdaQT6CuGZ8sHgA59swYVlXUZ9MswypKGhrRS4SBjCYnzjiI3uoHDw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GZyRmr68; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GZyRmr68" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A30A3C19425; Wed, 4 Feb 2026 04:13:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770178437; bh=KKxKic9bFydxriupw9qy85sFhl9TNgXLirXtszfLGTo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=GZyRmr68ONxuNJTR/ymLN+QtYyr0puoM1AQolgckMAboauiTtmshkf5NiCeZaOVcM f8N1FUfixFHxP23ORcSb4gUU3Ji19effwfRqOQe3phEaJD5yqXp5xVVgp6xfHzXN1A xgwTG/UUFWc02K8LHpLNDMLDMSOWQlTSq7lRv+UnqHr1sreTaE6mUMYMyMR1e2EC1/ NrLgS+oes2FHHxbMppQRN+MiyyhtAL2nB13Z2b01hU9nmTmTvPu+9JGg9w7CmruXbz YENwJN2gS29LsZQhzoFnREgg6CPTD4CroKHKpnQ9+tlAW7dShI+3R9/o+Bp9vvTd2s g37OiFHsPIH9w== Date: Tue, 3 Feb 2026 20:13:55 -0800 From: Jakub Kicinski To: xuanzhuo@linux.alibaba.com Cc: lorenzo@kernel.org, andrew+netdev@lunn.ch, pabeni@redhat.com, vadim.fedorenko@linux.dev, davem@davemloft.net, guwen@linux.alibaba.com, lulie@linux.alibaba.com, hkallweit1@gmail.com, edumazet@google.com, lukas.bulwahn@redhat.com, andrew@lunn.ch, dong100@mucse.com, dust.li@linux.alibaba.com, netdev@vger.kernel.org Subject: Re: [net-next,v25,6/6] eea: introduce callback for ndo_get_stats64 Message-ID: <20260203201355.675b99cb@kernel.org> In-Reply-To: <20260204040841.1703575-1-kuba@kernel.org> References: <20260202090638.46836-7-xuanzhuo@linux.alibaba.com> <20260204040841.1703575-1-kuba@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 3 Feb 2026 20:08:41 -0800 Jakub Kicinski wrote: > > +static void eea_stats(struct net_device *netdev, struct rtnl_link_stats64 *tot) > > +{ > > + struct eea_net *enet = netdev_priv(netdev); > > + u64 packets, bytes; > > + u32 start; > > + int i; > > + > > + spin_lock_bh(&enet->stats_lock); > > Can this cause a deadlock? The enet_bind_new_q_and_cfg() and > eea_free_rxtx_q_mem() functions use spin_lock(&enet->stats_lock), but > eea_stats() uses spin_lock_bh(&enet->stats_lock). > > If a thread holds stats_lock via spin_lock() (softirqs still enabled) and a > softirq fires that calls eea_stats() through ndo_get_stats64, the > spin_lock_bh() will attempt to acquire the already-held lock. > > Should all acquisition sites use spin_lock_bh()/spin_unlock_bh() for > consistency? AI suggestion is semi-right here, just remove the _bh() I don't think we actually read stats from BH. We read them under RCU, which is atomic context but not BH.