From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 615F12BD5B9; Wed, 20 May 2026 17:45:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299110; cv=none; b=KY6Cvi1v/to1H4jZWiEANgBP/B+QV495tElP5luchHlcY6CpjbTB+5HITtPFZatmEAMM+EUwqXl/jOlU9JHtDQ4GEZv96L/n3rd/F6UIvtT/HAS6YMgsFPzzZZLaii7Z8O2AI2AekEpLgUtlA+NNGM0DAhjXojbSq631TK5QJp4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299110; c=relaxed/simple; bh=8K66T0PXzYmD5gWT9lHDtK9rDv8nirpXiAArZlAtIco=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Nff+Se8cQEaHVfPJPGrXK6J0RZpAQK9BWCjSFpwLv/wJ1DjbGRev9Wu/GPO67cJjQzQVlGsie+8XptpUIVxqarrxnrIHw64wnfB/pUNlVBFOHVpJE2VjpHvaworV0Wp1tmoSylf7kMKCB0+IRLk01rJaFDxQJyXM4LA2CO+W/B4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EvGv04ff; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="EvGv04ff" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91AA71F000E9; Wed, 20 May 2026 17:45:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779299109; bh=39kPdvTN+/2QAbpC62sj2GxxJdbglc3F7SNN+jtEx+g=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=EvGv04ff1/1N2MEfu45Ahd9ub5/+yilm8v2eq8WB0uTx2Ukbskuor4bJs8DLRs28j rsRBQkXWjHoVu+GNFteR/VQRLTWxawM9ZeJburd3AzV5KvhmoYgRGzQiSa32Y10/eF iUVQvhp4pg0PR+gvcxOpvPqjXgQ0P33rliq/5Zdw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stanislav Fomichev , Maxime Chevallier , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 624/957] net: dsa: remove redundant netdev_lock_ops() from conduit ethtool ops Date: Wed, 20 May 2026 18:18:27 +0200 Message-ID: <20260520162148.062461498@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162134.554764788@linuxfoundation.org> References: <20260520162134.554764788@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stanislav Fomichev [ Upstream commit 0f99e0c3e19badaf3fdced0d3feba623e59eed41 ] DSA replaces the conduit (master) device's ethtool_ops with its own wrappers that aggregate stats from both the conduit and DSA switch ports. Taking the lock again inside the DSA wrappers causes a deadlock. Stumbled upon this when booting qemu with fbnic and CONFIG_NET_DSA_LOOP=y (which looks like some kind of testing device that auto-populates the ports of eth0). `ethtool -i` is enough to deadlock. This means we have basically zero coverage for DSA stuff with real ops locked devs. Remove the redundant netdev_lock_ops()/netdev_unlock_ops() calls from the DSA conduit ethtool wrappers. Fixes: 2bcf4772e45a ("net: ethtool: try to protect all callback with netdev instance lock") Signed-off-by: Stanislav Fomichev Reviewed-by: Maxime Chevallier Link: https://patch.msgid.link/20260414231035.1917035-1-sdf@fomichev.me Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/dsa/conduit.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) diff --git a/net/dsa/conduit.c b/net/dsa/conduit.c index a1b044467bd6f..8398d72d7e4d3 100644 --- a/net/dsa/conduit.c +++ b/net/dsa/conduit.c @@ -27,9 +27,7 @@ static int dsa_conduit_get_regs_len(struct net_device *dev) int len; if (ops && ops->get_regs_len) { - netdev_lock_ops(dev); len = ops->get_regs_len(dev); - netdev_unlock_ops(dev); if (len < 0) return len; ret += len; @@ -60,15 +58,11 @@ static void dsa_conduit_get_regs(struct net_device *dev, int len; if (ops && ops->get_regs_len && ops->get_regs) { - netdev_lock_ops(dev); len = ops->get_regs_len(dev); - if (len < 0) { - netdev_unlock_ops(dev); + if (len < 0) return; - } regs->len = len; ops->get_regs(dev, regs, data); - netdev_unlock_ops(dev); data += regs->len; } @@ -115,10 +109,8 @@ static void dsa_conduit_get_ethtool_stats(struct net_device *dev, int count, mcount = 0; if (ops && ops->get_sset_count && ops->get_ethtool_stats) { - netdev_lock_ops(dev); mcount = ops->get_sset_count(dev, ETH_SS_STATS); ops->get_ethtool_stats(dev, stats, data); - netdev_unlock_ops(dev); } list_for_each_entry(dp, &dst->ports, list) { @@ -149,10 +141,8 @@ static void dsa_conduit_get_ethtool_phy_stats(struct net_device *dev, if (count >= 0) phy_ethtool_get_stats(dev->phydev, stats, data); } else if (ops && ops->get_sset_count && ops->get_ethtool_phy_stats) { - netdev_lock_ops(dev); count = ops->get_sset_count(dev, ETH_SS_PHY_STATS); ops->get_ethtool_phy_stats(dev, stats, data); - netdev_unlock_ops(dev); } if (count < 0) @@ -176,13 +166,11 @@ static int dsa_conduit_get_sset_count(struct net_device *dev, int sset) struct dsa_switch_tree *dst = cpu_dp->dst; int count = 0; - netdev_lock_ops(dev); if (sset == ETH_SS_PHY_STATS && dev->phydev && (!ops || !ops->get_ethtool_phy_stats)) count = phy_ethtool_get_sset_count(dev->phydev); else if (ops && ops->get_sset_count) count = ops->get_sset_count(dev, sset); - netdev_unlock_ops(dev); if (count < 0) count = 0; @@ -239,7 +227,6 @@ static void dsa_conduit_get_strings(struct net_device *dev, u32 stringset, struct dsa_switch_tree *dst = cpu_dp->dst; int count, mcount = 0; - netdev_lock_ops(dev); if (stringset == ETH_SS_PHY_STATS && dev->phydev && !ops->get_ethtool_phy_stats) { mcount = phy_ethtool_get_sset_count(dev->phydev); @@ -253,7 +240,6 @@ static void dsa_conduit_get_strings(struct net_device *dev, u32 stringset, mcount = 0; ops->get_strings(dev, stringset, data); } - netdev_unlock_ops(dev); list_for_each_entry(dp, &dst->ports, list) { if (!dsa_port_is_dsa(dp) && !dsa_port_is_cpu(dp)) -- 2.53.0