From: Kevin Hao Date: Tue, 3 Feb 2026 02:18:31 +0000 (+0800) Subject: net: cpsw: Execute ndo_set_rx_mode callback in a work queue X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0b8c878d117319f2be34c8391a77e0f4d5c94d79;p=thirdparty%2Fkernel%2Flinux.git net: cpsw: Execute ndo_set_rx_mode callback in a work queue Commit 1767bb2d47b7 ("ipv6: mcast: Don't hold RTNL for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP.") removed the RTNL lock for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP operations. However, this change triggered the following call trace on my BeagleBone Black board: WARNING: net/8021q/vlan_core.c:236 at vlan_for_each+0x120/0x124, CPU#0: rpcbind/481 RTNL: assertion failed at net/8021q/vlan_core.c (236) Modules linked in: CPU: 0 UID: 997 PID: 481 Comm: rpcbind Not tainted 6.19.0-rc7-next-20260130-yocto-standard+ #35 PREEMPT Hardware name: Generic AM33XX (Flattened Device Tree) Call trace: unwind_backtrace from show_stack+0x28/0x2c show_stack from dump_stack_lvl+0x30/0x38 dump_stack_lvl from __warn+0xb8/0x11c __warn from warn_slowpath_fmt+0x130/0x194 warn_slowpath_fmt from vlan_for_each+0x120/0x124 vlan_for_each from cpsw_add_mc_addr+0x54/0x98 cpsw_add_mc_addr from __hw_addr_ref_sync_dev+0xc4/0xec __hw_addr_ref_sync_dev from __dev_mc_add+0x78/0x88 __dev_mc_add from igmp6_group_added+0x84/0xec igmp6_group_added from __ipv6_dev_mc_inc+0x1fc/0x2f0 __ipv6_dev_mc_inc from __ipv6_sock_mc_join+0x124/0x1b4 __ipv6_sock_mc_join from do_ipv6_setsockopt+0x84c/0x1168 do_ipv6_setsockopt from ipv6_setsockopt+0x88/0xc8 ipv6_setsockopt from do_sock_setsockopt+0xe8/0x19c do_sock_setsockopt from __sys_setsockopt+0x84/0xac __sys_setsockopt from ret_fast_syscall+0x0/0x54 This trace occurs because vlan_for_each() is called within cpsw_ndo_set_rx_mode(), which expects the RTNL lock to be held. Since modifying vlan_for_each() to operate without the RTNL lock is not straightforward, and because ndo_set_rx_mode() is invoked both with and without the RTNL lock across different code paths, simply adding rtnl_lock() in cpsw_ndo_set_rx_mode() is not a viable solution. To resolve this issue, we opt to execute the actual processing within a work queue, following the approach used by the icssg-prueth driver. Please note: To reproduce this issue, I manually reverted the changes to am335x-bone-common.dtsi from commit c477358e66a3 ("ARM: dts: am335x-bone: switch to new cpsw switch drv") in order to revert to the legacy cpsw driver. Fixes: 1767bb2d47b7 ("ipv6: mcast: Don't hold RTNL for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP.") Signed-off-by: Kevin Hao Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260203-bbb-v5-2-ea0ea217a85c@gmail.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c index 54c24cd3d3be..b0e18bdc2c85 100644 --- a/drivers/net/ethernet/ti/cpsw.c +++ b/drivers/net/ethernet/ti/cpsw.c @@ -305,12 +305,19 @@ static int cpsw_purge_all_mc(struct net_device *ndev, const u8 *addr, int num) return 0; } -static void cpsw_ndo_set_rx_mode(struct net_device *ndev) +static void cpsw_ndo_set_rx_mode_work(struct work_struct *work) { - struct cpsw_priv *priv = netdev_priv(ndev); + struct cpsw_priv *priv = container_of(work, struct cpsw_priv, rx_mode_work); struct cpsw_common *cpsw = priv->cpsw; + struct net_device *ndev = priv->ndev; int slave_port = -1; + rtnl_lock(); + if (!netif_running(ndev)) + goto unlock_rtnl; + + netif_addr_lock_bh(ndev); + if (cpsw->data.dual_emac) slave_port = priv->emac_port + 1; @@ -318,7 +325,7 @@ static void cpsw_ndo_set_rx_mode(struct net_device *ndev) /* Enable promiscuous mode */ cpsw_set_promiscious(ndev, true); cpsw_ale_set_allmulti(cpsw->ale, IFF_ALLMULTI, slave_port); - return; + goto unlock_addr; } else { /* Disable promiscuous mode */ cpsw_set_promiscious(ndev, false); @@ -331,6 +338,18 @@ static void cpsw_ndo_set_rx_mode(struct net_device *ndev) /* add/remove mcast address either for real netdev or for vlan */ __hw_addr_ref_sync_dev(&ndev->mc, ndev, cpsw_add_mc_addr, cpsw_del_mc_addr); + +unlock_addr: + netif_addr_unlock_bh(ndev); +unlock_rtnl: + rtnl_unlock(); +} + +static void cpsw_ndo_set_rx_mode(struct net_device *ndev) +{ + struct cpsw_priv *priv = netdev_priv(ndev); + + schedule_work(&priv->rx_mode_work); } static unsigned int cpsw_rxbuf_total_len(unsigned int len) @@ -1472,6 +1491,7 @@ static int cpsw_probe_dual_emac(struct cpsw_priv *priv) priv_sl2->ndev = ndev; priv_sl2->dev = &ndev->dev; priv_sl2->msg_enable = netif_msg_init(debug_level, CPSW_DEBUG); + INIT_WORK(&priv_sl2->rx_mode_work, cpsw_ndo_set_rx_mode_work); if (is_valid_ether_addr(data->slave_data[1].mac_addr)) { memcpy(priv_sl2->mac_addr, data->slave_data[1].mac_addr, @@ -1653,6 +1673,7 @@ static int cpsw_probe(struct platform_device *pdev) priv->dev = dev; priv->msg_enable = netif_msg_init(debug_level, CPSW_DEBUG); priv->emac_port = 0; + INIT_WORK(&priv->rx_mode_work, cpsw_ndo_set_rx_mode_work); if (is_valid_ether_addr(data->slave_data[0].mac_addr)) { memcpy(priv->mac_addr, data->slave_data[0].mac_addr, ETH_ALEN); @@ -1758,6 +1779,8 @@ clean_runtime_disable_ret: static void cpsw_remove(struct platform_device *pdev) { struct cpsw_common *cpsw = platform_get_drvdata(pdev); + struct net_device *ndev; + struct cpsw_priv *priv; int i, ret; ret = pm_runtime_resume_and_get(&pdev->dev); @@ -1770,9 +1793,15 @@ static void cpsw_remove(struct platform_device *pdev) return; } - for (i = 0; i < cpsw->data.slaves; i++) - if (cpsw->slaves[i].ndev) - unregister_netdev(cpsw->slaves[i].ndev); + for (i = 0; i < cpsw->data.slaves; i++) { + ndev = cpsw->slaves[i].ndev; + if (!ndev) + continue; + + priv = netdev_priv(ndev); + unregister_netdev(ndev); + disable_work_sync(&priv->rx_mode_work); + } cpts_release(cpsw->cpts); cpdma_ctlr_destroy(cpsw->dma);