Commit 0b8c878d authored by Kevin Hao's avatar Kevin Hao Committed by Jakub Kicinski
Browse files

net: cpsw: Execute ndo_set_rx_mode callback in a work queue 



Commit 1767bb2d ("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 c477358e ("ARM: dts: am335x-bone:
switch to new cpsw switch drv") in order to revert to the legacy cpsw
driver.

Fixes: 1767bb2d ("ipv6: mcast: Don't hold RTNL for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP.")
Signed-off-by: default avatarKevin Hao <haokexin@gmail.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260203-bbb-v5-2-ea0ea217a85c@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent c0b5dc73

drivers/net/ethernet/ti/cpsw.c

+35 −6
Original line number Diff line number Diff line
@@ -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 @@ static int cpsw_probe(struct platform_device *pdev) 
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);