hsr_for_each_port is called in many places without holding the RCU read lock, this may trigger warnings on debug kernels like: [ 40.457015] [ T201] WARNING: suspicious RCU usage [ 40.457020] [ T201] 6.17.0-rc2-virtme #1 Not tainted [ 40.457025] [ T201] ----------------------------- [ 40.457029] [ T201] net/hsr/hsr_main.c:137 RCU-list traversed in non-reader section!! [ 40.457036] [ T201] other info that might help us debug this: [ 40.457040] [ T201] rcu_scheduler_active = 2, debug_locks = 1 [ 40.457045] [ T201] 2 locks held by ip/201: [ 40.457050] [ T201] #0: ffffffff93040a40 (&ops->srcu){.+.+}-{0:0}, at: rtnl_link_ops_get+0xf2/0x280 [ 40.457080] [ T201] #1: ffffffff92e7f968 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x5e1/0xb20 [ 40.457102] [ T201] stack backtrace: [ 40.457108] [ T201] CPU: 2 UID: 0 PID: 201 Comm: ip Not tainted 6.17.0-rc2-virtme #1 PREEMPT(full) [ 40.457114] [ T201] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 40.457117] [ T201] Call Trace: [ 40.457120] [ T201] [ 40.457126] [ T201] dump_stack_lvl+0x6f/0xb0 [ 40.457136] [ T201] lockdep_rcu_suspicious.cold+0x4f/0xb1 [ 40.457148] [ T201] hsr_port_get_hsr+0xfe/0x140 [ 40.457158] [ T201] hsr_add_port+0x192/0x940 [ 40.457167] [ T201] ? __pfx_hsr_add_port+0x10/0x10 [ 40.457176] [ T201] ? lockdep_init_map_type+0x5c/0x270 [ 40.457189] [ T201] hsr_dev_finalize+0x4bc/0xbf0 [ 40.457204] [ T201] hsr_newlink+0x3c3/0x8f0 [ 40.457212] [ T201] ? __pfx_hsr_newlink+0x10/0x10 [ 40.457222] [ T201] ? rtnl_create_link+0x173/0xe40 [ 40.457233] [ T201] rtnl_newlink_create+0x2cf/0x750 [ 40.457243] [ T201] ? __pfx_rtnl_newlink_create+0x10/0x10 [ 40.457247] [ T201] ? __dev_get_by_name+0x12/0x50 [ 40.457252] [ T201] ? rtnl_dev_get+0xac/0x140 [ 40.457259] [ T201] ? __pfx_rtnl_dev_get+0x10/0x10 [ 40.457285] [ T201] __rtnl_newlink+0x22c/0xa50 [ 40.457305] [ T201] rtnl_newlink+0x637/0xb20 Fix it by wrapping the call with rcu_read_lock()/rcu_read_unlock(). Fixes: c5a759117210 ("net/hsr: Use list_head (and rcu) instead of array for slave devices.") Signed-off-by: Hangbin Liu --- net/hsr/hsr_device.c | 37 ++++++++++++++++++++++++++++++++----- net/hsr/hsr_main.c | 12 ++++++++++-- net/hsr/hsr_netlink.c | 4 ---- 3 files changed, 42 insertions(+), 11 deletions(-) diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c index 88657255fec1..67955b21b4a4 100644 --- a/net/hsr/hsr_device.c +++ b/net/hsr/hsr_device.c @@ -49,12 +49,15 @@ static bool hsr_check_carrier(struct hsr_port *master) ASSERT_RTNL(); + rcu_read_lock(); hsr_for_each_port(master->hsr, port) { if (port->type != HSR_PT_MASTER && is_slave_up(port->dev)) { + rcu_read_unlock(); netif_carrier_on(master->dev); return true; } } + rcu_read_unlock(); netif_carrier_off(master->dev); @@ -105,9 +108,12 @@ int hsr_get_max_mtu(struct hsr_priv *hsr) struct hsr_port *port; mtu_max = ETH_DATA_LEN; + + rcu_read_lock(); hsr_for_each_port(hsr, port) if (port->type != HSR_PT_MASTER) mtu_max = min(port->dev->mtu, mtu_max); + rcu_read_unlock(); if (mtu_max < HSR_HLEN) return 0; @@ -139,6 +145,7 @@ static int hsr_dev_open(struct net_device *dev) hsr = netdev_priv(dev); + rcu_read_lock(); hsr_for_each_port(hsr, port) { if (port->type == HSR_PT_MASTER) continue; @@ -159,6 +166,7 @@ static int hsr_dev_open(struct net_device *dev) netdev_warn(dev, "%s (%s) is not up; please bring it up to get a fully working HSR network\n", designation, port->dev->name); } + rcu_read_unlock(); if (!designation) netdev_warn(dev, "No slave devices configured\n"); @@ -172,6 +180,8 @@ static int hsr_dev_close(struct net_device *dev) struct hsr_priv *hsr; hsr = netdev_priv(dev); + + rcu_read_lock(); hsr_for_each_port(hsr, port) { if (port->type == HSR_PT_MASTER) continue; @@ -185,6 +195,7 @@ static int hsr_dev_close(struct net_device *dev) break; } } + rcu_read_unlock(); return 0; } @@ -205,10 +216,13 @@ static netdev_features_t hsr_features_recompute(struct hsr_priv *hsr, * may become enabled. */ features &= ~NETIF_F_ONE_FOR_ALL; + + rcu_read_lock(); hsr_for_each_port(hsr, port) features = netdev_increment_features(features, port->dev->features, mask); + rcu_read_unlock(); return features; } @@ -410,14 +424,11 @@ static void hsr_announce(struct timer_list *t) hsr = timer_container_of(hsr, t, announce_timer); - rcu_read_lock(); master = hsr_port_get_hsr(hsr, HSR_PT_MASTER); hsr->proto_ops->send_sv_frame(master, &interval, master->dev->dev_addr); if (is_admin_up(master->dev)) mod_timer(&hsr->announce_timer, jiffies + interval); - - rcu_read_unlock(); } /* Announce (supervision frame) timer function for RedBox @@ -430,7 +441,6 @@ static void hsr_proxy_announce(struct timer_list *t) unsigned long interval = 0; struct hsr_node *node; - rcu_read_lock(); /* RedBOX sends supervisory frames to HSR network with MAC addresses * of SAN nodes stored in ProxyNodeTable. */ @@ -438,6 +448,7 @@ static void hsr_proxy_announce(struct timer_list *t) if (!interlink) goto done; + rcu_read_lock(); list_for_each_entry_rcu(node, &hsr->proxy_node_db, mac_list) { if (hsr_addr_is_redbox(hsr, node->macaddress_A)) continue; @@ -484,6 +495,7 @@ static void hsr_set_rx_mode(struct net_device *dev) hsr = netdev_priv(dev); + rcu_read_lock(); hsr_for_each_port(hsr, port) { if (port->type == HSR_PT_MASTER) continue; @@ -497,6 +509,7 @@ static void hsr_set_rx_mode(struct net_device *dev) break; } } + rcu_read_unlock(); } static void hsr_change_rx_flags(struct net_device *dev, int change) @@ -506,6 +519,7 @@ static void hsr_change_rx_flags(struct net_device *dev, int change) hsr = netdev_priv(dev); + rcu_read_lock(); hsr_for_each_port(hsr, port) { if (port->type == HSR_PT_MASTER) continue; @@ -521,6 +535,7 @@ static void hsr_change_rx_flags(struct net_device *dev, int change) break; } } + rcu_read_unlock(); } static int hsr_ndo_vlan_rx_add_vid(struct net_device *dev, @@ -534,6 +549,7 @@ static int hsr_ndo_vlan_rx_add_vid(struct net_device *dev, hsr = netdev_priv(dev); + rcu_read_lock(); hsr_for_each_port(hsr, port) { if (port->type == HSR_PT_MASTER || port->type == HSR_PT_INTERLINK) @@ -547,6 +563,8 @@ static int hsr_ndo_vlan_rx_add_vid(struct net_device *dev, netdev_err(dev, "add vid failed for Slave-A\n"); if (is_slave_b_added) vlan_vid_del(port->dev, proto, vid); + + rcu_read_unlock(); return ret; } @@ -559,6 +577,8 @@ static int hsr_ndo_vlan_rx_add_vid(struct net_device *dev, netdev_err(dev, "add vid failed for Slave-B\n"); if (is_slave_a_added) vlan_vid_del(port->dev, proto, vid); + + rcu_read_unlock(); return ret; } @@ -568,6 +588,7 @@ static int hsr_ndo_vlan_rx_add_vid(struct net_device *dev, break; } } + rcu_read_unlock(); return 0; } @@ -580,6 +601,7 @@ static int hsr_ndo_vlan_rx_kill_vid(struct net_device *dev, hsr = netdev_priv(dev); + rcu_read_lock(); hsr_for_each_port(hsr, port) { switch (port->type) { case HSR_PT_SLAVE_A: @@ -590,6 +612,7 @@ static int hsr_ndo_vlan_rx_kill_vid(struct net_device *dev, break; } } + rcu_read_unlock(); return 0; } @@ -672,9 +695,13 @@ struct net_device *hsr_get_port_ndev(struct net_device *ndev, struct hsr_priv *hsr = netdev_priv(ndev); struct hsr_port *port; + rcu_read_lock(); hsr_for_each_port(hsr, port) - if (port->type == pt) + if (port->type == pt) { + rcu_read_unlock(); return port->dev; + } + rcu_read_unlock(); return NULL; } EXPORT_SYMBOL(hsr_get_port_ndev); diff --git a/net/hsr/hsr_main.c b/net/hsr/hsr_main.c index 192893c3f2ec..eec6e20a8494 100644 --- a/net/hsr/hsr_main.c +++ b/net/hsr/hsr_main.c @@ -22,9 +22,13 @@ static bool hsr_slave_empty(struct hsr_priv *hsr) { struct hsr_port *port; + rcu_read_lock(); hsr_for_each_port(hsr, port) - if (port->type != HSR_PT_MASTER) + if (port->type != HSR_PT_MASTER) { + rcu_read_unlock(); return false; + } + rcu_read_unlock(); return true; } @@ -134,9 +138,13 @@ struct hsr_port *hsr_port_get_hsr(struct hsr_priv *hsr, enum hsr_port_type pt) { struct hsr_port *port; + rcu_read_lock(); hsr_for_each_port(hsr, port) - if (port->type == pt) + if (port->type == pt) { + rcu_read_unlock(); return port; + } + rcu_read_unlock(); return NULL; } diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c index b120470246cc..f57c289e2322 100644 --- a/net/hsr/hsr_netlink.c +++ b/net/hsr/hsr_netlink.c @@ -241,10 +241,8 @@ void hsr_nl_ringerror(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN], kfree_skb(skb); fail: - rcu_read_lock(); master = hsr_port_get_hsr(hsr, HSR_PT_MASTER); netdev_warn(master->dev, "Could not send HSR ring error message\n"); - rcu_read_unlock(); } /* This is called when we haven't heard from the node with MAC address addr for @@ -278,10 +276,8 @@ void hsr_nl_nodedown(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN]) kfree_skb(skb); fail: - rcu_read_lock(); master = hsr_port_get_hsr(hsr, HSR_PT_MASTER); netdev_warn(master->dev, "Could not send HSR node down\n"); - rcu_read_unlock(); } /* HSR_C_GET_NODE_STATUS lets userspace query the internal HSR node table -- 2.50.1