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authorCong Wang <xiyou.wangcong@gmail.com>2020-06-09 00:53:01 +0300
committerDavid S. Miller <davem@davemloft.net>2020-06-09 22:59:45 +0300
commit845e0ebb4408d4473cf60d21224a897037e9a77a (patch)
tree053282d21248269b50668f920d39ba07b7a0277d /net/core
parent8027bc0307ce59759b90679fa5d8b22949586d20 (diff)
downloadlinux-845e0ebb4408d4473cf60d21224a897037e9a77a.tar.xz
net: change addr_list_lock back to static key
The dynamic key update for addr_list_lock still causes troubles, for example the following race condition still exists: CPU 0: CPU 1: (RCU read lock) (RTNL lock) dev_mc_seq_show() netdev_update_lockdep_key() -> lockdep_unregister_key() -> netif_addr_lock_bh() because lockdep doesn't provide an API to update it atomically. Therefore, we have to move it back to static keys and use subclass for nest locking like before. In commit 1a33e10e4a95 ("net: partially revert dynamic lockdep key changes"), I already reverted most parts of commit ab92d68fc22f ("net: core: add generic lockdep keys"). This patch reverts the rest and also part of commit f3b0a18bb6cb ("net: remove unnecessary variables and callback"). After this patch, addr_list_lock changes back to using static keys and subclasses to satisfy lockdep. Thanks to dev->lower_level, we do not have to change back to ->ndo_get_lock_subclass(). And hopefully this reduces some syzbot lockdep noises too. Reported-by: syzbot+f3a0e80c34b3fc28ac5e@syzkaller.appspotmail.com Cc: Taehee Yoo <ap420073@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/dev.c30
-rw-r--r--net/core/dev_addr_lists.c12
-rw-r--r--net/core/rtnetlink.c1
3 files changed, 22 insertions, 21 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 061496a1f640..6bc2388141f6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -439,6 +439,7 @@ static const char *const netdev_lock_name[] = {
"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
+static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
static inline unsigned short netdev_lock_pos(unsigned short dev_type)
{
@@ -460,11 +461,25 @@ static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
netdev_lock_name[i]);
}
+
+static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
+{
+ int i;
+
+ i = netdev_lock_pos(dev->type);
+ lockdep_set_class_and_name(&dev->addr_list_lock,
+ &netdev_addr_lock_key[i],
+ netdev_lock_name[i]);
+}
#else
static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
unsigned short dev_type)
{
}
+
+static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
+{
+}
#endif
/*******************************************************************************
@@ -9373,15 +9388,6 @@ void netif_tx_stop_all_queues(struct net_device *dev)
}
EXPORT_SYMBOL(netif_tx_stop_all_queues);
-void netdev_update_lockdep_key(struct net_device *dev)
-{
- lockdep_unregister_key(&dev->addr_list_lock_key);
- lockdep_register_key(&dev->addr_list_lock_key);
-
- lockdep_set_class(&dev->addr_list_lock, &dev->addr_list_lock_key);
-}
-EXPORT_SYMBOL(netdev_update_lockdep_key);
-
/**
* register_netdevice - register a network device
* @dev: device to register
@@ -9420,7 +9426,7 @@ int register_netdevice(struct net_device *dev)
return ret;
spin_lock_init(&dev->addr_list_lock);
- lockdep_set_class(&dev->addr_list_lock, &dev->addr_list_lock_key);
+ netdev_set_addr_lockdep_class(dev);
ret = dev_get_valid_name(net, dev, dev->name);
if (ret < 0)
@@ -9939,8 +9945,6 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
dev_net_set(dev, &init_net);
- lockdep_register_key(&dev->addr_list_lock_key);
-
dev->gso_max_size = GSO_MAX_SIZE;
dev->gso_max_segs = GSO_MAX_SEGS;
dev->upper_level = 1;
@@ -10028,8 +10032,6 @@ void free_netdev(struct net_device *dev)
free_percpu(dev->xdp_bulkq);
dev->xdp_bulkq = NULL;
- lockdep_unregister_key(&dev->addr_list_lock_key);
-
/* Compatibility with error handling in drivers */
if (dev->reg_state == NETREG_UNINITIALIZED) {
netdev_freemem(dev);
diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c
index 2f949b5a1eb9..6393ba930097 100644
--- a/net/core/dev_addr_lists.c
+++ b/net/core/dev_addr_lists.c
@@ -637,7 +637,7 @@ int dev_uc_sync(struct net_device *to, struct net_device *from)
if (to->addr_len != from->addr_len)
return -EINVAL;
- netif_addr_lock(to);
+ netif_addr_lock_nested(to);
err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len);
if (!err)
__dev_set_rx_mode(to);
@@ -667,7 +667,7 @@ int dev_uc_sync_multiple(struct net_device *to, struct net_device *from)
if (to->addr_len != from->addr_len)
return -EINVAL;
- netif_addr_lock(to);
+ netif_addr_lock_nested(to);
err = __hw_addr_sync_multiple(&to->uc, &from->uc, to->addr_len);
if (!err)
__dev_set_rx_mode(to);
@@ -691,7 +691,7 @@ void dev_uc_unsync(struct net_device *to, struct net_device *from)
return;
netif_addr_lock_bh(from);
- netif_addr_lock(to);
+ netif_addr_lock_nested(to);
__hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
__dev_set_rx_mode(to);
netif_addr_unlock(to);
@@ -858,7 +858,7 @@ int dev_mc_sync(struct net_device *to, struct net_device *from)
if (to->addr_len != from->addr_len)
return -EINVAL;
- netif_addr_lock(to);
+ netif_addr_lock_nested(to);
err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
if (!err)
__dev_set_rx_mode(to);
@@ -888,7 +888,7 @@ int dev_mc_sync_multiple(struct net_device *to, struct net_device *from)
if (to->addr_len != from->addr_len)
return -EINVAL;
- netif_addr_lock(to);
+ netif_addr_lock_nested(to);
err = __hw_addr_sync_multiple(&to->mc, &from->mc, to->addr_len);
if (!err)
__dev_set_rx_mode(to);
@@ -912,7 +912,7 @@ void dev_mc_unsync(struct net_device *to, struct net_device *from)
return;
netif_addr_lock_bh(from);
- netif_addr_lock(to);
+ netif_addr_lock_nested(to);
__hw_addr_unsync(&to->mc, &from->mc, to->addr_len);
__dev_set_rx_mode(to);
netif_addr_unlock(to);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 2269199c5891..9aedc15736ad 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2462,7 +2462,6 @@ static int do_set_master(struct net_device *dev, int ifindex,
err = ops->ndo_del_slave(upper_dev, dev);
if (err)
return err;
- netdev_update_lockdep_key(dev);
} else {
return -EOPNOTSUPP;
}