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authorDavid S. Miller <davem@davemloft.net>2020-09-28 15:00:15 -0700
committerDavid S. Miller <davem@davemloft.net>2020-09-28 15:00:15 -0700
commit0ba56b89fabc139849cf27e475287b0361f550d3 (patch)
tree1b876520c6009ad68b0eb4664a87eb6878be125e /net
parent1aad8049909a6d3379175ef2824a68ac35c0b564 (diff)
parent1fc70edb7d7b5ce1ae32b0cf90183f4879ad421a (diff)
Merge branch 'net-core-fix-a-lockdep-splat-in-the-dev_addr_list'
Taehee Yoo says: ==================== net: core: fix a lockdep splat in the dev_addr_list. This patchset is to avoid lockdep splat. When a stacked interface graph is changed, netif_addr_lock() is called recursively and it internally calls spin_lock_nested(). The parameter of spin_lock_nested() is 'dev->lower_level', this is called subclass. The problem of 'dev->lower_level' is that while 'dev->lower_level' is being used as a subclass of spin_lock_nested(), its value can be changed. So, spin_lock_nested() would be called recursively with the same subclass value, the lockdep understands a deadlock. In order to avoid this, a new variable is needed and it is going to be used as a parameter of spin_lock_nested(). The first and second patch is a preparation patch for the third patch. In the third patch, the problem will be fixed. The first patch is to add __netdev_upper_dev_unlink(). An existed netdev_upper_dev_unlink() is renamed to __netdev_upper_dev_unlink(). and netdev_upper_dev_unlink() is added as an wrapper of this function. The second patch is to add the netdev_nested_priv structure. netdev_walk_all_{ upper | lower }_dev() pass both private functions and "data" pointer to handle their own things. At this point, the data pointer type is void *. In order to make it easier to expand common variables and functions, this new netdev_nested_priv structure is added. The third patch is to add a new variable 'nested_level' into the net_device structure. This variable will be used as a parameter of spin_lock_nested() of dev->addr_list_lock. Due to this variable, it can avoid lockdep splat. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/bridge/br_arp_nd_proxy.c26
-rw-r--r--net/bridge/br_vlan.c20
-rw-r--r--net/core/dev.c164
-rw-r--r--net/core/dev_addr_lists.c12
4 files changed, 159 insertions, 63 deletions
diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c
index b18cdf03edb3..dfec65eca8a6 100644
--- a/net/bridge/br_arp_nd_proxy.c
+++ b/net/bridge/br_arp_nd_proxy.c
@@ -88,9 +88,10 @@ static void br_arp_send(struct net_bridge *br, struct net_bridge_port *p,
}
}
-static int br_chk_addr_ip(struct net_device *dev, void *data)
+static int br_chk_addr_ip(struct net_device *dev,
+ struct netdev_nested_priv *priv)
{
- __be32 ip = *(__be32 *)data;
+ __be32 ip = *(__be32 *)priv->data;
struct in_device *in_dev;
__be32 addr = 0;
@@ -107,11 +108,15 @@ static int br_chk_addr_ip(struct net_device *dev, void *data)
static bool br_is_local_ip(struct net_device *dev, __be32 ip)
{
- if (br_chk_addr_ip(dev, &ip))
+ struct netdev_nested_priv priv = {
+ .data = (void *)&ip,
+ };
+
+ if (br_chk_addr_ip(dev, &priv))
return true;
/* check if ip is configured on upper dev */
- if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip, &ip))
+ if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip, &priv))
return true;
return false;
@@ -361,9 +366,10 @@ static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p,
}
}
-static int br_chk_addr_ip6(struct net_device *dev, void *data)
+static int br_chk_addr_ip6(struct net_device *dev,
+ struct netdev_nested_priv *priv)
{
- struct in6_addr *addr = (struct in6_addr *)data;
+ struct in6_addr *addr = (struct in6_addr *)priv->data;
if (ipv6_chk_addr(dev_net(dev), addr, dev, 0))
return 1;
@@ -374,11 +380,15 @@ static int br_chk_addr_ip6(struct net_device *dev, void *data)
static bool br_is_local_ip6(struct net_device *dev, struct in6_addr *addr)
{
- if (br_chk_addr_ip6(dev, addr))
+ struct netdev_nested_priv priv = {
+ .data = (void *)addr,
+ };
+
+ if (br_chk_addr_ip6(dev, &priv))
return true;
/* check if ip is configured on upper dev */
- if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip6, addr))
+ if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip6, &priv))
return true;
return false;
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 61c94cefa843..ee8780080be5 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -1360,7 +1360,7 @@ static int br_vlan_is_bind_vlan_dev(const struct net_device *dev)
}
static int br_vlan_is_bind_vlan_dev_fn(struct net_device *dev,
- __always_unused void *data)
+ __always_unused struct netdev_nested_priv *priv)
{
return br_vlan_is_bind_vlan_dev(dev);
}
@@ -1383,9 +1383,9 @@ struct br_vlan_bind_walk_data {
};
static int br_vlan_match_bind_vlan_dev_fn(struct net_device *dev,
- void *data_in)
+ struct netdev_nested_priv *priv)
{
- struct br_vlan_bind_walk_data *data = data_in;
+ struct br_vlan_bind_walk_data *data = priv->data;
int found = 0;
if (br_vlan_is_bind_vlan_dev(dev) &&
@@ -1403,10 +1403,13 @@ br_vlan_get_upper_bind_vlan_dev(struct net_device *dev, u16 vid)
struct br_vlan_bind_walk_data data = {
.vid = vid,
};
+ struct netdev_nested_priv priv = {
+ .data = (void *)&data,
+ };
rcu_read_lock();
netdev_walk_all_upper_dev_rcu(dev, br_vlan_match_bind_vlan_dev_fn,
- &data);
+ &priv);
rcu_read_unlock();
return data.result;
@@ -1487,9 +1490,9 @@ struct br_vlan_link_state_walk_data {
};
static int br_vlan_link_state_change_fn(struct net_device *vlan_dev,
- void *data_in)
+ struct netdev_nested_priv *priv)
{
- struct br_vlan_link_state_walk_data *data = data_in;
+ struct br_vlan_link_state_walk_data *data = priv->data;
if (br_vlan_is_bind_vlan_dev(vlan_dev))
br_vlan_set_vlan_dev_state(data->br, vlan_dev);
@@ -1503,10 +1506,13 @@ static void br_vlan_link_state_change(struct net_device *dev,
struct br_vlan_link_state_walk_data data = {
.br = br
};
+ struct netdev_nested_priv priv = {
+ .data = (void *)&data,
+ };
rcu_read_lock();
netdev_walk_all_upper_dev_rcu(dev, br_vlan_link_state_change_fn,
- &data);
+ &priv);
rcu_read_unlock();
}
diff --git a/net/core/dev.c b/net/core/dev.c
index 266073e300b5..4906b44af850 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6812,9 +6812,10 @@ static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
return NULL;
}
-static int ____netdev_has_upper_dev(struct net_device *upper_dev, void *data)
+static int ____netdev_has_upper_dev(struct net_device *upper_dev,
+ struct netdev_nested_priv *priv)
{
- struct net_device *dev = data;
+ struct net_device *dev = (struct net_device *)priv->data;
return upper_dev == dev;
}
@@ -6831,10 +6832,14 @@ static int ____netdev_has_upper_dev(struct net_device *upper_dev, void *data)
bool netdev_has_upper_dev(struct net_device *dev,
struct net_device *upper_dev)
{
+ struct netdev_nested_priv priv = {
+ .data = (void *)upper_dev,
+ };
+
ASSERT_RTNL();
return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
- upper_dev);
+ &priv);
}
EXPORT_SYMBOL(netdev_has_upper_dev);
@@ -6851,8 +6856,12 @@ EXPORT_SYMBOL(netdev_has_upper_dev);
bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
struct net_device *upper_dev)
{
+ struct netdev_nested_priv priv = {
+ .data = (void *)upper_dev,
+ };
+
return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
- upper_dev);
+ &priv);
}
EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
@@ -6997,8 +7006,8 @@ static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
static int __netdev_walk_all_upper_dev(struct net_device *dev,
int (*fn)(struct net_device *dev,
- void *data),
- void *data)
+ struct netdev_nested_priv *priv),
+ struct netdev_nested_priv *priv)
{
struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
@@ -7010,7 +7019,7 @@ static int __netdev_walk_all_upper_dev(struct net_device *dev,
while (1) {
if (now != dev) {
- ret = fn(now, data);
+ ret = fn(now, priv);
if (ret)
return ret;
}
@@ -7046,8 +7055,8 @@ static int __netdev_walk_all_upper_dev(struct net_device *dev,
int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
int (*fn)(struct net_device *dev,
- void *data),
- void *data)
+ struct netdev_nested_priv *priv),
+ struct netdev_nested_priv *priv)
{
struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
@@ -7058,7 +7067,7 @@ int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
while (1) {
if (now != dev) {
- ret = fn(now, data);
+ ret = fn(now, priv);
if (ret)
return ret;
}
@@ -7094,10 +7103,15 @@ EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
static bool __netdev_has_upper_dev(struct net_device *dev,
struct net_device *upper_dev)
{
+ struct netdev_nested_priv priv = {
+ .flags = 0,
+ .data = (void *)upper_dev,
+ };
+
ASSERT_RTNL();
return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
- upper_dev);
+ &priv);
}
/**
@@ -7215,8 +7229,8 @@ static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
int netdev_walk_all_lower_dev(struct net_device *dev,
int (*fn)(struct net_device *dev,
- void *data),
- void *data)
+ struct netdev_nested_priv *priv),
+ struct netdev_nested_priv *priv)
{
struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
@@ -7227,7 +7241,7 @@ int netdev_walk_all_lower_dev(struct net_device *dev,
while (1) {
if (now != dev) {
- ret = fn(now, data);
+ ret = fn(now, priv);
if (ret)
return ret;
}
@@ -7262,8 +7276,8 @@ EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
static int __netdev_walk_all_lower_dev(struct net_device *dev,
int (*fn)(struct net_device *dev,
- void *data),
- void *data)
+ struct netdev_nested_priv *priv),
+ struct netdev_nested_priv *priv)
{
struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
@@ -7275,7 +7289,7 @@ static int __netdev_walk_all_lower_dev(struct net_device *dev,
while (1) {
if (now != dev) {
- ret = fn(now, data);
+ ret = fn(now, priv);
if (ret)
return ret;
}
@@ -7364,22 +7378,34 @@ static u8 __netdev_lower_depth(struct net_device *dev)
return max_depth;
}
-static int __netdev_update_upper_level(struct net_device *dev, void *data)
+static int __netdev_update_upper_level(struct net_device *dev,
+ struct netdev_nested_priv *__unused)
{
dev->upper_level = __netdev_upper_depth(dev) + 1;
return 0;
}
-static int __netdev_update_lower_level(struct net_device *dev, void *data)
+static int __netdev_update_lower_level(struct net_device *dev,
+ struct netdev_nested_priv *priv)
{
dev->lower_level = __netdev_lower_depth(dev) + 1;
+
+#ifdef CONFIG_LOCKDEP
+ if (!priv)
+ return 0;
+
+ if (priv->flags & NESTED_SYNC_IMM)
+ dev->nested_level = dev->lower_level - 1;
+ if (priv->flags & NESTED_SYNC_TODO)
+ net_unlink_todo(dev);
+#endif
return 0;
}
int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
int (*fn)(struct net_device *dev,
- void *data),
- void *data)
+ struct netdev_nested_priv *priv),
+ struct netdev_nested_priv *priv)
{
struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
@@ -7390,7 +7416,7 @@ int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
while (1) {
if (now != dev) {
- ret = fn(now, data);
+ ret = fn(now, priv);
if (ret)
return ret;
}
@@ -7650,6 +7676,7 @@ static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
static int __netdev_upper_dev_link(struct net_device *dev,
struct net_device *upper_dev, bool master,
void *upper_priv, void *upper_info,
+ struct netdev_nested_priv *priv,
struct netlink_ext_ack *extack)
{
struct netdev_notifier_changeupper_info changeupper_info = {
@@ -7706,9 +7733,9 @@ static int __netdev_upper_dev_link(struct net_device *dev,
__netdev_update_upper_level(dev, NULL);
__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
- __netdev_update_lower_level(upper_dev, NULL);
+ __netdev_update_lower_level(upper_dev, priv);
__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
- NULL);
+ priv);
return 0;
@@ -7733,8 +7760,13 @@ int netdev_upper_dev_link(struct net_device *dev,
struct net_device *upper_dev,
struct netlink_ext_ack *extack)
{
+ struct netdev_nested_priv priv = {
+ .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
+ .data = NULL,
+ };
+
return __netdev_upper_dev_link(dev, upper_dev, false,
- NULL, NULL, extack);
+ NULL, NULL, &priv, extack);
}
EXPORT_SYMBOL(netdev_upper_dev_link);
@@ -7757,21 +7789,19 @@ int netdev_master_upper_dev_link(struct net_device *dev,
void *upper_priv, void *upper_info,
struct netlink_ext_ack *extack)
{
+ struct netdev_nested_priv priv = {
+ .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
+ .data = NULL,
+ };
+
return __netdev_upper_dev_link(dev, upper_dev, true,
- upper_priv, upper_info, extack);
+ upper_priv, upper_info, &priv, extack);
}
EXPORT_SYMBOL(netdev_master_upper_dev_link);
-/**
- * netdev_upper_dev_unlink - Removes a link to upper device
- * @dev: device
- * @upper_dev: new upper device
- *
- * Removes a link to device which is upper to this one. The caller must hold
- * the RTNL lock.
- */
-void netdev_upper_dev_unlink(struct net_device *dev,
- struct net_device *upper_dev)
+static void __netdev_upper_dev_unlink(struct net_device *dev,
+ struct net_device *upper_dev,
+ struct netdev_nested_priv *priv)
{
struct netdev_notifier_changeupper_info changeupper_info = {
.info = {
@@ -7796,9 +7826,28 @@ void netdev_upper_dev_unlink(struct net_device *dev,
__netdev_update_upper_level(dev, NULL);
__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
- __netdev_update_lower_level(upper_dev, NULL);
+ __netdev_update_lower_level(upper_dev, priv);
__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
- NULL);
+ priv);
+}
+
+/**
+ * netdev_upper_dev_unlink - Removes a link to upper device
+ * @dev: device
+ * @upper_dev: new upper device
+ *
+ * Removes a link to device which is upper to this one. The caller must hold
+ * the RTNL lock.
+ */
+void netdev_upper_dev_unlink(struct net_device *dev,
+ struct net_device *upper_dev)
+{
+ struct netdev_nested_priv priv = {
+ .flags = NESTED_SYNC_TODO,
+ .data = NULL,
+ };
+
+ __netdev_upper_dev_unlink(dev, upper_dev, &priv);
}
EXPORT_SYMBOL(netdev_upper_dev_unlink);
@@ -7834,6 +7883,10 @@ int netdev_adjacent_change_prepare(struct net_device *old_dev,
struct net_device *dev,
struct netlink_ext_ack *extack)
{
+ struct netdev_nested_priv priv = {
+ .flags = 0,
+ .data = NULL,
+ };
int err;
if (!new_dev)
@@ -7841,8 +7894,8 @@ int netdev_adjacent_change_prepare(struct net_device *old_dev,
if (old_dev && new_dev != old_dev)
netdev_adjacent_dev_disable(dev, old_dev);
-
- err = netdev_upper_dev_link(new_dev, dev, extack);
+ err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
+ extack);
if (err) {
if (old_dev && new_dev != old_dev)
netdev_adjacent_dev_enable(dev, old_dev);
@@ -7857,6 +7910,11 @@ void netdev_adjacent_change_commit(struct net_device *old_dev,
struct net_device *new_dev,
struct net_device *dev)
{
+ struct netdev_nested_priv priv = {
+ .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
+ .data = NULL,
+ };
+
if (!new_dev || !old_dev)
return;
@@ -7864,7 +7922,7 @@ void netdev_adjacent_change_commit(struct net_device *old_dev,
return;
netdev_adjacent_dev_enable(dev, old_dev);
- netdev_upper_dev_unlink(old_dev, dev);
+ __netdev_upper_dev_unlink(old_dev, dev, &priv);
}
EXPORT_SYMBOL(netdev_adjacent_change_commit);
@@ -7872,13 +7930,18 @@ void netdev_adjacent_change_abort(struct net_device *old_dev,
struct net_device *new_dev,
struct net_device *dev)
{
+ struct netdev_nested_priv priv = {
+ .flags = 0,
+ .data = NULL,
+ };
+
if (!new_dev)
return;
if (old_dev && new_dev != old_dev)
netdev_adjacent_dev_enable(dev, old_dev);
- netdev_upper_dev_unlink(new_dev, dev);
+ __netdev_upper_dev_unlink(new_dev, dev, &priv);
}
EXPORT_SYMBOL(netdev_adjacent_change_abort);
@@ -10062,6 +10125,19 @@ static void netdev_wait_allrefs(struct net_device *dev)
void netdev_run_todo(void)
{
struct list_head list;
+#ifdef CONFIG_LOCKDEP
+ struct list_head unlink_list;
+
+ list_replace_init(&net_unlink_list, &unlink_list);
+
+ while (!list_empty(&unlink_list)) {
+ struct net_device *dev = list_first_entry(&unlink_list,
+ struct net_device,
+ unlink_list);
+ list_del(&dev->unlink_list);
+ dev->nested_level = dev->lower_level - 1;
+ }
+#endif
/* Snapshot list, allow later requests */
list_replace_init(&net_todo_list, &list);
@@ -10274,6 +10350,10 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
dev->gso_max_segs = GSO_MAX_SEGS;
dev->upper_level = 1;
dev->lower_level = 1;
+#ifdef CONFIG_LOCKDEP
+ dev->nested_level = 0;
+ INIT_LIST_HEAD(&dev->unlink_list);
+#endif
INIT_LIST_HEAD(&dev->napi_list);
INIT_LIST_HEAD(&dev->unreg_list);
diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c
index 54cd568e7c2f..fa1c37ec40c9 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_nested(to);
+ netif_addr_lock(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_nested(to);
+ netif_addr_lock(to);
err = __hw_addr_sync_multiple(&to->uc, &from->uc, to->addr_len);
if (!err)
__dev_set_rx_mode(to);
@@ -700,7 +700,7 @@ void dev_uc_unsync(struct net_device *to, struct net_device *from)
* larger.
*/
netif_addr_lock_bh(from);
- netif_addr_lock_nested(to);
+ netif_addr_lock(to);
__hw_addr_unsync(&to->uc, &from->uc, to->addr_len);
__dev_set_rx_mode(to);
netif_addr_unlock(to);
@@ -867,7 +867,7 @@ int dev_mc_sync(struct net_device *to, struct net_device *from)
if (to->addr_len != from->addr_len)
return -EINVAL;
- netif_addr_lock_nested(to);
+ netif_addr_lock(to);
err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len);
if (!err)
__dev_set_rx_mode(to);
@@ -897,7 +897,7 @@ 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_nested(to);
+ netif_addr_lock(to);
err = __hw_addr_sync_multiple(&to->mc, &from->mc, to->addr_len);
if (!err)
__dev_set_rx_mode(to);
@@ -922,7 +922,7 @@ void dev_mc_unsync(struct net_device *to, struct net_device *from)
/* See the above comments inside dev_uc_unsync(). */
netif_addr_lock_bh(from);
- netif_addr_lock_nested(to);
+ netif_addr_lock(to);
__hw_addr_unsync(&to->mc, &from->mc, to->addr_len);
__dev_set_rx_mode(to);
netif_addr_unlock(to);