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authorJakub Kicinski <kuba@kernel.org>2025-01-14 19:53:13 -0800
committerJakub Kicinski <kuba@kernel.org>2025-01-15 19:13:34 -0800
commit1b23cdbd2bbc4b40e21c12ae86c2781e347ff0f8 (patch)
treeb7850b8a31313cd675088a784039fc236d308756 /include/linux/netdevice.h
parent5112457f3d8e41f987908266068af88ef9f3ab78 (diff)
net: protect netdev->napi_list with netdev_lock()
Hold netdev->lock when NAPIs are getting added or removed. This will allow safe access to NAPI instances of a net_device without rtnl_lock. Create a family of helpers which assume the lock is already taken. Switch iavf to them, as it makes extensive use of netdev->lock, already. Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250115035319.559603-6-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux/netdevice.h')
-rw-r--r--include/linux/netdevice.h54
1 files changed, 47 insertions, 7 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index cac81b0a166f..3130a8c807dd 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2456,7 +2456,7 @@ struct net_device {
* Drivers are free to use it for other protection.
*
* Protects:
- * @net_shaper_hierarchy, @reg_state
+ * @napi_list, @net_shaper_hierarchy, @reg_state
*
* Partially protects (writers must hold both @lock and rtnl_lock):
* @up
@@ -2712,8 +2712,19 @@ static inline void netif_napi_set_irq(struct napi_struct *napi, int irq)
*/
#define NAPI_POLL_WEIGHT 64
-void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
- int (*poll)(struct napi_struct *, int), int weight);
+void netif_napi_add_weight_locked(struct net_device *dev,
+ struct napi_struct *napi,
+ int (*poll)(struct napi_struct *, int),
+ int weight);
+
+static inline void
+netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
+ int (*poll)(struct napi_struct *, int), int weight)
+{
+ netdev_lock(dev);
+ netif_napi_add_weight_locked(dev, napi, poll, weight);
+ netdev_unlock(dev);
+}
/**
* netif_napi_add() - initialize a NAPI context
@@ -2732,6 +2743,13 @@ netif_napi_add(struct net_device *dev, struct napi_struct *napi,
}
static inline void
+netif_napi_add_locked(struct net_device *dev, struct napi_struct *napi,
+ int (*poll)(struct napi_struct *, int))
+{
+ netif_napi_add_weight_locked(dev, napi, poll, NAPI_POLL_WEIGHT);
+}
+
+static inline void
netif_napi_add_tx_weight(struct net_device *dev,
struct napi_struct *napi,
int (*poll)(struct napi_struct *, int),
@@ -2741,6 +2759,15 @@ netif_napi_add_tx_weight(struct net_device *dev,
netif_napi_add_weight(dev, napi, poll, weight);
}
+static inline void
+netif_napi_add_config_locked(struct net_device *dev, struct napi_struct *napi,
+ int (*poll)(struct napi_struct *, int), int index)
+{
+ napi->index = index;
+ napi->config = &dev->napi_config[index];
+ netif_napi_add_weight_locked(dev, napi, poll, NAPI_POLL_WEIGHT);
+}
+
/**
* netif_napi_add_config - initialize a NAPI context with persistent config
* @dev: network device
@@ -2752,9 +2779,9 @@ static inline void
netif_napi_add_config(struct net_device *dev, struct napi_struct *napi,
int (*poll)(struct napi_struct *, int), int index)
{
- napi->index = index;
- napi->config = &dev->napi_config[index];
- netif_napi_add_weight(dev, napi, poll, NAPI_POLL_WEIGHT);
+ netdev_lock(dev);
+ netif_napi_add_config_locked(dev, napi, poll, index);
+ netdev_unlock(dev);
}
/**
@@ -2774,6 +2801,8 @@ static inline void netif_napi_add_tx(struct net_device *dev,
netif_napi_add_tx_weight(dev, napi, poll, NAPI_POLL_WEIGHT);
}
+void __netif_napi_del_locked(struct napi_struct *napi);
+
/**
* __netif_napi_del - remove a NAPI context
* @napi: NAPI context
@@ -2782,7 +2811,18 @@ static inline void netif_napi_add_tx(struct net_device *dev,
* containing @napi. Drivers might want to call this helper to combine
* all the needed RCU grace periods into a single one.
*/
-void __netif_napi_del(struct napi_struct *napi);
+static inline void __netif_napi_del(struct napi_struct *napi)
+{
+ netdev_lock(napi->dev);
+ __netif_napi_del_locked(napi);
+ netdev_unlock(napi->dev);
+}
+
+static inline void netif_napi_del_locked(struct napi_struct *napi)
+{
+ __netif_napi_del_locked(napi);
+ synchronize_net();
+}
/**
* netif_napi_del - remove a NAPI context