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authorJakub Kicinski <kuba@kernel.org>2025-01-14 19:53:14 -0800
committerJakub Kicinski <kuba@kernel.org>2025-01-15 19:13:34 -0800
commit413f0271f3966e0c73d4937963f19335af19e628 (patch)
tree2dbbae26011130382d7864b13982b04d447c5e11 /net/core
parent1b23cdbd2bbc4b40e21c12ae86c2781e347ff0f8 (diff)
net: protect NAPI enablement with netdev_lock()
Wrap napi_enable() / napi_disable() with netdev_lock(). Provide the "already locked" flavor of the API. iavf needs the usual adjustment. A number of drivers call napi_enable() under a spin lock, so they have to be modified to take netdev_lock() first, then spin lock then call napi_enable_locked(). Protecting napi_enable() implies that napi->napi_id is protected by netdev_lock(). Acked-by: Francois Romieu <romieu@fr.zoreil.com> # via-velocity Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250115035319.559603-7-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/dev.c41
1 files changed, 34 insertions, 7 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 235707c0f631..cfd88bc6ce5f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6958,11 +6958,13 @@ void netif_napi_add_weight_locked(struct net_device *dev,
}
EXPORT_SYMBOL(netif_napi_add_weight_locked);
-void napi_disable(struct napi_struct *n)
+void napi_disable_locked(struct napi_struct *n)
{
unsigned long val, new;
might_sleep();
+ netdev_assert_locked(n->dev);
+
set_bit(NAPI_STATE_DISABLE, &n->state);
val = READ_ONCE(n->state);
@@ -6985,16 +6987,25 @@ void napi_disable(struct napi_struct *n)
clear_bit(NAPI_STATE_DISABLE, &n->state);
}
-EXPORT_SYMBOL(napi_disable);
+EXPORT_SYMBOL(napi_disable_locked);
/**
- * napi_enable - enable NAPI scheduling
- * @n: NAPI context
+ * napi_disable() - prevent NAPI from scheduling
+ * @n: NAPI context
*
- * Resume NAPI from being scheduled on this context.
- * Must be paired with napi_disable.
+ * Stop NAPI from being scheduled on this context.
+ * Waits till any outstanding processing completes.
+ * Takes netdev_lock() for associated net_device.
*/
-void napi_enable(struct napi_struct *n)
+void napi_disable(struct napi_struct *n)
+{
+ netdev_lock(n->dev);
+ napi_disable_locked(n);
+ netdev_unlock(n->dev);
+}
+EXPORT_SYMBOL(napi_disable);
+
+void napi_enable_locked(struct napi_struct *n)
{
unsigned long new, val = READ_ONCE(n->state);
@@ -7011,6 +7022,22 @@ void napi_enable(struct napi_struct *n)
new |= NAPIF_STATE_THREADED;
} while (!try_cmpxchg(&n->state, &val, new));
}
+EXPORT_SYMBOL(napi_enable_locked);
+
+/**
+ * napi_enable() - enable NAPI scheduling
+ * @n: NAPI context
+ *
+ * Enable scheduling of a NAPI instance.
+ * Must be paired with napi_disable().
+ * Takes netdev_lock() for associated net_device.
+ */
+void napi_enable(struct napi_struct *n)
+{
+ netdev_lock(n->dev);
+ napi_enable_locked(n);
+ netdev_unlock(n->dev);
+}
EXPORT_SYMBOL(napi_enable);
static void flush_gro_hash(struct napi_struct *napi)