Commit 413f0271 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

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: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115035319.559603-7-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 1b23cdbd

drivers/net/ethernet/amd/pcnet32.c

+9 −2
Original line number Diff line number Diff line
@@ -462,7 +462,7 @@ static void pcnet32_netif_start(struct net_device *dev) 
	val = lp->a->read_csr(ioaddr, CSR3);

	val &= 0x00ff;

	lp->a->write_csr(ioaddr, CSR3, val);

	napi_enable(&lp->napi);

	napi_enable_locked(&lp->napi);

}



/*
@@ -889,6 +889,7 @@ static int pcnet32_set_ringparam(struct net_device *dev, 
	if (netif_running(dev))

		pcnet32_netif_stop(dev);



	netdev_lock(dev);

	spin_lock_irqsave(&lp->lock, flags);

	lp->a->write_csr(ioaddr, CSR0, CSR0_STOP);	/* stop the chip */
@@ -920,6 +921,7 @@ static int pcnet32_set_ringparam(struct net_device *dev, 
	}



	spin_unlock_irqrestore(&lp->lock, flags);

	netdev_unlock(dev);



	netif_info(lp, drv, dev, "Ring Param Settings: RX: %d, TX: %d\n",

		   lp->rx_ring_size, lp->tx_ring_size);
@@ -985,6 +987,7 @@ static int pcnet32_loopback_test(struct net_device *dev, uint64_t * data1) 
	if (netif_running(dev))

		pcnet32_netif_stop(dev);



	netdev_lock(dev);

	spin_lock_irqsave(&lp->lock, flags);

	lp->a->write_csr(ioaddr, CSR0, CSR0_STOP);	/* stop the chip */
@@ -1122,6 +1125,7 @@ static int pcnet32_loopback_test(struct net_device *dev, uint64_t * data1) 
		lp->a->write_bcr(ioaddr, 20, 4);	/* return to 16bit mode */

	}

	spin_unlock_irqrestore(&lp->lock, flags);

	netdev_unlock(dev);



	return rc;

}				/* end pcnet32_loopback_test  */
@@ -2101,6 +2105,7 @@ static int pcnet32_open(struct net_device *dev) 
		return -EAGAIN;

	}



	netdev_lock(dev);

	spin_lock_irqsave(&lp->lock, flags);

	/* Check for a valid station address */

	if (!is_valid_ether_addr(dev->dev_addr)) {
@@ -2266,7 +2271,7 @@ static int pcnet32_open(struct net_device *dev) 
		goto err_free_ring;

	}



	napi_enable(&lp->napi);

	napi_enable_locked(&lp->napi);



	/* Re-initialize the PCNET32, and start it when done. */

	lp->a->write_csr(ioaddr, 1, (lp->init_dma_addr & 0xffff));
@@ -2300,6 +2305,7 @@ static int pcnet32_open(struct net_device *dev) 
		     lp->a->read_csr(ioaddr, CSR0));



	spin_unlock_irqrestore(&lp->lock, flags);

	netdev_unlock(dev);



	return 0;		/* Always succeed */
@@ -2315,6 +2321,7 @@ static int pcnet32_open(struct net_device *dev) 


err_free_irq:

	spin_unlock_irqrestore(&lp->lock, flags);

	netdev_unlock(dev);

	free_irq(dev->irq, dev);

	return rc;

}

drivers/net/ethernet/intel/iavf/iavf_main.c

+2 −2
Original line number Diff line number Diff line
@@ -1180,7 +1180,7 @@ static void iavf_napi_enable_all(struct iavf_adapter *adapter) 


		q_vector = &adapter->q_vectors[q_idx];

		napi = &q_vector->napi;

		napi_enable(napi);

		napi_enable_locked(napi);

	}

}
@@ -1196,7 +1196,7 @@ static void iavf_napi_disable_all(struct iavf_adapter *adapter) 


	for (q_idx = 0; q_idx < q_vectors; q_idx++) {

		q_vector = &adapter->q_vectors[q_idx];

		napi_disable(&q_vector->napi);

		napi_disable_locked(&q_vector->napi);

	}

}

drivers/net/ethernet/marvell/mvneta.c

+4 −1
Original line number Diff line number Diff line
@@ -4392,6 +4392,7 @@ static int mvneta_cpu_online(unsigned int cpu, struct hlist_node *node) 
	if (pp->neta_armada3700)

		return 0;



	netdev_lock(port->napi.dev);

	spin_lock(&pp->lock);

	/*

	 * Configuring the driver for a new CPU while the driver is
@@ -4418,7 +4419,7 @@ static int mvneta_cpu_online(unsigned int cpu, struct hlist_node *node) 


	/* Mask all ethernet port interrupts */

	on_each_cpu(mvneta_percpu_mask_interrupt, pp, true);

	napi_enable(&port->napi);

	napi_enable_locked(&port->napi);



	/*

	 * Enable per-CPU interrupts on the CPU that is
@@ -4439,6 +4440,8 @@ static int mvneta_cpu_online(unsigned int cpu, struct hlist_node *node) 
		    MVNETA_CAUSE_LINK_CHANGE);

	netif_tx_start_all_queues(pp->dev);

	spin_unlock(&pp->lock);

	netdev_unlock(port->napi.dev);



	return 0;

}

drivers/net/ethernet/via/via-velocity.c

+4 −2
Original line number Diff line number Diff line
@@ -2320,7 +2320,8 @@ static int velocity_change_mtu(struct net_device *dev, int new_mtu) 
		if (ret < 0)

			goto out_free_tmp_vptr_1;



		napi_disable(&vptr->napi);

		netdev_lock(dev);

		napi_disable_locked(&vptr->napi);



		spin_lock_irqsave(&vptr->lock, flags);
@@ -2342,12 +2343,13 @@ static int velocity_change_mtu(struct net_device *dev, int new_mtu) 


		velocity_give_many_rx_descs(vptr);



		napi_enable(&vptr->napi);

		napi_enable_locked(&vptr->napi);



		mac_enable_int(vptr->mac_regs);

		netif_start_queue(dev);



		spin_unlock_irqrestore(&vptr->lock, flags);

		netdev_unlock(dev);



		velocity_free_rings(tmp_vptr);

include/linux/netdevice.h

+3 −8
Original line number Diff line number Diff line
@@ -382,7 +382,7 @@ struct napi_struct { 
	struct sk_buff		*skb;

	struct list_head	rx_list; /* Pending GRO_NORMAL skbs */

	int			rx_count; /* length of rx_list */

	unsigned int		napi_id;

	unsigned int		napi_id; /* protected by netdev_lock */

	struct hrtimer		timer;

	struct task_struct	*thread;

	unsigned long		gro_flush_timeout;
@@ -570,16 +570,11 @@ static inline bool napi_complete(struct napi_struct *n) 


int dev_set_threaded(struct net_device *dev, bool threaded);



/**

 *	napi_disable - prevent NAPI from scheduling

 *	@n: NAPI context

 *

 * Stop NAPI from being scheduled on this context.

 * Waits till any outstanding processing completes.

 */

void napi_disable(struct napi_struct *n);

void napi_disable_locked(struct napi_struct *n);



void napi_enable(struct napi_struct *n);

void napi_enable_locked(struct napi_struct *n);



/**

 *	napi_synchronize - wait until NAPI is not running