Commit a2ba9902 authored by David Yang's avatar David Yang Committed by Paolo Abeni
Browse files

xen/netfront: Use u64_stats_t with u64_stats_sync properly 



On 64bit arches, struct u64_stats_sync is empty and provides no help
against load/store tearing. Convert to u64_stats_t to ensure atomic
operations.

Signed-off-by: default avatarDavid Yang <mmyangfl@gmail.com>
Link: https://patch.msgid.link/20260121082550.2389249-1-mmyangfl@gmail.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent cbe38d2e

drivers/net/xen-netfront.c

+12 −12
Original line number Diff line number Diff line
@@ -97,8 +97,8 @@ struct netfront_cb { 
static DECLARE_WAIT_QUEUE_HEAD(module_wq);



struct netfront_stats {

	u64			packets;

	u64			bytes;

	u64_stats_t		packets;

	u64_stats_t		bytes;

	struct u64_stats_sync	syncp;

};
@@ -634,8 +634,8 @@ static int xennet_xdp_xmit_one(struct net_device *dev, 
		notify_remote_via_irq(queue->tx_irq);



	u64_stats_update_begin(&tx_stats->syncp);

	tx_stats->bytes += xdpf->len;

	tx_stats->packets++;

	u64_stats_add(&tx_stats->bytes, xdpf->len);

	u64_stats_inc(&tx_stats->packets);

	u64_stats_update_end(&tx_stats->syncp);



	return 0;
@@ -843,8 +843,8 @@ static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev 
		notify_remote_via_irq(queue->tx_irq);



	u64_stats_update_begin(&tx_stats->syncp);

	tx_stats->bytes += skb->len;

	tx_stats->packets++;

	u64_stats_add(&tx_stats->bytes, skb->len);

	u64_stats_inc(&tx_stats->packets);

	u64_stats_update_end(&tx_stats->syncp);



	if (!netfront_tx_slot_available(queue))
@@ -1249,8 +1249,8 @@ static int handle_incoming_queue(struct netfront_queue *queue, 
		}



		u64_stats_update_begin(&rx_stats->syncp);

		rx_stats->packets++;

		rx_stats->bytes += skb->len;

		u64_stats_inc(&rx_stats->packets);

		u64_stats_add(&rx_stats->bytes, skb->len);

		u64_stats_update_end(&rx_stats->syncp);



		/* Pass it up. */
@@ -1400,14 +1400,14 @@ static void xennet_get_stats64(struct net_device *dev, 


		do {

			start = u64_stats_fetch_begin(&tx_stats->syncp);

			tx_packets = tx_stats->packets;

			tx_bytes = tx_stats->bytes;

			tx_packets = u64_stats_read(&tx_stats->packets);

			tx_bytes = u64_stats_read(&tx_stats->bytes);

		} while (u64_stats_fetch_retry(&tx_stats->syncp, start));



		do {

			start = u64_stats_fetch_begin(&rx_stats->syncp);

			rx_packets = rx_stats->packets;

			rx_bytes = rx_stats->bytes;

			rx_packets = u64_stats_read(&rx_stats->packets);

			rx_bytes = u64_stats_read(&rx_stats->bytes);

		} while (u64_stats_fetch_retry(&rx_stats->syncp, start));



		tot->rx_packets += rx_packets;