Commit 5c05b3db authored by David Yang's avatar David Yang Committed by Jakub Kicinski
Browse files

netdevsim: 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/20260123211101.2929547-1-mmyangfl@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent a84a1fe0

drivers/net/netdevsim/netdevsim.h

+4 −4
Original line number Diff line number Diff line
@@ -109,10 +109,10 @@ struct netdevsim { 
	int rq_reset_mode;



	struct {

		u64 rx_packets;

		u64 rx_bytes;

		u64 tx_packets;

		u64 tx_bytes;

		u64_stats_t rx_packets;

		u64_stats_t rx_bytes;

		u64_stats_t tx_packets;

		u64_stats_t tx_bytes;

		struct u64_stats_sync syncp;

		struct psp_dev *dev;

		u32 spi;

drivers/net/netdevsim/psp.c

+10 −8
Original line number Diff line number Diff line
@@ -72,10 +72,12 @@ nsim_do_psp(struct sk_buff *skb, struct netdevsim *ns, 
		skb->decrypted = 1;



		u64_stats_update_begin(&ns->psp.syncp);

		ns->psp.tx_packets++;

		ns->psp.rx_packets++;

		ns->psp.tx_bytes += skb->len - skb_inner_transport_offset(skb);

		ns->psp.rx_bytes += skb->len - skb_inner_transport_offset(skb);

		u64_stats_inc(&ns->psp.tx_packets);

		u64_stats_inc(&ns->psp.rx_packets);

		u64_stats_add(&ns->psp.tx_bytes,

			      skb->len - skb_inner_transport_offset(skb));

		u64_stats_add(&ns->psp.rx_bytes,

			      skb->len - skb_inner_transport_offset(skb));

		u64_stats_update_end(&ns->psp.syncp);

	} else {

		struct ipv6hdr *ip6h __maybe_unused;
@@ -183,10 +185,10 @@ static void nsim_get_stats(struct psp_dev *psd, struct psp_dev_stats *stats) 


	do {

		start = u64_stats_fetch_begin(&ns->psp.syncp);

		stats->rx_bytes = ns->psp.rx_bytes;

		stats->rx_packets = ns->psp.rx_packets;

		stats->tx_bytes = ns->psp.tx_bytes;

		stats->tx_packets = ns->psp.tx_packets;

		stats->rx_bytes = u64_stats_read(&ns->psp.rx_bytes);

		stats->rx_packets = u64_stats_read(&ns->psp.rx_packets);

		stats->tx_bytes = u64_stats_read(&ns->psp.tx_bytes);

		stats->tx_packets = u64_stats_read(&ns->psp.tx_packets);

	} while (u64_stats_fetch_retry(&ns->psp.syncp, start));

}