Subject: [PATCH 5.10 68/80] net: Use u64_stats_fetch_begin_irq() for stats fetch.

From: Greg Kroah-Hartman <[email-masked]>
Date: Tue, 6 Sep 2022 15:31:05 +0200

From: Sebastian Andrzej Siewior <[email-masked]>

commit 278d3ba61563ceed3cb248383ced19e14ec7bc1f upstream.

On 32bit-UP u64_stats_fetch_begin() disables only preemption. If the
reader is in preemptible context and the writer side
(u64_stats_update_begin*()) runs in an interrupt context (IRQ or
softirq) then the writer can update the stats during the read operation.
This update remains undetected.

Use u64_stats_fetch_begin_irq() to ensure the stats fetch on 32bit-UP
are not interrupted by a writer. 32bit-SMP remains unaffected by this
change.

Cc: "David S. Miller" <[email-masked]>
Cc: Catherine Sullivan <[email-masked]>
Cc: David Awogbemila <[email-masked]>
Cc: Dimitris Michailidis <[email-masked]>
Cc: Eric Dumazet <[email-masked]>
Cc: Hans Ulli Kroll <[email-masked]>
Cc: Jakub Kicinski <[email-masked]>
Cc: Jeroen de Borst <[email-masked]>
Cc: Johannes Berg <[email-masked]>
Cc: Linus Walleij <[email-masked]>
Cc: Paolo Abeni <[email-masked]>
Cc: Simon Horman <[email-masked]>
Cc: [email-masked]
Cc: [email-masked]
Cc: [email-masked]
Cc: [email-masked]
Cc: [email-masked]
Signed-off-by: Sebastian Andrzej Siewior <[email-masked]>
Reviewed-by: Simon Horman <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
Signed-off-by: Greg Kroah-Hartman <[email-masked]>
---
 drivers/net/ethernet/cortina/gemini.c                |   24 +++++++++----------
 drivers/net/ethernet/google/gve/gve_ethtool.c        |   16 ++++++------
 drivers/net/ethernet/google/gve/gve_main.c           |   12 ++++-----
 drivers/net/ethernet/huawei/hinic/hinic_rx.c         |    4 +--
 drivers/net/ethernet/huawei/hinic/hinic_tx.c         |    4 +--
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c  |    8 +++---
 drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c |    8 +++---
 drivers/net/netdevsim/netdev.c                       |    4 +--
 net/mac80211/sta_info.c                              |    8 +++---
 net/mpls/af_mpls.c                                   |    4 +--
 10 files changed, 46 insertions(+), 46 deletions(-)

--- a/drivers/net/ethernet/cortina/gemini.c
+++ b/drivers/net/ethernet/cortina/gemini.c
@@ -1920,7 +1920,7 @@ static void gmac_get_stats64(struct net_
 
 	/* Racing with RX NAPI */
 	do {
-		start = u64_stats_fetch_begin(&port->rx_stats_syncp);
+		start = u64_stats_fetch_begin_irq(&port->rx_stats_syncp);
 
 		stats->rx_packets = port->stats.rx_packets;
 		stats->rx_bytes = port->stats.rx_bytes;
@@ -1932,11 +1932,11 @@ static void gmac_get_stats64(struct net_
 		stats->rx_crc_errors = port->stats.rx_crc_errors;
 		stats->rx_frame_errors = port->stats.rx_frame_errors;
 
-	} while (u64_stats_fetch_retry(&port->rx_stats_syncp, start));
+	} while (u64_stats_fetch_retry_irq(&port->rx_stats_syncp, start));
 
 	/* Racing with MIB and TX completion interrupts */
 	do {
-		start = u64_stats_fetch_begin(&port->ir_stats_syncp);
+		start = u64_stats_fetch_begin_irq(&port->ir_stats_syncp);
 
 		stats->tx_errors = port->stats.tx_errors;
 		stats->tx_packets = port->stats.tx_packets;
@@ -1946,15 +1946,15 @@ static void gmac_get_stats64(struct net_
 		stats->rx_missed_errors = port->stats.rx_missed_errors;
 		stats->rx_fifo_errors = port->stats.rx_fifo_errors;
 
-	} while (u64_stats_fetch_retry(&port->ir_stats_syncp, start));
+	} while (u64_stats_fetch_retry_irq(&port->ir_stats_syncp, start));
 
 	/* Racing with hard_start_xmit */
 	do {
-		start = u64_stats_fetch_begin(&port->tx_stats_syncp);
+		start = u64_stats_fetch_begin_irq(&port->tx_stats_syncp);
 
 		stats->tx_dropped = port->stats.tx_dropped;
 
-	} while (u64_stats_fetch_retry(&port->tx_stats_syncp, start));
+	} while (u64_stats_fetch_retry_irq(&port->tx_stats_syncp, start));
 
 	stats->rx_dropped += stats->rx_missed_errors;
 }
@@ -2032,18 +2032,18 @@ static void gmac_get_ethtool_stats(struc
 	/* Racing with MIB interrupt */
 	do {
 		p = values;
-		start = u64_stats_fetch_begin(&port->ir_stats_syncp);
+		start = u64_stats_fetch_begin_irq(&port->ir_stats_syncp);
 
 		for (i = 0; i < RX_STATS_NUM; i++)
 			*p++ = port->hw_stats[i];
 
-	} while (u64_stats_fetch_retry(&port->ir_stats_syncp, start));
+	} while (u64_stats_fetch_retry_irq(&port->ir_stats_syncp, start));
 	values = p;
 
 	/* Racing with RX NAPI */
 	do {
 		p = values;
-		start = u64_stats_fetch_begin(&port->rx_stats_syncp);
+		start = u64_stats_fetch_begin_irq(&port->rx_stats_syncp);
 
 		for (i = 0; i < RX_STATUS_NUM; i++)
 			*p++ = port->rx_stats[i];
@@ -2051,13 +2051,13 @@ static void gmac_get_ethtool_stats(struc
 			*p++ = port->rx_csum_stats[i];
 		*p++ = port->rx_napi_exits;
 
-	} while (u64_stats_fetch_retry(&port->rx_stats_syncp, start));
+	} while (u64_stats_fetch_retry_irq(&port->rx_stats_syncp, start));
 	values = p;
 
 	/* Racing with TX start_xmit */
 	do {
 		p = values;
-		start = u64_stats_fetch_begin(&port->tx_stats_syncp);
+		start = u64_stats_fetch_begin_irq(&port->tx_stats_syncp);
 
 		for (i = 0; i < TX_MAX_FRAGS; i++) {
 			*values++ = port->tx_frag_stats[i];
@@ -2066,7 +2066,7 @@ static void gmac_get_ethtool_stats(struc
 		*values++ = port->tx_frags_linearized;
 		*values++ = port->tx_hw_csummed;
 
-	} while (u64_stats_fetch_retry(&port->tx_stats_syncp, start));
+	} while (u64_stats_fetch_retry_irq(&port->tx_stats_syncp, start));
 }
 
 static int gmac_get_ksettings(struct net_device *netdev,
--- a/drivers/net/ethernet/google/gve/gve_ethtool.c
+++ b/drivers/net/ethernet/google/gve/gve_ethtool.c
@@ -172,14 +172,14 @@ gve_get_ethtool_stats(struct net_device
 				struct gve_rx_ring *rx = &priv->rx[ring];
 
 				start =
-				  u64_stats_fetch_begin(&priv->rx[ring].statss);
+				  u64_stats_fetch_begin_irq(&priv->rx[ring].statss);
 				tmp_rx_pkts = rx->rpackets;
 				tmp_rx_bytes = rx->rbytes;
 				tmp_rx_skb_alloc_fail = rx->rx_skb_alloc_fail;
 				tmp_rx_buf_alloc_fail = rx->rx_buf_alloc_fail;
 				tmp_rx_desc_err_dropped_pkt =
 					rx->rx_desc_err_dropped_pkt;
-			} while (u64_stats_fetch_retry(&priv->rx[ring].statss,
+			} while (u64_stats_fetch_retry_irq(&priv->rx[ring].statss,
 						       start));
 			rx_pkts += tmp_rx_pkts;
 			rx_bytes += tmp_rx_bytes;
@@ -193,10 +193,10 @@ gve_get_ethtool_stats(struct net_device
 		if (priv->tx) {
 			do {
 				start =
-				  u64_stats_fetch_begin(&priv->tx[ring].statss);
+				  u64_stats_fetch_begin_irq(&priv->tx[ring].statss);
 				tmp_tx_pkts = priv->tx[ring].pkt_done;
 				tmp_tx_bytes = priv->tx[ring].bytes_done;
-			} while (u64_stats_fetch_retry(&priv->tx[ring].statss,
+			} while (u64_stats_fetch_retry_irq(&priv->tx[ring].statss,
 						       start));
 			tx_pkts += tmp_tx_pkts;
 			tx_bytes += tmp_tx_bytes;
@@ -254,13 +254,13 @@ gve_get_ethtool_stats(struct net_device
 			data[i++] = rx->cnt;
 			do {
 				start =
-				  u64_stats_fetch_begin(&priv->rx[ring].statss);
+				  u64_stats_fetch_begin_irq(&priv->rx[ring].statss);
 				tmp_rx_bytes = rx->rbytes;
 				tmp_rx_skb_alloc_fail = rx->rx_skb_alloc_fail;
 				tmp_rx_buf_alloc_fail = rx->rx_buf_alloc_fail;
 				tmp_rx_desc_err_dropped_pkt =
 					rx->rx_desc_err_dropped_pkt;
-			} while (u64_stats_fetch_retry(&priv->rx[ring].statss,
+			} while (u64_stats_fetch_retry_irq(&priv->rx[ring].statss,
 						       start));
 			data[i++] = tmp_rx_bytes;
 			/* rx dropped packets */
@@ -313,9 +313,9 @@ gve_get_ethtool_stats(struct net_device
 			data[i++] = tx->done;
 			do {
 				start =
-				  u64_stats_fetch_begin(&priv->tx[ring].statss);
+				  u64_stats_fetch_begin_irq(&priv->tx[ring].statss);
 				tmp_tx_bytes = tx->bytes_done;
-			} while (u64_stats_fetch_retry(&priv->tx[ring].statss,
+			} while (u64_stats_fetch_retry_irq(&priv->tx[ring].statss,
 						       start));
 			data[i++] = tmp_tx_bytes;
 			data[i++] = tx->wake_queue;
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -40,10 +40,10 @@ static void gve_get_stats(struct net_dev
 		for (ring = 0; ring < priv->rx_cfg.num_queues; ring++) {
 			do {
 				start =
-				  u64_stats_fetch_begin(&priv->rx[ring].statss);
+				  u64_stats_fetch_begin_irq(&priv->rx[ring].statss);
 				packets = priv->rx[ring].rpackets;
 				bytes = priv->rx[ring].rbytes;
-			} while (u64_stats_fetch_retry(&priv->rx[ring].statss,
+			} while (u64_stats_fetch_retry_irq(&priv->rx[ring].statss,
 						       start));
 			s->rx_packets += packets;
 			s->rx_bytes += bytes;
@@ -53,10 +53,10 @@ static void gve_get_stats(struct net_dev
 		for (ring = 0; ring < priv->tx_cfg.num_queues; ring++) {
 			do {
 				start =
-				  u64_stats_fetch_begin(&priv->tx[ring].statss);
+				  u64_stats_fetch_begin_irq(&priv->tx[ring].statss);
 				packets = priv->tx[ring].pkt_done;
 				bytes = priv->tx[ring].bytes_done;
-			} while (u64_stats_fetch_retry(&priv->tx[ring].statss,
+			} while (u64_stats_fetch_retry_irq(&priv->tx[ring].statss,
 						       start));
 			s->tx_packets += packets;
 			s->tx_bytes += bytes;
@@ -1041,9 +1041,9 @@ void gve_handle_report_stats(struct gve_
 	if (priv->tx) {
 		for (idx = 0; idx < priv->tx_cfg.num_queues; idx++) {
 			do {
-				start = u64_stats_fetch_begin(&priv->tx[idx].statss);
+				start = u64_stats_fetch_begin_irq(&priv->tx[idx].statss);
 				tx_bytes = priv->tx[idx].bytes_done;
-			} while (u64_stats_fetch_retry(&priv->tx[idx].statss, start));
+			} while (u64_stats_fetch_retry_irq(&priv->tx[idx].statss, start));
 			stats[stats_idx++] = (struct stats) {
 				.stat_name = cpu_to_be32(TX_WAKE_CNT),
 				.value = cpu_to_be64(priv->tx[idx].wake_queue),
--- a/drivers/net/ethernet/huawei/hinic/hinic_rx.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_rx.c
@@ -74,14 +74,14 @@ void hinic_rxq_get_stats(struct hinic_rx
 	unsigned int start;
 
 	do {
-		start = u64_stats_fetch_begin(&rxq_stats->syncp);
+		start = u64_stats_fetch_begin_irq(&rxq_stats->syncp);
 		stats->pkts = rxq_stats->pkts;
 		stats->bytes = rxq_stats->bytes;
 		stats->errors = rxq_stats->csum_errors +
 				rxq_stats->other_errors;
 		stats->csum_errors = rxq_stats->csum_errors;
 		stats->other_errors = rxq_stats->other_errors;
-	} while (u64_stats_fetch_retry(&rxq_stats->syncp, start));
+	} while (u64_stats_fetch_retry_irq(&rxq_stats->syncp, start));
 }
 
 /**
--- a/drivers/net/ethernet/huawei/hinic/hinic_tx.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_tx.c
@@ -98,14 +98,14 @@ void hinic_txq_get_stats(struct hinic_tx
 	unsigned int start;
 
 	do {
-		start = u64_stats_fetch_begin(&txq_stats->syncp);
+		start = u64_stats_fetch_begin_irq(&txq_stats->syncp);
 		stats->pkts    = txq_stats->pkts;
 		stats->bytes   = txq_stats->bytes;
 		stats->tx_busy = txq_stats->tx_busy;
 		stats->tx_wake = txq_stats->tx_wake;
 		stats->tx_dropped = txq_stats->tx_dropped;
 		stats->big_frags_pkts = txq_stats->big_frags_pkts;
-	} while (u64_stats_fetch_retry(&txq_stats->syncp, start));
+	} while (u64_stats_fetch_retry_irq(&txq_stats->syncp, start));
 }
 
 /**
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -3373,21 +3373,21 @@ static void nfp_net_stat64(struct net_de
 		unsigned int start;
 
 		do {
-			start = u64_stats_fetch_begin(&r_vec->rx_sync);
+			start = u64_stats_fetch_begin_irq(&r_vec->rx_sync);
 			data[0] = r_vec->rx_pkts;
 			data[1] = r_vec->rx_bytes;
 			data[2] = r_vec->rx_drops;
-		} while (u64_stats_fetch_retry(&r_vec->rx_sync, start));
+		} while (u64_stats_fetch_retry_irq(&r_vec->rx_sync, start));
 		stats->rx_packets += data[0];
 		stats->rx_bytes += data[1];
 		stats->rx_dropped += data[2];
 
 		do {
-			start = u64_stats_fetch_begin(&r_vec->tx_sync);
+			start = u64_stats_fetch_begin_irq(&r_vec->tx_sync);
 			data[0] = r_vec->tx_pkts;
 			data[1] = r_vec->tx_bytes;
 			data[2] = r_vec->tx_errors;
-		} while (u64_stats_fetch_retry(&r_vec->tx_sync, start));
+		} while (u64_stats_fetch_retry_irq(&r_vec->tx_sync, start));
 		stats->tx_packets += data[0];
 		stats->tx_bytes += data[1];
 		stats->tx_errors += data[2];
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
@@ -494,7 +494,7 @@ static u64 *nfp_vnic_get_sw_stats(struct
 		unsigned int start;
 
 		do {
-			start = u64_stats_fetch_begin(&nn->r_vecs[i].rx_sync);
+			start = u64_stats_fetch_begin_irq(&nn->r_vecs[i].rx_sync);
 			data[0] = nn->r_vecs[i].rx_pkts;
 			tmp[0] = nn->r_vecs[i].hw_csum_rx_ok;
 			tmp[1] = nn->r_vecs[i].hw_csum_rx_inner_ok;
@@ -502,10 +502,10 @@ static u64 *nfp_vnic_get_sw_stats(struct
 			tmp[3] = nn->r_vecs[i].hw_csum_rx_error;
 			tmp[4] = nn->r_vecs[i].rx_replace_buf_alloc_fail;
 			tmp[5] = nn->r_vecs[i].hw_tls_rx;
-		} while (u64_stats_fetch_retry(&nn->r_vecs[i].rx_sync, start));
+		} while (u64_stats_fetch_retry_irq(&nn->r_vecs[i].rx_sync, start));
 
 		do {
-			start = u64_stats_fetch_begin(&nn->r_vecs[i].tx_sync);
+			start = u64_stats_fetch_begin_irq(&nn->r_vecs[i].tx_sync);
 			data[1] = nn->r_vecs[i].tx_pkts;
 			data[2] = nn->r_vecs[i].tx_busy;
 			tmp[6] = nn->r_vecs[i].hw_csum_tx;
@@ -515,7 +515,7 @@ static u64 *nfp_vnic_get_sw_stats(struct
 			tmp[10] = nn->r_vecs[i].hw_tls_tx;
 			tmp[11] = nn->r_vecs[i].tls_tx_fallback;
 			tmp[12] = nn->r_vecs[i].tls_tx_no_fallback;
-		} while (u64_stats_fetch_retry(&nn->r_vecs[i].tx_sync, start));
+		} while (u64_stats_fetch_retry_irq(&nn->r_vecs[i].tx_sync, start));
 
 		data += NN_RVEC_PER_Q_STATS;
 
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -67,10 +67,10 @@ nsim_get_stats64(struct net_device *dev,
 	unsigned int start;
 
 	do {
-		start = u64_stats_fetch_begin(&ns->syncp);
+		start = u64_stats_fetch_begin_irq(&ns->syncp);
 		stats->tx_bytes = ns->tx_bytes;
 		stats->tx_packets = ns->tx_packets;
-	} while (u64_stats_fetch_retry(&ns->syncp, start));
+	} while (u64_stats_fetch_retry_irq(&ns->syncp, start));
 }
 
 static int
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2175,9 +2175,9 @@ static inline u64 sta_get_tidstats_msdu(
 	u64 value;
 
 	do {
-		start = u64_stats_fetch_begin(&rxstats->syncp);
+		start = u64_stats_fetch_begin_irq(&rxstats->syncp);
 		value = rxstats->msdu[tid];
-	} while (u64_stats_fetch_retry(&rxstats->syncp, start));
+	} while (u64_stats_fetch_retry_irq(&rxstats->syncp, start));
 
 	return value;
 }
@@ -2241,9 +2241,9 @@ static inline u64 sta_get_stats_bytes(st
 	u64 value;
 
 	do {
-		start = u64_stats_fetch_begin(&rxstats->syncp);
+		start = u64_stats_fetch_begin_irq(&rxstats->syncp);
 		value = rxstats->bytes;
-	} while (u64_stats_fetch_retry(&rxstats->syncp, start));
+	} while (u64_stats_fetch_retry_irq(&rxstats->syncp, start));
 
 	return value;
 }
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -1078,9 +1078,9 @@ static void mpls_get_stats(struct mpls_d
 
 		p = per_cpu_ptr(mdev->stats, i);
 		do {
-			start = u64_stats_fetch_begin(&p->syncp);
+			start = u64_stats_fetch_begin_irq(&p->syncp);
 			local = p->stats;
-		} while (u64_stats_fetch_retry(&p->syncp, start));
+		} while (u64_stats_fetch_retry_irq(&p->syncp, start));
 
 		stats->rx_packets	+= local.rx_packets;
 		stats->rx_bytes		+= local.rx_bytes;