Commit 278d3ba6 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by David S. Miller
Browse files

net: Use u64_stats_fetch_begin_irq() for stats fetch. 



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" <davem@davemloft.net>
Cc: Catherine Sullivan <csully@google.com>
Cc: David Awogbemila <awogbemila@google.com>
Cc: Dimitris Michailidis <dmichail@fungible.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jeroen de Borst <jeroendb@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <simon.horman@corigine.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: oss-drivers@corigine.com
Cc: stable@vger.kernel.org
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: default avatarSimon Horman <simon.horman@corigine.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3f8ae9fe

drivers/net/ethernet/cortina/gemini.c

+12 −12
Original line number Diff line number Diff line
@@ -1919,7 +1919,7 @@ static void gmac_get_stats64(struct net_device *netdev, 


	/* 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;
@@ -1931,11 +1931,11 @@ static void gmac_get_stats64(struct net_device *netdev, 
		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;
@@ -1945,15 +1945,15 @@ static void gmac_get_stats64(struct net_device *netdev, 
		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;

}
@@ -2031,18 +2031,18 @@ static void gmac_get_ethtool_stats(struct net_device *netdev, 
	/* 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];
@@ -2050,13 +2050,13 @@ static void gmac_get_ethtool_stats(struct net_device *netdev, 
			*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];
@@ -2065,7 +2065,7 @@ static void gmac_get_ethtool_stats(struct net_device *netdev, 
		*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,

drivers/net/ethernet/fungible/funeth/funeth_txrx.h

+2 −2
Original line number Diff line number Diff line
@@ -206,9 +206,9 @@ struct funeth_rxq { 


#define FUN_QSTAT_READ(q, seq, stats_copy) \

	do { \

		seq = u64_stats_fetch_begin(&(q)->syncp); \

		seq = u64_stats_fetch_begin_irq(&(q)->syncp); \

		stats_copy = (q)->stats; \

	} while (u64_stats_fetch_retry(&(q)->syncp, (seq)))

	} while (u64_stats_fetch_retry_irq(&(q)->syncp, (seq)))



#define FUN_INT_NAME_LEN (IFNAMSIZ + 16)

drivers/net/ethernet/google/gve/gve_ethtool.c

+8 −8
Original line number Diff line number Diff line
@@ -177,14 +177,14 @@ gve_get_ethtool_stats(struct net_device *netdev, 
				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;
@@ -198,10 +198,10 @@ gve_get_ethtool_stats(struct net_device *netdev, 
		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;
@@ -259,13 +259,13 @@ gve_get_ethtool_stats(struct net_device *netdev, 
			data[i++] = rx->fill_cnt - 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;

			data[i++] = rx->rx_cont_packet_cnt;
@@ -331,9 +331,9 @@ gve_get_ethtool_stats(struct net_device *netdev, 
			}

			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;

drivers/net/ethernet/google/gve/gve_main.c

+6 −6
Original line number Diff line number Diff line
@@ -51,10 +51,10 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s) 
		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;
@@ -64,10 +64,10 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s) 
		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;
@@ -1274,9 +1274,9 @@ void gve_handle_report_stats(struct gve_priv *priv) 
			}



			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),

drivers/net/ethernet/huawei/hinic/hinic_rx.c

+2 −2
Original line number Diff line number Diff line
@@ -74,14 +74,14 @@ void hinic_rxq_get_stats(struct hinic_rxq *rxq, struct hinic_rxq_stats *stats) 
	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));

}



/**