From 278d3ba61563ceed3cb248383ced19e14ec7bc1f Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 25 Aug 2022 13:36:45 +0200 Subject: 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" Cc: Catherine Sullivan Cc: David Awogbemila Cc: Dimitris Michailidis Cc: Eric Dumazet Cc: Hans Ulli Kroll Cc: Jakub Kicinski Cc: Jeroen de Borst Cc: Johannes Berg Cc: Linus Walleij Cc: Paolo Abeni Cc: Simon Horman 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: Sebastian Andrzej Siewior Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- drivers/net/ethernet/google/gve/gve_ethtool.c | 16 ++++++++-------- drivers/net/ethernet/google/gve/gve_main.c | 12 ++++++------ 2 files changed, 14 insertions(+), 14 deletions(-) (limited to 'drivers/net/ethernet/google/gve') diff --git a/drivers/net/ethernet/google/gve/gve_ethtool.c b/drivers/net/ethernet/google/gve/gve_ethtool.c index 50b384910c83..7b9a2d9d9624 100644 --- a/drivers/net/ethernet/google/gve/gve_ethtool.c +++ b/drivers/net/ethernet/google/gve/gve_ethtool.c @@ -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; diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c index 6cafee55efc3..044db3ebb071 100644 --- a/drivers/net/ethernet/google/gve/gve_main.c +++ b/drivers/net/ethernet/google/gve/gve_main.c @@ -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), -- cgit