From: Eric Dumazet edumazet@google.com
[ Upstream commit 2f57d4975fa027eabd35fdf23a49f8222ef3abf2 ]
gve_get_stats() can report wrong numbers if/when u64_stats_fetch_retry() returns true.
What is needed here is to sample values in temporary variables, and only use them after each loop is ended.
Fixes: f5cedc84a30d ("gve: Add transmit and receive support") Signed-off-by: Eric Dumazet edumazet@google.com Cc: Catherine Sullivan csully@google.com Cc: Sagi Shahar sagis@google.com Cc: Jon Olson jonolson@google.com Cc: Willem de Bruijn willemb@google.com Cc: Luigi Rizzo lrizzo@google.com Cc: Jeroen de Borst jeroendb@google.com Cc: Tao Liu xliutaox@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/google/gve/gve_main.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c index f8dfa7501f65..5b450c6100ad 100644 --- a/drivers/net/ethernet/google/gve/gve_main.c +++ b/drivers/net/ethernet/google/gve/gve_main.c @@ -30,6 +30,7 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s) { struct gve_priv *priv = netdev_priv(dev); unsigned int start; + u64 packets, bytes; int ring;
if (priv->rx) { @@ -37,10 +38,12 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s) do { start = u64_stats_fetch_begin(&priv->rx[ring].statss); - s->rx_packets += priv->rx[ring].rpackets; - s->rx_bytes += priv->rx[ring].rbytes; + packets = priv->rx[ring].rpackets; + bytes = priv->rx[ring].rbytes; } while (u64_stats_fetch_retry(&priv->rx[ring].statss, start)); + s->rx_packets += packets; + s->rx_bytes += bytes; } } if (priv->tx) { @@ -48,10 +51,12 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s) do { start = u64_stats_fetch_begin(&priv->tx[ring].statss); - s->tx_packets += priv->tx[ring].pkt_done; - s->tx_bytes += priv->tx[ring].bytes_done; + packets = priv->tx[ring].pkt_done; + bytes = priv->tx[ring].bytes_done; } while (u64_stats_fetch_retry(&priv->tx[ring].statss, start)); + s->tx_packets += packets; + s->tx_bytes += bytes; } } }