typhoon: fix a race in typhoon_do_get_stats

Its important to store 'final' values in counters,
not using them as temporary variables,
or this might break some SNMP applications.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Dillow <dave@thedillows.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 24 deletions

diff --git a/drivers/net/typhoon.c b/drivers/net/typhoon.c
index 2e50077ff450..3f4681f78262 100644
--- a/drivers/net/typhoon.c
+++ b/drivers/net/typhoon.c
@@ -962,36 +962,34 @@ typhoon_do_get_stats(struct typhoon *tp)
          * The extra status reported would be a good candidate for
          * ethtool_ops->get_{strings,stats}()
          */
-        stats->tx_packets = le32_to_cpu(s->txPackets);
-        stats->tx_bytes = le64_to_cpu(s->txBytes);
-        stats->tx_errors = le32_to_cpu(s->txCarrierLost);
-        stats->tx_carrier_errors = le32_to_cpu(s->txCarrierLost);
-        stats->collisions = le32_to_cpu(s->txMultipleCollisions);
-        stats->rx_packets = le32_to_cpu(s->rxPacketsGood);
-        stats->rx_bytes = le64_to_cpu(s->rxBytesGood);
-        stats->rx_fifo_errors = le32_to_cpu(s->rxFifoOverruns);
+        stats->tx_packets = le32_to_cpu(s->txPackets) +
+                        saved->tx_packets;
+        stats->tx_bytes = le64_to_cpu(s->txBytes) +
+                        saved->tx_bytes;
+        stats->tx_errors = le32_to_cpu(s->txCarrierLost) +
+                        saved->tx_errors;
+        stats->tx_carrier_errors = le32_to_cpu(s->txCarrierLost) +
+                        saved->tx_carrier_errors;
+        stats->collisions = le32_to_cpu(s->txMultipleCollisions) +
+                        saved->collisions;
+        stats->rx_packets = le32_to_cpu(s->rxPacketsGood) +
+                        saved->rx_packets;
+        stats->rx_bytes = le64_to_cpu(s->rxBytesGood) +
+                        saved->rx_bytes;
+        stats->rx_fifo_errors = le32_to_cpu(s->rxFifoOverruns) +
+                        saved->rx_fifo_errors;
         stats->rx_errors = le32_to_cpu(s->rxFifoOverruns) +
-                        le32_to_cpu(s->BadSSD) + le32_to_cpu(s->rxCrcErrors);
-        stats->rx_crc_errors = le32_to_cpu(s->rxCrcErrors);
-        stats->rx_length_errors = le32_to_cpu(s->rxOversized);
+                        le32_to_cpu(s->BadSSD) + le32_to_cpu(s->rxCrcErrors) +
+                        saved->rx_errors;
+        stats->rx_crc_errors = le32_to_cpu(s->rxCrcErrors) +
+                        saved->rx_crc_errors;
+        stats->rx_length_errors = le32_to_cpu(s->rxOversized) +
+                        saved->rx_length_errors;
         tp->speed = (s->linkStatus & TYPHOON_LINK_100MBPS) ?
                         SPEED_100 : SPEED_10;
         tp->duplex = (s->linkStatus & TYPHOON_LINK_FULL_DUPLEX) ?
                         DUPLEX_FULL : DUPLEX_HALF;
 
-        /* add in the saved statistics
-         */
-        stats->tx_packets += saved->tx_packets;
-        stats->tx_bytes += saved->tx_bytes;
-        stats->tx_errors += saved->tx_errors;
-        stats->collisions += saved->collisions;
-        stats->rx_packets += saved->rx_packets;
-        stats->rx_bytes += saved->rx_bytes;
-        stats->rx_fifo_errors += saved->rx_fifo_errors;
-        stats->rx_errors += saved->rx_errors;
-        stats->rx_crc_errors += saved->rx_crc_errors;
-        stats->rx_length_errors += saved->rx_length_errors;
-
         return 0;
 }