From 15970e1b23f5c25db88c613fddf9131de086f28e Mon Sep 17 00:00:00 2001 From: Joshua Washington Date: Wed, 2 Apr 2025 00:10:37 +0000 Subject: [PATCH] gve: handle overflow when reporting TX consumed descriptors When the tx tail is less than the head (in cases of wraparound), the TX consumed descriptor statistic in DQ will be reported as UINT32_MAX - head + tail, which is incorrect. Mask the difference of head and tail according to the ring size when reporting the statistic. Cc: stable@vger.kernel.org Fixes: 2c9198356d56 ("gve: Add consumed counts to ethtool stats") Signed-off-by: Joshua Washington Signed-off-by: Harshitha Ramamurthy Reviewed-by: Michal Swiatkowski Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250402001037.2717315-1-hramamurthy@google.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/google/gve/gve_ethtool.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/google/gve/gve_ethtool.c b/drivers/net/ethernet/google/gve/gve_ethtool.c index 31a21ccf4863..4dea1fdce748 100644 --- a/drivers/net/ethernet/google/gve/gve_ethtool.c +++ b/drivers/net/ethernet/google/gve/gve_ethtool.c @@ -392,7 +392,9 @@ gve_get_ethtool_stats(struct net_device *netdev, */ data[i++] = 0; data[i++] = 0; - data[i++] = tx->dqo_tx.tail - tx->dqo_tx.head; + data[i++] = + (tx->dqo_tx.tail - tx->dqo_tx.head) & + tx->mask; } do { start =