The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 18d8e67df184081bc6ce6220a2dd965cfd3d7e6b Mon Sep 17 00:00:00 2001
From: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Date: Tue, 16 Aug 2022 16:53:49 +0300
Subject: [PATCH] net: mscc: ocelot: fix race between ndo_get_stats64 and
ocelot_check_stats_work
The 2 methods can run concurrently, and one will change the window of
counters (SYS_STAT_CFG_STAT_VIEW) that the other sees. The fix is
similar to what commit 7fbf6795d127 ("net: mscc: ocelot: fix mutex lock
error during ethtool stats read") has done for ethtool -S.
Fixes: a556c76adc05 ("net: mscc: Add initial Ocelot switch support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 9d8cea16245e..6b9d37138844 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -726,6 +726,8 @@ static void ocelot_get_stats64(struct net_device *dev,
struct ocelot *ocelot = priv->port.ocelot;
int port = priv->port.index;
+ spin_lock(&ocelot->stats_lock);
+
/* Configure the port to read the stats from */
ocelot_write(ocelot, SYS_STAT_CFG_STAT_VIEW(port),
SYS_STAT_CFG);
@@ -758,6 +760,8 @@ static void ocelot_get_stats64(struct net_device *dev,
stats->tx_dropped = ocelot_read(ocelot, SYS_COUNT_TX_DROPS) +
ocelot_read(ocelot, SYS_COUNT_TX_AGING);
stats->collisions = ocelot_read(ocelot, SYS_COUNT_TX_COLLISION);
+
+ spin_unlock(&ocelot->stats_lock);
}
static int ocelot_port_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
