From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 29811d6e19d795efcf26644b66c4152abbac35a6 ]
DPNIs and DPSW objects can connect and disconnect at runtime from DPMAC objects on the same fsl-mc bus. The DPMAC object also holds "ethtool -S" unstructured counters. Those counters are only shown for the entity owning the netdev (DPNI, DPSW) if it's connected to a DPMAC.
The ethtool stringset code path is split into multiple callbacks, but currently, connecting and disconnecting the DPMAC takes the rtnl_lock(). This blocks the entire ethtool code path from running, see ethnl_default_doit() -> rtnl_lock() -> ops->prepare_data() -> strset_prepare_data().
This is going to be a problem if we are going to no longer require rtnl_lock() when connecting/disconnecting the DPMAC, because the DPMAC could appear between ops->get_sset_count() and ops->get_strings(). If it appears out of the blue, we will provide a stringset into an array that was dimensioned thinking the DPMAC wouldn't be there => array accessed out of bounds.
There isn't really a good way to work around that, and I don't want to put too much pressure on the ethtool framework by playing locking games. Just make the DPMAC counters be always available. They'll be zeroes if the DPNI or DPSW isn't connected to a DPMAC.
Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Reviewed-by: Andrew Lunn andrew@lunn.ch Reviewed-by: Ioana Ciornei ioana.ciornei@nxp.com Tested-by: Ioana Ciornei ioana.ciornei@nxp.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c | 12 +++--------- .../ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c | 11 ++--------- 2 files changed, 5 insertions(+), 18 deletions(-)
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c index eea7d7a07c00..8381cbdb9461 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c @@ -186,7 +186,6 @@ static int dpaa2_eth_set_pauseparam(struct net_device *net_dev, static void dpaa2_eth_get_strings(struct net_device *netdev, u32 stringset, u8 *data) { - struct dpaa2_eth_priv *priv = netdev_priv(netdev); u8 *p = data; int i;
@@ -200,22 +199,17 @@ static void dpaa2_eth_get_strings(struct net_device *netdev, u32 stringset, strscpy(p, dpaa2_ethtool_extras[i], ETH_GSTRING_LEN); p += ETH_GSTRING_LEN; } - if (dpaa2_eth_has_mac(priv)) - dpaa2_mac_get_strings(p); + dpaa2_mac_get_strings(p); break; } }
static int dpaa2_eth_get_sset_count(struct net_device *net_dev, int sset) { - int num_ss_stats = DPAA2_ETH_NUM_STATS + DPAA2_ETH_NUM_EXTRA_STATS; - struct dpaa2_eth_priv *priv = netdev_priv(net_dev); - switch (sset) { case ETH_SS_STATS: /* ethtool_get_stats(), ethtool_get_drvinfo() */ - if (dpaa2_eth_has_mac(priv)) - num_ss_stats += dpaa2_mac_get_sset_count(); - return num_ss_stats; + return DPAA2_ETH_NUM_STATS + DPAA2_ETH_NUM_EXTRA_STATS + + dpaa2_mac_get_sset_count(); default: return -EOPNOTSUPP; } diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c index 720c9230cab5..40ee57ef55be 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch-ethtool.c @@ -145,14 +145,9 @@ dpaa2_switch_set_link_ksettings(struct net_device *netdev, static int dpaa2_switch_ethtool_get_sset_count(struct net_device *netdev, int sset) { - struct ethsw_port_priv *port_priv = netdev_priv(netdev); - int num_ss_stats = DPAA2_SWITCH_NUM_COUNTERS; - switch (sset) { case ETH_SS_STATS: - if (port_priv->mac) - num_ss_stats += dpaa2_mac_get_sset_count(); - return num_ss_stats; + return DPAA2_SWITCH_NUM_COUNTERS + dpaa2_mac_get_sset_count(); default: return -EOPNOTSUPP; } @@ -161,7 +156,6 @@ dpaa2_switch_ethtool_get_sset_count(struct net_device *netdev, int sset) static void dpaa2_switch_ethtool_get_strings(struct net_device *netdev, u32 stringset, u8 *data) { - struct ethsw_port_priv *port_priv = netdev_priv(netdev); u8 *p = data; int i;
@@ -172,8 +166,7 @@ static void dpaa2_switch_ethtool_get_strings(struct net_device *netdev, ETH_GSTRING_LEN); p += ETH_GSTRING_LEN; } - if (port_priv->mac) - dpaa2_mac_get_strings(p); + dpaa2_mac_get_strings(p); break; } }