6.5-stable review patch. If anyone has any objections, please let me know.
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From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit ea32690daf4fa525dc5a4d164bd00ed8c756e1c6 ]
sja1105_fdb_add() runs from the dsa_owq, and sja1105_port_mcast_flood() runs from switchdev_deferred_process_work(). Prior to the blamed commit, they used to be indirectly serialized through the rtnl_lock(), which no longer holds true because dsa_owq dropped that.
So, it is now possible that we traverse the static config BLK_IDX_L2_LOOKUP elements concurrently compared to when we change them, in sja1105_static_fdb_change(). That is not ideal, since it might result in data corruption.
Introduce a mutex which serializes accesses to the hardware FDB and to the static config elements for the L2 Address Lookup table.
I can't find a good reason to add locking around sja1105_fdb_dump(). I'll add it later if needed.
Fixes: 0faf890fc519 ("net: dsa: drop rtnl_lock from dsa_slave_switchdev_event_work") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/dsa/sja1105/sja1105.h | 2 + drivers/net/dsa/sja1105/sja1105_main.c | 56 ++++++++++++++++++++------ 2 files changed, 45 insertions(+), 13 deletions(-)
diff --git a/drivers/net/dsa/sja1105/sja1105.h b/drivers/net/dsa/sja1105/sja1105.h index 0617d5ccd3ff1..8c66d3bf61f02 100644 --- a/drivers/net/dsa/sja1105/sja1105.h +++ b/drivers/net/dsa/sja1105/sja1105.h @@ -266,6 +266,8 @@ struct sja1105_private { * the switch doesn't confuse them with one another. */ struct mutex mgmt_lock; + /* Serializes accesses to the FDB */ + struct mutex fdb_lock; /* PTP two-step TX timestamp ID, and its serialization lock */ spinlock_t ts_id_lock; u8 ts_id; diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c index ba65a95b0c372..79927191ac623 100644 --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -1805,6 +1805,7 @@ static int sja1105_fdb_add(struct dsa_switch *ds, int port, struct dsa_db db) { struct sja1105_private *priv = ds->priv; + int rc;
if (!vid) { switch (db.type) { @@ -1819,12 +1820,16 @@ static int sja1105_fdb_add(struct dsa_switch *ds, int port, } }
- return priv->info->fdb_add_cmd(ds, port, addr, vid); + mutex_lock(&priv->fdb_lock); + rc = priv->info->fdb_add_cmd(ds, port, addr, vid); + mutex_unlock(&priv->fdb_lock); + + return rc; }
-static int sja1105_fdb_del(struct dsa_switch *ds, int port, - const unsigned char *addr, u16 vid, - struct dsa_db db) +static int __sja1105_fdb_del(struct dsa_switch *ds, int port, + const unsigned char *addr, u16 vid, + struct dsa_db db) { struct sja1105_private *priv = ds->priv;
@@ -1844,6 +1849,20 @@ static int sja1105_fdb_del(struct dsa_switch *ds, int port, return priv->info->fdb_del_cmd(ds, port, addr, vid); }
+static int sja1105_fdb_del(struct dsa_switch *ds, int port, + const unsigned char *addr, u16 vid, + struct dsa_db db) +{ + struct sja1105_private *priv = ds->priv; + int rc; + + mutex_lock(&priv->fdb_lock); + rc = __sja1105_fdb_del(ds, port, addr, vid, db); + mutex_unlock(&priv->fdb_lock); + + return rc; +} + static int sja1105_fdb_dump(struct dsa_switch *ds, int port, dsa_fdb_dump_cb_t *cb, void *data) { @@ -1906,6 +1925,8 @@ static void sja1105_fast_age(struct dsa_switch *ds, int port) }; int i;
+ mutex_lock(&priv->fdb_lock); + for (i = 0; i < SJA1105_MAX_L2_LOOKUP_COUNT; i++) { struct sja1105_l2_lookup_entry l2_lookup = {0}; u8 macaddr[ETH_ALEN]; @@ -1919,7 +1940,7 @@ static void sja1105_fast_age(struct dsa_switch *ds, int port) if (rc) { dev_err(ds->dev, "Failed to read FDB: %pe\n", ERR_PTR(rc)); - return; + break; }
if (!(l2_lookup.destports & BIT(port))) @@ -1931,14 +1952,16 @@ static void sja1105_fast_age(struct dsa_switch *ds, int port)
u64_to_ether_addr(l2_lookup.macaddr, macaddr);
- rc = sja1105_fdb_del(ds, port, macaddr, l2_lookup.vlanid, db); + rc = __sja1105_fdb_del(ds, port, macaddr, l2_lookup.vlanid, db); if (rc) { dev_err(ds->dev, "Failed to delete FDB entry %pM vid %lld: %pe\n", macaddr, l2_lookup.vlanid, ERR_PTR(rc)); - return; + break; } } + + mutex_unlock(&priv->fdb_lock); }
static int sja1105_mdb_add(struct dsa_switch *ds, int port, @@ -2962,7 +2985,9 @@ static int sja1105_port_mcast_flood(struct sja1105_private *priv, int to, { struct sja1105_l2_lookup_entry *l2_lookup; struct sja1105_table *table; - int match; + int match, rc; + + mutex_lock(&priv->fdb_lock);
table = &priv->static_config.tables[BLK_IDX_L2_LOOKUP]; l2_lookup = table->entries; @@ -2975,7 +3000,8 @@ static int sja1105_port_mcast_flood(struct sja1105_private *priv, int to, if (match == table->entry_count) { NL_SET_ERR_MSG_MOD(extack, "Could not find FDB entry for unknown multicast"); - return -ENOSPC; + rc = -ENOSPC; + goto out; }
if (flags.val & BR_MCAST_FLOOD) @@ -2983,10 +3009,13 @@ static int sja1105_port_mcast_flood(struct sja1105_private *priv, int to, else l2_lookup[match].destports &= ~BIT(to);
- return sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP, - l2_lookup[match].index, - &l2_lookup[match], - true); + rc = sja1105_dynamic_config_write(priv, BLK_IDX_L2_LOOKUP, + l2_lookup[match].index, + &l2_lookup[match], true); +out: + mutex_unlock(&priv->fdb_lock); + + return rc; }
static int sja1105_port_pre_bridge_flags(struct dsa_switch *ds, int port, @@ -3356,6 +3385,7 @@ static int sja1105_probe(struct spi_device *spi) mutex_init(&priv->ptp_data.lock); mutex_init(&priv->dynamic_config_lock); mutex_init(&priv->mgmt_lock); + mutex_init(&priv->fdb_lock); spin_lock_init(&priv->ts_id_lock);
rc = sja1105_parse_dt(priv);