From: Horatiu Vultur <horatiu.vultur@microchip.com>
Date: Thu, 14 Jul 2022 19:40:38 +0000 (+0200)
Subject: net: lan966x: Fix usage of lan966x->mac_lock when entry is removed
X-Git-Tag: v5.19-rc8~21^2~18^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=99343cfa4f7560abf933fff7ab3ea58a6905c917;p=thirdparty%2Flinux.git

net: lan966x: Fix usage of lan966x->mac_lock when entry is removed

To remove an entry to the MAC table, it is required first to setup the
entry and then issue a command for the MAC to forget the entry.
So if it happens for two threads to remove simultaneously an entry
in MAC table then it would be a race condition.
Fix this by using lan966x->mac_lock to protect the HW access.

Fixes: e18aba8941b40 ("net: lan966x: add mactable support")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c b/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c
index 4f8fd5cde9506..d0b8eba0a66d9 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c
@@ -119,11 +119,13 @@ int lan966x_mac_learn(struct lan966x *lan966x, int port,
 	return __lan966x_mac_learn(lan966x, port, false, mac, vid, type);
 }
 
-int lan966x_mac_forget(struct lan966x *lan966x,
-		       const unsigned char mac[ETH_ALEN],
-		       unsigned int vid,
-		       enum macaccess_entry_type type)
+static int lan966x_mac_forget_locked(struct lan966x *lan966x,
+				     const unsigned char mac[ETH_ALEN],
+				     unsigned int vid,
+				     enum macaccess_entry_type type)
 {
+	lockdep_assert_held(&lan966x->mac_lock);
+
 	lan966x_mac_select(lan966x, mac, vid);
 
 	/* Issue a forget command */
@@ -134,6 +136,20 @@ int lan966x_mac_forget(struct lan966x *lan966x,
 	return lan966x_mac_wait_for_completion(lan966x);
 }
 
+int lan966x_mac_forget(struct lan966x *lan966x,
+		       const unsigned char mac[ETH_ALEN],
+		       unsigned int vid,
+		       enum macaccess_entry_type type)
+{
+	int ret;
+
+	spin_lock(&lan966x->mac_lock);
+	ret = lan966x_mac_forget_locked(lan966x, mac, vid, type);
+	spin_unlock(&lan966x->mac_lock);
+
+	return ret;
+}
+
 int lan966x_mac_cpu_learn(struct lan966x *lan966x, const char *addr, u16 vid)
 {
 	return lan966x_mac_learn(lan966x, PGID_CPU, addr, vid, ENTRYTYPE_LOCKED);