[PATCH AUTOSEL for 3.18 045/101] macvlan: Do not return error when setting the same mac address

[Sasha Levin]

From: Vlad Yasevich <vyasevich@xxxxxxxxx>

[ Upstream commit e26f43faa0d79dd06e9e94829696b68b9940c2ee ]

The user currently gets an EBUSY error when attempting to set
the mac address on a macvlan device to the same value.

This should really be a no-op as nothing changes.  Catch
the condition and return early.

Signed-off-by: Vladislav Yasevich <vyasevic@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 drivers/net/macvlan.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index c0818ec3d427..fe7b49cbfba5 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -681,6 +681,10 @@ static int macvlan_set_mac_address(struct net_device *dev, void *p)
 	if (!is_valid_ether_addr(addr->sa_data))
 		return -EADDRNOTAVAIL;
 
+	/* If the addresses are the same, this is a no-op */
+	if (ether_addr_equal(dev->dev_addr, addr->sa_data))
+		return 0;
+
 	if (vlan->mode == MACVLAN_MODE_PASSTHRU) {
 		dev_set_mac_address(vlan->lowerdev, addr);
 		return 0;
-- 
2.15.1