[PATCH net 1/1] net: dsa: sja1105: fix error handling on NULL returned by xpcs_create()

There is a possibility xpcs_create() returned a NULL and this is not
handled properly in the sja1105 driver.

Fixed this by using IS_ERR_ON_NULL() instead of IS_ERR().

Fixes: 3ad1d171548e ("net: dsa: sja1105: migrate to xpcs for SGMII")
Cc: Vladimir Olten <vladimir.oltean@nxp.com>
Signed-off-by: Wong Vee Khee <redacted>
---
 drivers/net/dsa/sja1105/sja1105_mdio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/dsa/sja1105/sja1105_mdio.c b/drivers/net/dsa/sja1105/sja1105_mdio.c
index 19aea8fb76f6..2c69a759ce6e 100644
--- a/drivers/net/dsa/sja1105/sja1105_mdio.c
+++ b/drivers/net/dsa/sja1105/sja1105_mdio.c

@@ -438,7 +438,7 @@ static int sja1105_mdiobus_pcs_register(struct sja1105_private *priv)
 		}
 
 		xpcs = xpcs_create(mdiodev, priv->phy_mode[port]);
-		if (IS_ERR(xpcs)) {
+		if (IS_ERR_OR_NULL(xpcs)) {
 			rc = PTR_ERR(xpcs);
 			goto out_pcs_free;
 		}

-- 
2.25.1

Hi VK,

On Tue, Aug 10, 2021 at 02:35:13PM +0800, Wong Vee Khee wrote:

I think posting to 'net' is a bit drastic for this patch. I agree it is
an issue but it has bothered absolutely nobody so far, and if sending
this patch to 'net' means you'll be blocked with your patches until the
'net'->'net-next' merge, I'm not sure it's worth it.

Anyway, I don't think that PTR_ERR(xpcs) does the right thing when
IS_NULL(xpcs). So how about you make this change:

-----------------------------[ cut here ]-----------------------------

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index a5d150c5f3d8..ca12bf986d4d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c

@@ -415,7 +415,7 @@ int stmmac_xpcs_setup(struct mii_bus *bus)
 			continue;
 
 		xpcs = xpcs_create(mdiodev, mode);
-		if (IS_ERR_OR_NULL(xpcs)) {
+		if (IS_ERR(xpcs)) {
 			mdio_device_free(mdiodev);
 			continue;
 		}

diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index 63fda3fc40aa..4bd61339823c 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c

@@ -1089,7 +1089,7 @@ struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev,
 
 	xpcs = kzalloc(sizeof(*xpcs), GFP_KERNEL);
 	if (!xpcs)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	xpcs->mdiodev = mdiodev;
 
-----------------------------[ cut here ]-----------------------------

On Tue, Aug 10, 2021 at 08:25:29AM +0000, Vladimir Oltean wrote:

Hi VK,

On Tue, Aug 10, 2021 at 02:35:13PM +0800, Wong Vee Khee wrote:

quoted

There is a possibility xpcs_create() returned a NULL and this is not
handled properly in the sja1105 driver.

Fixed this by using IS_ERR_ON_NULL() instead of IS_ERR().

Fixes: 3ad1d171548e ("net: dsa: sja1105: migrate to xpcs for SGMII")
Cc: Vladimir Olten <vladimir.oltean@nxp.com>
Signed-off-by: Wong Vee Khee <redacted>
---
 drivers/net/dsa/sja1105/sja1105_mdio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/dsa/sja1105/sja1105_mdio.c b/drivers/net/dsa/sja1105/sja1105_mdio.c
index 19aea8fb76f6..2c69a759ce6e 100644
--- a/drivers/net/dsa/sja1105/sja1105_mdio.c
+++ b/drivers/net/dsa/sja1105/sja1105_mdio.c

@@ -438,7 +438,7 @@ static int sja1105_mdiobus_pcs_register(struct sja1105_private *priv)
 		}
 
 		xpcs = xpcs_create(mdiodev, priv->phy_mode[port]);
-		if (IS_ERR(xpcs)) {
+		if (IS_ERR_OR_NULL(xpcs)) {
 			rc = PTR_ERR(xpcs);
 			goto out_pcs_free;
 		}

-- 
2.25.1

I think posting to 'net' is a bit drastic for this patch. I agree it is
an issue but it has bothered absolutely nobody so far, and if sending
this patch to 'net' means you'll be blocked with your patches until the
'net'->'net-next' merge, I'm not sure it's worth it.

Sounds reasonable for me. I will marked V2 to target net-next.