Re: [PATCH net 1/1] net: dsa: sja1105: fix error handling on NULL returned by xpcs_create()
From: Vladimir Oltean
Date: Tue Aug 10 2021 - 04:25:36 EST
Hi VK,
On Tue, Aug 10, 2021 at 02:35:13PM +0800, Wong Vee Khee wrote:
> 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@xxxxxxx>
> Signed-off-by: Wong Vee Khee <vee.khee.wong@xxxxxxxxxxxxxxx>
> ---
> 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.
Anyway, I don't think that PTR_ERR(xpcs) does the right thing when
IS_NULL(xpcs). So how about you make this change:
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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;
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