2023-04-04 07:49:15

by Yang Li

Subject: [PATCH net-next v3] net/mlx5e: Remove NULL check before dev_{put, hold}

./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c:35:2-9: WARNING: NULL check before dev_{put, hold} functions is not needed.
./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c:72:2-10: WARNING: NULL check before dev_{put, hold} functions is not needed.
./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c:80:2-9: WARNING: NULL check before dev_{put, hold} functions is not needed.
./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c:35:2-9: WARNING: NULL check before dev_{put, hold} functions is not needed.
./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c:734:2-9: WARNING: NULL check before dev_{put, hold} functions is not needed.
./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c:769:2-9: WARNING: NULL check before dev_{put, hold} functions is not needed.
./drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c:1450:2-10: WARNING: NULL check before dev_{put, hold} functions is not needed.

Reported-by: Abaci Robot <[email protected]>
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=4667
Signed-off-by: Yang Li <[email protected]>
---

change in v3:
--According to Leon's suggestion, do this cleanup for whole driver.

drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c | 9 +++------
.../net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c | 10 +++-------
drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c | 3 +--
3 files changed, 7 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
index 00a04fdd756f..20f6e7ed7475 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
@@ -31,8 +31,7 @@ static void mlx5e_tc_tun_route_attr_cleanup(struct mlx5e_tc_tun_route_attr *attr
{
if (attr->n)
neigh_release(attr->n);
- if (attr->route_dev)
- dev_put(attr->route_dev);
+ dev_put(attr->route_dev);
}

struct mlx5e_tc_tunnel *mlx5e_get_tc_tun(struct net_device *tunnel_dev)
@@ -68,16 +67,14 @@ static int get_route_and_out_devs(struct mlx5e_priv *priv,
* while holding rcu read lock. Take the net_device for correctness
* sake.
*/
- if (uplink_upper)
- dev_hold(uplink_upper);
+ dev_hold(uplink_upper);
rcu_read_unlock();

dst_is_lag_dev = (uplink_upper &&
netif_is_lag_master(uplink_upper) &&
real_dev == uplink_upper &&
mlx5_lag_is_sriov(priv->mdev));
- if (uplink_upper)
- dev_put(uplink_upper);
+ dev_put(uplink_upper);

/* if the egress device isn't on the same HW e-switch or
* it's a LAG device, use the uplink
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c
index 20c2d2ecaf93..2cb2ba857155 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c
@@ -32,9 +32,7 @@ static int mlx5e_set_int_port_tunnel(struct mlx5e_priv *priv,
&attr->action, out_index);

out:
- if (route_dev)
- dev_put(route_dev);
-
+ dev_put(route_dev);
return err;
}

@@ -730,8 +728,7 @@ static int mlx5e_set_vf_tunnel(struct mlx5_eswitch *esw,
}

out:
- if (route_dev)
- dev_put(route_dev);
+ dev_put(route_dev);
return err;
}

@@ -765,8 +762,7 @@ static int mlx5e_update_vf_tunnel(struct mlx5_eswitch *esw,
mlx5e_tc_match_to_reg_mod_hdr_change(esw->dev, mod_hdr_acts, VPORT_TO_REG, act_id, data);

out:
- if (route_dev)
- dev_put(route_dev);
+ dev_put(route_dev);
return err;
}

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c
index 5d331b940f4d..f0216bf6e215 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c
@@ -1446,8 +1446,7 @@ struct net_device *mlx5_lag_get_roce_netdev(struct mlx5_core_dev *dev)
} else {
ndev = ldev->pf[MLX5_LAG_P1].netdev;
}
- if (ndev)
- dev_hold(ndev);
+ dev_hold(ndev);

unlock:
spin_unlock_irqrestore(&lag_lock, flags);
--
2.20.1.7.g153144c

2023-04-04 16:51:03

by Leon Romanovsky

Subject: Re: [PATCH net-next v3] net/mlx5e: Remove NULL check before dev_{put, hold}

On Tue, Apr 04, 2023 at 03:29:32PM +0800, Yang Li wrote:
> ./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c:35:2-9: WARNING: NULL check before dev_{put, hold} functions is not needed.
> ./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c:72:2-10: WARNING: NULL check before dev_{put, hold} functions is not needed.
> ./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c:80:2-9: WARNING: NULL check before dev_{put, hold} functions is not needed.
> ./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c:35:2-9: WARNING: NULL check before dev_{put, hold} functions is not needed.
> ./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c:734:2-9: WARNING: NULL check before dev_{put, hold} functions is not needed.
> ./drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c:769:2-9: WARNING: NULL check before dev_{put, hold} functions is not needed.
> ./drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c:1450:2-10: WARNING: NULL check before dev_{put, hold} functions is not needed.
>
> Reported-by: Abaci Robot <[email protected]>
> Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=4667
> Signed-off-by: Yang Li <[email protected]>
> ---
>
> change in v3:
> --According to Leon's suggestion, do this cleanup for whole driver.
>
> drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c | 9 +++------
> .../net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c | 10 +++-------
> drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c | 3 +--
> 3 files changed, 7 insertions(+), 15 deletions(-)
>

Thanks,
Reviewed-by: Leon Romanovsky <[email protected]>