Merge branch 'ethtool-ringparam-upper-bound'

Tariq Toukan says:

====================
ethtool ringparam upper bound

This patchset by Jenny adds sanity checks in ethtool ringparam
operation for input upper bounds, similarly to what's done in
ethtool_set_channels.

The checks are added in patch 1, using a call to get_ringparam
prior to calling set_ringparam NDO.

Patch 2 changes the function's behavior in mlx4_en, so that
it returns an error for out-of-range input, instead of rounding
it to closest valid, similar to mlx5e.

Patch 3 removes the upper bound checks in mlx5e_ethtool_set_ringparam
as it becomes redundant.

Series generated against net-next commit:
f66faae2f80a Merge branch 'ipv6-ipv4-nexthop-align'
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 24 insertions, 21 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
index bf1f04164885..ebc1f566a4d9 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -1094,12 +1094,21 @@ static int mlx4_en_set_ringparam(struct net_device *dev,
         if (param->rx_jumbo_pending || param->rx_mini_pending)
                 return -EINVAL;
 
+        if (param->rx_pending < MLX4_EN_MIN_RX_SIZE) {
+                en_warn(priv, "%s: rx_pending (%d) < min (%d)\n",
+                        __func__, param->rx_pending,
+                        MLX4_EN_MIN_RX_SIZE);
+                return -EINVAL;
+        }
+        if (param->tx_pending < MLX4_EN_MIN_TX_SIZE) {
+                en_warn(priv, "%s: tx_pending (%d) < min (%lu)\n",
+                        __func__, param->tx_pending,
+                        MLX4_EN_MIN_TX_SIZE);
+                return -EINVAL;
+        }
+
         rx_size = roundup_pow_of_two(param->rx_pending);
-        rx_size = max_t(u32, rx_size, MLX4_EN_MIN_RX_SIZE);
-        rx_size = min_t(u32, rx_size, MLX4_EN_MAX_RX_SIZE);
         tx_size = roundup_pow_of_two(param->tx_pending);
-        tx_size = max_t(u32, tx_size, MLX4_EN_MIN_TX_SIZE);
-        tx_size = min_t(u32, tx_size, MLX4_EN_MAX_TX_SIZE);
 
         if (rx_size == (priv->port_up ? priv->rx_ring[0]->actual_size :
                                         priv->rx_ring[0]->size) &&
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
index 8f05efa5c829..1554780d1810 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
@@ -296,7 +296,6 @@ int mlx5e_ethtool_set_ringparam(struct mlx5e_priv *priv,
         struct mlx5e_channels new_channels = {};
         u32 rx_pending_wqes;
         u32 min_rq_size;
-        u32 max_rq_size;
         u8 log_rq_size;
         u8 log_sq_size;
         u32 num_mtts;
@@ -315,8 +314,6 @@ int mlx5e_ethtool_set_ringparam(struct mlx5e_priv *priv,
 
         min_rq_size = mlx5e_rx_wqes_to_packets(priv, rq_wq_type,
                                                1 << mlx5_min_log_rq_size(rq_wq_type));
-        max_rq_size = mlx5e_rx_wqes_to_packets(priv, rq_wq_type,
-                                               1 << mlx5_max_log_rq_size(rq_wq_type));
         rx_pending_wqes = mlx5e_packets_to_rx_wqes(priv, rq_wq_type,
                                                    param->rx_pending);
 
@@ -326,12 +323,6 @@ int mlx5e_ethtool_set_ringparam(struct mlx5e_priv *priv,
                             min_rq_size);
                 return -EINVAL;
         }
-        if (param->rx_pending > max_rq_size) {
-                netdev_info(priv->netdev, "%s: rx_pending (%d) > max (%d)\n",
-                            __func__, param->rx_pending,
-                            max_rq_size);
-                return -EINVAL;
-        }
 
         num_mtts = MLX5E_REQUIRED_MTTS(rx_pending_wqes);
         if (priv->channels.params.rq_wq_type == MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ &&
@@ -347,12 +338,6 @@ int mlx5e_ethtool_set_ringparam(struct mlx5e_priv *priv,
                             1 << MLX5E_PARAMS_MINIMUM_LOG_SQ_SIZE);
                 return -EINVAL;
         }
-        if (param->tx_pending > (1 << MLX5E_PARAMS_MAXIMUM_LOG_SQ_SIZE)) {
-                netdev_info(priv->netdev, "%s: tx_pending (%d) > max (%d)\n",
-                            __func__, param->tx_pending,
-                            1 << MLX5E_PARAMS_MAXIMUM_LOG_SQ_SIZE);
-                return -EINVAL;
-        }
 
         log_rq_size = order_base_2(rx_pending_wqes);
         log_sq_size = order_base_2(param->tx_pending);
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index fff6314f4c5e..107b122c8969 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1693,14 +1693,23 @@ static int ethtool_get_ringparam(struct net_device *dev, void __user *useraddr)
 
 static int ethtool_set_ringparam(struct net_device *dev, void __user *useraddr)
 {
-        struct ethtool_ringparam ringparam;
+        struct ethtool_ringparam ringparam, max = { .cmd = ETHTOOL_GRINGPARAM };
 
-        if (!dev->ethtool_ops->set_ringparam)
+        if (!dev->ethtool_ops->set_ringparam || !dev->ethtool_ops->get_ringparam)
                 return -EOPNOTSUPP;
 
         if (copy_from_user(&ringparam, useraddr, sizeof(ringparam)))
                 return -EFAULT;
 
+        dev->ethtool_ops->get_ringparam(dev, &max);
+
+        /* ensure new ring parameters are within the maximums */
+        if (ringparam.rx_pending > max.rx_max_pending ||
+            ringparam.rx_mini_pending > max.rx_mini_max_pending ||
+            ringparam.rx_jumbo_pending > max.rx_jumbo_max_pending ||
+            ringparam.tx_pending > max.tx_max_pending)
+                return -EINVAL;
+
         return dev->ethtool_ops->set_ringparam(dev, &ringparam);
 }