[PATCH net-next v2] net/mlx5e: xsk: dynamically allocate mlx5e_channel_param

[PATCH net-next v2] net/mlx5e: xsk: dynamically allocate mlx5e_channel_param

[Maxim Mikityanskiy]

From: Arnd Bergmann <arnd@arndb.de>

The structure is too large to put on the stack, resulting in a
warning on 32-bit ARM:

drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c:59:5: error: stack frame size of 1344 bytes in function
      'mlx5e_open_xsk' [-Werror,-Wframe-larger-than=]

Use kvzalloc() instead.

Fixes: a038e9794541 ("net/mlx5e: Add XSK zero-copy support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
---
v2 changes: use kvzalloc/kvfree and fix a memory leak.

 .../mellanox/mlx5/core/en/xsk/setup.c         | 27 ++++++++++++-------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c
index aaffa6f68dc0..f701e4f3c076 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c
@@ -60,24 +60,28 @@ int mlx5e_open_xsk(struct mlx5e_priv *priv, struct mlx5e_params *params,
 		   struct mlx5e_xsk_param *xsk, struct xdp_umem *umem,
 		   struct mlx5e_channel *c)
 {
-	struct mlx5e_channel_param cparam = {};
+	struct mlx5e_channel_param *cparam;
 	struct dim_cq_moder icocq_moder = {};
 	int err;
 
 	if (!mlx5e_validate_xsk_param(params, xsk, priv->mdev))
 		return -EINVAL;
 
-	mlx5e_build_xsk_cparam(priv, params, xsk, &cparam);
+	cparam = kvzalloc(sizeof(*cparam), GFP_KERNEL);
+	if (!cparam)
+		return -ENOMEM;
 
-	err = mlx5e_open_cq(c, params->rx_cq_moderation, &cparam.rx_cq, &c->xskrq.cq);
+	mlx5e_build_xsk_cparam(priv, params, xsk, cparam);
+
+	err = mlx5e_open_cq(c, params->rx_cq_moderation, &cparam->rx_cq, &c->xskrq.cq);
 	if (unlikely(err))
-		return err;
+		goto err_free_cparam;
 
-	err = mlx5e_open_rq(c, params, &cparam.rq, xsk, umem, &c->xskrq);
+	err = mlx5e_open_rq(c, params, &cparam->rq, xsk, umem, &c->xskrq);
 	if (unlikely(err))
 		goto err_close_rx_cq;
 
-	err = mlx5e_open_cq(c, params->tx_cq_moderation, &cparam.tx_cq, &c->xsksq.cq);
+	err = mlx5e_open_cq(c, params->tx_cq_moderation, &cparam->tx_cq, &c->xsksq.cq);
 	if (unlikely(err))
 		goto err_close_rq;
 
@@ -87,21 +91,23 @@ int mlx5e_open_xsk(struct mlx5e_priv *priv, struct mlx5e_params *params,
 	 * is disabled and then reenabled, but the SQ continues receiving CQEs
 	 * from the old UMEM.
 	 */
-	err = mlx5e_open_xdpsq(c, params, &cparam.xdp_sq, umem, &c->xsksq, true);
+	err = mlx5e_open_xdpsq(c, params, &cparam->xdp_sq, umem, &c->xsksq, true);
 	if (unlikely(err))
 		goto err_close_tx_cq;
 
-	err = mlx5e_open_cq(c, icocq_moder, &cparam.icosq_cq, &c->xskicosq.cq);
+	err = mlx5e_open_cq(c, icocq_moder, &cparam->icosq_cq, &c->xskicosq.cq);
 	if (unlikely(err))
 		goto err_close_sq;
 
 	/* Create a dedicated SQ for posting NOPs whenever we need an IRQ to be
 	 * triggered and NAPI to be called on the correct CPU.
 	 */
-	err = mlx5e_open_icosq(c, params, &cparam.icosq, &c->xskicosq);
+	err = mlx5e_open_icosq(c, params, &cparam->icosq, &c->xskicosq);
 	if (unlikely(err))
 		goto err_close_icocq;
 
+	kvfree(cparam);
+
 	spin_lock_init(&c->xskicosq_lock);
 
 	set_bit(MLX5E_CHANNEL_STATE_XSK, c->state);
@@ -123,6 +129,9 @@ int mlx5e_open_xsk(struct mlx5e_priv *priv, struct mlx5e_params *params,
 err_close_rx_cq:
 	mlx5e_close_cq(&c->xskrq.cq);
 
+err_free_cparam:
+	kvfree(cparam);
+
 	return err;
 }
 
-- 
2.19.1

Re: [PATCH net-next v2] net/mlx5e: xsk: dynamically allocate mlx5e_channel_param

[David Miller]

From: Maxim Mikityanskiy <maximmi@mellanox.com>
Date: Tue, 23 Jul 2019 12:02:26 +0000

> From: Arnd Bergmann <arnd@arndb.de>
> 
> The structure is too large to put on the stack, resulting in a
> warning on 32-bit ARM:
> 
> drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c:59:5: error: stack frame size of 1344 bytes in function
>       'mlx5e_open_xsk' [-Werror,-Wframe-larger-than=]
> 
> Use kvzalloc() instead.
> 
> Fixes: a038e9794541 ("net/mlx5e: Add XSK zero-copy support")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
> ---
> v2 changes: use kvzalloc/kvfree and fix a memory leak.

I'll apply this directly to net-next.

Thanks Maxim.