2019-07-08 17:50:32

by Arnd Bergmann

[permalink] [raw]
Subject: [PATCH] [net-next] net/mlx5e: xsk: dynamically allocate mlx5e_channel_param

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 kzalloc() instead.

Fixes: a038e9794541 ("net/mlx5e: Add XSK zero-copy support")
Signed-off-by: Arnd Bergmann <[email protected]>
---
.../mellanox/mlx5/core/en/xsk/setup.c | 25 ++++++++++++-------
1 file changed, 16 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..db9bbec68dbf 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 = kzalloc(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_kfree_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;

@@ -87,18 +91,18 @@ 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;

@@ -123,6 +127,9 @@ int mlx5e_open_xsk(struct mlx5e_priv *priv, struct mlx5e_params *params,
err_close_rx_cq:
mlx5e_close_cq(&c->xskrq.cq);

+err_kfree_cparam:
+ kfree(cparam);
+
return err;
}

--
2.20.0


2019-07-08 19:30:55

by Maxim Mikityanskiy

[permalink] [raw]
Subject: Re: [PATCH] [net-next] net/mlx5e: xsk: dynamically allocate mlx5e_channel_param

On 2019-07-08 15:55, Arnd Bergmann wrote:
> 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 kzalloc() instead.
>
> Fixes: a038e9794541 ("net/mlx5e: Add XSK zero-copy support")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> .../mellanox/mlx5/core/en/xsk/setup.c | 25 ++++++++++++-------
> 1 file changed, 16 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..db9bbec68dbf 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 = kzalloc(sizeof(*cparam), GFP_KERNEL);

Similar code in mlx5e_open_channels (en_main.c) uses kvzalloc. Although
the struct is currently smaller than a page anyway, and there should be
no difference in behavior now, I suggest using the same alloc function
to keep code uniform.

> + 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_kfree_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;
>
> @@ -87,18 +91,18 @@ 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;
>

Here is kfree missing. It's a memory leak in the good path.

Thanks!

> @@ -123,6 +127,9 @@ int mlx5e_open_xsk(struct mlx5e_priv *priv, struct mlx5e_params *params,
> err_close_rx_cq:
> mlx5e_close_cq(&c->xskrq.cq);
>
> +err_kfree_cparam:
> + kfree(cparam);
> +
> return err;
> }
>
>

2019-07-23 21:25:46

by Maxim Mikityanskiy

[permalink] [raw]
Subject: Re: [PATCH] [net-next] net/mlx5e: xsk: dynamically allocate mlx5e_channel_param

On 2019-07-08 18:16, Maxim Mikityanskiy wrote:
> On 2019-07-08 15:55, Arnd Bergmann wrote:
>> - mlx5e_build_xsk_cparam(priv, params, xsk, &cparam);
>> + cparam = kzalloc(sizeof(*cparam), GFP_KERNEL);
>
> Similar code in mlx5e_open_channels (en_main.c) uses kvzalloc. Although
> the struct is currently smaller than a page anyway, and there should be
> no difference in behavior now, I suggest using the same alloc function
> to keep code uniform.
>
>> /* 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;
>>
>
> Here is kfree missing. It's a memory leak in the good path.

Arnd, I'm going to take over your patch and respin it, addressing my own
comments, because it's been quite a while, and we want to have this fix.

Thanks for spotting it.

2019-07-23 21:38:24

by Arnd Bergmann

[permalink] [raw]
Subject: Re: [PATCH] [net-next] net/mlx5e: xsk: dynamically allocate mlx5e_channel_param

On Tue, Jul 23, 2019 at 1:21 PM Maxim Mikityanskiy <[email protected]> wrote:
> On 2019-07-08 18:16, Maxim Mikityanskiy wrote:
> > On 2019-07-08 15:55, Arnd Bergmann wrote:
> >> - mlx5e_build_xsk_cparam(priv, params, xsk, &cparam);
> >> + cparam = kzalloc(sizeof(*cparam), GFP_KERNEL);
> >
> > Similar code in mlx5e_open_channels (en_main.c) uses kvzalloc. Although
> > the struct is currently smaller than a page anyway, and there should be
> > no difference in behavior now, I suggest using the same alloc function
> > to keep code uniform.
> >
> >> /* 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;
> >>
> >
> > Here is kfree missing. It's a memory leak in the good path.
>
> Arnd, I'm going to take over your patch and respin it, addressing my own
> comments, because it's been quite a while, and we want to have this fix.
>
> Thanks for spotting it.

Thanks for taking care of it now. I was planning to do a respin, but
the reply got lost in the depth of my inbox so I forgot about it.

Arnd