Subject: Re: [PATCH 3/4] crypto: caam: Unembed net_dev structure from qi

From: Simon Horman <[email-masked]>
Date: Fri, 28 Jun 2024 17:32:26 +0100

On Mon, Jun 24, 2024 at 09:21:21AM -0700, Breno Leitao wrote:
> Embedding net_device into structures prohibits the usage of flexible
> arrays in the net_device structure. For more details, see the discussion
> at [1].
> 
> Un-embed the net_devices from struct caam_qi_pcpu_priv by converting them
> into pointers, and allocating them dynamically. Use the leverage
> alloc_netdev_dummy() to allocate the net_device object at
> caam_qi_init().
> 
> The free of the device occurs at caam_qi_shutdown().
> 
> Link: https://lore.kernel.org/all/[email-masked]/ [1]
> Signed-off-by: Breno Leitao <[email-masked]>
> ---
> PS: Unfortunately due to lack of hardware, this was not tested in real
> hardware.
> 
>  drivers/crypto/caam/qi.c | 43 ++++++++++++++++++++++++++++++++--------
>  1 file changed, 35 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/crypto/caam/qi.c b/drivers/crypto/caam/qi.c

...

> @@ -530,6 +530,7 @@ static void caam_qi_shutdown(void *data)
>  
>  		if (kill_fq(qidev, per_cpu(pcpu_qipriv.rsp_fq, i)))
>  			dev_err(qidev, "Rsp FQ kill failed, cpu: %d\n", i);
> +		free_netdev(pcpu_qipriv.net_dev);

Hi Breno,

I don't think you can access pcpu_qipriv.net_dev like this,
as pcpu_qipriv is a per-cpu variable. Perhaps this?

	free_netdev(per_cpu(pcpu_qipriv.net_dev, i));

Flagged by Sparse.

>  	}
>  
>  	qman_delete_cgr_safe(&priv->cgr);

...