Re: [PATCH] gianfar: reduce stack usage in gianfar_ethtool.c

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mercredi 10 août 2011 à 00:39 +0800, stufever@gmail.com a écrit :
> From: Wang Shaoyan <wangshaoyan.pt@taobao.com>
> 
>   drivers/net/gianfar_ethtool.c:765: warning: the frame size of 2048 bytes is larger than 1024 bytes
> 
> Signed-off-by: Wang Shaoyan <wangshaoyan.pt@taobao.com>
> ---
>  drivers/net/gianfar_ethtool.c |   20 +++++++++++++++++---
>  1 files changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/gianfar_ethtool.c b/drivers/net/gianfar_ethtool.c
> index 6e35069..134fe1b 100644
> --- a/drivers/net/gianfar_ethtool.c
> +++ b/drivers/net/gianfar_ethtool.c
> @@ -686,10 +686,21 @@ static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow, u
>  {
>  	unsigned int last_rule_idx = priv->cur_filer_idx;
>  	unsigned int cmp_rqfpr;
> -	unsigned int local_rqfpr[MAX_FILER_IDX + 1];
> -	unsigned int local_rqfcr[MAX_FILER_IDX + 1];
> +	unsigned int *local_rqfpr;
> +	unsigned int *local_rqfcr;
>  	int i = 0x0, k = 0x0;
>  	int j = MAX_FILER_IDX, l = 0x0;
> +	int ret = 1;
> +
> +	local_rqfpr = kmalloc(sizeof(unsigned int) * (MAX_FILER_IDX + 1),
> +		GFP_KERNEL);
> +	local_rqfcr = kmalloc(sizeof(unsigned int) * (MAX_FILER_IDX + 1),
> +		GFP_KERNEL);
> +	if (!local_rqfpr || !local_rqfcr) {
> +		pr_err("Out of memory\n");

	Please remove this pr_err(), kmalloc() will complain already.

> +		ret = 0;
> +		got err;
> +	}
>  
>  	switch (class) {
>  	case TCP_V4_FLOW:
> @@ -765,7 +776,10 @@ static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow, u
>  		priv->cur_filer_idx = priv->cur_filer_idx - 1;
>  	}
>  
> -	return 1;
> +err:
> +	kfree(local_rqfcr);
> +	kfree(local_rqfpr);
> +	return ret;
>  }
>  

You should now track all "return 0;" done in this function to make sure
no memory leak is added by your patch.