Re: [PATCH 1/3] net-gianfar: Less function calls in gfar_ethflow_to_filer_table() after error detection

Julia Lawall
2016-01-01T12:35:21Z

On Fri, 1 Jan 2016, SF Markus Elfring wrote:

> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Fri, 1 Jan 2016 11:16:04 +0100
>
> The kfree() function was called in one case by the
> gfar_ethflow_to_filer_table() function during error handling
> even if a passed variable contained a null pointer.
>
> * Return directly if a memory allocation failed at the beginning.
>
> * Adjust jump targets according to the Linux coding style convention.
>
> This issue was detected by using the Coccinelle software.
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
> drivers/net/ethernet/freescale/gianfar_ethtool.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/gianfar_ethtool.c b/drivers/net/ethernet/freescale/gianfar_ethtool.c
> index 4b0ee85..be4941e 100644
> --- a/drivers/net/ethernet/freescale/gianfar_ethtool.c
> +++ b/drivers/net/ethernet/freescale/gianfar_ethtool.c
> @@ -778,11 +778,13 @@ static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow,
>
> local_rqfpr = kmalloc_array(MAX_FILER_IDX + 1, sizeof(unsigned int),
> GFP_KERNEL);
> + if (!local_rqfpr)
> + return 1;

Why return 1? Previously 0 was returned.

Normally, one returns -ENOMEM for this case, but it looks like this
function is returning 0 on failure.

julia

> local_rqfcr = kmalloc_array(MAX_FILER_IDX + 1, sizeof(unsigned int),
> GFP_KERNEL);
> - if (!local_rqfpr || !local_rqfcr) {
> + if (!local_rqfcr) {
> ret = 0;
> - goto err;
> + goto free_fpr;
> }
>
> switch (class) {
> @@ -802,7 +804,7 @@ static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow,
> netdev_err(priv->ndev,
> "Right now this class is not supported\n");
> ret = 0;
> - goto err;
> + goto free_fcr;
> }
>
> for (i = 0; i < MAX_FILER_IDX + 1; i++) {
> @@ -819,7 +821,7 @@ static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow,
> netdev_err(priv->ndev,
> "No parse rule found, can't create hash rules\n");
> ret = 0;
> - goto err;
> + goto free_fcr;
> }
>
> /* If a match was found, then it begins the starting of a cluster rule
> @@ -862,9 +864,9 @@ static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow,
> break;
> priv->cur_filer_idx = priv->cur_filer_idx - 1;
> }
> -
> -err:
> +free_fcr:
> kfree(local_rqfcr);
> +free_fpr:
> kfree(local_rqfpr);
> return ret;
> }
> --
> 2.6.3
>
> --
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