Re: [PATCH] fsl_ucc_hdlc: add a check of the return value from hdlc_open

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 25/08/2023 à 16:31, Alexandra Diupina a écrit :
> [Vous ne recevez pas souvent de courriers de adiupina@astralinux.ru. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]
> 
> Process the result of hold_open() and return it from
> uhdlc_open() in case of an error
> It is necessary to pass the error code up the control flow,
> similar to a possible error in request_irq()
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: c19b6d246a35 ("drivers/net: support hdlc function for QE-UCC")
> Signed-off-by: Alexandra Diupina <adiupina@astralinux.ru>
> ---
>   drivers/net/wan/fsl_ucc_hdlc.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
> index 47c2ad7a3e42..cdd9489c712e 100644
> --- a/drivers/net/wan/fsl_ucc_hdlc.c
> +++ b/drivers/net/wan/fsl_ucc_hdlc.c
> @@ -708,6 +708,7 @@ static int uhdlc_open(struct net_device *dev)
>          hdlc_device *hdlc = dev_to_hdlc(dev);
>          struct ucc_hdlc_private *priv = hdlc->priv;
>          struct ucc_tdm *utdm = priv->utdm;
> +       int rc = 0;

rc not usefull outside the block below, no point in having it at all.

> 
>          if (priv->hdlc_busy != 1) {
>                  if (request_irq(priv->ut_info->uf_info.irq,
> @@ -731,10 +732,12 @@ static int uhdlc_open(struct net_device *dev)
>                  napi_enable(&priv->napi);
>                  netdev_reset_queue(dev);
>                  netif_start_queue(dev);
> -               hdlc_open(dev);
> +               rc = hdlc_open(dev);
> +               if (rc)
> +                       return rc;

Don't need that rc variable. Just do:

	return hdlc_open(dev);

>          }
> 
> -       return 0;
> +       return rc;

Change not needed, leave return 0 here.

>   }
> 
>   static void uhdlc_memclean(struct ucc_hdlc_private *priv)
> --
> 2.30.2
>