Re: [PATCH] scsi: ibmvfc: Mark expected switch fall-throughs

[Kees Cook <keescook@chromium.org>]

On Sun, Jul 28, 2019 at 07:26:08PM -0500, Gustavo A. R. Silva wrote:
> Mark switch cases where we are expecting to fall through.
> 
> This patch fixes the following warnings:
> 
> drivers/scsi/ibmvscsi/ibmvfc.c: In function 'ibmvfc_npiv_login_done':
> drivers/scsi/ibmvscsi/ibmvfc.c:4022:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    ibmvfc_retry_host_init(vhost);
>    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/scsi/ibmvscsi/ibmvfc.c:4023:2: note: here
>   case IBMVFC_MAD_DRIVER_FAILED:
>   ^~~~
> drivers/scsi/ibmvscsi/ibmvfc.c: In function 'ibmvfc_bsg_request':
> drivers/scsi/ibmvscsi/ibmvfc.c:1830:11: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    port_id = (bsg_request->rqst_data.h_els.port_id[0] << 16) |
>    ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     (bsg_request->rqst_data.h_els.port_id[1] << 8) |
>     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     bsg_request->rqst_data.h_els.port_id[2];
>     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/scsi/ibmvscsi/ibmvfc.c:1833:2: note: here
>   case FC_BSG_RPT_ELS:
>   ^~~~
> drivers/scsi/ibmvscsi/ibmvfc.c:1838:11: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    port_id = (bsg_request->rqst_data.h_ct.port_id[0] << 16) |
>    ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     (bsg_request->rqst_data.h_ct.port_id[1] << 8) |
>     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     bsg_request->rqst_data.h_ct.port_id[2];
>     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/scsi/ibmvscsi/ibmvfc.c:1841:2: note: here
>   case FC_BSG_RPT_CT:
>   ^~~~
> 
> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/scsi/ibmvscsi/ibmvfc.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
> index 8cdbac076a1b..df897df5cafe 100644
> --- a/drivers/scsi/ibmvscsi/ibmvfc.c
> +++ b/drivers/scsi/ibmvscsi/ibmvfc.c
> @@ -1830,6 +1830,7 @@ static int ibmvfc_bsg_request(struct bsg_job *job)
>  		port_id = (bsg_request->rqst_data.h_els.port_id[0] << 16) |
>  			(bsg_request->rqst_data.h_els.port_id[1] << 8) |
>  			bsg_request->rqst_data.h_els.port_id[2];
> +		/* fall through */
>  	case FC_BSG_RPT_ELS:
>  		fc_flags = IBMVFC_FC_ELS;
>  		break;
> @@ -1838,6 +1839,7 @@ static int ibmvfc_bsg_request(struct bsg_job *job)
>  		port_id = (bsg_request->rqst_data.h_ct.port_id[0] << 16) |
>  			(bsg_request->rqst_data.h_ct.port_id[1] << 8) |
>  			bsg_request->rqst_data.h_ct.port_id[2];
> +		/* fall through */
>  	case FC_BSG_RPT_CT:
>  		fc_flags = IBMVFC_FC_CT_IU;
>  		break;
> @@ -4020,6 +4022,7 @@ static void ibmvfc_npiv_login_done(struct ibmvfc_event *evt)
>  		return;
>  	case IBMVFC_MAD_CRQ_ERROR:
>  		ibmvfc_retry_host_init(vhost);
> +		/* fall through */
>  	case IBMVFC_MAD_DRIVER_FAILED:
>  		ibmvfc_free_event(evt);
>  		return;
> -- 
> 2.22.0
> 

-- 
Kees Cook