Re: [PATCH] scsi: scsi_transport_spi: fix function pointer check.

[James Bottomley]

On Sat, 2020-06-27 at 06:32 -0700, trix@xxxxxxxxxx wrote:
> From: Tom Rix <trix@xxxxxxxxxx>
> 
> clang static analysis flags several null function pointer problems.
> 
> drivers/scsi/scsi_transport_spi.c:374:1: warning: Called function
> pointer is null (null dereference) [core.CallAndMessage]
> spi_transport_max_attr(offset, "%d\n");
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Reviewing the store_spi_store_max macro
> 
> 	if (i->f->set_##field)
> 		return -EINVAL;
> 
> should be
> 
> 	if (!i->f->set_##field)
> 		return -EINVAL;
> 
> Signed-off-by: Tom Rix <trix@xxxxxxxxxx>

Fixes: 9b161a4d3e83 "[SCSI] scsi_transport_spi: convert to attribute groups")

Gosh that's an old bug ... clearly no-one is manually setting width or
offset.

Reviewed-by: James Bottomley <jejb@xxxxxxxxxxxxx>

James


> ---
>  drivers/scsi/scsi_transport_spi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/scsi_transport_spi.c
> b/drivers/scsi/scsi_transport_spi.c
> index f8661062ef95..f3d5b1bbd5aa 100644
> --- a/drivers/scsi/scsi_transport_spi.c
> +++ b/drivers/scsi/scsi_transport_spi.c
> @@ -339,7 +339,7 @@ store_spi_transport_##field(struct device *dev, 	
> 		\
>  	struct spi_transport_attrs *tp				
> 	\
>  		= (struct spi_transport_attrs *)&starget-
> >starget_data;	\
>  									
> \
> -	if (i->f->set_##field)					
> 	\
> +	if (!i->f->set_##field)					
> 	\
>  		return -EINVAL;					
> 	\
>  	val = simple_strtoul(buf, NULL, 0);				
> \
>  	if (val > tp->max_##field)					
> \