Re: [PATCH] qla2xxx: Increase the size of struct qla_fcp_prio_cfg to FCP_PRIO_CFG_SIZE

[Roman Bolshakov <r.bolshakov@yadro.com>]

On Mon, Apr 13, 2020 at 08:56:18PM -0700, Bart Van Assche wrote:
> On 2020-04-13 08:30, Roman Bolshakov wrote:
> > On Sun, Apr 05, 2020 at 04:13:39PM -0700, Bart Van Assche wrote:
> >> This patch fixes the following Coverity complaint without changing any
> >> functionality:
> >>
> >> CID 337793 (#1 of 1): Wrong size argument (SIZEOF_MISMATCH)
> >> suspicious_sizeof: Passing argument ha->fcp_prio_cfg of type
> >> struct qla_fcp_prio_cfg * and argument 32768UL to function memset is
> >> suspicious because a multiple of sizeof (struct qla_fcp_prio_cfg) /*48*/
> >> is expected.
> >>
> >> memset(ha->fcp_prio_cfg, 0, FCP_PRIO_CFG_SIZE);
> >>
> >> ---
> >>  drivers/scsi/qla2xxx/qla_fw.h | 3 ++-
> >>  drivers/scsi/qla2xxx/qla_os.c | 1 +
> >>  2 files changed, 3 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/scsi/qla2xxx/qla_fw.h b/drivers/scsi/qla2xxx/qla_fw.h
> >> index f9bad5bd7198..647e67c6ba5e 100644
> >> --- a/drivers/scsi/qla2xxx/qla_fw.h
> >> +++ b/drivers/scsi/qla2xxx/qla_fw.h
> >> @@ -2217,8 +2217,9 @@ struct qla_fcp_prio_cfg {
> >>  #define FCP_PRIO_ATTR_PERSIST   0x2
> >>  	uint8_t  reserved;      /* Reserved for future use          */
> >>  #define FCP_PRIO_CFG_HDR_SIZE   0x10
> >> -	struct qla_fcp_prio_entry entry[1];     /* fcp priority entries  */
> >> +	struct qla_fcp_prio_entry entry[1023]; /* fcp priority entries  */
> >>  #define FCP_PRIO_CFG_ENTRY_SIZE 0x20
> >> +	uint8_t  reserved2[16];
> >>  };
> >>  
> >>  #define FCP_PRIO_CFG_SIZE       (32*1024) /* fcp prio data per port*/
> > 
> > A new constant may be introduced to define size of qla_fcp_prio_entry.
> > That would let to drop the magic 32 number here and allow to add one
> > more BUILD_BUG_ON for sizeof(struct qla_fcp_prio_entry).
> 
> The constant FCP_PRIO_CFG_ENTRY_SIZE is only used once, namely in the
> following code:
> 
> 	len = ha->fcp_prio_cfg->num_entries * FCP_PRIO_CFG_ENTRY_SIZE;
> 
> How about removing the definition of FCP_PRIO_CFG_ENTRY_SIZE and
> changing FCP_PRIO_CFG_ENTRY_SIZE in the above calculation into
> sizeof(struct qla_fcp_prio_entry)?
> 

Hi Bart,

I overlooked the FCP_PRIO_CFG_ENTRY_SIZE definition in the hunk :)
Since it's already there, we can just replace 32 with it and add
BUILD_BUG_ON using the definition.

What you propose is also reasonable if used with BUILD_BUG_ON that has
numeric literal for FCP_PRIO_CFG_ENTRY_SIZE.

Thanks,
Roman