Re: [bug report] hwmon: (pmbus/ibm-cffps) Add new manufacturer debugfs entries

[Eddie James <eajames@linux.ibm.com>]

On 1/7/20 7:53 AM, Guenter Roeck wrote:
> On 1/7/20 5:32 AM, Dan Carpenter wrote:
>> Hello Eddie James,
>>
>> The patch bb3c0a27ed1d: "hwmon: (pmbus/ibm-cffps) Add new
>> manufacturer debugfs entries" from Dec 19, 2019, leads to the
>> following static checker warning:
>>
>>     drivers/hwmon/pmbus/ibm-cffps.c:257 ibm_cffps_debugfs_write()
>>     error: uninitialized symbol 'data'.
>>
>> drivers/hwmon/pmbus/ibm-cffps.c
>>     238  static ssize_t ibm_cffps_debugfs_write(struct file *file,
>>     239                                         const char __user 
>> *buf, size_t count,
>>     240                                         loff_t *ppos)
>>     241  {
>>     242          u8 data;
>>     243          ssize_t rc;
>>     244          int *idxp = file->private_data;
>>     245          int idx = *idxp;
>>     246          struct ibm_cffps *psu = to_psu(idxp, idx);
>>     247
>>     248          switch (idx) {
>>     249          case CFFPS_DEBUGFS_ON_OFF_CONFIG:
>>     250                  pmbus_set_page(psu->client, 0);
>>     251
>>     252                  rc = simple_write_to_buffer(&data, 1, ppos, 
>> buf, count);
>> ^^^^^^^^^^^^^^
>> If "ppos >= 1" then "data" isn't initialized but "rc" is zero.
>>
>
> If rc == 0 (ie if no data was read) we should probably bail out here 
> (either return
> an error or 0).


I'll make the change.


Good catch Dan, thanks!

Eddie


>
> Guenter
>
>>     253                  if (rc < 0)
>>     254                          return rc;
>>     255
>>     256                  rc = i2c_smbus_write_byte_data(psu->client,
>>     257 PMBUS_ON_OFF_CONFIG, data);
>>     258                  if (rc)
>>     259                          return rc;
>>     260
>>     261                  rc = 1;
>>     262                  break;
>>     263          default:
>>     264                  return -EINVAL;
>>     265          }
>>     266
>>     267          return rc;
>>     268  }
>>
>> regards,
>> dan carpenter
>>
>