re: iwlwifi: refactor the SAR tables from mvm to acpi

re: iwlwifi: refactor the SAR tables from mvm to acpi

[Colin Ian King]

Hi,

Static analysis with Coverity has detected a potential issue with the
following commit:

commit 39c1a9728f938c7255ce507c8d56b73e8a4ebddf
Author: Ihab Zhaika <ihab.zhaika@intel.com>
Date:   Fri Nov 15 09:28:11 2019 +0200

    iwlwifi: refactor the SAR tables from mvm to acpi


in function iwl_sar_get_ewrd_table() we have an array index pos being
initialized to 3 and then incremented each time a loop iterates:

        for (i = 0; i < n_profiles; i++) {
                /* the tables start at element 3 */
                int pos = 3;

                /* The EWRD profiles officially go from 2 to 4, but we
                 * save them in sar_profiles[1-3] (because we don't
                 * have profile 0).  So in the array we start from 1.
                 */
                ret = iwl_sar_set_profile(&wifi_pkg->package.elements[pos],
                                          &fwrt->sar_profiles[i + 1],
                                          enabled);
                if (ret < 0)
                        break;

                /* go to the next table */
                pos += ACPI_SAR_TABLE_SIZE;
        }

So, each iteration is always accessing package.elements[3]. I'm not sure
if that is intentional. If it is, then the increment of pos is not
required.  Either way, it's not clear what the original intention is.

Colin

Re: iwlwifi: refactor the SAR tables from mvm to acpi

[Luciano Coelho]

On Fri, 2019-12-20 at 00:02 +0000, Colin Ian King wrote:
> Hi,
> 
> Static analysis with Coverity has detected a potential issue with the
> following commit:
> 
> commit 39c1a9728f938c7255ce507c8d56b73e8a4ebddf
> Author: Ihab Zhaika <ihab.zhaika@intel.com>
> Date:   Fri Nov 15 09:28:11 2019 +0200
> 
>     iwlwifi: refactor the SAR tables from mvm to acpi
> 
> 
> in function iwl_sar_get_ewrd_table() we have an array index pos being
> initialized to 3 and then incremented each time a loop iterates:
> 
>         for (i = 0; i < n_profiles; i++) {
>                 /* the tables start at element 3 */
>                 int pos = 3;
> 
>                 /* The EWRD profiles officially go from 2 to 4, but we
>                  * save them in sar_profiles[1-3] (because we don't
>                  * have profile 0).  So in the array we start from 1.
>                  */
>                 ret = iwl_sar_set_profile(&wifi_pkg->package.elements[pos],
>                                           &fwrt->sar_profiles[i + 1],
>                                           enabled);
>                 if (ret < 0)
>                         break;
> 
>                 /* go to the next table */
>                 pos += ACPI_SAR_TABLE_SIZE;
>         }
> 
> So, each iteration is always accessing package.elements[3]. I'm not sure
> if that is intentional. If it is, then the increment of pos is not
> required.  Either way, it's not clear what the original intention is.

Good catch, thanks! We'll fix it.

--
Cheers,
Luca.