On 14/04/2021 18:49, Sylwester Nawrocki wrote:
> On 14.04.2021 17:25, Krzysztof Kozlowski wrote:
>> On 14/04/2021 17:12, Krzysztof Kozlowski wrote:
>>> The driver can be matched by legacy platform way or OF-device matching.
>>> In the first case, of_match_node() can return NULL, which immediately
>>> would be dereferenced to get the match data.
>>>
>>> Addresses-Coverity: Dereference null return value
>>> Fixes: cd1b00eb24b0 ("mmc: sdhci-s3c: Add device tree support")
>>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx>
>
>>> -#ifdef CONFIG_OF
>>> -static const struct of_device_id sdhci_s3c_dt_match[];
>>> -#endif
>>> -
>>> static inline struct sdhci_s3c_drv_data *sdhci_s3c_get_driver_data(
>>> struct platform_device *pdev)
>>> {
>>> #ifdef CONFIG_OF
>>> - if (pdev->dev.of_node) {
>>> - const struct of_device_id *match;
>>> - match = of_match_node(sdhci_s3c_dt_match, pdev->dev.of_node);
>>
>> Now I have second thoughts whether NULL pointer can actually happen. If
>> device is matched via platform/board files, maybe the pdev->dev.of_node
>> will be NULL thus skipping this branch?
>>
>> Could there be a case where device is matched via platform_device_id()
>> (which has different name than compatible!) and (pdev->dev.of_node) is
>> still assigned? Maybe in case of out of tree DTS?
>
> That seems unlikely, the platform device would need to be initialized
> via board file and then its of_node assigned somehow. It doesn't make
> much sense to me. We either use board file or dtb to instantiate devices.
>
>> Anyway, the patch makes the code simpler/smaller, so I still think it is
>> reasonable. Just the severity of issue is questionable...
>
> Yes, the patch looks good. Similar cleanups are already done in most of
> the s3c/s5p/exynos drivers.
Thanks Sylwester, I'll resend with different description.
Best regards,
Krzysztof
