Re: [PATCH v3 07/18] arm64: defconfig: Enable Qualcomm minidump driver

From: Krzysztof Kozlowski
Date: Thu May 04 2023 - 11:24:35 EST


On 04/05/2023 16:43, Mukesh Ojha wrote:
>
>
> On 5/4/2023 6:02 PM, Krzysztof Kozlowski wrote:
>> On 04/05/2023 13:45, Mukesh Ojha wrote:
>>>
>>>
>>> On 5/4/2023 4:53 PM, Krzysztof Kozlowski wrote:
>>>> On 03/05/2023 19:02, Mukesh Ojha wrote:
>>>>> Previous patches add the Qualcomm minidump driver support, so
>>>>> lets enable minidump config so that it can be used by kernel
>>>>> clients.
>>>>>
>>>>> Signed-off-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
>>>>
>>>> This patchset is split too much. Defconfig change is one change. Not two
>>>> or three.
>>>>
>>>>> ---
>>>>> arch/arm64/configs/defconfig | 1 +
>>>>> 1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
>>>>> index a24609e..831c942 100644
>>>>> --- a/arch/arm64/configs/defconfig
>>>>> +++ b/arch/arm64/configs/defconfig
>>>>> @@ -1250,6 +1250,7 @@ CONFIG_QCOM_STATS=m
>>>>> CONFIG_QCOM_WCNSS_CTRL=m
>>>>> CONFIG_QCOM_APR=m
>>>>> CONFIG_QCOM_ICC_BWMON=m
>>>>> +CONFIG_QCOM_MINIDUMP=y
>>>>
>>>> This must be a module.
>>>
>>> Why do you think this should be a module ?
>>>
>>> Is it because, it is lying here among others '=m' ?
>>
>> Because we want and insist on everything being a module. That's the
>> generic rule. There are exceptions, so if this justifies being an
>> exception, please bring appropriate arguments.
>>
>>>
>>> Or you have some other reasoning ? like it is for qcom specific
>>> soc and can not be used outside ? but that is not true for
>>> all configs mentioned here.
>>>
>>> The reason behind making it as '=y' was, to collect information from
>>> core kernel data structure as well as the information like percpu data,
>>> run queue, irq stat kind of information on kernel crash on a target
>>> running some perf configuration(android phone).
>>
>> I don't understand why =m stops you from all that.
>
> How do i get kernel symbol address from a modules
> can we use kallsyms_lookup_name from modules ?

You allow it to be a module in patch #4, so I think you solved it,
right? Otherwise it could not be a module?

Anyway, where do you use kallsyms_lookup_name()? I cannot find it in
your patch.

Best regards,
Krzysztof