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Message-ID: <12131791-c775-cfc3-824a-e59c4e0ea338@linaro.org>
Date:   Thu, 4 May 2023 17:24:26 +0200
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Subject: Re: [PATCH v3 07/18] arm64: defconfig: Enable Qualcomm minidump
 driver
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To:     Mukesh Ojha <quic_mojha@quicinc.com>, agross@kernel.org,
        andersson@kernel.org, konrad.dybcio@linaro.org, corbet@lwn.net,
        keescook@chromium.org, tony.luck@intel.com, gpiccoli@igalia.com,
        catalin.marinas@arm.com, will@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, robh+dt@kernel.org,
        linus.walleij@linaro.org, linux-gpio@vger.kernel.org,
        srinivas.kandagatla@linaro.org
Cc:     linux-arm-msm@vger.kernel.org, linux-remoteproc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org
References: <1683133352-10046-1-git-send-email-quic_mojha@quicinc.com>
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 <a4118697-d575-6499-ed8e-656e51ca0da3@linaro.org>
 <2fb1658a-3a38-7eb4-0e6e-d8c61981bdab@quicinc.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <2fb1658a-3a38-7eb4-0e6e-d8c61981bdab@quicinc.com>
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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@quicinc.com>
>>>>
>>>> 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