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Subject: Re: [PATCH] soc: qcom: geni: Fix NULL pointer dereference
To:     Matthias Kaehlcke <mka@chromium.org>
Cc:     bjorn.andersson@linaro.org, linux-kernel@vger.kernel.org,
        saipraka@codeaurora.org, msavaliy@codeaurora.org
References: <1594996342-26964-1-git-send-email-akashast@codeaurora.org>
 <20200717144840.GT3191083@google.com>
From:   Akash Asthana <akashast@codeaurora.org>
Message-ID: <238543d2-60fc-8c76-e345-a9de04a7562c@codeaurora.org>
Date:   Mon, 20 Jul 2020 14:31:15 +0530
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Hi Matthias,

On 7/17/2020 8:18 PM, Matthias Kaehlcke wrote:
> Please make sure to cc the linux-arm-msm@vger list for patches of
> Qualcomm code.
Sure.
> On Fri, Jul 17, 2020 at 08:02:22PM +0530, Akash Asthana wrote:
>> pdev struct doesn't exits for the devices whose status are disabled
> s/exits/exist/
ok
>
>> from DT node, in such cases NULL is returned from 'of_find_device_by_node'
>> Later when we try to get drvdata from pdev struct NULL pointer dereference
>> is triggered.
>>
>> Add a NULL check for return values to fix the issue.
>>
>> We were hitting this issue when one of QUP is disabled.
>>
>> Fixes: 048eb908a1f2 ("soc: qcom-geni-se: Add interconnect support to fix earlycon crash")
>> Reported-by: Sai Prakash Ranjan <saipraka@codeaurora.org>
>> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
>> ---
>>   drivers/soc/qcom/qcom-geni-se.c | 8 +++++++-
>>   1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
>> index 355d503..6e5fe65 100644
>> --- a/drivers/soc/qcom/qcom-geni-se.c
>> +++ b/drivers/soc/qcom/qcom-geni-se.c
>> @@ -820,6 +820,7 @@ void geni_remove_earlycon_icc_vote(void)
>>   	struct geni_wrapper *wrapper;
>>   	struct device_node *parent;
>>   	struct device_node *child;
>> +	struct platform_device *wrapper_pdev;
> nit: since there is no other 'pdev' in this function you could just name
> it 'pdev', which is less clunky. The variable is only used immediately
> after it is assigned, so it's clear from the context that it refers to
> the 'wrapper'.

ok

Thankyou for review!.


regards,

Akash

>
> Reviewed-by: Matthias Kaehlcke <mka@chromium.org>

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