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Message-ID: <bf29c39f-8d9f-465a-bbc2-45bdb77711b8@kylinos.cn>
Date:   Thu, 30 Nov 2023 17:43:27 +0800
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Subject: Re: [PATCH] platform/mellanox: Add a null pointer check in
 mlxbf_pmc_create_groups
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To:     =?UTF-8?Q?Ilpo_J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
Cc:     Hans de Goede <hdegoede@redhat.com>, vadimp@nvidia.com,
        jiri@resnulli.us, shravankr@nvidia.com, kunwu.chan@hotmail.com,
        platform-driver-x86@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>
References: <20231127063433.1549064-1-chentao@kylinos.cn>
 <1701224213463629.329.seg@mailgw>
From:   Kunwu Chan <chentao@kylinos.cn>
In-Reply-To: <1701224213463629.329.seg@mailgw>
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Thanks for your reply.

Cause i don't know how to deal with in some scenario，such as in 
'mlxbf_pmc_init_perftype_counter', when 'attr->dev_attr.attr.name' is 
null, should return '-ENOMEM' or 'continue' the loop?

So I'm going to solve it one by one.

Thanks again,
Kunwu

On 2023/11/28 17:51, Ilpo Järvinen wrote:
> On Mon, 27 Nov 2023, Kunwu Chan wrote:
> 
>> devm_kasprintf() returns a pointer to dynamically allocated memory
>> which can be NULL upon failure.
>>
>> Fixes: 1a218d312e65 ("platform/mellanox: mlxbf-pmc: Add Mellanox BlueField PMC driver")
>> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
>> ---
>>   drivers/platform/mellanox/mlxbf-pmc.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/platform/mellanox/mlxbf-pmc.c b/drivers/platform/mellanox/mlxbf-pmc.c
>> index 0b427fc24a96..59bbe5e13f6b 100644
>> --- a/drivers/platform/mellanox/mlxbf-pmc.c
>> +++ b/drivers/platform/mellanox/mlxbf-pmc.c
>> @@ -1882,6 +1882,8 @@ static int mlxbf_pmc_create_groups(struct device *dev, int blk_num)
>>   	pmc->block[blk_num].block_attr_grp.attrs = pmc->block[blk_num].block_attr;
>>   	pmc->block[blk_num].block_attr_grp.name = devm_kasprintf(
>>   		dev, GFP_KERNEL, pmc->block_name[blk_num]);
>> +	if (!pmc->block[blk_num].block_attr_grp.name)
>> +		return -ENOMEM;
>>   	pmc->groups[pmc->group_num] = &pmc->block[blk_num].block_attr_grp;
>>   	pmc->group_num++;
> 
> I'm totally lost, why did you fix only one devm_kasprintf() location?
> Don't all of them need this check?
>