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Message-ID: <2c9d570c-f780-0484-a26c-78b115e1a6a3@linux.alibaba.com>
Date:   Fri, 22 Sep 2023 16:05:22 +0800
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Subject: Re: [PATCH net-next 01/18] net/smc: decouple ism_dev from SMC-D
 device dump
To:     Simon Horman <horms@kernel.org>
Cc:     kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@linux.ibm.com,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, alibuda@linux.alibaba.com,
        tonylu@linux.alibaba.com, linux-s390@vger.kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
References: <1695134522-126655-1-git-send-email-guwen@linux.alibaba.com>
 <1695134522-126655-2-git-send-email-guwen@linux.alibaba.com>
 <20230921204153.GQ224399@kernel.org>
From:   Wen Gu <guwen@linux.alibaba.com>
In-Reply-To: <20230921204153.GQ224399@kernel.org>
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On 2023/9/22 04:41, Simon Horman wrote:
> On Tue, Sep 19, 2023 at 10:41:45PM +0800, Wen Gu wrote:
>> This patch helps to decouple ISM device from SMC-D device, allowing
>> different underlying device forms, such as virtual ISM devices.
>>
>> Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
>> ---
>>   net/smc/smc_ism.c | 8 +++++---
>>   1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
>> index fbee249..0045fee 100644
>> --- a/net/smc/smc_ism.c
>> +++ b/net/smc/smc_ism.c
>> @@ -230,12 +230,11 @@ static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
>>   	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
>>   	struct smc_pci_dev smc_pci_dev;
>>   	struct nlattr *port_attrs;
>> +	struct device *priv_dev;
>>   	struct nlattr *attrs;
>> -	struct ism_dev *ism;
>>   	int use_cnt = 0;
>>   	void *nlh;
>>   
>> -	ism = smcd->priv;
>>   	nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
>>   			  &smc_gen_nl_family, NLM_F_MULTI,
>>   			  SMC_NETLINK_GET_DEV_SMCD);
>> @@ -250,7 +249,10 @@ static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
>>   	if (nla_put_u8(skb, SMC_NLA_DEV_IS_CRIT, use_cnt > 0))
>>   		goto errattr;
>>   	memset(&smc_pci_dev, 0, sizeof(smc_pci_dev));
> 
> Hi Wen Gu,
> 
> priv_dev is uninitialised here.
> 
>> -	smc_set_pci_values(to_pci_dev(ism->dev.parent), &smc_pci_dev);
>> +	if (smcd->ops->get_dev)
>> +		priv_dev = smcd->ops->get_dev(smcd);
> 
> It is conditionally initialised here.
> 
>> +	if (priv_dev->parent)
> 
> But unconditionally dereferenced here.
> 
> As flagged by clang-16 W=1, and Smatch
> 

Hi Simon. Yes, I fixed it in v3. Thank you!

>> +		smc_set_pci_values(to_pci_dev(priv_dev->parent), &smc_pci_dev);
>>   	if (nla_put_u32(skb, SMC_NLA_DEV_PCI_FID, smc_pci_dev.pci_fid))
>>   		goto errattr;
>>   	if (nla_put_u16(skb, SMC_NLA_DEV_PCI_CHID, smc_pci_dev.pci_pchid))
>> -- 
>> 1.8.3.1
>>
>>