Re: [PATCH net-next 01/18] net/smc: decouple ism_dev from SMC-D device dump

Wen Gu
2023-09-22T08:16:04Z

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
>>
>>