[PATCH 5/7] net/nfp: fix resource leak for exit of CoreNIC firmware

[Ferruh Yigit]

On 12/1/2023 3:00 AM, Chaoyong He wrote:
>> On 11/30/2023 8:52 AM, Chaoyong He wrote:
>>> Fix the resource leak problem in the exit logic of CoreNIC firmware.
>>>
>>> Fixes: 646ea79ce481 ("net/nfp: move PF functions into its own file")
>>> Cc: stable at dpdk.org
>>>
>>> Signed-off-by: Chaoyong He <chaoyong.he at corigine.com>
>>> Reviewed-by: Long Wu <long.wu at corigine.com>
>>> Reviewed-by: Peng Zhang <peng.zhang at corigine.com>
>>
>> <...>
>>
>>> +static int
>>> +nfp_pf_secondary_uninit(struct nfp_pf_dev *pf_dev) {
>>> +	free(pf_dev->sym_tbl);
>>> +	rte_free(pf_dev);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>>  /* Reset and stop device. The device can not be restarted. */  static
>>> int  nfp_net_close(struct rte_eth_dev *dev) @@ -333,14 +381,25 @@
>>> nfp_net_close(struct rte_eth_dev *dev)
>>>  	struct rte_pci_device *pci_dev;
>>>  	struct nfp_app_fw_nic *app_fw_nic;
>>>
>>> -	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
>>> -		return 0;
>>> -
>>>  	hw = dev->data->dev_private;
>>>  	pf_dev = hw->pf_dev;
>>>  	pci_dev = RTE_ETH_DEV_TO_PCI(dev);
>>>  	app_fw_nic = NFP_PRIV_TO_APP_FW_NIC(pf_dev->app_fw_priv);
>>>
>>> +	/*
>>> +	 * In secondary process, a released eth device can be found by its
>> name
>>> +	 * in shared memory.
>>> +	 * If the state of the eth device is RTE_ETH_DEV_UNUSED, it means the
>>> +	 * eth device has been released.
>>> +	 */
>>> +	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
>>> +		if (dev->state == RTE_ETH_DEV_UNUSED)
>>> +			return 0;
>>> +
>>> +		nfp_pf_secondary_uninit(pf_dev);
>>> +		return 0;
>>> +	}
>>> +
>>>
>>
>> Mostly expectation is secondary process doesn't free shared resources, but
>> init and free done by primary process.
> 
> I agree.
> Maybe the comment here make reader a little confused.
> But the `nfp_pf_secondary_uninit()` does not free any shared resources, it only free two memory which private to each secondary process.
> 

What freed is not process private, it is in the shared memory:

 	hw = dev->data->dev_private;
 	pf_dev = hw->pf_dev;
	rte_free(pf_dev);


And when there are multiple secondaries, one of them frees `pf_dev`, how
this is not effecting others that may use `pf_dev`?


>> When there are multiple secondaries active, and if one of them closes the port,
>> will system behave properly? Can you please double check above logic?
> 
> Yes, the system behave properly.
>