Re: [Intel-wired-lan] [[PATCH v2 iwl-next] v2 2/4] idpf: Acquire the lock before accessing the xn->salt

[Przemek Kitszel <przemyslaw.kitszel@intel.com>]

On 8/28/24 23:29, Jacob Keller wrote:
> 
> 
> On 8/26/2024 11:10 AM, Manoj Vishwanathan wrote:
>> The transaction salt was being accessed before acquiring the
>> idpf_vc_xn_lock when idpf has to forward the virtchnl reply.
>>
>> Fixes: 34c21fa894a1a (“idpf: implement virtchnl transaction manager”)
>> Signed-off-by: Manoj Vishwanathan <manojvishy@google.com>
>> ---
> 
> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
> 
>>   drivers/net/ethernet/intel/idpf/idpf_virtchnl.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
>> index 70986e12da28..30eec674d594 100644
>> --- a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
>> +++ b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
>> @@ -612,14 +612,15 @@ idpf_vc_xn_forward_reply(struct idpf_adapter *adapter,
>>   		return -EINVAL;
>>   	}
>>   	xn = &adapter->vcxn_mngr->ring[xn_idx];
>> +	idpf_vc_xn_lock(xn);
> 
> Could look at implementing cleanup.h based locking here so that we could
> use guard or scope_guard and not have to litter the exit paths with unlocks.

only scope_guard() for networking code

> 
> I don't think that needs to be done in this patch, though.

+1

> 
>>   	salt = FIELD_GET(IDPF_VC_XN_SALT_M, msg_info);
>>   	if (xn->salt != salt) {
>>   		dev_err_ratelimited(&adapter->pdev->dev, "Transaction salt does not match (%02x != %02x)\n",
>>   				    xn->salt, salt);
>> +		idpf_vc_xn_unlock(xn);
>>   		return -EINVAL;
>>   	}
>>   
>> -	idpf_vc_xn_lock(xn);
>>   	switch (xn->state) {
>>   	case IDPF_VC_XN_WAITING:
>>   		/* success */