Re: [PATCH v2 net 4/4] ixgbevf: Fix passing 0 to ERR_PTR in ixgbevf_run_xdp()

[Yue Haibing]

On 2024/10/18 20:23, Maciej Fijalkowski wrote:
> On Fri, Oct 18, 2024 at 10:37:34AM +0800, Yue Haibing wrote:
>> ixgbevf_run_xdp() converts customed xdp action to a negative error code
>> with the sk_buff pointer type which be checked with IS_ERR in
>> ixgbevf_clean_rx_irq(). Remove this error pointer handing instead use
>> plain int return value.
>>
>> Fixes: c7aec59657b6 ("ixgbevf: Add XDP support for pass and drop actions")
>> Signed-off-by: Yue Haibing <yuehaibing@xxxxxxxxxx>
>> ---
>>  .../net/ethernet/intel/ixgbevf/ixgbevf_main.c | 23 ++++++++-----------
>>  1 file changed, 10 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
>> index 149911e3002a..183d2305d058 100644
>> --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
>> +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
>> @@ -732,10 +732,6 @@ static bool ixgbevf_cleanup_headers(struct ixgbevf_ring *rx_ring,
>>  				    union ixgbe_adv_rx_desc *rx_desc,
>>  				    struct sk_buff *skb)
>>  {
>> -	/* XDP packets use error pointer so abort at this point */
>> -	if (IS_ERR(skb))
>> -		return true;
>> -
>>  	/* verify that the packet does not have any known errors */
>>  	if (unlikely(ixgbevf_test_staterr(rx_desc,
>>  					  IXGBE_RXDADV_ERR_FRAME_ERR_MASK))) {
>> @@ -1044,9 +1040,9 @@ static int ixgbevf_xmit_xdp_ring(struct ixgbevf_ring *ring,
>>  	return IXGBEVF_XDP_TX;
>>  }
>>  
>> -static struct sk_buff *ixgbevf_run_xdp(struct ixgbevf_adapter *adapter,
>> -				       struct ixgbevf_ring  *rx_ring,
>> -				       struct xdp_buff *xdp)
>> +static int ixgbevf_run_xdp(struct ixgbevf_adapter *adapter,
>> +			   struct ixgbevf_ring *rx_ring,
>> +			   struct xdp_buff *xdp)
> 
> ditto

yuehaibing@localhost:~/code/net$ ./scripts/checkpatch.pl 0004-ixgbevf-Fix-passing-0-to-ERR_PTR-in-ixgbevf_run_xdp.patch
total: 0 errors, 0 warnings, 0 checks, 67 lines checked

0004-ixgbevf-Fix-passing-0-to-ERR_PTR-in-ixgbevf_run_xdp.patch has no obvious style problems and is ready for submission.

> 
>>  {
>>  	int result = IXGBEVF_XDP_PASS;
>>  	struct ixgbevf_ring *xdp_ring;
>> @@ -1080,7 +1076,7 @@ static struct sk_buff *ixgbevf_run_xdp(struct ixgbevf_adapter *adapter,
>>  		break;
>>  	}
>>  xdp_out:
>> -	return ERR_PTR(-result);
>> +	return result;
>>  }
>>  
>>  static unsigned int ixgbevf_rx_frame_truesize(struct ixgbevf_ring *rx_ring,
>> @@ -1122,6 +1118,7 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector,
>>  	struct sk_buff *skb = rx_ring->skb;
>>  	bool xdp_xmit = false;
>>  	struct xdp_buff xdp;
>> +	int xdp_res;
>>  
>>  	/* Frame size depend on rx_ring setup when PAGE_SIZE=4K */
>>  #if (PAGE_SIZE < 8192)
>> @@ -1165,11 +1162,11 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector,
>>  			/* At larger PAGE_SIZE, frame_sz depend on len size */
>>  			xdp.frame_sz = ixgbevf_rx_frame_truesize(rx_ring, size);
>>  #endif
>> -			skb = ixgbevf_run_xdp(adapter, rx_ring, &xdp);
>> +			xdp_res = ixgbevf_run_xdp(adapter, rx_ring, &xdp);
>>  		}
>>  
>> -		if (IS_ERR(skb)) {
>> -			if (PTR_ERR(skb) == -IXGBEVF_XDP_TX) {
>> +		if (xdp_res) {
>> +			if (xdp_res == IXGBEVF_XDP_TX) {
>>  				xdp_xmit = true;
>>  				ixgbevf_rx_buffer_flip(rx_ring, rx_buffer,
>>  						       size);
>> @@ -1189,7 +1186,7 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector,
>>  		}
>>  
>>  		/* exit if we failed to retrieve a buffer */
>> -		if (!skb) {
>> +		if (!xdp_res && !skb) {
>>  			rx_ring->rx_stats.alloc_rx_buff_failed++;
>>  			rx_buffer->pagecnt_bias++;
>>  			break;
>> @@ -1203,7 +1200,7 @@ static int ixgbevf_clean_rx_irq(struct ixgbevf_q_vector *q_vector,
>>  			continue;
>>  
>>  		/* verify the packet layout is correct */
>> -		if (ixgbevf_cleanup_headers(rx_ring, rx_desc, skb)) {
>> +		if (xdp_res || ixgbevf_cleanup_headers(rx_ring, rx_desc, skb)) {
>>  			skb = NULL;
>>  			continue;
>>  		}
>> -- 
>> 2.34.1
>>
> 
> .