Re: [dpdk-dev] [PATCH 03/10] net/virtio: fix compilation with -Og

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 10/6/2017 12:17 AM, Ferruh Yigit wrote:
> On 9/11/2017 4:13 PM, Olivier Matz wrote:
>> The compilation with gcc-6.3.0 and EXTRA_CFLAGS=-Og gives the following
>> error:
>>
>>   CC virtio_rxtx.o
>>   virtio_rxtx.c: In function ‘virtio_rx_offload’:
>>   virtio_rxtx.c:680:10: error: ‘csum’ may be used uninitialized in
>>                         this function [-Werror=maybe-uninitialized]
>>        csum = ~csum;
>>        ~~~~~^~~~~~~
>>
>> The function rte_raw_cksum_mbuf() may indeed return an error, and
>> in this case, csum won't be initialized. Fix it by initializing csum
>> to 0.
> 
> After this fix if rte_raw_cksum_mbuf() returns error csum still will be
> wrong and since compiler warning suppressed it may be harder to find the
> root cause.
> 
> For this case checking rte_raw_cksum_mbuf() return value seems better
> idea but I will cc the maintainer for decision.

Trying harder to add maintainer!

> 
>>
>> Fixes: 96cb6711939e ("net/virtio: support Rx checksum offload")
>> Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
>> ---
>>  drivers/net/virtio/virtio_rxtx.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
>> index 45a9c919a..cab3a1675 100644
>> --- a/drivers/net/virtio/virtio_rxtx.c
>> +++ b/drivers/net/virtio/virtio_rxtx.c
>> @@ -671,7 +671,7 @@ virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr)
>>  			 * In case of SCTP, this will be wrong since it's a CRC
>>  			 * but there's nothing we can do.
>>  			 */
>> -			uint16_t csum, off;
>> +			uint16_t csum = 0, off;
>>  
>>  			rte_raw_cksum_mbuf(m, hdr->csum_start,
>>  				rte_pktmbuf_pkt_len(m) - hdr->csum_start,
>>
>