[dpdk-dev] kni: fix unit test segfault

  To clean alloc_q, which has physicall addresses of the mbufs, kni lib
free the pkt_mempool, but this leads a crash in kni unit test.

KNI library shouldn't free the pkt_mempool.

Implementation updated to find the mbufs in the alloc_q and return them
back to mempool.

Fixes: 8eba5ebd1811 ("kni: fix possible memory leak")

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
 lib/librte_kni/rte_kni.c | 34 ++++++++++++++++++++++------------
 1 file changed, 22 insertions(+), 12 deletions(-)
  

Hi Ferruh,
Even w/o this patch, I mostly find mbufs returned by rte_kni_rx_burst() 
always 0
(or sometimes 1) where as more than 32000 mbufs approx created in 
ingress side
for this test.

   dpdk/test/test $ ./test -l 0,1,2 --socket-mem 1024

Am I missing something required for this unit test ?.

Thanks,
Gowrishankar

On Wednesday 03 May 2017 09:40 PM, Ferruh Yigit wrote:
> To clean alloc_q, which has physicall addresses of the mbufs, kni lib
> free the pkt_mempool, but this leads a crash in kni unit test.
>
> KNI library shouldn't free the pkt_mempool.
>
> Implementation updated to find the mbufs in the alloc_q and return them
> back to mempool.
>
> Fixes: 8eba5ebd1811 ("kni: fix possible memory leak")
>
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
> ---
>   lib/librte_kni/rte_kni.c | 34 ++++++++++++++++++++++------------
>   1 file changed, 22 insertions(+), 12 deletions(-)
>
> diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
> index 52fcd4b..c3f9208 100644
> --- a/lib/librte_kni/rte_kni.c
> +++ b/lib/librte_kni/rte_kni.c
> @@ -451,17 +451,35 @@ kni_free_fifo(struct rte_kni_fifo *fifo)
>   	} while (ret);
>   }
>
> +static void *
> +va2pa(struct rte_mbuf *m)
> +{
> +	return (void *)((unsigned long)m -
> +			((unsigned long)m->buf_addr -
> +			 (unsigned long)m->buf_physaddr));
> +}
> +
>   static void
> -kni_free_fifo_phy(struct rte_mempool *pktmbuf_pool, struct rte_kni_fifo *fifo)
> +obj_free(struct rte_mempool *mp __rte_unused, void *opaque, void *obj,
> +		unsigned obj_idx __rte_unused)
> +{
> +	struct rte_mbuf *m = obj;
> +	void *mbuf_phys = opaque;
> +
> +	if (va2pa(m) == mbuf_phys)
> +		rte_pktmbuf_free(m);
> +}
> +
> +static void
> +kni_free_fifo_phy(struct rte_mempool *mp, struct rte_kni_fifo *fifo)
>   {
>   	void *mbuf_phys;
>   	int ret;
>
> -	rte_mempool_free(pktmbuf_pool);
> -
> -	/* All mbufs alredy freed with rte_mempoll_free, just free the fifo */
>   	do {
>   		ret = kni_fifo_get(fifo, &mbuf_phys, 1);
> +		if (ret)
> +			rte_mempool_obj_iter(mp, obj_free, mbuf_phys);
>   	} while (ret);
>   }
>
> @@ -557,14 +575,6 @@ rte_kni_handle_request(struct rte_kni *kni)
>   	return 0;
>   }
>
> -static void *
> -va2pa(struct rte_mbuf *m)
> -{
> -	return (void *)((unsigned long)m -
> -			((unsigned long)m->buf_addr -
> -			 (unsigned long)m->buf_physaddr));
> -}
> -
>   unsigned
>   rte_kni_tx_burst(struct rte_kni *kni, struct rte_mbuf **mbufs, unsigned num)
>   {
  

On 5/4/2017 6:23 AM, gowrishankar muthukrishnan wrote:
> Hi Ferruh,
> Even w/o this patch, I mostly find mbufs returned by rte_kni_rx_burst() 
> always 0
> (or sometimes 1) where as more than 32000 mbufs approx created in 
> ingress side
> for this test.
> 
>    dpdk/test/test $ ./test -l 0,1,2 --socket-mem 1024
> 
> Am I missing something required for this unit test ?.

Hi Gowrishankar,

KNI module should be inserted with one of the loopback options [1] for
the unit test.

[1]
There are two loopback options supported, both loopbacks Rx/Tx path in
kernel side, this is easy way to test KNI.

options are: lo_mode_fifo and lo_mode_fifo_skb

usage:
insmod build/kmod/rte_kni.ko lo_mode=lo_mode_fifo
or
insmod build/kmod/rte_kni.ko lo_mode=lo_mode_fifo_skb


Regards,
ferruh

> 
> Thanks,
> Gowrishankar
> 
> On Wednesday 03 May 2017 09:40 PM, Ferruh Yigit wrote:
>> To clean alloc_q, which has physicall addresses of the mbufs, kni lib
>> free the pkt_mempool, but this leads a crash in kni unit test.
>>
>> KNI library shouldn't free the pkt_mempool.
>>
>> Implementation updated to find the mbufs in the alloc_q and return them
>> back to mempool.
>>
>> Fixes: 8eba5ebd1811 ("kni: fix possible memory leak")
>>
>> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
>> ---
>>   lib/librte_kni/rte_kni.c | 34 ++++++++++++++++++++++------------
>>   1 file changed, 22 insertions(+), 12 deletions(-)
>>
>> diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
>> index 52fcd4b..c3f9208 100644
>> --- a/lib/librte_kni/rte_kni.c
>> +++ b/lib/librte_kni/rte_kni.c
>> @@ -451,17 +451,35 @@ kni_free_fifo(struct rte_kni_fifo *fifo)
>>   	} while (ret);
>>   }
>>
>> +static void *
>> +va2pa(struct rte_mbuf *m)
>> +{
>> +	return (void *)((unsigned long)m -
>> +			((unsigned long)m->buf_addr -
>> +			 (unsigned long)m->buf_physaddr));
>> +}
>> +
>>   static void
>> -kni_free_fifo_phy(struct rte_mempool *pktmbuf_pool, struct rte_kni_fifo *fifo)
>> +obj_free(struct rte_mempool *mp __rte_unused, void *opaque, void *obj,
>> +		unsigned obj_idx __rte_unused)
>> +{
>> +	struct rte_mbuf *m = obj;
>> +	void *mbuf_phys = opaque;
>> +
>> +	if (va2pa(m) == mbuf_phys)
>> +		rte_pktmbuf_free(m);
>> +}
>> +
>> +static void
>> +kni_free_fifo_phy(struct rte_mempool *mp, struct rte_kni_fifo *fifo)
>>   {
>>   	void *mbuf_phys;
>>   	int ret;
>>
>> -	rte_mempool_free(pktmbuf_pool);
>> -
>> -	/* All mbufs alredy freed with rte_mempoll_free, just free the fifo */
>>   	do {
>>   		ret = kni_fifo_get(fifo, &mbuf_phys, 1);
>> +		if (ret)
>> +			rte_mempool_obj_iter(mp, obj_free, mbuf_phys);
>>   	} while (ret);
>>   }
>>
>> @@ -557,14 +575,6 @@ rte_kni_handle_request(struct rte_kni *kni)
>>   	return 0;
>>   }
>>
>> -static void *
>> -va2pa(struct rte_mbuf *m)
>> -{
>> -	return (void *)((unsigned long)m -
>> -			((unsigned long)m->buf_addr -
>> -			 (unsigned long)m->buf_physaddr));
>> -}
>> -
>>   unsigned
>>   rte_kni_tx_burst(struct rte_kni *kni, struct rte_mbuf **mbufs, unsigned num)
>>   {
> 
>
  

03/05/2017 18:10, Ferruh Yigit:
> To clean alloc_q, which has physicall addresses of the mbufs, kni lib
> free the pkt_mempool, but this leads a crash in kni unit test.
> 
> KNI library shouldn't free the pkt_mempool.
> 
> Implementation updated to find the mbufs in the alloc_q and return them
> back to mempool.
> 
> Fixes: 8eba5ebd1811 ("kni: fix possible memory leak")
> 
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>

Cc: stable@dpdk.org

Applied, thanks