Re: [dpdk-dev] [PATCH] librte_ether: fix crashes in rte_ethdev functions.

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Iremonger, Bernard
> Sent: Monday, December 21, 2015 11:40 AM
> To: Qiu, Michael; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] librte_ether: fix crashes in rte_ethdev functions.
> 
> Hi Michael,
> 
> > -----Original Message-----
> > From: Qiu, Michael
> > Sent: Monday, December 21, 2015 9:03 AM
> > To: Iremonger, Bernard <bernard.iremonger@intel.com>; dev@dpdk.org
> > Subject: Re: [dpdk-dev] [PATCH] librte_ether: fix crashes in rte_ethdev
> > functions.
> >
> > On 2015/12/18 1:24, Bernard Iremonger wrote:
> > > The nb_rx_queues and nb_tx_queues are initialised before the tx_queue
> > > and rx_queue arrays are allocated. The arrays are allocated when the
> > > ethdev port is started.
> > >
> > > If any of the following functions are called before the ethdev port is
> > > started there is a segmentation fault:
> > >
> > > rte_eth_stats_get
> > > rte_eth_stats_reset
> > > rte_eth_xstats_get
> > > rte_eth_xstats_reset
> > >
> > > Fixes: af75078fece3 ("first public release")
> > > Fixes: ce757f5c9a4d ("ethdev: new method to retrieve extended
> > > statistics")
> > > Fixes: d4fef8b0d5e5 ("ethdev: expose generic and driver specific stats
> > > in xstats")
> > > Signed-off-by: Bernard Iremonger <bernard.iremonger@intel.com>
> > > ---
> > >  lib/librte_ether/rte_ethdev.c | 16 ++++++++++++----
> > >  1 file changed, 12 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/lib/librte_ether/rte_ethdev.c
> > > b/lib/librte_ether/rte_ethdev.c index ed971b4..a0ee84d 100644
> > > --- a/lib/librte_ether/rte_ethdev.c
> > > +++ b/lib/librte_ether/rte_ethdev.c
> > > @@ -1441,7 +1441,10 @@ rte_eth_stats_get(uint8_t port_id, struct
> > rte_eth_stats *stats)
> > >  	memset(stats, 0, sizeof(*stats));
> > >
> > >  	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->stats_get, -
> > ENOTSUP);
> > > -	(*dev->dev_ops->stats_get)(dev, stats);
> > > +
> > > +	if (dev->data->dev_started)
> > > +		(*dev->dev_ops->stats_get)(dev, stats);
> > > +

So why it would be no possible now to get statistics on the stopped device?
Konstantin

> >
> > My question is should we mark an error or a warning here and return an
> > error so that the caller knows what happens?
> >
> > Thanks,
> > Michael
> 
> <snip>
> 
> In other cases in rte_ethdev.c where there is a check on "dev->data->dev_started" there is a RTE_PMD_DEBUG_TRACE()  line. I will
> add a RTE_PMD_DEBUG_TRACE()  line.
> The rte_eth_stats_reset() and rte_eth_xstats_reset() functions return void.
> Not sure if an error is required for the rte_eth_stats_get() and rte_eth_xstats_get() functions as the stats information returned is all
> zero's at present.
> 
> Regards,
> 
> Bernard.