Re: [PATCH v1] afpacket: fix critical issue reported by klocwork

["John W. Linville" <linville-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org>]

On Fri, Feb 20, 2015 at 11:19:59AM +0100, Thomas Monjalon wrote:
> Hi Cunming,
> 
> You would have more chance to have a review by CC'ing John.
> I checked your patch and have a comment below.
> 
> 2015-02-12 17:08, Cunming Liang:
> > Klocwork report 'req' might be used uninitialized.
> > In some cases it can 'goto error' when '*internals' not been set.
> > The result is unexpected checking the value of '*internals'.
> > 
> > Signed-off-by: Cunming Liang <cunming.liang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> > ---
> >  lib/librte_pmd_af_packet/rte_eth_af_packet.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/lib/librte_pmd_af_packet/rte_eth_af_packet.c b/lib/librte_pmd_af_packet/rte_eth_af_packet.c
> > index 1ffe1cd..185607d 100644
> > --- a/lib/librte_pmd_af_packet/rte_eth_af_packet.c
> > +++ b/lib/librte_pmd_af_packet/rte_eth_af_packet.c
> > @@ -439,13 +439,15 @@ rte_pmd_init_internals(const char *name,
> >  	size_t ifnamelen;
> >  	unsigned k_idx;
> >  	struct sockaddr_ll sockaddr;
> > -	struct tpacket_req *req;
> > +	struct tpacket_req *req = NULL;
> 
> If *internals is set to NULL, there should be no case where req used
> and undefined.

I agree -- it looks to me like req is protected by checking for
*internals == NULL.  I don't think this patch is necessary.
 
> >  	struct pkt_rx_queue *rx_queue;
> >  	struct pkt_tx_queue *tx_queue;
> >  	int rc, qsockfd, tpver, discard;
> >  	unsigned int i, q, rdsize;
> >  	int fanout_arg __rte_unused, bypass __rte_unused;
> >  
> > +	*internals = NULL;
> > +
> >  	for (k_idx = 0; k_idx < kvlist->count; k_idx++) {
> >  		pair = &kvlist->pairs[k_idx];
> >  		if (strstr(pair->key, ETH_AF_PACKET_IFACE_ARG) != NULL)
> > 
> 
> 
> 
> 

-- 
John W. Linville		Someday the world will need a hero, and you
linville-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org			might be all we have.  Be ready.