Re: [dpdk-dev] Packet data out of bounds after rte_eth_rx_burst

[Dor Green <dorgreen1@gmail.com>]

I changed it to free and it still happens. Note that the segmentation fault
happens before that anyway.

I am using 1.7.1 at the moment. I can try using a newer version.
On 23 Mar 2015 17:00, "Bruce Richardson" <bruce.richardson@intel.com> wrote:

> On Mon, Mar 23, 2015 at 04:24:18PM +0200, Dor Green wrote:
> > I'm running a small app which captures packets on a single lcore and
> > then passes it to other workers for processing.
> >
> > Before even sending it to processing, when checking some minor
> > information in the packet mbuf's data I get a segfault.
> >
> > This code, for example gets a segfault:
> >
> > struct rte_mbuf *pkts[PKTS_BURST_SIZE];
> >
> > for (p = 0; p < portnb; ++p) {
> >     nbrx = rte_eth_rx_burst(p, 0, pkts, PKTS_BURST_SIZE);
> >
> >     if (unlikely(nbrx == 0)) {
> >         continue;
> >     }
> >
> >     for (i = 0; likely(i < nbrx); i++) {
> >         printf("Pkt %c\n", pkts[i]->pkt->data[0]);
> >         rte_mempool_put(pktmbuf_pool, (void *const)pkts[i]);
> >     }
> > }
> >
> > This doesn't happen on most packets, but when I used packets from a
> > certain cap it happened often (SSL traffic). In gdb the packet objects
> > looked like this:
> > {next = 0x0, data = 0x62132136406a6f6, data_len = 263, nb_segs = 1
> > '\001', in_port = 0 '\000', pkt_len = 263, vlan_macip = {data = 55111,
> > f = {l3_len = 327, l2_len = 107, vlan_tci = 0}}, hash = {
> >     rss = 311317915, fdir = {hash = 21915, id = 4750}, sched =
> > 311317915}} (Invalid)
> >  {next = 0x0, data = 0x7ffe43d8f640, data_len = 73, nb_segs = 1
> > '\001', in_port = 0 '\000', pkt_len = 73, vlan_macip = {data = 0, f =
> > {l3_len = 0, l2_len = 0, vlan_tci = 0}}, hash = {rss = 311317915,
> >     fdir = {hash = 21915, id = 4750}, sched = 311317915}} (Valid)
> > {next = 0x0, data = 0x7ffe43d7fa40, data_len = 74, nb_segs = 1 '\001',
> > in_port = 0 '\000', pkt_len = 74, vlan_macip = {data = 0, f = {l3_len
> > = 0, l2_len = 0, vlan_tci = 0}}, hash = {rss = 311317915,
> >     fdir = {hash = 21915, id = 4750}, sched = 311317915}} (Valid)
> > {next = 0x0, data = 0x7ffe43d7ff80, data_len = 66, nb_segs = 1 '\001',
> > in_port = 0 '\000', pkt_len = 66, vlan_macip = {data = 0, f = {l3_len
> > = 0, l2_len = 0, vlan_tci = 0}}, hash = {rss = 311317915,
> >     fdir = {hash = 21915, id = 4750}, sched = 311317915}} (Valid)
> > {next = 0x0, data = 0x28153a8e63b3afc4, data_len = 263, nb_segs = 1
> > '\001', in_port = 0 '\000', pkt_len = 263, vlan_macip = {data = 59535,
> > f = {l3_len = 143, l2_len = 116, vlan_tci = 0}}, hash = {
> >     rss = 311317915, fdir = {hash = 21915, id = 4750}, sched =
> > 311317915}} (Invalid)
> >
> > Note that in the first packet, the length does not match the actual
> > packet length (it does in the last though). The rest of the packets
> > are placed in the hugemem range as they should be.
> >
> > I'm running on Linux 3.2.0-77, the NIC is "10G 2P X520", I have 4 1GB
> > huge pages.
> >
> > Any ideas will be appreciated.
>
> What version of DPDK are you using? If you update the code to work with the
> latest code (or 2.0.0-rc2), does the problem still occur? Also, does it
> make
> any difference calling rte_pktmbuf_free rather thatn calling mempool_put
> directly?
>
> /Bruce
>