6394 ::mac_flow -s segfaults
Reviewed by: Jason King <jason.brian.king@gmail.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>

*** 326,351 ****
          }
          case MAC_FLOW_STATS: {
                  uint64_t                totibytes = 0;
                  uint64_t                totobytes = 0;
                  mac_soft_ring_set_t     *mac_srs;
!                 mac_rx_stats_t          *mac_rx_stat;
!                 mac_tx_stats_t          *mac_tx_stat;
                  int                     i;
  
                  for (i = 0; i < fe.fe_rx_srs_cnt; i++) {
                          mac_srs = (mac_soft_ring_set_t *)(fe.fe_rx_srs[i]);
!                         mac_rx_stat = &mac_srs->srs_rx.sr_stat;
!                         totibytes += mac_rx_stat->mrs_intrbytes +
!                             mac_rx_stat->mrs_pollbytes +
!                             mac_rx_stat->mrs_lclbytes;
                  }
                  mac_srs = (mac_soft_ring_set_t *)(fe.fe_tx_srs);
                  if (mac_srs != NULL) {
!                         mac_tx_stat = &mac_srs->srs_tx.st_stat;
!                         totobytes = mac_tx_stat->mts_obytes;
                  }
                  mdb_printf("%?p %-32s %16llu %16llu\n",
                      addr, fe.fe_flow_name, totibytes, totobytes);
  
                  break;
          }
--- 326,371 ----
          }
          case MAC_FLOW_STATS: {
                  uint64_t                totibytes = 0;
                  uint64_t                totobytes = 0;
                  mac_soft_ring_set_t     *mac_srs;
!                 mac_rx_stats_t          mac_rx_stat;
!                 mac_tx_stats_t          mac_tx_stat;
                  int                     i;
  
+                 /*
+                  * Sum bytes for all Rx SRS.
+                  */
                  for (i = 0; i < fe.fe_rx_srs_cnt; i++) {
                          mac_srs = (mac_soft_ring_set_t *)(fe.fe_rx_srs[i]);
!                         if (mdb_vread(&mac_rx_stat, sizeof (mac_rx_stats_t),
!                             (uintptr_t)&mac_srs->srs_rx.sr_stat) == -1) {
!                                 mdb_warn("failed to read mac_rx_stats_t at %p",
!                                     &mac_srs->srs_rx.sr_stat);
!                                 return (DCMD_ERR);
                          }
+ 
+                         totibytes += mac_rx_stat.mrs_intrbytes +
+                             mac_rx_stat.mrs_pollbytes +
+                             mac_rx_stat.mrs_lclbytes;
+                 }
+ 
+                 /*
+                  * Sum bytes for Tx SRS.
+                  */
                  mac_srs = (mac_soft_ring_set_t *)(fe.fe_tx_srs);
                  if (mac_srs != NULL) {
!                         if (mdb_vread(&mac_tx_stat, sizeof (mac_tx_stats_t),
!                             (uintptr_t)&mac_srs->srs_tx.st_stat) == -1) {
!                                 mdb_warn("failed to read max_tx_stats_t at %p",
!                                     &mac_srs->srs_tx.st_stat);
!                                 return (DCMD_ERR);
                          }
+ 
+                         totobytes = mac_tx_stat.mts_obytes;
+                 }
+ 
                  mdb_printf("%?p %-32s %16llu %16llu\n",
                      addr, fe.fe_flow_name, totibytes, totobytes);
  
                  break;
          }