netstat -ia broken

[Thomas Klausner <tk%giga.or.at@localhost>]

Hi!

Since the last update (7.99.33/amd64/20160705), my bulk builds leave
behind netstat processes with 99% CPU.

Looking at the ps output, they are: "netstat -ia".
When I run this manually, I get

netstat: kvm_read: Bad address
                          default
netstat: kvm_read: Bad address
                          default
netstat: kvm_read: Bad address
                          default
...

repeated forever.

When I run this in the debugger and break on kvm_read, I see:
Breakpoint 1, kread (addr=18446744071586812096, buf=0x7f7fffd001b0 "\020\002\320\377\177\177", size=16) at /disk/6/archive/foreign/src/usr.bin/netstat/main.c:778
778     {
(gdb) n
780             if (kvm_read(kvmd, addr, buf, size) != size) {
(gdb)
785     }
(gdb)
intpr_kvm (ifnetaddr=<optimized out>, pfunc=0x0) at /disk/6/archive/foreign/src/usr.bin/netstat/if.c:291
291             ifnetaddr = (u_long)ifhead.tqh_first;
(gdb)
293             intpr_header();
(gdb)
Name  Mtu   Network       Address              Ipkts Ierrs    Opkts Oerrs Colls
333                                     ifaddraddr = 0;
(gdb)
332                             if (kread(ifaddraddr, (char *)&ifaddr, sizeof ifaddr)) {
(gdb)
340                             print_addr(sa, (void *)&ifaddr, &ifnet.if_data, &ifnet);
(gdb)
296             while (ifnetaddr || ifaddraddr) {
(gdb)
300                     if (ifaddraddr == 0) {
(gdb)
301                             if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet))
(gdb)

Breakpoint 1, kread (addr=18446742429720715368, buf=0x7f7fffd00320 "", size=864) at /disk/6/archive/foreign/src/usr.bin/netstat/main.c:778
778     {
(gdb)
780             if (kvm_read(kvmd, addr, buf, size) != size) {
(gdb)
785     }
(gdb)
intpr_kvm (ifnetaddr=18446742429720715368, pfunc=0x0) at /disk/6/archive/foreign/src/usr.bin/netstat/if.c:303
303                             memmove(name, ifnet.if_xname, IFNAMSIZ);
(gdb)
304                             name[IFNAMSIZ - 1] = '\0';      /* sanity */
(gdb)
305                             ifnetaddr = (u_long)ifnet.if_list.tqe_next;
(gdb)
306                             if (interface != 0 && strcmp(name, interface) != 0)
(gdb)
308                             cp = strchr(name, '\0');
(gdb)
310                             if (pfunc) {
(gdb)
315                             if ((ifnet.if_flags & IFF_UP) == 0)
(gdb)
317                             *cp = '\0';
(gdb)
318                             ifaddraddr = (u_long)ifnet.if_addrlist.tqh_first;
(gdb)
320                     if (vflag)
(gdb)
323                             n = 5;
(gdb)
324                     printf("%-*.*s %-5llu ", n, n, name,
(gdb)
326                     if (ifaddraddr == 0) {
(gdb)
332                             if (kread(ifaddraddr, (char *)&ifaddr, sizeof ifaddr)) {
(gdb)

Breakpoint 1, kread (addr=18446742429716530072, buf=0x7f7fffd001e0 "", size=312) at /disk/6/archive/foreign/src/usr.bin/netstat/main.c:778
778     {
(gdb)
780             if (kvm_read(kvmd, addr, buf, size) != size) {
(gdb)
785     }
(gdb)
intpr_kvm (ifnetaddr=18446742429724440680, pfunc=0x0) at /disk/6/archive/foreign/src/usr.bin/netstat/if.c:340
340                             print_addr(sa, (void *)&ifaddr, &ifnet.if_data, &ifnet);
(gdb)
wm0   1500  <Link>        XX:XX:XX:XX:XX:XX 683913683     3 588894983     0     0
342                     ifaddraddr = (u_long)ifaddr.ifa.ifa_list.tqe_next;
(gdb)
296             while (ifnetaddr || ifaddraddr) {
(gdb)
300                     if (ifaddraddr == 0) {
(gdb)
320                     if (vflag)
(gdb)
324                     printf("%-*.*s %-5llu ", n, n, name,
(gdb)
332                             if (kread(ifaddraddr, (char *)&ifaddr, sizeof ifaddr)) {
(gdb)

Breakpoint 1, kread (addr=18446742429743568272, buf=0x7f7fffd001e0 "\030Da:�\376\377\377", size=312) at /disk/6/archive/foreign/src/usr.bin/netstat/main.c:778
778     {
(gdb)
780             if (kvm_read(kvmd, addr, buf, size) != size) {
(gdb)
785     }
(gdb)
intpr_kvm (ifnetaddr=18446742429724440680, pfunc=0x0) at /disk/6/archive/foreign/src/usr.bin/netstat/if.c:340
340                             print_addr(sa, (void *)&ifaddr, &ifnet.if_data, &ifnet);
(gdb)

Breakpoint 1, kread (addr=72057589742961159, buf=0x7f7fffcffd50 "bc:ee:7b:dc:50:28", size=48) at /disk/6/archive/foreign/src/usr.bin/netstat/main.c:778
778     {
(gdb)
780             if (kvm_read(kvmd, addr, buf, size) != size) {
(gdb)
781                     warnx("%s", kvm_geterr(kvmd));
(gdb)
netstat: kvm_read: Bad address
785     }
(gdb)


 Thomas