Index: gnu/usr.bin/gdb/kgdb/kthr.c
===================================================================
--- gnu/usr.bin/gdb/kgdb/kthr.c
+++ gnu/usr.bin/gdb/kgdb/kthr.c
@@ -97,6 +97,7 @@
 			if (td.td_tid == dumptid)
 				kt->pcb = dumppcb;
 			else if (td.td_state == TDS_RUNNING &&
+			    td.td_oncpu != NOCPU &&
 			    CPU_ISSET(td.td_oncpu, &stopped_cpus))
 				kt->pcb = kgdb_trgt_core_pcb(td.td_oncpu);
 			else