Make sure there is a good default thread name for all threads.

sys/kern/kern_exec.c

@@ -523,6 +523,7 @@ interpret:
 	len = min(ndp->ni_cnd.cn_namelen,MAXCOMLEN);
 	bcopy(ndp->ni_cnd.cn_nameptr, p->p_comm, len);
 	p->p_comm[len] = 0;
+	bcopy(p->p_comm, td->td_name, sizeof(td->td_name));
 
 	/*
 	 * mark as execed, wakeup the process that vforked (if any) and tell

sys/kern/kern_thread.c

@@ -232,6 +232,7 @@ proc_linkup(struct proc *p, struct thread *td)
 		/* XXX p_ksi may be null if ksiginfo zone is not ready */
 		p->p_ksi->ksi_flags = KSI_EXT | KSI_INS;
 	}
+	bcopy(p->p_comm, td->td_name, sizeof(td->td_name));
 	LIST_INIT(&p->p_mqnotifier);
 	p->p_numthreads = 0;
 	thread_link(td, p);