diff --git a/head/sys/kern/kern_time.c b/head/sys/kern/kern_time.c
--- a/head/sys/kern/kern_time.c
+++ b/head/sys/kern/kern_time.c
@@ -254,13 +254,16 @@
 kern_thread_cputime(struct thread *targettd, struct timespec *ats)
 {
 	uint64_t runtime, curtime, switchtime;
+	struct proc *p;
 
 	if (targettd == NULL) { /* current thread */
-		critical_enter();
+		p = curthread->td_proc;
+		PROC_LOCK_ASSERT(p, MA_OWNED);
+		PROC_STATLOCK(p);
 		switchtime = PCPU_GET(switchtime);
 		curtime = cpu_ticks();
 		runtime = curthread->td_runtime;
-		critical_exit();
+		PROC_STATUNLOCK(p);
 		runtime += curtime - switchtime;
 	} else {
 		PROC_LOCK_ASSERT(targettd->td_proc, MA_OWNED);
@@ -362,7 +365,9 @@
 		ats->tv_nsec = 0;
 		break;
 	case CLOCK_THREAD_CPUTIME_ID:
+		PROC_LOCK(p);
 		kern_thread_cputime(NULL, ats);
+		PROC_UNLOCK(p);
 		break;
 	case CLOCK_PROCESS_CPUTIME_ID:
 		PROC_LOCK(p);