Index: sys/kern/kern_syscalls.c
===================================================================
--- sys/kern/kern_syscalls.c
+++ sys/kern/kern_syscalls.c
@@ -75,14 +75,12 @@
 }
 
 int
-syscall_thread_enter(struct thread *td, struct sysent *se)
+_syscall_thread_enter(struct thread *td, struct sysent *se)
 {
 	u_int32_t cnt, oldcnt;
 
 	do {
 		oldcnt = se->sy_thrcnt;
-		if ((oldcnt & SY_THR_STATIC) != 0)
-			return (0);
 		if ((oldcnt & (SY_THR_DRAINING | SY_THR_ABSENT)) != 0)
 			return (ENOSYS);
 		cnt = oldcnt + SY_THR_INCR;
@@ -91,14 +89,12 @@
 }
 
 void
-syscall_thread_exit(struct thread *td, struct sysent *se)
+_syscall_thread_exit(struct thread *td, struct sysent *se)
 {
 	u_int32_t cnt, oldcnt;
 
 	do {
 		oldcnt = se->sy_thrcnt;
-		if ((oldcnt & SY_THR_STATIC) != 0)
-			return;
 		cnt = oldcnt - SY_THR_INCR;
 	} while (atomic_cmpset_rel_32(&se->sy_thrcnt, oldcnt, cnt) == 0);
 }
Index: sys/sys/sysent.h
===================================================================
--- sys/sys/sysent.h
+++ sys/sys/sysent.h
@@ -257,8 +257,27 @@
 int	lkmnosys(struct thread *, struct nosys_args *);
 int	lkmressys(struct thread *, struct nosys_args *);
 
-int	syscall_thread_enter(struct thread *td, struct sysent *se);
-void	syscall_thread_exit(struct thread *td, struct sysent *se);
+int	_syscall_thread_enter(struct thread *td, struct sysent *se);
+void	_syscall_thread_exit(struct thread *td, struct sysent *se);
+
+static inline int
+syscall_thread_enter(struct thread *td, struct sysent *se)
+{
+
+	if ((se->sy_thrcnt & SY_THR_STATIC) != 0)
+		return (0);
+
+	return (_syscall_thread_enter(td, se));
+}
+
+static inline void
+syscall_thread_exit(struct thread *td, struct sysent *se)
+{
+
+	if ((se->sy_thrcnt & SY_THR_STATIC) != 0)
+		return;
+	_syscall_thread_exit(td, se);
+}
 
 int shared_page_alloc(int size, int align);
 int shared_page_fill(int size, int align, const void *data);