Index: sys/riscv/riscv/stack_machdep.c
===================================================================
--- sys/riscv/riscv/stack_machdep.c
+++ sys/riscv/riscv/stack_machdep.c
@@ -57,8 +57,7 @@
 		    (vm_offset_t)frame->fp >= td->td_kstack +
 		    td->td_kstack_pages * PAGE_SIZE)
 			break;
-		unwind_frame(frame);
-		if (!INKERNEL((vm_offset_t)frame->pc))
+		if (unwind_frame(frame) < 0)
 			break;
 		if (stack_put(st, frame->pc) == -1)
 			break;
Index: sys/riscv/riscv/unwind.c
===================================================================
--- sys/riscv/riscv/unwind.c
+++ sys/riscv/riscv/unwind.c
@@ -53,5 +53,7 @@
 	frame->fp = ((uintptr_t *)fp)[-2];
 	frame->pc = ((uintptr_t *)fp)[-1] - 4;
 
+	if (!INKERNEL(frame->pc))
+		return (-1);
 	return (0);
 }