Index: sys/riscv/riscv/copyinout.S
===================================================================
--- sys/riscv/riscv/copyinout.S
+++ sys/riscv/riscv/copyinout.S
@@ -118,7 +118,7 @@
 	beqz	a2, copyout_end	/* If len == 0 then skip loop */
 	add	a3, a1, a2
 	li	a4, VM_MAXUSER_ADDRESS
-	bgt	a3, a4, copyio_fault_nopcb
+	bgeu	a3, a4, copyio_fault_nopcb
 
 	copycommon
 
@@ -136,7 +136,7 @@
 	beqz	a2, copyin_end	/* If len == 0 then skip loop */
 	add	a3, a0, a2
 	li	a4, VM_MAXUSER_ADDRESS
-	bgt	a3, a4, copyio_fault_nopcb
+	bgeu	a3, a4, copyio_fault_nopcb
 
 	copycommon
 
@@ -159,7 +159,7 @@
 	ENTER_USER_ACCESS(a7)
 
 	li	a7, VM_MAXUSER_ADDRESS
-1:	bgt	a0, a7, copyio_fault
+1:	bgeu	a0, a7, copyio_fault
 	lb	a4, 0(a0)	/* Load from uaddr */
 	addi	a0, a0, 1
 	sb	a4, 0(a1)	/* Store in kaddr */