Index: head/sys/riscv/include/stack.h
===================================================================
--- head/sys/riscv/include/stack.h
+++ head/sys/riscv/include/stack.h
@@ -41,9 +41,9 @@
 			 (va) <= VM_MAX_KERNEL_ADDRESS)
 
 struct unwind_state {
-	uint64_t fp;
-	uint64_t sp;
-	uint64_t pc;
+	uintptr_t fp;
+	uintptr_t sp;
+	uintptr_t pc;
 };
 
 int unwind_frame(struct unwind_state *);
Index: head/sys/riscv/riscv/db_trace.c
===================================================================
--- head/sys/riscv/riscv/db_trace.c
+++ head/sys/riscv/riscv/db_trace.c
@@ -108,9 +108,9 @@
 				db_printf("--- exception %ld, tval = %#lx\n",
 				    tf->tf_scause & EXCP_MASK,
 				    tf->tf_stval);
-			frame->sp = (uint64_t)tf->tf_sp;
-			frame->fp = (uint64_t)tf->tf_s[0];
-			frame->pc = (uint64_t)tf->tf_sepc;
+			frame->sp = tf->tf_sp;
+			frame->fp = tf->tf_s[0];
+			frame->pc = tf->tf_sepc;
 			if (!INKERNEL(frame->fp))
 				break;
 			continue;
@@ -132,9 +132,9 @@
 
 	ctx = kdb_thr_ctx(thr);
 
-	frame.sp = (uint64_t)ctx->pcb_sp;
-	frame.fp = (uint64_t)ctx->pcb_s[0];
-	frame.pc = (uint64_t)ctx->pcb_ra;
+	frame.sp = ctx->pcb_sp;
+	frame.fp = ctx->pcb_s[0];
+	frame.pc = ctx->pcb_ra;
 	db_stack_trace_cmd(&frame);
 	return (0);
 }
@@ -143,12 +143,12 @@
 db_trace_self(void)
 {
 	struct unwind_state frame;
-	uint64_t sp;
+	uintptr_t sp;
 
 	__asm __volatile("mv %0, sp" : "=&r" (sp));
 
 	frame.sp = sp;
-	frame.fp = (uint64_t)__builtin_frame_address(0);
-	frame.pc = (uint64_t)db_trace_self;
+	frame.fp = (uintptr_t)__builtin_frame_address(0);
+	frame.pc = (uintptr_t)db_trace_self;
 	db_stack_trace_cmd(&frame);
 }
Index: head/sys/riscv/riscv/stack_machdep.c
===================================================================
--- head/sys/riscv/riscv/stack_machdep.c
+++ head/sys/riscv/riscv/stack_machdep.c
@@ -86,13 +86,13 @@
 stack_save(struct stack *st)
 {
 	struct unwind_state frame;
-	uint64_t sp;
+	uintptr_t sp;
 
 	__asm __volatile("mv %0, sp" : "=&r" (sp));
 
 	frame.sp = sp;
-	frame.fp = (uint64_t)__builtin_frame_address(0);
-	frame.pc = (uint64_t)stack_save;
+	frame.fp = (uintptr_t)__builtin_frame_address(0);
+	frame.pc = (uintptr_t)stack_save;
 
 	stack_capture(st, &frame);
 }
Index: head/sys/riscv/riscv/unwind.c
===================================================================
--- head/sys/riscv/riscv/unwind.c
+++ head/sys/riscv/riscv/unwind.c
@@ -42,7 +42,7 @@
 int
 unwind_frame(struct unwind_state *frame)
 {
-	uint64_t fp;
+	uintptr_t fp;
 
 	fp = frame->fp;
 
@@ -50,8 +50,8 @@
 		return (-1);
 
 	frame->sp = fp;
-	frame->fp = *(uint64_t *)(fp - 16);
-	frame->pc = *(uint64_t *)(fp - 8) - 4;
+	frame->fp = ((uintptr_t *)fp)[-2];
+	frame->pc = ((uintptr_t *)fp)[-1] - 4;
 
 	return (0);
 }