From afc7a9c4e9ac838bf3e2e6148402d11d3756ce95 Mon Sep 17 00:00:00 2001
From: Yifan Wu <shinbokuow@163.com>
Date: Sun, 3 Jan 2021 17:42:58 +0800
Subject: [PATCH] Flush icache before returning to user.

---
 os/src/trap/mod.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/os/src/trap/mod.rs b/os/src/trap/mod.rs
index 8eb34445..4f5126b2 100644
--- a/os/src/trap/mod.rs
+++ b/os/src/trap/mod.rs
@@ -102,6 +102,7 @@ pub fn trap_return() -> ! {
     }
     let restore_va = __restore as usize - __alltraps as usize + TRAMPOLINE;
     unsafe {
+        llvm_asm!("fence.i" :::: "volatile");
         llvm_asm!("jr $0" :: "r"(restore_va), "{a0}"(trap_cx_ptr), "{a1}"(user_satp) :: "volatile");
     }
     panic!("Unreachable in back_to_user!");