lab-04: mmap, munmap

user/src/bin/ch4_mmap2.rs

@@ -0,0 +1,26 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::mmap;
+
+/*
+理想结果：程序触发访存异常，被杀死。不输出 error 就算过。
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 2;
+    assert_eq!(0, mmap(start, len, prot));
+    let addr: *mut u8 = start as *mut u8;
+    unsafe {
+        // *addr = start as u8; // can't write, R == 0 && W == 1 is illegal in riscv
+        assert!(*addr != 0);
+    }
+    println!("Should cause error, Test 04_2 fail!");
+    0
+}