lab-04: mmap, munmap

user/src/bin/ch4_mmap0.rs

@@ -0,0 +1,33 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::mmap;
+
+/*
+理想结果：输出 Test 04_1 OK!
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 3;
+    assert_eq!(0, mmap(start, len, prot));
+    for i in start..(start + len) {
+        let addr: *mut u8 = i as *mut u8;
+        unsafe {
+            *addr = i as u8;
+        }
+    }
+    for i in start..(start + len) {
+        let addr: *mut u8 = i as *mut u8;
+        unsafe {
+            assert_eq!(*addr, i as u8);
+        }
+    }
+    println!("Test 04_1 OK!");
+    0
+}

user/src/bin/ch4_mmap1.rs

@@ -0,0 +1,25 @@
+#![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 = 1;
+    assert_eq!(0, mmap(start, len, prot));
+    let addr: *mut u8 = start as *mut u8;
+    unsafe {
+        *addr = start as u8;
+    }
+    println!("Should cause error, Test 04_2 fail!");
+    0
+}

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
+}

user/src/bin/ch4_mmap3.rs

@@ -0,0 +1,25 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::mmap;
+
+/*
+理想结果：对于错误的 mmap 返回 -1，最终输出 Test 04_4 test OK!
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 3;
+    assert_eq!(0, mmap(start, len, prot));
+    assert_eq!(mmap(start - len, len + 1, prot), -1);
+    assert_eq!(mmap(start + len + 1, len, prot), -1);
+    assert_eq!(mmap(start + len, len, 0), -1);
+    assert_eq!(mmap(start + len, len, prot | 8), -1);
+    println!("Test 04_4 test OK!");
+    0
+}

user/src/bin/ch4_unmap.rs

@@ -0,0 +1,36 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{mmap, munmap};
+
+/*
+理想结果：输出 Test 04_5 ummap OK!
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 3;
+    assert_eq!(0, mmap(start, len, prot));
+    assert_eq!(mmap(start + len, len * 2, prot), 0);
+    assert_eq!(munmap(start, len), 0);
+    assert_eq!(mmap(start - len, len + 1, prot), 0);
+    for i in (start - len)..(start + len * 3) {
+        let addr: *mut u8 = i as *mut u8;
+        unsafe {
+            *addr = i as u8;
+        }
+    }
+    for i in (start - len)..(start + len * 3) {
+        let addr: *mut u8 = i as *mut u8;
+        unsafe {
+            assert_eq!(*addr, i as u8);
+        }
+    }
+    println!("Test 04_5 ummap OK!");
+    0
+}

user/src/bin/ch4_unmap2.rs

@@ -0,0 +1,23 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::{mmap, munmap};
+
+/*
+理想结果：输出 Test 04_6 ummap2 OK!
+*/
+
+#[no_mangle]
+fn main() -> i32 {
+    let start: usize = 0x10000000;
+    let len: usize = 4096;
+    let prot: usize = 3;
+    assert_eq!(0, mmap(start, len, prot));
+    assert_eq!(munmap(start, len + 1), -1);
+    assert_eq!(munmap(start + 1, len - 1), -1);
+    println!("Test 04_6 ummap2 OK!");
+    0
+}

user/src/bin/ch4b_sbrk.rs

@@ -0,0 +1,47 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use user_lib::sbrk;
+use core::ptr::slice_from_raw_parts_mut;
+
+#[no_mangle]
+fn main() -> i32 {
+    println!("Test sbrk start.");
+    const PAGE_SIZE: usize = 0x1000;
+    let origin_brk = sbrk(0);
+    println!("origin break point = {:x}", origin_brk);
+    let brk = sbrk(PAGE_SIZE as i32);
+    if brk != origin_brk {
+        return -1
+    }
+    let brk = sbrk(0);
+    println!("one page allocated,  break point = {:x}", brk);
+    println!("try write to allocated page");
+    let new_page = unsafe { &mut *slice_from_raw_parts_mut(origin_brk as usize as *const u8 as *mut u8, PAGE_SIZE) };
+    for pos in 0..PAGE_SIZE {
+        new_page[pos] = 1;
+    }
+    println!("write ok");
+    sbrk(PAGE_SIZE as i32 * 10);
+    let brk = sbrk(0);
+    println!("10 page allocated,  break point = {:x}", brk);
+    sbrk(PAGE_SIZE as i32 * -11);
+    let brk = sbrk(0);
+    println!("11 page DEALLOCATED,  break point = {:x}", brk);
+    println!("try DEALLOCATED more one page, should be failed.");
+    let ret = sbrk(PAGE_SIZE as i32 * -1);
+    if ret != -1 {
+        println!("Test sbrk failed!");
+        return -1
+    }
+    println!("Test sbrk almost OK!");
+    println!("now write to deallocated page, should cause page fault.");
+    for pos in 0..PAGE_SIZE {
+        new_page[pos] = 2;
+    }
+    println!("Test sbrk failed!");
+    0
+}

user/src/lib.rs

@@ -38,3 +38,11 @@ pub fn get_time() -> isize {
 pub fn sbrk(size: i32) -> isize {
     sys_sbrk(size)
 }
+
+pub fn munmap(start: usize, len: usize) -> isize {
+    sys_munmap(start, len)
+}
+
+pub fn mmap(start: usize, len: usize, prot: usize) -> isize {
+    sys_mmap(start, len, prot)
+}

user/src/syscall.rs

@@ -5,6 +5,8 @@ const SYSCALL_EXIT: usize = 93;
 const SYSCALL_YIELD: usize = 124;
 const SYSCALL_GET_TIME: usize = 169;
 const SYSCALL_SBRK: usize = 214;
+pub const SYSCALL_MMAP: usize = 222;
+pub const SYSCALL_MUNMAP: usize = 215;
 
 fn syscall(id: usize, args: [usize; 3]) -> isize {
     let mut ret: isize;
@@ -39,3 +41,11 @@ pub fn sys_get_time() -> isize {
 pub fn sys_sbrk(size: i32) -> isize {
     syscall(SYSCALL_SBRK, [size as usize, 0, 0])
 }
+
+pub fn sys_mmap(start: usize, len: usize, prot: usize) -> isize {
+    syscall(SYSCALL_MMAP, [start, len, prot])
+}
+
+pub fn sys_munmap(start: usize, len: usize) -> isize {
+    syscall(SYSCALL_MUNMAP, [start, len, 0])
+}