ch4 lab; fix switch time; rm task_info

Author: lythesia

os/src/mm/memory_set.rs

@@ -374,6 +374,10 @@ impl MemorySet {
     pub fn token(&self) -> usize {
         self.page_table.token()
     }
+
+    pub fn page_table_mut(&mut self) -> &mut PageTable {
+        &mut self.page_table
+    }
 }
 
 #[allow(unused)]

os/src/mm/mod.rs

@@ -4,9 +4,9 @@ mod heap_allocator;
 mod memory_set;
 mod page_table;
 
-pub use address::{PhysPageNum, VirtAddr};
+pub use address::*;
 pub use memory_set::{remap_test, MapPermission, MemorySet, KERNEL_SPACE};
-pub use page_table::translated_byte_buffer;
+pub use page_table::*;
 
 pub fn init() {
     heap_allocator::init_heap();

os/src/mm/page_table.rs

@@ -182,7 +182,7 @@ impl PageTable {
     }
 }
 
-pub fn translated_byte_buffer(token: usize, ptr: *const u8, len: usize) -> Vec<&'static [u8]> {
+pub fn translated_byte_buffer(token: usize, ptr: *const u8, len: usize) -> Vec<&'static mut [u8]> {
     let page_table = PageTable::from_token(token);
     let mut start = ptr as usize;
     let end = start + len;
@@ -201,9 +201,9 @@ pub fn translated_byte_buffer(token: usize, ptr: *const u8, len: usize) -> Vec<&
         let end_va = VirtAddr::from(vpn).min(VirtAddr::from(end));
         // 5. 非end时, 当前page的[start_va.offset..]都是需要的空间; end时, 则到end_va.offset为止
         if end_va.page_offset() == 0 {
-            v.push(&ppn.get_bytes_array()[start_va.page_offset()..]);
+            v.push(&mut ppn.get_bytes_array()[start_va.page_offset()..]);
         } else {
-            v.push(&ppn.get_bytes_array()[start_va.page_offset()..end_va.page_offset()]);
+            v.push(&mut ppn.get_bytes_array()[start_va.page_offset()..end_va.page_offset()]);
         }
         start = end_va.into();
     }

os/src/syscall/mem.rs

@@ -0,0 +1,40 @@
+use crate::{
+    mm::{MapPermission, VirtAddr},
+    task,
+};
+
+const VA_MAX: usize = usize::MAX;
+
+/// `start` must be 4k aligned, `prot` arrange as (hi->lo) xwr
+pub fn sys_mmap(start: usize, len: usize, prot: usize) -> isize {
+    // 4k align
+    if start & 0xfff != 0 ||
+    // only last 3 bits allowed
+        prot & !0x7 != 0 ||
+    // no perm specified, meaningless
+        prot & 0x7 == 0 ||
+    // theoretically no space (avoid overflow)
+        VA_MAX - len <= start
+    {
+        return -1;
+    }
+
+    let start_vpn = VirtAddr::from(start).floor();
+    let end_vpn = VirtAddr::from(start + len).ceil();
+    let map_perm = MapPermission::from_bits_truncate((prot << 1) as u8) | MapPermission::U;
+    task::current_task_map_new_area(start_vpn, end_vpn, map_perm)
+}
+
+pub fn sys_munmap(start: usize, len: usize) -> isize {
+    // 4k align
+    if start & 0xfff != 0 ||
+    // theoretically no space
+    VA_MAX - len <= start
+    {
+        return -1;
+    }
+
+    let start_vpn = VirtAddr::from(start).floor();
+    let end_vpn = VirtAddr::from(start + len).ceil();
+    task::current_task_unmap_area(start_vpn, end_vpn)
+}

os/src/syscall/mod.rs

@@ -1,24 +1,26 @@
 mod fs;
+mod mem;
 mod process;
 
 use fs::*;
+use mem::*;
 use process::*;
 
-// use crate::task::TaskInfo;
-
 const SYSCALL_WRITE: usize = 64;
 const SYSCALL_EXIT: usize = 93;
 const SYSCALL_YIELD: usize = 124;
 const SYSCALL_GET_TIME: usize = 169;
-// const SYSCALL_TASK_INFO: usize = 410;
+const SYSCALL_MUNMAP: usize = 215;
+const SYSCALL_MMAP: usize = 222;
 
 pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
     match syscall_id {
         SYSCALL_WRITE => sys_write(args[0], args[1] as *const u8, args[2]),
         SYSCALL_EXIT => sys_exit(args[0] as i32),
         SYSCALL_YIELD => sys_yield(),
-        SYSCALL_GET_TIME => sys_get_time(),
-        // SYSCALL_TASK_INFO => sys_task_info(args[0] as *mut TaskInfo),
+        SYSCALL_GET_TIME => sys_get_time(args[0] as *mut TimeVal),
+        SYSCALL_MUNMAP => sys_munmap(args[0], args[1]),
+        SYSCALL_MMAP => sys_mmap(args[0], args[1], args[2]),
         _ => panic!("Unsupported syscall_id: {}", syscall_id),
     }
 }

os/src/syscall/process.rs

@@ -1,4 +1,4 @@
-use crate::{task::*, timer::get_time_ms};
+use crate::{mm, task::*, timer};
 
 /// task exits and submit an exit code
 pub fn sys_exit(exit_code: i32) -> ! {
@@ -13,19 +13,32 @@ pub fn sys_yield() -> isize {
     0
 }
 
-/// get time in ms
-pub fn sys_get_time() -> isize {
-    get_time_ms() as isize
+#[repr(C)]
+#[derive(Debug)]
+pub struct TimeVal {
+    pub sec: usize,
+    pub usec: usize,
 }
 
-// /// get info of current task
-// pub fn sys_task_info(ti: *mut TaskInfo) -> isize {
-//     unsafe {
-//         *ti = TaskInfo {
-//             status: get_current_task_status(),
-//             call: get_current_task_syscall_times(),
-//             time: get_current_task_run_time(),
-//         }
-//     }
-//     0
-// }
+/// get time
+pub fn sys_get_time(ts: *mut TimeVal) -> isize {
+    let us = timer::get_time_us();
+    let dst_vs = mm::translated_byte_buffer(
+        current_user_token(),
+        ts as *const u8,
+        core::mem::size_of::<TimeVal>(),
+    );
+    let ts = TimeVal {
+        sec: us / 1_000_000,
+        usec: us % 1_000_000,
+    };
+    let ts_ptr = (&ts as *const TimeVal) as *const u8;
+    for (i, dst) in dst_vs.into_iter().enumerate() {
+        let len = dst.len();
+        unsafe {
+            let src = core::slice::from_raw_parts(ts_ptr.wrapping_add(i * len), len);
+            dst.copy_from_slice(src);
+        }
+    }
+    0
+}

os/src/task/context.rs

@@ -1,5 +1,3 @@
-use crate::trap::trap_return;
-
 /// Task Context
 #[repr(C)]
 pub struct TaskContext {
@@ -20,9 +18,10 @@ impl TaskContext {
         }
     }
 
+    // 想办法第一次调用switch_cost, 然后正常走trap_return
     pub fn goto_trap_return(kstack_ptr: usize) -> Self {
         Self {
-            ra: trap_return as usize,
+            ra: crate::trap::pre_trap_return as usize,
             sp: kstack_ptr,
             s: [0; 12],
         }

os/src/task/mod.rs

@@ -3,17 +3,23 @@ use context::TaskContext;
 use lazy_static::lazy_static;
 use task::{TaskControlBlock, TaskStatus};
 
-use crate::{loader, sbi::shutdown, sync::UPSafeCell, timer::get_time_us, trap::TrapContext};
+use crate::{
+    loader,
+    mm::{MapPermission, VPNRange, VirtPageNum},
+    sbi::shutdown,
+    sync::UPSafeCell,
+    timer::get_time_us,
+    trap::TrapContext,
+};
 
 mod context;
 mod switch;
 mod task;
 
 lazy_static! {
     pub static ref TASK_MANAGER: TaskManager = {
-        log::info!("init TASK_MANAGER");
         let num_app = loader::get_num_app();
-        log::info!("num_app = {}", num_app);
+        log::info!("init TASK_MANAGER: num_app = {}", num_app);
         let mut tasks = Vec::new();
 
         for i in 0..num_app {
@@ -159,34 +165,6 @@ impl TaskManager {
         inner.tasks[curr].user_time += inner.refresh_stop_watch();
     }
 
-    // fn current_task(&self) -> usize {
-    //     let inner = self.inner.exclusive_access();
-    //     inner.curr_task
-    // }
-
-    // fn current_task_status(&self) -> TaskStatus {
-    //     let inner = self.inner.exclusive_access();
-    //     inner.tasks[inner.curr_task].task_status
-    // }
-
-    // fn current_task_run_time(&self) -> usize {
-    //     let inner = self.inner.exclusive_access();
-    //     let curr = &inner.tasks[inner.curr_task];
-    //     curr.kernel_time + curr.user_time
-    // }
-
-    // fn record_syscall(&self, id: usize) {
-    //     let mut inner = self.inner.exclusive_access();
-    //     let curr = inner.curr_task;
-    //     inner.tasks[curr].syscall_times[id] += 1;
-    // }
-
-    // // todo: opt copy?
-    // fn current_task_syscall_times(&self) -> [usize; MAX_SYSCALL_NUM] {
-    //     let inner = self.inner.exclusive_access();
-    //     inner.tasks[inner.curr_task].syscall_times.clone()
-    // }
-
     fn get_current_token(&self) -> usize {
         let inner = self.inner.exclusive_access();
         let current = inner.curr_task;
@@ -247,38 +225,42 @@ pub fn user_time_end() {
     TASK_MANAGER.user_time_end()
 }
 
-// #[repr(C)]
-// pub struct TaskInfo {
-//     pub status: TaskStatus,
-//     pub call: [usize; MAX_SYSCALL_NUM],
-//     pub time: usize,
-// }
-
-// pub fn get_current_task_id() -> usize {
-//     TASK_MANAGER.current_task()
-// }
-
-// pub fn get_current_task_status() -> TaskStatus {
-//     TASK_MANAGER.current_task_status()
-// }
-
-// pub fn get_current_task_run_time() -> usize {
-//     TASK_MANAGER.current_task_run_time()
-// }
-
-// pub fn current_task_record_syscall(id: usize) {
-//     TASK_MANAGER.record_syscall(id);
-// }
-
-// pub fn get_current_task_syscall_times() -> [usize; MAX_SYSCALL_NUM] {
-//     let si = TASK_MANAGER.current_task_syscall_times();
-//     si
-// }
-
 pub fn current_user_token() -> usize {
     TASK_MANAGER.get_current_token()
 }
 
 pub fn current_trap_cx() -> &'static mut TrapContext {
     TASK_MANAGER.get_current_trap_cx()
 }
+
+pub fn current_task_map_new_area(
+    start_vpn: VirtPageNum,
+    end_vpn: VirtPageNum,
+    map_perm: MapPermission,
+) -> isize {
+    let mut inner = TASK_MANAGER.inner.exclusive_access();
+    let current = inner.curr_task;
+    let curr_mem_set = &mut inner.tasks[current].memory_set;
+    for vpn in VPNRange::new(start_vpn, end_vpn) {
+        match curr_mem_set.translate(vpn) {
+            Some(pte) if pte.is_valid() => return -1, // mapped already
+            _ => {}
+        }
+    }
+    curr_mem_set.insert_framed_area(start_vpn.into(), end_vpn.into(), map_perm);
+    0
+}
+
+pub fn current_task_unmap_area(start_vpn: VirtPageNum, end_vpn: VirtPageNum) -> isize {
+    let mut inner = TASK_MANAGER.inner.exclusive_access();
+    let current = inner.curr_task;
+    let curr_mem_set = &mut inner.tasks[current].memory_set;
+    for vpn in VPNRange::new(start_vpn, end_vpn) {
+        match curr_mem_set.translate(vpn) {
+            Some(pte) if !pte.is_valid() => return -1, // not valid
+            Some(_) => curr_mem_set.page_table_mut().unmap(vpn),
+            _ => return -1, // no entry
+        }
+    }
+    0
+}

os/src/task/task.rs

@@ -26,7 +26,6 @@ pub struct TaskControlBlock {
 
     pub user_time: usize,
     pub kernel_time: usize,
-    // pub syscall_times: [usize; MAX_SYSCALL_NUM],
 }
 
 impl TaskControlBlock {

os/src/trap/mod.rs

@@ -9,7 +9,6 @@ use riscv::register::{
 use crate::{
     config::{TRAMPOLINE, TRAP_CONTEXT},
     syscall::syscall,
-    task::{current_trap_cx, current_user_token},
 };
 
 mod context;
@@ -45,15 +44,14 @@ pub fn trap_handler() -> ! {
     crate::task::user_time_end();
     // 应用的 Trap 上下文不在内核地址空间，因此我们调用 current_trap_cx 来获取当前应用的 Trap 上下文的可变引用
     // 而不是像之前那样作为参数传入 trap_handler
-    let cx = current_trap_cx();
+    let cx = crate::task::current_trap_cx();
     let scause = scause::read();
     let stval = stval::read();
 
     match scause.cause() {
         scause::Trap::Exception(Exception::UserEnvCall) => {
             cx.sepc += 4;
             let syscall_id = cx.x[17];
-            // task::current_task_record_syscall(syscall_id);
             cx.x[10] = syscall(syscall_id, [cx.x[10], cx.x[11], cx.x[12]]) as usize;
         }
         scause::Trap::Exception(Exception::StorePageFault)
@@ -89,7 +87,7 @@ pub fn trap_return() -> ! {
     // __restore的参数a0, Trap 上下文在应用地址空间中的虚拟地址
     let trap_cx_ptr = TRAP_CONTEXT;
     // __restore的参数a1, 应用地址空间的 token
-    let user_satp = current_user_token();
+    let user_satp = crate::task::current_user_token();
 
     extern "C" {
         fn __alltraps();
@@ -114,11 +112,11 @@ pub fn trap_return() -> ! {
     }
 }
 
-// #[no_mangle]
-// pub unsafe fn switch_cost(cx: &mut TrapContext) -> &mut TrapContext {
-//     task::SWITCH_TIME_COUNT += timer::get_time_us() - task::SWITCH_TIME_START;
-//     cx
-// }
+#[no_mangle]
+pub unsafe fn pre_trap_return() -> ! {
+    crate::task::SWITCH_TIME_COUNT += crate::timer::get_time_us() - crate::task::SWITCH_TIME_START;
+    trap_return()
+}
 
 #[no_mangle]
 pub fn trap_from_kernel() -> ! {