Merge dev: ch7 updates

easy-fs-fuse/src/main.rs

@@ -118,7 +118,8 @@ fn efs_test() -> std::io::Result<()> {
     let filea = root_inode.find("filea").unwrap();
     let greet_str = "Hello, world!";
     filea.write_at(0, greet_str.as_bytes());
-    let mut buffer = [0u8; 512];
+    //let mut buffer = [0u8; 512];
+    let mut buffer = [0u8; 233];
     let len = filea.read_at(0, &mut buffer);
     assert_eq!(
         greet_str,
@@ -159,6 +160,9 @@ fn efs_test() -> std::io::Result<()> {
     random_str_test(100 * BLOCK_SZ);
     random_str_test(70 * BLOCK_SZ + BLOCK_SZ / 7);
     random_str_test((12 + 128) * BLOCK_SZ);
+    random_str_test(400 * BLOCK_SZ);
+    random_str_test(1000 * BLOCK_SZ);
+    random_str_test(2000 * BLOCK_SZ);
 
     Ok(())
 }

easy-fs/src/efs.rs

@@ -80,9 +80,7 @@ impl EasyFileSystem {
         )
         .lock()
         .modify(root_inode_offset, |disk_inode: &mut DiskInode| {
-            disk_inode.initialize(
-                DiskInodeType::Directory,efs.alloc_data()
-            );
+            disk_inode.initialize(DiskInodeType::Directory);
         });
         Arc::new(Mutex::new(efs))
     }
@@ -158,6 +156,14 @@ impl EasyFileSystem {
     }
 
     pub fn dealloc_data(&mut self, block_id: u32) {
+        get_block_cache(
+            block_id as usize,
+            Arc::clone(&self.block_device)
+        )
+        .lock()
+        .modify(0, |data_block: &mut DataBlock| {
+            data_block.iter_mut().for_each(|p| { *p = 0; })
+        });
         self.data_bitmap.dealloc(
             &self.block_device,
             (block_id - self.data_area_start_block) as usize

easy-fs/src/layout.rs

@@ -8,8 +8,14 @@ use alloc::sync::Arc;
 use alloc::vec::Vec;
 
 const EFS_MAGIC: u32 = 0x3b800001;
-const INODE_DIRECT_COUNT: usize = 60;
+const INODE_DIRECT_COUNT: usize = 28;
 const NAME_LENGTH_LIMIT: usize = 27;
+const INODE_INDIRECT1_COUNT: usize = BLOCK_SZ / 4;
+const INODE_INDIRECT2_COUNT: usize = INODE_INDIRECT1_COUNT * INODE_INDIRECT1_COUNT;
+const DIRECT_BOUND: usize = INODE_DIRECT_COUNT;
+const INDIRECT1_BOUND: usize = DIRECT_BOUND + INODE_INDIRECT1_COUNT;
+#[allow(unused)]
+const INDIRECT2_BOUND: usize = INDIRECT1_BOUND + INODE_INDIRECT2_COUNT;
 
 #[repr(C)]
 pub struct SuperBlock {
@@ -76,11 +82,11 @@ pub struct DiskInode {
 }
 
 impl DiskInode {
-    /// indirect1 block is allocated when the file is created.
-    pub fn initialize(&mut self, type_: DiskInodeType, indirect1: u32) {
+    /// indirect1 and indirect2 block are allocated only when they are needed.
+    pub fn initialize(&mut self, type_: DiskInodeType) {
         self.size = 0;
         self.direct.iter_mut().for_each(|v| *v = 0);
-        self.indirect1 = indirect1;
+        self.indirect1 = 0;
         self.indirect2 = 0;
         self.type_ = type_;
     }
@@ -91,57 +97,146 @@ impl DiskInode {
     pub fn is_file(&self) -> bool {
         self.type_ == DiskInodeType::File
     }
-    pub fn blocks(&self) -> u32 {
-        Self::_blocks(self.size)
+    /// Return block number correspond to size.
+    pub fn data_blocks(&self) -> u32 {
+        Self::_data_blocks(self.size)
     }
-    fn _blocks(size: u32) -> u32 {
+    fn _data_blocks(size: u32) -> u32 {
         (size + BLOCK_SZ as u32 - 1) / BLOCK_SZ as u32
     }
+    /// Return number of blocks needed include indirect1/2.
+    pub fn total_blocks(size: u32) -> u32 {
+        let data_blocks = Self::_data_blocks(size) as usize;
+        let mut total = data_blocks as usize;
+        // indirect1
+        if data_blocks > INODE_DIRECT_COUNT {
+            total += 1;
+        }
+        // indirect2
+        if data_blocks > INDIRECT1_BOUND {
+            total += 1;
+            // sub indirect1
+            total += (data_blocks - INDIRECT1_BOUND + INODE_INDIRECT1_COUNT - 1) / INODE_INDIRECT1_COUNT;
+        }
+        total as u32
+    }
+    pub fn blocks_num_needed(&self, new_size: u32) -> u32 {
+        assert!(new_size >= self.size);
+        Self::total_blocks(new_size) - Self::total_blocks(self.size)
+    }
     pub fn get_block_id(&self, inner_id: u32, block_device: &Arc<dyn BlockDevice>) -> u32 {
         let inner_id = inner_id as usize;
         if inner_id < INODE_DIRECT_COUNT {
             self.direct[inner_id]
-        } else {
-            // only support indirect1 now
+        } else if inner_id < INDIRECT1_BOUND {
             get_block_cache(self.indirect1 as usize, Arc::clone(block_device))
                 .lock()
                 .read(0, |indirect_block: &IndirectBlock| {
                     indirect_block[inner_id - INODE_DIRECT_COUNT]
                 })
+        } else {
+            let last = inner_id - INDIRECT1_BOUND;
+            let indirect1 = get_block_cache(
+                self.indirect2 as usize,
+                Arc::clone(block_device)
+            )
+            .lock()
+            .read(0, |indirect2: &IndirectBlock| {
+                indirect2[last / INODE_INDIRECT1_COUNT]
+            });
+            get_block_cache(
+                indirect1 as usize,
+                Arc::clone(block_device)
+            )
+            .lock()
+            .read(0, |indirect1: &IndirectBlock| {
+                indirect1[last % INODE_INDIRECT1_COUNT]
+            })
         }
     }
-    pub fn blocks_num_needed(&self, new_size: u32) -> u32 {
-        assert!(new_size >= self.size);
-        Self::_blocks(new_size) - self.blocks()
-    }
     pub fn increase_size(
         &mut self,
         new_size: u32,
         new_blocks: Vec<u32>,
         block_device: &Arc<dyn BlockDevice>,
     ) {
-        assert_eq!(new_blocks.len() as u32, self.blocks_num_needed(new_size));
-        let last_blocks = self.blocks();
+        let mut current_blocks = self.data_blocks();
         self.size = new_size;
-        let current_blocks = self.blocks();
+        let mut total_blocks = self.data_blocks();
+        let mut new_blocks = new_blocks.into_iter();
+        // fill direct
+        while current_blocks < total_blocks.min(INODE_DIRECT_COUNT as u32) {
+            self.direct[current_blocks as usize] = new_blocks.next().unwrap();
+            current_blocks += 1;
+        }
+        // alloc indirect1
+        if total_blocks > INODE_DIRECT_COUNT as u32{
+            if current_blocks == INODE_DIRECT_COUNT as u32 {
+                self.indirect1 = new_blocks.next().unwrap();
+            }
+            current_blocks -= INODE_DIRECT_COUNT as u32;
+            total_blocks -= INODE_DIRECT_COUNT as u32;
+        } else {
+            return;
+        }
+        // fill indirect1
         get_block_cache(
             self.indirect1 as usize,
             Arc::clone(block_device)
         )
         .lock()
-        .modify(0, |indirect_block: &mut IndirectBlock| {
-            for i in 0..current_blocks - last_blocks {
-                let inner_id = (last_blocks + i) as usize;
-                let new_block = new_blocks[i as usize];
-                if inner_id < INODE_DIRECT_COUNT {
-                    self.direct[inner_id] = new_block;
-                } else {
-                    indirect_block[inner_id - INODE_DIRECT_COUNT] = new_block;
-                }
+        .modify(0, |indirect1: &mut IndirectBlock| {
+            while current_blocks < total_blocks.min(INODE_INDIRECT1_COUNT as u32) {
+                indirect1[current_blocks as usize] = new_blocks.next().unwrap();
+                current_blocks += 1;
             }
         });
+        // alloc indirect2
+        if total_blocks > INODE_INDIRECT1_COUNT as u32 {
+            if current_blocks == INODE_INDIRECT1_COUNT as u32 {
+                self.indirect2 = new_blocks.next().unwrap();
+            }
+            current_blocks -= INODE_INDIRECT1_COUNT as u32;
+            total_blocks -= INODE_INDIRECT1_COUNT as u32;
+        } else {
+            return;
+        }
+        // fill indirect2 from (a0, b0) -> (a1, b1)
+        let mut a0 = current_blocks as usize / INODE_INDIRECT1_COUNT;
+        let mut b0 = current_blocks as usize % INODE_INDIRECT1_COUNT;
+        let a1 = total_blocks as usize / INODE_INDIRECT1_COUNT;
+        let b1 = total_blocks as usize % INODE_INDIRECT1_COUNT;
+        // alloc low-level indirect1
+        get_block_cache(
+            self.indirect2 as usize,
+            Arc::clone(block_device)
+        )
+        .lock()
+        .modify(0, |indirect2: &mut IndirectBlock| {
+            while (a0 < a1) || (a0 == a1 && b0 < b1) {
+                if b0 == 0 {
+                    indirect2[a0] = new_blocks.next().unwrap();
+                }
+                // fill current
+                get_block_cache(
+                    indirect2[a0] as usize,
+                    Arc::clone(block_device)
+                )
+                .lock()
+                .modify(0, |indirect1: &mut IndirectBlock| {
+                    indirect1[b0] = new_blocks.next().unwrap();
+                });
+                // move to next
+                b0 += 1;
+                if b0 == INODE_INDIRECT1_COUNT {
+                    b0 = 0;
+                    a0 += 1;
+                }
+            } 
+        });
     }
-    /// Clear size to zero and return blocks that should be deallocated.
+    
+    /*
     pub fn clear_size(&mut self, block_device: &Arc<dyn BlockDevice>) -> Vec<u32> {
         let mut v: Vec<u32> = Vec::new();
         let blocks = self.blocks() as usize;
@@ -165,6 +260,97 @@ impl DiskInode {
         }
         v
     }
+    */
+
+    /// Clear size to zero and return blocks that should be deallocated.
+    ///
+    /// We will clear the block contents to zero later.
+    pub fn clear_size(&mut self, block_device: &Arc<dyn BlockDevice>) -> Vec<u32> {
+        let mut v: Vec<u32> = Vec::new();
+        let mut data_blocks = self.data_blocks() as usize;
+        self.size = 0;
+        let mut current_blocks = 0usize;
+        // direct
+        while current_blocks < data_blocks.min(INODE_DIRECT_COUNT) {
+            v.push(self.direct[current_blocks]);
+            self.direct[current_blocks] = 0;
+            current_blocks += 1;
+        }
+        // indirect1 block
+        if data_blocks > INODE_DIRECT_COUNT {
+            v.push(self.indirect1);
+            data_blocks -= INODE_DIRECT_COUNT;
+            current_blocks = 0;
+        } else {
+            return v;
+        }
+        // indirect1
+        get_block_cache(
+            self.indirect1 as usize,
+            Arc::clone(block_device),
+        )
+        .lock()
+        .modify(0, |indirect1: &mut IndirectBlock| {
+            while current_blocks < data_blocks.min(INODE_INDIRECT1_COUNT) {
+                v.push(indirect1[current_blocks]);
+                //indirect1[current_blocks] = 0;
+                current_blocks += 1;
+            }
+        });
+        self.indirect1 = 0;
+        // indirect2 block
+        if data_blocks > INODE_INDIRECT1_COUNT {
+            v.push(self.indirect2);
+            data_blocks -= INODE_INDIRECT1_COUNT;
+        } else {
+            return v;
+        }
+        // indirect2
+        assert!(data_blocks <= INODE_INDIRECT2_COUNT);
+        let a1 = data_blocks / INODE_INDIRECT1_COUNT;
+        let b1 = data_blocks % INODE_INDIRECT1_COUNT;
+        get_block_cache(
+            self.indirect2 as usize,
+            Arc::clone(block_device),
+        )
+        .lock()
+        .modify(0, |indirect2: &mut IndirectBlock| {
+            // full indirect1 blocks
+            for i in 0..a1 {
+                v.push(indirect2[i]);
+                get_block_cache(
+                    indirect2[i] as usize,
+                    Arc::clone(block_device),
+                )
+                .lock()
+                .modify(0, |indirect1: &mut IndirectBlock| {
+                    for j in 0..INODE_INDIRECT1_COUNT {
+                        v.push(indirect1[j]);
+                        //indirect1[j] = 0;
+                    }
+                });
+                //indirect2[i] = 0;
+            }
+            // last indirect1 block
+            if b1 > 0 {
+                v.push(indirect2[a1]);
+                get_block_cache(
+                    indirect2[a1] as usize,
+                    Arc::clone(block_device),
+                )
+                .lock()
+                .modify(0, |indirect1: &mut IndirectBlock| {
+                    for j in 0..b1 {
+                        v.push(indirect1[j]);
+                        //indirect1[j] = 0;
+                    }
+                });
+                //indirect2[a1] = 0;
+            }
+        });
+        self.indirect2 = 0;
+        v
+    }
     pub fn read_at(
         &self,
         offset: usize,

easy-fs/src/vfs.rs

@@ -122,22 +122,18 @@ impl Inode {
         }).is_some() {
             return None;
         }
-        //println!("same file does not exist in Inode::create.");
         // create a new file
         // alloc a inode with an indirect block
         let new_inode_id = fs.alloc_inode();
-        let indirect1 = fs.alloc_data();
         // initialize inode
         let (new_inode_block_id, new_inode_block_offset) 
             = fs.get_disk_inode_pos(new_inode_id);
-        //println!("new_inode_id={} ({},{})", new_inode_id, new_inode_block_id, new_inode_block_offset);
         get_block_cache(
             new_inode_block_id as usize,
             Arc::clone(&self.block_device)
         ).lock().modify(new_inode_block_offset, |new_inode: &mut DiskInode| {
-            new_inode.initialize(DiskInodeType::File, indirect1);
+            new_inode.initialize(DiskInodeType::File);
         });
-        //println!("new inode has been initialized.");
         self.modify_disk_inode(|root_inode| {
             // append file in the dirent
             let file_count = (root_inode.size as usize) / DIRENT_SZ;
@@ -152,7 +148,6 @@ impl Inode {
                 &self.block_device,
             );
         });
-        //println!("new file has been inserted into root inode.");
         // release efs lock manually because we will acquire it again in Inode::new
         drop(fs);
         // return inode
@@ -202,7 +197,9 @@ impl Inode {
     pub fn clear(&self) {
         let mut fs = self.fs.lock();
         self.modify_disk_inode(|disk_inode| {
+            let size = disk_inode.size;
             let data_blocks_dealloc = disk_inode.clear_size(&self.block_device);
+            assert!(data_blocks_dealloc.len() == DiskInode::total_blocks(size) as usize);
             for data_block in data_blocks_dealloc.into_iter() {
                 fs.dealloc_data(data_block);
             }

os/Makefile

@@ -6,7 +6,7 @@ KERNEL_BIN := $(KERNEL_ELF).bin
 DISASM_TMP := target/$(TARGET)/$(MODE)/asm
 FS_IMG := ../user/target/$(TARGET)/$(MODE)/fs.img
 SDCARD := /dev/sdb
-APPS := ../user/src/bin
+APPS := ../user/src/bin/*
 
 # BOARD
 BOARD ?= qemu

os/src/mm/address.rs

@@ -115,6 +115,11 @@ impl VirtPageNum {
 }
 
 impl PhysAddr {
+    pub fn get_ref<T>(&self) -> &'static T {
+        unsafe {
+            (self.0 as *const T).as_ref().unwrap()
+        }
+    }
     pub fn get_mut<T>(&self) -> &'static mut T {
         unsafe {
             (self.0 as *mut T).as_mut().unwrap()

os/src/mm/mod.rs

@@ -13,6 +13,7 @@ pub use page_table::{
     PageTableEntry,
     translated_byte_buffer,
     translated_str,
+    translated_ref,
     translated_refmut,
     UserBuffer,
     UserBufferIterator,

os/src/mm/page_table.rs

@@ -174,6 +174,7 @@ pub fn translated_byte_buffer(token: usize, ptr: *const u8, len: usize) -> Vec<&
     v
 }
 
+/// Load a string from other address spaces into kernel space without an end `\0`.
 pub fn translated_str(token: usize, ptr: *const u8) -> String {
     let page_table = PageTable::from_token(token);
     let mut string = String::new();
@@ -182,14 +183,18 @@ pub fn translated_str(token: usize, ptr: *const u8) -> String {
         let ch: u8 = *(page_table.translate_va(VirtAddr::from(va)).unwrap().get_mut());
         if ch == 0 {
             break;
-        } else {
-            string.push(ch as char);
-            va += 1;
         }
+        string.push(ch as char);
+        va += 1;
     }
     string
 }
 
+pub fn translated_ref<T>(token: usize, ptr: *const T) -> &'static T {
+    let page_table = PageTable::from_token(token);
+    page_table.translate_va(VirtAddr::from(ptr as usize)).unwrap().get_ref()
+}
+
 pub fn translated_refmut<T>(token: usize, ptr: *mut T) -> &'static mut T {
     let page_table = PageTable::from_token(token);
     let va = ptr as usize;

os/src/syscall/fs.rs

@@ -6,6 +6,7 @@ use crate::mm::{
 };
 use crate::task::{current_user_token, current_task};
 use crate::fs::{make_pipe, OpenFlags, open_file};
+use alloc::sync::Arc;
 
 pub fn sys_write(fd: usize, buf: *const u8, len: usize) -> isize {
     let token = current_user_token();
@@ -93,4 +94,18 @@ pub fn sys_pipe(pipe: *mut usize) -> isize {
     *translated_refmut(token, pipe) = read_fd;
     *translated_refmut(token, unsafe { pipe.add(1) }) = write_fd;
     0
+}
+
+pub fn sys_dup(fd: usize) -> isize {
+    let task = current_task().unwrap();
+    let mut inner = task.acquire_inner_lock();
+    if fd >= inner.fd_table.len() {
+        return -1;
+    }
+    if inner.fd_table[fd].is_none() {
+        return -1;
+    }
+    let new_fd = inner.alloc_fd();
+    inner.fd_table[new_fd] = Some(Arc::clone(inner.fd_table[fd].as_ref().unwrap()));
+    new_fd as isize
 }

os/src/syscall/mod.rs

@@ -1,3 +1,4 @@
+const SYSCALL_DUP: usize = 24;
 const SYSCALL_OPEN: usize = 56;
 const SYSCALL_CLOSE: usize = 57;
 const SYSCALL_PIPE: usize = 59;
@@ -19,6 +20,7 @@ use process::*;
 
 pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
     match syscall_id {
+        SYSCALL_DUP=> sys_dup(args[0]),
         SYSCALL_OPEN => sys_open(args[0] as *const u8, args[1] as u32),
         SYSCALL_CLOSE => sys_close(args[0]),
         SYSCALL_PIPE => sys_pipe(args[0] as *mut usize),
@@ -29,7 +31,7 @@ pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
         SYSCALL_GET_TIME => sys_get_time(),
         SYSCALL_GETPID => sys_getpid(),
         SYSCALL_FORK => sys_fork(),
-        SYSCALL_EXEC => sys_exec(args[0] as *const u8),
+        SYSCALL_EXEC => sys_exec(args[0] as *const u8, args[1] as *const usize),
         SYSCALL_WAITPID => sys_waitpid(args[0] as isize, args[1] as *mut i32),
         _ => panic!("Unsupported syscall_id: {}", syscall_id),
     }

os/src/syscall/process.rs

@@ -9,12 +9,15 @@ use crate::timer::get_time_ms;
 use crate::mm::{
     translated_str,
     translated_refmut,
+    translated_ref,
 };
 use crate::fs::{
     open_file,
     OpenFlags,
 };
 use alloc::sync::Arc;
+use alloc::vec::Vec;
+use alloc::string::String;
 
 pub fn sys_exit(exit_code: i32) -> ! {
     exit_current_and_run_next(exit_code);
@@ -48,14 +51,25 @@ pub fn sys_fork() -> isize {
     new_pid as isize
 }
 
-pub fn sys_exec(path: *const u8) -> isize {
+pub fn sys_exec(path: *const u8, mut args: *const usize) -> isize {
     let token = current_user_token();
     let path = translated_str(token, path);
+    let mut args_vec: Vec<String> = Vec::new();
+    loop {
+        let arg_str_ptr = *translated_ref(token, args);
+        if arg_str_ptr == 0 {
+            break;
+        }
+        args_vec.push(translated_str(token, arg_str_ptr as *const u8));
+        unsafe { args = args.add(1); }
+    }
     if let Some(app_inode) = open_file(path.as_str(), OpenFlags::RDONLY) {
         let all_data = app_inode.read_all();
         let task = current_task().unwrap();
-        task.exec(all_data.as_slice());
-        0
+        let argc = args_vec.len();
+        task.exec(all_data.as_slice(), args_vec);
+        // return argc because cx.x[10] will be covered with it later
+        argc as isize
     } else {
         -1
     }

os/src/task/task.rs

@@ -1,4 +1,10 @@
-use crate::mm::{MemorySet, PhysPageNum, KERNEL_SPACE, VirtAddr};
+use crate::mm::{
+    MemorySet,
+    PhysPageNum,
+    KERNEL_SPACE, 
+    VirtAddr,
+    translated_refmut,
+};
 use crate::trap::{TrapContext, trap_handler};
 use crate::config::{TRAP_CONTEXT};
 use super::TaskContext;
@@ -6,6 +12,7 @@ use super::{PidHandle, pid_alloc, KernelStack};
 use alloc::sync::{Weak, Arc};
 use alloc::vec;
 use alloc::vec::Vec;
+use alloc::string::String;
 use spin::{Mutex, MutexGuard};
 use crate::fs::{File, Stdin, Stdout};
 
@@ -106,13 +113,35 @@ impl TaskControlBlock {
         );
         task_control_block
     }
-    pub fn exec(&self, elf_data: &[u8]) {
+    pub fn exec(&self, elf_data: &[u8], args: Vec<String>) {
         // memory_set with elf program headers/trampoline/trap context/user stack
-        let (memory_set, user_sp, entry_point) = MemorySet::from_elf(elf_data);
+        let (memory_set, mut user_sp, entry_point) = MemorySet::from_elf(elf_data);
         let trap_cx_ppn = memory_set
             .translate(VirtAddr::from(TRAP_CONTEXT).into())
             .unwrap()
             .ppn();
+        // push arguments on user stack
+        user_sp -= (args.len() + 1) * core::mem::size_of::<usize>();
+        let argv_base = user_sp;
+        let mut argv: Vec<_> = (0..=args.len())
+            .map(|arg| {
+                translated_refmut(
+                    memory_set.token(),
+                    (argv_base + arg * core::mem::size_of::<usize>()) as *mut usize
+                )
+            })
+            .collect();
+        *argv[args.len()] = 0;
+        for i in 0..args.len() {
+            user_sp -= args[i].len() + 1;
+            *argv[i] = user_sp;
+            let mut p = user_sp;
+            for c in args[i].as_bytes() {
+                *translated_refmut(memory_set.token(), p as *mut u8) = *c;
+                p += 1;
+            }
+            *translated_refmut(memory_set.token(), p as *mut u8) = 0;
+        }
 
         // **** hold current PCB lock
         let mut inner = self.acquire_inner_lock();
@@ -121,14 +150,16 @@ impl TaskControlBlock {
         // update trap_cx ppn
         inner.trap_cx_ppn = trap_cx_ppn;
         // initialize trap_cx
-        let trap_cx = inner.get_trap_cx();
-        *trap_cx = TrapContext::app_init_context(
+        let mut trap_cx = TrapContext::app_init_context(
             entry_point,
             user_sp,
             KERNEL_SPACE.lock().token(),
             self.kernel_stack.get_top(),
             trap_handler as usize,
         );
+        trap_cx.x[10] = args.len();
+        trap_cx.x[11] = argv_base;
+        *inner.get_trap_cx() = trap_cx;
         // **** release current PCB lock
     }
     pub fn fork(self: &Arc<TaskControlBlock>) -> Arc<TaskControlBlock> {

os/src/trap/context.rs

@@ -1,6 +1,7 @@
 use riscv::register::sstatus::{Sstatus, self, SPP};
 
 #[repr(C)]
+#[derive(Debug)]
 pub struct TrapContext {
     pub x: [usize; 32],
     pub sstatus: Sstatus,

os/src/trap/mod.rs

@@ -88,6 +88,7 @@ pub fn trap_handler() -> ! {
             panic!("Unsupported trap {:?}, stval = {:#x}!", scause.cause(), stval);
         }
     }
+    //println!("before trap_return");
     trap_return();
 }
 

user/src/bin/cat.rs

@@ -0,0 +1,34 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+extern crate alloc;
+
+use user_lib::{
+    open,
+    OpenFlags,
+    close,
+    read,
+};
+use alloc::string::String;
+
+#[no_mangle]
+pub fn main(argc: usize, argv: &[&str]) -> i32 {
+    assert!(argc == 2);
+    let fd = open(argv[1], OpenFlags::RDONLY);
+    if fd == -1 {
+        panic!("Error occured when opening file");
+    }
+    let fd = fd as usize;
+    let mut buf = [0u8; 16];
+    let mut s = String::new();
+    loop {
+        let size = read(fd, &mut buf) as usize;
+        if size == 0 { break; }
+        s.push_str(core::str::from_utf8(&buf[..size]).unwrap());
+    }
+    println!("{}", s);
+    close(fd);
+    0
+}

user/src/bin/cmdline_args.rs

@@ -0,0 +1,16 @@
+#![no_std]
+#![no_main]
+
+extern crate alloc;
+
+#[macro_use]
+extern crate user_lib;
+
+#[no_mangle]
+pub fn main(argc: usize, argv: &[&str]) -> i32 {
+    println!("argc = {}", argc);
+    for i in 0..argc {
+        println!("argv[{}] = {}", i, argv[i]);
+    }
+    0
+}

user/src/bin/initproc.rs

@@ -14,7 +14,7 @@ use user_lib::{
 #[no_mangle]
 fn main() -> i32 {
     if fork() == 0 {
-        exec("user_shell\0");
+        exec("user_shell\0", &[0 as *const u8]);
     } else {
         loop {
             let mut exit_code: i32 = 0;

user/src/bin/run_pipe_test.rs

@@ -10,7 +10,7 @@ use user_lib::{fork, exec, wait};
 pub fn main() -> i32 {
     for i in 0..1000 {
         if fork() == 0 {
-            exec("pipe_large_test\0");
+            exec("pipe_large_test\0", &[0 as *const u8]);
         } else {
             let mut _unused: i32 = 0;
             wait(&mut _unused);

user/src/bin/user_shell.rs

@@ -12,7 +12,16 @@ const DL: u8 = 0x7fu8;
 const BS: u8 = 0x08u8;
 
 use alloc::string::String;
-use user_lib::{fork, exec, waitpid};
+use alloc::vec::Vec;
+use user_lib::{
+    fork,
+    exec,
+    waitpid,
+    open,
+    OpenFlags,
+    close,
+    dup,
+};
 use user_lib::console::getchar;
 
 #[no_mangle]
@@ -26,11 +35,78 @@ pub fn main() -> i32 {
             LF | CR => {
                 println!("");
                 if !line.is_empty() {
-                    line.push('\0');
+                    let args: Vec<_> = line.as_str().split(' ').collect();
+                    let mut args_copy: Vec<String> = args
+                    .iter()
+                    .map(|&arg| {
+                        let mut string = String::new();
+                        string.push_str(arg);
+                        string
+                    })
+                    .collect();
+
+                    args_copy
+                    .iter_mut()
+                    .for_each(|string| {
+                        string.push('\0');
+                    });
+
+                    // redirect input
+                    let mut input = String::new();
+                    if let Some((idx, _)) = args_copy
+                    .iter()
+                    .enumerate()
+                    .find(|(_, arg)| arg.as_str() == "<\0") {
+                        input = args_copy[idx + 1].clone();
+                        args_copy.drain(idx..=idx + 1);
+                    }
+
+                    // redirect output
+                    let mut output = String::new();
+                    if let Some((idx, _)) = args_copy
+                    .iter()
+                    .enumerate()
+                    .find(|(_, arg)| arg.as_str() == ">\0") {
+                        output = args_copy[idx + 1].clone();
+                        args_copy.drain(idx..=idx + 1);
+                    }
+
+                    let mut args_addr: Vec<*const u8> = args_copy
+                        .iter()
+                        .map(|arg| arg.as_ptr())
+                        .collect();
+                    args_addr.push(0 as *const u8);
                     let pid = fork();
                     if pid == 0 {
+                        // input redirection
+                        if !input.is_empty() {
+                            let input_fd = open(input.as_str(), OpenFlags::RDONLY);
+                            if input_fd == -1 {
+                                println!("Error when opening file {}", input);
+                                return -4;
+                            }
+                            let input_fd = input_fd as usize;
+                            close(0);
+                            assert_eq!(dup(input_fd), 0);
+                            close(input_fd);
+                        }
+                        // output redirection
+                        if !output.is_empty() {
+                            let output_fd = open(
+                                output.as_str(),
+                                OpenFlags::CREATE | OpenFlags::WRONLY
+                            );
+                            if output_fd == -1 {
+                                println!("Error when opening file {}", output);
+                                return -4;
+                            }
+                            let output_fd = output_fd as usize;
+                            close(1);
+                            assert_eq!(dup(output_fd), 1);
+                            close(output_fd);
+                        }
                         // child process
-                        if exec(line.as_str()) == -1 {
+                        if exec(args_copy[0].as_str(), args_addr.as_slice()) == -1 {
                             println!("Error when executing!");
                             return -4;
                         }

user/src/bin/usertests.rs

@@ -26,7 +26,7 @@ pub fn main() -> i32 {
         println!("Usertests: Running {}", test);
         let pid = fork();
         if pid == 0 {
-            exec(*test);
+            exec(*test, &[0 as *const u8]);
             panic!("unreachable!");
         } else {
             let mut exit_code: i32 = Default::default();

user/src/lib.rs

@@ -15,8 +15,9 @@ extern crate bitflags;
 
 use syscall::*;
 use buddy_system_allocator::LockedHeap;
+use alloc::vec::Vec;
 
-const USER_HEAP_SIZE: usize = 16384;
+const USER_HEAP_SIZE: usize = 32768;
 
 static mut HEAP_SPACE: [u8; USER_HEAP_SIZE] = [0; USER_HEAP_SIZE];
 
@@ -30,17 +31,31 @@ pub fn handle_alloc_error(layout: core::alloc::Layout) -> ! {
 
 #[no_mangle]
 #[link_section = ".text.entry"]
-pub extern "C" fn _start() -> ! {
+pub extern "C" fn _start(argc: usize, argv: usize) -> ! {
     unsafe {
         HEAP.lock()
             .init(HEAP_SPACE.as_ptr() as usize, USER_HEAP_SIZE);
     }
-    exit(main());
+    let mut v: Vec<&'static str> = Vec::new();
+    for i in 0..argc {
+        let str_start = unsafe {
+            ((argv + i * core::mem::size_of::<usize>()) as *const usize).read_volatile()
+        };
+        let len = (0usize..).find(|i| unsafe {
+            ((str_start + *i) as *const u8).read_volatile() == 0
+        }).unwrap();
+        v.push(
+            core::str::from_utf8(unsafe {
+                core::slice::from_raw_parts(str_start as *const u8, len)
+            }).unwrap()
+        );
+    }
+    exit(main(argc, v.as_slice()));
 }
 
 #[linkage = "weak"]
 #[no_mangle]
-fn main() -> i32 {
+fn main(_argc: usize, _argv: &[&str]) -> i32 {
     panic!("Cannot find main!");
 }
 
@@ -54,6 +69,7 @@ bitflags! {
     }
 }
 
+pub fn dup(fd: usize) -> isize { sys_dup(fd) }
 pub fn open(path: &str, flags: OpenFlags) -> isize { sys_open(path, flags.bits) }
 pub fn close(fd: usize) -> isize { sys_close(fd) }
 pub fn pipe(pipe_fd: &mut [usize]) -> isize { sys_pipe(pipe_fd) }
@@ -64,7 +80,7 @@ pub fn yield_() -> isize { sys_yield() }
 pub fn get_time() -> isize { sys_get_time() }
 pub fn getpid() -> isize { sys_getpid() }
 pub fn fork() -> isize { sys_fork() }
-pub fn exec(path: &str) -> isize { sys_exec(path) }
+pub fn exec(path: &str, args: &[*const u8]) -> isize { sys_exec(path, args) }
 pub fn wait(exit_code: &mut i32) -> isize {
     loop {
         match sys_waitpid(-1, exit_code as *mut _) {

user/src/syscall.rs

@@ -1,3 +1,4 @@
+const SYSCALL_DUP: usize = 24;
 const SYSCALL_OPEN: usize = 56;
 const SYSCALL_CLOSE: usize = 57;
 const SYSCALL_PIPE: usize = 59;
@@ -24,6 +25,10 @@ fn syscall(id: usize, args: [usize; 3]) -> isize {
     ret
 }
 
+pub fn sys_dup(fd: usize) -> isize {
+    syscall(SYSCALL_DUP, [fd, 0, 0])
+}
+
 pub fn sys_open(path: &str, flags: u32) -> isize {
     syscall(SYSCALL_OPEN, [path.as_ptr() as usize, flags as usize, 0])
 }
@@ -65,8 +70,8 @@ pub fn sys_fork() -> isize {
     syscall(SYSCALL_FORK, [0, 0, 0])
 }
 
-pub fn sys_exec(path: &str) -> isize {
-    syscall(SYSCALL_EXEC, [path.as_ptr() as usize, 0, 0])
+pub fn sys_exec(path: &str, args: &[*const u8]) -> isize {
+    syscall(SYSCALL_EXEC, [path.as_ptr() as usize, args.as_ptr() as usize, 0])
 }
 
 pub fn sys_waitpid(pid: isize, exit_code: *mut i32) -> isize {