Substituted to the original ch7 code.

os/src/syscall/fs.rs

@@ -1,6 +1,12 @@
-use crate::mm::{UserBuffer, translated_byte_buffer, translated_refmut};
+use crate::mm::{
+    UserBuffer,
+    translated_byte_buffer,
+    translated_refmut,
+    translated_str,
+};
 use crate::task::{current_user_token, current_task};
-use crate::fs::make_pipe;
+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();
@@ -10,6 +16,9 @@ pub fn sys_write(fd: usize, buf: *const u8, len: usize) -> isize {
         return -1;
     }
     if let Some(file) = &inner.fd_table[fd] {
+        if !file.writable() {
+            return -1;
+        }
         let file = file.clone();
         // release current task TCB manually to avoid multi-borrow
         drop(inner);
@@ -30,6 +39,9 @@ pub fn sys_read(fd: usize, buf: *const u8, len: usize) -> isize {
     }
     if let Some(file) = &inner.fd_table[fd] {
         let file = file.clone();
+        if !file.readable() {
+            return -1;
+        }
         // release current task TCB manually to avoid multi-borrow
         drop(inner);
         file.read(
@@ -40,6 +52,23 @@ pub fn sys_read(fd: usize, buf: *const u8, len: usize) -> isize {
     }
 }
 
+pub fn sys_open(path: *const u8, flags: u32) -> isize {
+    let task = current_task().unwrap();
+    let token = current_user_token();
+    let path = translated_str(token, path);
+    if let Some(inode) = open_file(
+        path.as_str(),
+        OpenFlags::from_bits(flags).unwrap()
+    ) {
+        let mut inner = task.inner_exclusive_access();
+        let fd = inner.alloc_fd();
+        inner.fd_table[fd] = Some(inode);
+        fd as isize
+    } else {
+        -1
+    }
+}
+
 pub fn sys_close(fd: usize) -> isize {
     let task = current_task().unwrap();
     let mut inner = task.inner_exclusive_access();
@@ -65,4 +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.inner_exclusive_access();
+    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 +1,5 @@
+const SYSCALL_DUP: usize = 24;
+const SYSCALL_OPEN: usize = 56;
 const SYSCALL_CLOSE: usize = 57;
 const SYSCALL_PIPE: usize = 59;
 const SYSCALL_READ: usize = 63;
@@ -18,6 +20,8 @@ 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),
         SYSCALL_READ => sys_read(args[0], args[1] as *const u8, args[2]),
@@ -27,7 +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

@@ -9,9 +9,15 @@ use crate::timer::get_time_ms;
 use crate::mm::{
     translated_str,
     translated_refmut,
+    translated_ref,
+};
+use crate::fs::{
+    open_file,
+    OpenFlags,
 };
-use crate::loader::get_app_data_by_name;
 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);
@@ -45,13 +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);
-    if let Some(data) = get_app_data_by_name(path.as_str()) {
+    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(data);
-        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
     }
@@ -63,7 +81,7 @@ pub fn sys_waitpid(pid: isize, exit_code_ptr: *mut i32) -> isize {
     let task = current_task().unwrap();
     // find a child process
 
-    // ---- access current TCB exclusively
+    // ---- access current PCB exclusively
     let mut inner = task.inner_exclusive_access();
     if inner.children
         .iter()
@@ -76,16 +94,16 @@ pub fn sys_waitpid(pid: isize, exit_code_ptr: *mut i32) -> isize {
         .iter()
         .enumerate()
         .find(|(_, p)| {
-            // ++++ temporarily access child PCB lock exclusively
+            // ++++ temporarily access child PCB exclusively
             p.inner_exclusive_access().is_zombie() && (pid == -1 || pid as usize == p.getpid())
             // ++++ release child PCB
         });
     if let Some((idx, _)) = pair {
         let child = inner.children.remove(idx);
-        // confirm that child will be deallocated after removing from children list
+        // confirm that child will be deallocated after being removed from children list
         assert_eq!(Arc::strong_count(&child), 1);
         let found_pid = child.getpid();
-        // ++++ temporarily access child TCB exclusively
+        // ++++ temporarily access child PCB exclusively
         let exit_code = child.inner_exclusive_access().exit_code;
         // ++++ release child PCB
         *translated_refmut(inner.memory_set.token(), exit_code_ptr) = exit_code;
@@ -93,5 +111,5 @@ pub fn sys_waitpid(pid: isize, exit_code_ptr: *mut i32) -> isize {
     } else {
         -2
     }
-    // ---- release current PCB lock automatically
+    // ---- release current PCB automatically
 }