exec ?

Author: soohoonc

src/os/src/kernel/fs.rs

@@ -31,6 +31,12 @@ impl FileSystem {
                 content: "Hello from filesystem!".to_string(),
             },
         );
+        files.insert(
+            "program.exe".to_string(),
+            File {
+                content: "Executable program content".to_string(),
+            },
+        );
 
         Self { files }
     }

src/os/src/kernel/proc.rs

@@ -15,6 +15,7 @@ pub enum ProcessState {
 pub struct Process {
     pub pid: PID,
     pub parent_pid: Option<PID>,
+    pub program_name: String,
     pub state: ProcessState,
     pub exit_status: Option<ExitStatus>,
     pub children: HashSet<PID>,
@@ -31,6 +32,7 @@ impl Process {
         Self {
             pid,
             parent_pid,
+            program_name: "init".to_string(),
             state: ProcessState::Ready,
             exit_status: None,
             children: HashSet::new(),
@@ -84,11 +86,13 @@ impl ProcessControlBlock {
         Ok(child_pid)
     }
 
-    pub fn exec(&mut self, pid: PID) -> Result<(), String> {
+    pub fn exec(&mut self, pid: PID, program_name: String) -> Result<(), String> {
         let process = self
             .processes
             .get_mut(&pid)
             .ok_or_else(|| format!("Process {} not found", pid))?;
+
+        process.program_name = program_name;
         process.state = ProcessState::Ready;
 
         Ok(())

src/os/src/kernel/syscall.rs

@@ -54,7 +54,7 @@ pub fn syscall_dispatch(
         }
         SYS_GETPID => sys_getpid(current_pid),
         SYS_KILL => sys_kill(&mut kernel.process_table, current_pid, args.args[0] as PID),
-        SYS_EXEC => Ok(0),
+        SYS_EXEC => sys_exec(kernel, current_pid, args.args[0] as u32),
         SYS_READ => {
             let fd = FileDescriptor(args.args[0] as u32);
             let count = args.args[1] as usize;
@@ -261,3 +261,20 @@ pub fn sys_close(
         Err(SyscallError::EBADF)
     }
 }
+
+pub fn sys_exec(
+    kernel: &mut super::Kernel,
+    current_pid: PID,
+    _path_len: u32,
+) -> SyscallResult<i32> {
+    let program_name = "program.exe".to_string();
+
+    if !kernel.filesystem.files.contains_key(&program_name) {
+        return Err(SyscallError::EBADF);
+    }
+
+    match kernel.process_table.exec(current_pid, program_name) {
+        Ok(()) => Ok(0),
+        Err(_) => Err(SyscallError::ESRCH),
+    }
+}