Change dup syscall return type

src/api/fs.rs

@@ -248,9 +248,10 @@ pub fn reopen(path: &str, handle: usize, append: bool) -> Result<usize, ()> {
         create_file(path)
     };
     if let Some(old_handle) = res {
-        syscall::dup(old_handle, handle);
-        syscall::close(old_handle);
-        return Ok(handle);
+        if syscall::dup(old_handle, handle).is_ok() {
+            syscall::close(old_handle);
+            return Ok(handle);
+        }
     }
     Err(())
 }

src/api/syscall.rs

@@ -60,12 +60,12 @@ pub fn open(path: &str, flags: u8) -> Option<usize> {
     }
 }
 
-pub fn dup(old_handle: usize, new_handle: usize) -> Option<usize> {
+pub fn dup(old_handle: usize, new_handle: usize) -> Result<(), ()> {
     let res = unsafe { syscall!(DUP, old_handle, new_handle) } as isize;
     if res >= 0 {
-        Some(res as usize)
+        Ok(())
     } else {
-        None
+        Err(())
     }
 }
 

src/sys/syscall/service.rs

@@ -65,7 +65,7 @@ pub fn open(path: &str, flags: u8) -> isize {
 pub fn dup(old_handle: usize, new_handle: usize) -> isize {
     if let Some(file) = sys::process::handle(old_handle) {
         sys::process::update_handle(new_handle, *file);
-        return new_handle as isize;
+        return 0;
     }
     -1
 }