feat(fs): add sys_dup3 (#755)

* feat(fs): add sys_dup3

kernel/src/filesystem/vfs/syscall.rs

@@ -1020,6 +1020,21 @@ impl Syscall {
         return Self::do_dup2(oldfd, newfd, &mut fd_table_guard);
     }
 
+    pub fn dup3(oldfd: i32, newfd: i32, flags: u32) -> Result<usize, SystemError> {
+        let flags = FileMode::from_bits_truncate(flags);
+        if (flags.bits() & !FileMode::O_CLOEXEC.bits()) != 0 {
+            return Err(SystemError::EINVAL);
+        }
+
+        if oldfd == newfd {
+            return Err(SystemError::EINVAL);
+        }
+
+        let binding = ProcessManager::current_pcb().fd_table();
+        let mut fd_table_guard = binding.write();
+        return Self::do_dup3(oldfd, newfd, flags, &mut fd_table_guard);
+    }
+
     fn do_dup2(
         oldfd: i32,
         newfd: i32,

kernel/src/syscall/mod.rs

@@ -399,6 +399,13 @@ impl Syscall {
                 Self::dup2(oldfd, newfd)
             }
 
+            SYS_DUP3 => {
+                let oldfd: i32 = args[0] as c_int;
+                let newfd: i32 = args[1] as c_int;
+                let flags: u32 = args[2] as u32;
+                Self::dup3(oldfd, newfd, flags)
+            }
+
             SYS_SOCKET => Self::socket(args[0], args[1], args[2]),
             SYS_SETSOCKOPT => {
                 let optval = args[3] as *const u8;