Implement ioctl() FIOCLEX command

kernel/src/fs/file_table.rs

@@ -311,6 +311,10 @@ impl FileTableEntry {
         self.flags.store(flags.bits(), Ordering::Relaxed);
     }
 
+    pub fn clear_flags(&self) {
+        self.flags.store(0, Ordering::Relaxed);
+    }
+
     pub fn register_observer(&self, epoll: Weak<dyn Observer<FdEvents>>) {
         self.subject.register_observer(epoll, ());
     }

kernel/src/fs/utils/ioctl.rs

@@ -27,6 +27,10 @@ pub enum IoctlCmd {
     FIONBIO = 0x5421,
     /// the calling process gives up this controlling terminal
     TIOCNOTTY = 0x5422,
+    /// Clear the close on exec flag on a file descriptor
+    FIONCLEX = 0x5450,
+    /// Set the close on exec flag on a file descriptor
+    FIOCLEX = 0x5451,
     /// Enable or disable asynchronous I/O mode.
     FIOASYNC = 0x5452,
     /// Get Pty Number

kernel/src/syscall/ioctl.rs

@@ -3,7 +3,7 @@
 use super::SyscallReturn;
 use crate::{
     fs::{
-        file_table::FileDesc,
+        file_table::{FdFlags, FileDesc},
         utils::{IoctlCmd, StatusFlags},
     },
     prelude::*,
@@ -39,6 +39,23 @@ pub fn sys_ioctl(fd: FileDesc, cmd: u32, arg: Vaddr, ctx: &Context) -> Result<Sy
             file.set_status_flags(flags)?;
             0
         }
+        IoctlCmd::FIOCLEX => {
+            // Sets the close-on-exec flag of the file.
+            // Follow the implementation of fcntl()
+
+            let flags = FdFlags::CLOEXEC;
+            let file_table = ctx.process.file_table().lock();
+            let entry = file_table.get_entry(fd)?;
+            entry.set_flags(flags);
+            0
+        }
+        IoctlCmd::FIONCLEX => {
+            // Clears the close-on-exec flag of the file.
+            let file_table = ctx.process.file_table().lock();
+            let entry = file_table.get_entry(fd)?;
+            entry.clear_flags();
+            0
+        }
         _ => file.ioctl(ioctl_cmd, arg)?,
     };
     Ok(SyscallReturn::Return(res as _))