From 89d04ecf7de4baddda8244db26c365678381ae26 Mon Sep 17 00:00:00 2001
From: Wang Taojie <12210519@mail.sustech.edu.cn>
Date: Thu, 10 Oct 2024 23:24:52 +0800
Subject: [PATCH] Implement ioctl() FIOCLEX command

---
 kernel/src/fs/file_table.rs  |  4 ++++
 kernel/src/fs/utils/ioctl.rs |  4 ++++
 kernel/src/syscall/ioctl.rs  | 19 ++++++++++++++++++-
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/kernel/src/fs/file_table.rs b/kernel/src/fs/file_table.rs
index 45f316673..dbdda393c 100644
--- a/kernel/src/fs/file_table.rs
+++ b/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, ());
     }
diff --git a/kernel/src/fs/utils/ioctl.rs b/kernel/src/fs/utils/ioctl.rs
index d0dc222b8..7e82fb02e 100644
--- a/kernel/src/fs/utils/ioctl.rs
+++ b/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
diff --git a/kernel/src/syscall/ioctl.rs b/kernel/src/syscall/ioctl.rs
index 50a0139b5..26b69b9bb 100644
--- a/kernel/src/syscall/ioctl.rs
+++ b/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 _))