From 91ba44e2fa2e315b102be5a56dc036007019d160 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Mon, 17 Nov 2025 17:39:44 -0700
Subject: [PATCH] Implement F_DUPFD_CLOEXEC

---
 Cargo.lock           |  4 ++--
 src/syscall/debug.rs |  1 +
 src/syscall/fs.rs    | 13 +++++++------
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 0a1a41c231..9aa5bb9a57 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -208,8 +208,8 @@ checksum = "64072665120942deff5fd5425d6c1811b854f4939e7f1c01ce755f64432bbea7"
 
 [[package]]
 name = "redox_syscall"
-version = "0.5.17"
-source = "git+https://gitlab.redox-os.org/redox-os/syscall.git?branch=master#aedadf4d5cb915e0c6a22a5c7358fa853354e21d"
+version = "0.5.18"
+source = "git+https://gitlab.redox-os.org/redox-os/syscall.git?branch=master#2d346f1d610a358d74cd40360cf7e5dcfc2120d7"
 dependencies = [
  "bitflags 2.9.4",
 ]
diff --git a/src/syscall/debug.rs b/src/syscall/debug.rs
index d3c81ae3fc..f65965b8d2 100644
--- a/src/syscall/debug.rs
+++ b/src/syscall/debug.rs
@@ -111,6 +111,7 @@ pub fn format_call(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize) -
                 F_SETFD => "F_SETFD",
                 F_SETFL => "F_SETFL",
                 F_GETFL => "F_GETFL",
+                F_DUPFD_CLOEXEC => "F_DUPFD_CLOEXEC",
                 _ => "UNKNOWN",
             },
             c,
diff --git a/src/syscall/fs.rs b/src/syscall/fs.rs
index 3fb1f309bd..5ce467b46f 100644
--- a/src/syscall/fs.rs
+++ b/src/syscall/fs.rs
@@ -265,6 +265,7 @@ pub fn close(fd: FileHandle, token: &mut CleanLockToken) -> Result<()> {
 fn duplicate_file(
     fd: FileHandle,
     user_buf: UserSliceRo,
+    cloexec: bool,
     token: &mut CleanLockToken,
 ) -> Result<FileDescriptor> {
     let (caller_ctx, file) = {
@@ -279,7 +280,7 @@ fn duplicate_file(
     if user_buf.is_empty() {
         Ok(FileDescriptor {
             description: Arc::clone(&file.description),
-            cloexec: false,
+            cloexec,
         })
     } else {
         let description = { *file.description.read() };
@@ -306,14 +307,14 @@ fn duplicate_file(
 
         Ok(FileDescriptor {
             description: new_description,
-            cloexec: false,
+            cloexec,
         })
     }
 }
 
 /// Duplicate file descriptor
 pub fn dup(fd: FileHandle, buf: UserSliceRo, token: &mut CleanLockToken) -> Result<FileHandle> {
-    let new_file = duplicate_file(fd, buf, token)?;
+    let new_file = duplicate_file(fd, buf, false, token)?;
 
     context::current()
         .read(token.token())
@@ -332,7 +333,7 @@ pub fn dup2(
         Ok(new_fd)
     } else {
         let _ = close(new_fd, token);
-        let new_file = duplicate_file(fd, buf, token)?;
+        let new_file = duplicate_file(fd, buf, false, token)?;
 
         let context_ref = context::current();
         let context = context_ref.read(token.token());
@@ -526,9 +527,9 @@ pub fn fcntl(fd: FileHandle, cmd: usize, arg: usize, token: &mut CleanLockToken)
 
     let description = file.description.read();
 
-    if cmd == F_DUPFD {
+    if cmd == F_DUPFD || cmd == F_DUPFD_CLOEXEC {
         // Not in match because 'files' cannot be locked
-        let new_file = duplicate_file(fd, UserSlice::empty(), token)?;
+        let new_file = duplicate_file(fd, UserSlice::empty(), cmd == F_DUPFD_CLOEXEC, token)?;
 
         let context_lock = context::current();
         let context = context_lock.read(token.token());