From ec216e56e281ff82fe62d5a2ccdb0fa4c2ad8961 Mon Sep 17 00:00:00 2001
From: 4lDO2 <4lDO2@protonmail.com>
Date: Wed, 25 Sep 2024 20:28:50 +0200
Subject: [PATCH] Preserve umask across execv.

---
 redox-rt/src/proc.rs       | 5 +++++
 src/platform/auxv_defs.rs  | 3 +++
 src/platform/mod.rs        | 9 +++++++++
 src/platform/redox/exec.rs | 1 +
 4 files changed, 18 insertions(+)

diff --git a/redox-rt/src/proc.rs b/redox-rt/src/proc.rs
index 360c18a14b..81fad4f262 100644
--- a/redox-rt/src/proc.rs
+++ b/redox-rt/src/proc.rs
@@ -51,6 +51,8 @@ pub struct ExtraInfo<'a> {
     pub sigignmask: u64,
     // POSIX also states that the sigprocmask must be preserved across execs.
     pub sigprocmask: u64,
+    /// File mode creation mask (POSIX)
+    pub umask: u32,
 }
 
 pub fn fexec_impl<A, E>(
@@ -422,6 +424,9 @@ where
         push(extrainfo.sigprocmask as usize)?;
         push(AT_REDOX_INHERITED_SIGPROCMASK)?;
 
+        push(extrainfo.umask as usize)?;
+        push(AT_REDOX_UMASK);
+
         push(0)?;
 
         for env in envs {
diff --git a/src/platform/auxv_defs.rs b/src/platform/auxv_defs.rs
index 814eab2499..ae9a6d36a1 100644
--- a/src/platform/auxv_defs.rs
+++ b/src/platform/auxv_defs.rs
@@ -45,3 +45,6 @@ pub const AT_REDOX_INHERITED_SIGPROCMASK_HI: usize = 37;
 pub const AT_REDOX_INITIAL_DEFAULT_SCHEME_PTR: usize = 38;
 #[cfg(target_os = "redox")]
 pub const AT_REDOX_INITIAL_DEFAULT_SCHEME_LEN: usize = 39;
+
+#[cfg(target_os = "redox")]
+pub const AT_REDOX_UMASK: usize = 40;
diff --git a/src/platform/mod.rs b/src/platform/mod.rs
index 9fd855a7da..9b51834582 100644
--- a/src/platform/mod.rs
+++ b/src/platform/mod.rs
@@ -287,6 +287,10 @@ pub fn get_auxv(auxvs: &[[usize; 2]], key: usize) -> Option<usize> {
 pub unsafe fn init(auxvs: Box<[[usize; 2]]>) {
     redox_rt::initialize();
 
+    use syscall::MODE_PERM;
+
+    use crate::header::sys_stat::S_ISVTX;
+
     use self::auxv_defs::*;
 
     if let (Some(cwd_ptr), Some(cwd_len)) = (
@@ -320,6 +324,11 @@ pub unsafe fn init(auxvs: Box<[[usize; 2]]>) {
         inherited_sigprocmask |= (mask as u64) << 32;
     }
     redox_rt::signal::set_sigmask(Some(inherited_sigprocmask), None).unwrap();
+
+    if let Some(umask) = get_auxv(&auxvs, AT_REDOX_UMASK) {
+        let _ =
+            redox_rt::sys::swap_umask((umask as u32) & u32::from(MODE_PERM) & !(S_ISVTX as u32));
+    }
 }
 #[cfg(not(target_os = "redox"))]
 pub fn init(auxvs: Box<[[usize; 2]]>) {}
diff --git a/src/platform/redox/exec.rs b/src/platform/redox/exec.rs
index 6b8c3856c7..990502bdd6 100644
--- a/src/platform/redox/exec.rs
+++ b/src/platform/redox/exec.rs
@@ -317,6 +317,7 @@ pub fn execve(
             default_scheme: Some(&default_scheme),
             sigignmask: 0,
             sigprocmask,
+            umask: redox_rt::sys::get_umask(),
         };
         fexec_impl(
             exec_fd_guard,