Preserve umask across execv.

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;

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]]>) {}

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,