src/spawner/mod.rs

@@ -105,6 +105,8 @@ impl<'a> Spawner<'a> {
                     let pipe = self.pipes.get_mut(s).unwrap().take_read()?;
                     builder.keep_fd(&pipe);
 
+                    builder.mount("/proc", "/proc").remount_proc();
+
                     let closure = || match self.pipe_trigger(pipe, entrypoint, name) {
                         Ok(()) => exitcode::OK,
                         Err(e) => {
@@ -129,6 +131,8 @@ impl<'a> Spawner<'a> {
                     let socket = self.sockets.get_mut(s).unwrap().take_read()?;
                     builder.keep_fd(&socket);
 
+                    builder.mount("/proc", "/proc").remount_proc();
+
                     let closure = || match self.file_socket_trigger(socket, entrypoint, name) {
                         Ok(()) => exitcode::OK,
                         Err(e) => {
@@ -327,6 +331,10 @@ impl<'a> Spawner<'a> {
                 Environment::DomainName(name) => {
                     builder.set_domain_name(name);
                 }
+
+                Environment::Procfs => {
+                    builder.mount("/proc", "/proc").remount_proc();
+                }
             }
         }
     }

src/specification.rs

@@ -117,6 +117,8 @@ pub enum Environment {
 
     Hostname(String),
     DomainName(String),
+
+    Procfs,
 }
 
 #[derive(Serialize, Deserialize, PartialEq, Eq, Hash, Debug)]

src/void.rs

@@ -33,6 +33,8 @@ pub struct VoidBuilder {
 
     mounts: HashMap<PathBuf, PathBuf>,
     fds: HashSet<RawFd>,
+
+    remount_proc: bool,
 }
 
 impl VoidBuilder {
@@ -42,6 +44,7 @@ impl VoidBuilder {
             domain_name: None,
             mounts: HashMap::new(),
             fds: HashSet::new(),
+            remount_proc: false,
         }
     }
 
@@ -65,6 +68,11 @@ impl VoidBuilder {
         self
     }
 
+    pub fn remount_proc(&mut self) -> &mut Self {
+        self.remount_proc = true;
+        self
+    }
+
     pub fn spawn(&mut self, child_fn: impl FnOnce() -> i32) -> Result<VoidHandle> {
         let mut args = CloneArgs::new(
             CloneFlags::CLONE_NEWCGROUP
@@ -252,12 +260,29 @@ impl VoidBuilder {
                 fs::write(&dst, b"")?;
             }
 
-            // bind mount
+            // rbind mount
             mount(
                 Some(&src),
                 &dst,
                 Option::<&str>::None,
-                MsFlags::MS_BIND,
+                MsFlags::MS_BIND | MsFlags::MS_REC,
+                Option::<&str>::None,
+            )
+            .map_err(|e| Error::Nix {
+                msg: "mount",
+                src: e,
+            })?;
+        }
+
+        // remount proc
+        if self.remount_proc {
+            debug!("remounting /proc`");
+
+            mount(
+                Some("proc"),
+                "/proc",
+                Some("proc"),
+                MsFlags::empty(),
                 Option::<&str>::None,
             )
             .map_err(|e| Error::Nix {