ksud: tell prctl interface about our mounts (5ec1cff#16)

Author: backslashxx

userspace/ksud/src/magic_mount.rs

@@ -20,6 +20,9 @@ use std::fs::{DirEntry, FileType, create_dir, create_dir_all, read_dir, read_lin
 use std::os::unix::fs::{FileTypeExt, symlink};
 use std::path::{Path, PathBuf};
 
+use libc::{prctl, c_long};  
+use std::ffi::CString;  
+
 const REPLACE_DIR_XATTR: &str = "trusted.overlay.opaque";
 
 #[derive(PartialEq, Eq, Hash, Clone, Debug)]
@@ -201,6 +204,12 @@ fn mount_mirror<P: AsRef<Path>, WP: AsRef<Path>>(
         );
         fs::File::create(&work_dir_path)?;
         bind_mount(&path, &work_dir_path)?;
+        if let Ok(c_path) = CString::new(path.to_string_lossy().as_ref()) {
+        	let mut dummy: u32 = 0; // provide dummy pointer
+        	unsafe {  
+			prctl(0xDEADBEEFu32 as i32, 10001, c_path.as_ptr(), &mut dummy as *mut u32 as *mut libc::c_void, &mut dummy as *mut u32 as *mut libc::c_void);
+		}
+	}
     } else if file_type.is_dir() {
         log::debug!(
             "mount mirror dir {} -> {}",
@@ -257,6 +266,12 @@ fn do_magic_mount<P: AsRef<Path>, WP: AsRef<Path>>(
                     work_dir_path.display()
                 );
                 bind_mount(module_path, target_path)?;
+		if let Ok(c_path) = CString::new(path.to_string_lossy().as_ref()) {
+			let mut dummy: u32 = 0; // provide dummy pointer
+			unsafe {  
+				prctl(0xDEADBEEFu32 as i32, 10001, c_path.as_ptr(), &mut dummy as *mut u32 as *mut libc::c_void, &mut dummy as *mut u32 as *mut libc::c_void);
+			}
+		}
             } else {
                 bail!("cannot mount root file {}!", path.display());
             }
@@ -404,6 +419,12 @@ fn do_magic_mount<P: AsRef<Path>, WP: AsRef<Path>>(
                 );
                 move_mount(&work_dir_path, &path).context("move self")?;
                 mount_change(&path, MountPropagationFlags::PRIVATE).context("make self private")?;
+		if let Ok(c_path) = CString::new(path.to_string_lossy().as_ref()) {
+			let mut dummy: u32 = 0; // provide dummy pointer
+			unsafe {  
+				prctl(0xDEADBEEFu32 as i32, 10001, c_path.as_ptr(), &mut dummy as *mut u32 as *mut libc::c_void, &mut dummy as *mut u32 as *mut libc::c_void);
+			}
+		}
             }
         }
         Whiteout => {