From f963e40a5fed6e89529e83ac3b20d0f9d7f378b9 Mon Sep 17 00:00:00 2001
From: 5ec1cff <56485584+5ec1cff@users.noreply.github.com>
Date: Mon, 17 Apr 2023 12:05:13 +0800
Subject: [PATCH] ksud: fix bind mount failed again (#395)

This fixes https://github.com/Dr-TSNG/ZygiskOnKernelSU/issues/18
---
 userspace/ksud/src/event.rs |  4 +++-
 userspace/ksud/src/mount.rs | 15 ++++-----------
 2 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/userspace/ksud/src/event.rs b/userspace/ksud/src/event.rs
index 6c97101a..0c34b3db 100644
--- a/userspace/ksud/src/event.rs
+++ b/userspace/ksud/src/event.rs
@@ -164,11 +164,13 @@ pub fn on_post_data_fs() -> Result<()> {
         warn!("load system.prop failed: {}", e);
     }
 
-    // mount moduke systemlessly by overlay
+    // mount module systemlessly by overlay
     if let Err(e) = mount_systemlessly(module_dir) {
         warn!("do systemless mount failed: {}", e);
     }
 
+    std::env::set_current_dir("/").with_context(|| "failed to chdir to /")?;
+
     Ok(())
 }
 
diff --git a/userspace/ksud/src/mount.rs b/userspace/ksud/src/mount.rs
index 704849e1..424f02e8 100644
--- a/userspace/ksud/src/mount.rs
+++ b/userspace/ksud/src/mount.rs
@@ -11,12 +11,6 @@ use crate::defs::KSU_OVERLAY_SOURCE;
 use log::{info, warn};
 #[cfg(any(target_os = "linux", target_os = "android"))]
 use procfs::process::Process;
-#[cfg(any(target_os = "linux", target_os = "android"))]
-use std::fs::File;
-#[cfg(any(target_os = "linux", target_os = "android"))]
-use std::os::fd::AsRawFd;
-#[cfg(any(target_os = "linux", target_os = "android"))]
-use std::os::unix::fs::OpenOptionsExt;
 use std::path::Path;
 
 pub struct AutoMountExt4 {
@@ -32,6 +26,7 @@ impl AutoMountExt4 {
         let result = Mount::builder()
             .fstype(FilesystemType::from("ext4"))
             .flags(MountFlags::empty())
+            .create_loop(true)
             .mount(src, mnt)
             .map(|mount| {
                 Ok(Self {
@@ -106,6 +101,7 @@ fn mount_image(src: &str, target: &str, autodrop: bool) -> Result<()> {
     if autodrop {
         Mount::builder()
             .fstype(FilesystemType::from("ext4"))
+            .create_loop(true)
             .mount_autodrop(src, target, UnmountFlags::empty())
             .with_context(|| format!("Failed to do mount: {src} -> {target}"))?;
     } else {
@@ -225,11 +221,8 @@ fn mount_overlay_child(
 #[cfg(any(target_os = "linux", target_os = "android"))]
 pub fn mount_overlay(root: &String, module_roots: &Vec<String>) -> Result<()> {
     info!("mount overlay for {}", root);
-    let stock_root = File::options()
-        .read(true)
-        .custom_flags(libc::O_PATH)
-        .open(root)?;
-    let stock_root = format!("/proc/self/fd/{}", stock_root.as_raw_fd());
+    std::env::set_current_dir(root).with_context(|| format!("failed to chdir to {root}"))?;
+    let stock_root = ".";
 
     // collect child mounts before mounting the root
     let mounts = Process::myself()?