ksud: refine mount

- `magic_mount` now takes the tmp_path from its argument
- `.notmpfs` and `.nomount` now behave the same

skip:
ksud: cache tmp path (74ce44de21963fddc83897846eed28eca89d78aa)

Co-authored-by: shatyuka <shatyuka@qq.com>
Signed-off-by: Faris <rsuntk@yukiprjkt.my.id>

userspace/ksud/src/init_event.rs

@@ -7,6 +7,7 @@ use crate::{
     module::{handle_updated_modules, prune_modules},
     restorecon, uid_scanner, utils,
 };
+use crate::utils::find_tmp_path;
 use anyhow::{Context, Result};
 use log::{info, warn};
 use rustix::fs::{MountFlags, mount};
@@ -86,11 +87,15 @@ pub fn on_post_data_fs() -> Result<()> {
         warn!("KPM: Failed to load KPM modules: {}", e);
     }
 
+    let tmpfs_path = find_tmp_path();
+    // for compatibility
+    let no_mount = Path::new(NO_TMPFS_PATH).exists() || Path::new(NO_MOUNT_PATH).exists();
+
     // mount temp dir
-    if !Path::new(NO_TMPFS_PATH).exists() {
+    if !no_mount {
         if let Err(e) = mount(
             KSU_MOUNT_SOURCE,
-            utils::get_tmp_path(),
+            &tmpfs_path,
             "tmpfs",
             MountFlags::empty(),
             "",
@@ -113,9 +118,10 @@ pub fn on_post_data_fs() -> Result<()> {
     }
 
     // mount module systemlessly by magic mount
-    if !Path::new(NO_MOUNT_PATH).exists() {
-        if let Err(e) = mount_modules_systemlessly() {
-            warn!("do systemless mount failed: {}", e);
+    #[cfg(target_os = "android")]
+    if !no_mount {
+        if let Err(e) = crate::magic_mount::magic_mount(&tmpfs_path) {
+            warn!("do systemless mount failed: {e}");
         }
     } else {
         info!("no mount requested");
@@ -148,7 +154,7 @@ pub fn on_post_data_fs() -> Result<()> {
 
 #[cfg(target_os = "android")]
 pub fn mount_modules_systemlessly() -> Result<()> {
-    crate::magic_mount::magic_mount()
+    crate::magic_mount::magic_mount(&find_tmp_path())
 }
 
 #[cfg(not(target_os = "android"))]