fix: fix self exe path error && opt: Optimize ensure_dir_exists processing (#541)

* fix: fix self exe path error

* opt: Optimize ensure_dir_exists processing

---------

Signed-off-by: Tools-app <localhost.hutao@gmail.com>

userspace/ksud/src/utils.rs

@@ -45,13 +45,11 @@ pub fn ensure_file_exists<T: AsRef<Path>>(file: T) -> Result<()> {
 }
 
 pub fn ensure_dir_exists<T: AsRef<Path>>(dir: T) -> Result<()> {
-    let result = create_dir_all(&dir).map_err(Error::from);
-    if dir.as_ref().is_dir() {
-        result
-    } else if result.is_ok() {
-        bail!("{} is not a regular directory", dir.as_ref().display())
+    let result = create_dir_all(&dir);
+    if dir.as_ref().is_dir() && result.is_err() {
+        Ok(())
     } else {
-        result
+        bail!("{} is not a regular directory", dir.as_ref().display())
     }
 }
 
@@ -207,7 +205,10 @@ fn link_ksud_to_bin() -> Result<()> {
 
 pub fn install(magiskboot: Option<PathBuf>) -> Result<()> {
     ensure_dir_exists(defs::ADB_DIR)?;
-    std::fs::copy("/proc/self/exe", defs::DAEMON_PATH)?;
+    std::fs::copy(
+        std::env::current_exe().with_context(|| "Failed to get self exe path")?,
+        defs::DAEMON_PATH,
+    )?;
     restorecon::lsetfilecon(defs::DAEMON_PATH, restorecon::ADB_CON)?;
     // install binary assets
     assets::ensure_binaries(false).with_context(|| "Failed to extract assets")?;