Update freedesktop.rs

src/freedesktop.rs

@@ -737,8 +737,14 @@ fn get_mount_points() -> Result<Vec<MountPoint>, Error> {
     use once_cell::sync::Lazy;
     use std::sync::Mutex;
 
-    // The same as above applies to getmntinfo() function.
-    // NetBSD does not support statfs since 2005, so we need to use statvfs.
+    // The getmntinfo() function writes the array of structures to an internal
+    // static object and returns a pointer to that object.  Subsequent calls to
+    // getmntinfo() will modify the same object. This means that the function is
+    // not threadsafe. To help prevent multiple threads using it concurrently
+    // via get_mount_points a Mutex is used.
+    // We understand that threads can still call `libc::getmntinfo(…)` directly
+    // to bypass the lock and trigger UB.
+    // NetBSD does not support statfs since 2005, so we need to use statvfs instead.
     static LOCK: Lazy<Mutex<()>> = Lazy::new(|| Mutex::new(()));
     let _lock = LOCK.lock().unwrap();