Use java.io for reading cgroup files

Author: pejovica

src/java.base/linux/classes/jdk/internal/platform/CgroupUtil.java

@@ -26,14 +26,17 @@
 package jdk.internal.platform;
 
 import java.io.BufferedReader;
+import java.io.FileReader;
 import java.io.IOException;
 import java.io.UncheckedIOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.security.AccessController;
 import java.security.PrivilegedActionException;
 import java.security.PrivilegedExceptionAction;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Stream;
 
@@ -64,29 +67,34 @@ static void unwrapIOExceptionAndRethrow(PrivilegedActionException pae) throws IO
 
     static String readStringValue(CgroupSubsystemController controller, String param) throws IOException {
         PrivilegedExceptionAction<BufferedReader> pea = () ->
-                Files.newBufferedReader(Paths.get(controller.path(), param));
+                new BufferedReader(new FileReader(Paths.get(controller.path(), param).toString(), StandardCharsets.UTF_8));
         try (@SuppressWarnings("removal") BufferedReader bufferedReader =
                      AccessController.doPrivileged(pea)) {
             String line = bufferedReader.readLine();
             return line;
         } catch (PrivilegedActionException e) {
             unwrapIOExceptionAndRethrow(e);
             throw new InternalError(e.getCause());
-        } catch (UncheckedIOException e) {
-            throw e.getCause();
         }
     }
 
     @SuppressWarnings("removal")
     public static List<String> readAllLinesPrivileged(Path path) throws IOException {
         try {
-            PrivilegedExceptionAction<List<String>> pea = () -> Files.readAllLines(path);
+            PrivilegedExceptionAction<List<String>> pea = () -> {
+                try (BufferedReader bufferedReader = new BufferedReader(new FileReader(path.toString(), StandardCharsets.UTF_8))) {
+                    String line;
+                    List<String> lines = new ArrayList<>();
+                    while ((line = bufferedReader.readLine()) != null) {
+                        lines.add(line);
+                    }
+                    return lines;
+                }
+            };
             return AccessController.doPrivileged(pea);
         } catch (PrivilegedActionException e) {
             unwrapIOExceptionAndRethrow(e);
             throw new InternalError(e.getCause());
-        } catch (UncheckedIOException e) {
-            throw e.getCause();
         }
     }
 }