diff --git a/tests/src/android/os/cts/FileUtils.java b/tests/src/android/os/cts/FileUtils.java
index 6b71b86..ea31c54 100644
--- a/tests/src/android/os/cts/FileUtils.java
+++ b/tests/src/android/os/cts/FileUtils.java
@@ -25,6 +25,7 @@
 /** Bits and pieces copied from hidden API of android.os.FileUtils. */
 public class FileUtils {
 
+    public static final int S_IFMT  = 0170000;
     public static final int S_IFSOCK = 0140000;
     public static final int S_IFLNK = 0120000;
     public static final int S_IFREG = 0100000;
@@ -73,8 +74,18 @@
         public long ctime;
 
         public boolean hasModeFlag(int flag) {
+            if (((S_IRWXU | S_IRWXG | S_IRWXO) & flag) != flag) {
+                throw new IllegalArgumentException("Inappropriate flag " + flag);
+            }
             return (mode & flag) == flag;
         }
+
+        public boolean isOfType(int type) {
+            if ((type & S_IFMT) != type) {
+                throw new IllegalArgumentException("Unknown type " + type);
+            }
+            return (mode & S_IFMT) == type;
+        }
     }
 
     /**
diff --git a/tests/tests/permission/src/android/permission/cts/FileSystemPermissionTest.java b/tests/tests/permission/src/android/permission/cts/FileSystemPermissionTest.java
index 3abcbb6..2a9a2f2 100644
--- a/tests/tests/permission/src/android/permission/cts/FileSystemPermissionTest.java
+++ b/tests/tests/permission/src/android/permission/cts/FileSystemPermissionTest.java
@@ -660,30 +660,40 @@
         assertTrue("Cannot find /system partition", foundSystem);
     }
 
-    private static final Set<File> DEV_EXCEPTIONS = new HashSet<File>(
+    public void testAllBlockDevicesAreSecure() throws Exception {
+        Set<File> insecure = getAllInsecureDevicesInDirAndSubdir(new File("/dev"), FileUtils.S_IFBLK);
+        assertTrue("Found insecure block devices: " + insecure.toString(),
+                insecure.isEmpty());
+    }
+
+    private static final Set<File> CHAR_DEV_EXCEPTIONS = new HashSet<File>(
             Arrays.asList(
-                // Known good devices- should be present everywhere
+                // All exceptions should be alphabetical and associated with a bug number.
+                new File("/dev/alarm"),      // b/9035217
                 new File("/dev/ashmem"),
                 new File("/dev/binder"),
                 new File("/dev/full"),
                 new File("/dev/ion"),
+                new File("/dev/log/events"), // b/9035217
+                new File("/dev/log/main"),   // b/9035217
+                new File("/dev/log/radio"),  // b/9035217
+                new File("/dev/log/system"), // b/9035217
                 new File("/dev/null"),
                 new File("/dev/random"),
                 new File("/dev/tty"),
                 new File("/dev/urandom"),
                 new File("/dev/zero")
-                // Other exceptions go below here, along with a bug #
             ));
 
-    public void testAllDevicesAreSecure() throws Exception {
-        Set<File> insecure = getAllInsecureDevicesInDirAndSubdir(new File("/dev"));
-        insecure.removeAll(DEV_EXCEPTIONS);
-        assertTrue("Found insecure: " + insecure.toString(),
+    public void testAllCharacterDevicesAreSecure() throws Exception {
+        Set<File> insecure = getAllInsecureDevicesInDirAndSubdir(new File("/dev"), FileUtils.S_IFCHR);
+        insecure.removeAll(CHAR_DEV_EXCEPTIONS);
+        assertTrue("Found insecure character devices: " + insecure.toString(),
                 insecure.isEmpty());
     }
 
     private static Set<File>
-    getAllInsecureDevicesInDirAndSubdir(File dir) throws Exception {
+    getAllInsecureDevicesInDirAndSubdir(File dir, int type) throws Exception {
         assertTrue(dir.isDirectory());
         Set<File> retval = new HashSet<File>();
 
@@ -702,7 +712,7 @@
         /* recurse into subdirectories */
         if (subDirectories != null) {
             for (File f : subDirectories) {
-                retval.addAll(getAllInsecureDevicesInDirAndSubdir(f));
+                retval.addAll(getAllInsecureDevicesInDirAndSubdir(f, type));
             }
         }
 
@@ -714,7 +724,7 @@
         for (File f: filesInThisDirectory) {
             FileUtils.FileStatus status = new FileUtils.FileStatus();
             FileUtils.getFileStatus(f.getAbsolutePath(), status, false);
-            if (status.hasModeFlag(FileUtils.S_IFBLK) || status.hasModeFlag(FileUtils.S_IFCHR)) {
+            if (status.isOfType(type)) {
                 if (f.canRead() || f.canWrite() || f.canExecute()) {
                     retval.add(f);
                 }
diff --git a/tests/tests/permission/src/android/permission/cts/FileUtils.java b/tests/tests/permission/src/android/permission/cts/FileUtils.java
index 5a869de..56e773a 100644
--- a/tests/tests/permission/src/android/permission/cts/FileUtils.java
+++ b/tests/tests/permission/src/android/permission/cts/FileUtils.java
@@ -19,6 +19,7 @@
 /** Bits and pieces copied from hidden API of android.os.FileUtils. */
 public class FileUtils {
 
+    public static final int S_IFMT  = 0170000;
     public static final int S_IFSOCK = 0140000;
     public static final int S_IFLNK = 0120000;
     public static final int S_IFREG = 0100000;
@@ -31,14 +32,17 @@
     public static final int S_ISGID = 0002000;
     public static final int S_ISVTX = 0001000;
 
+    public static final int S_IRWXU = 00700;
     public static final int S_IRUSR = 00400;
     public static final int S_IWUSR = 00200;
     public static final int S_IXUSR = 00100;
 
+    public static final int S_IRWXG = 00070;
     public static final int S_IRGRP = 00040;
     public static final int S_IWGRP = 00020;
     public static final int S_IXGRP = 00010;
 
+    public static final int S_IRWXO = 00007;
     public static final int S_IROTH = 00004;
     public static final int S_IWOTH = 00002;
     public static final int S_IXOTH = 00001;
@@ -64,8 +68,18 @@
         public long ctime;
 
         public boolean hasModeFlag(int flag) {
+            if (((S_IRWXU | S_IRWXG | S_IRWXO) & flag) != flag) {
+                throw new IllegalArgumentException("Inappropriate flag " + flag);
+            }
             return (mode & flag) == flag;
         }
+
+        public boolean isOfType(int type) {
+            if ((type & S_IFMT) != type) {
+                throw new IllegalArgumentException("Unknown type " + type);
+            }
+            return (mode & S_IFMT) == type;
+        }
     }
 
     /**