AppArmor: add "file" details to securityfs

Create the "file" directory in the securityfs for tracking features
related to files.

Signed-off-by: Kees Cook <kees@ubuntu.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
diff --git a/security/apparmor/include/apparmorfs.h b/security/apparmor/include/apparmorfs.h
index 16e6545..7ea4769 100644
--- a/security/apparmor/include/apparmorfs.h
+++ b/security/apparmor/include/apparmorfs.h
@@ -17,6 +17,7 @@
 
 enum aa_fs_type {
 	AA_FS_TYPE_BOOLEAN,
+	AA_FS_TYPE_STRING,
 	AA_FS_TYPE_U64,
 	AA_FS_TYPE_FOPS,
 	AA_FS_TYPE_DIR,
@@ -31,6 +32,7 @@
 	enum aa_fs_type v_type;
 	union {
 		bool boolean;
+		char *string;
 		unsigned long u64;
 		struct aa_fs_entry *files;
 	} v;
@@ -43,6 +45,10 @@
 	{ .name = (_name), .mode = 0444, \
 	  .v_type = AA_FS_TYPE_BOOLEAN, .v.boolean = (_value), \
 	  .file_ops = &aa_fs_seq_file_ops }
+#define AA_FS_FILE_STRING(_name, _value) \
+	{ .name = (_name), .mode = 0444, \
+	  .v_type = AA_FS_TYPE_STRING, .v.string = (_value), \
+	  .file_ops = &aa_fs_seq_file_ops }
 #define AA_FS_FILE_U64(_name, _value) \
 	{ .name = (_name), .mode = 0444, \
 	  .v_type = AA_FS_TYPE_U64, .v.u64 = (_value), \