audit: use union for audit_field values since they are mutually exclusive

Since only one of val, uid, gid and lsm* are used at any given time, combine
them to reduce the size of the struct audit_field.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 1ae00891aff9..36dffeccebdb 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -66,12 +66,16 @@ struct audit_krule {
 
 struct audit_field {
 	u32				type;
-	u32				val;
-	kuid_t				uid;
-	kgid_t				gid;
+	union {
+		u32			val;
+		kuid_t			uid;
+		kgid_t			gid;
+		struct {
+			char		*lsm_str;
+			void		*lsm_rule;
+		};
+	};
 	u32				op;
-	char				*lsm_str;
-	void				*lsm_rule;
 };
 
 extern int is_audit_feature_set(int which);