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);