apparmor: remove parent task info from audit logging

The reporting of the parent task info is a vestage from old versions of
apparmor. The need for this information was removed by unique null-
profiles before apparmor was upstreamed so remove this info from logging.

Signed-off-by: John Johansen <john.johansen@canonical.com>

security/apparmor/audit.c

@@ -111,7 +111,6 @@ static const char *const aa_audit_type[] = {
 static void audit_pre(struct audit_buffer *ab, void *ca)
 {
 	struct common_audit_data *sa = ca;
-	struct task_struct *tsk = sa->u.tsk ? sa->u.tsk : current;
 
 	if (aa_g_audit_header) {
 		audit_log_format(ab, "apparmor=");
@@ -132,11 +131,6 @@ static void audit_pre(struct audit_buffer *ab, void *ca)
 
 	if (sa->aad->profile) {
 		struct aa_profile *profile = sa->aad->profile;
-		pid_t pid;
-		rcu_read_lock();
-		pid = rcu_dereference(tsk->real_parent)->pid;
-		rcu_read_unlock();
-		audit_log_format(ab, " parent=%d", pid);
 		if (profile->ns != root_ns) {
 			audit_log_format(ab, " namespace=");
 			audit_log_untrustedstring(ab, profile->ns->base.hname);

security/apparmor/include/audit.h

@@ -109,7 +109,6 @@ struct apparmor_audit_data {
 	void *profile;
 	const char *name;
 	const char *info;
-	struct task_struct *tsk;
 	union {
 		void *target;
 		struct {