[PATCH] make set_loginuid obey audit_enabled

Hi,

I was doing some testing and noticed that when the audit system was disabled,
I was still getting messages about the loginuid being set. The following patch
makes audit_set_loginuid look at in_syscall to determine if it should create
an audit event. The loginuid will continue to be set as long as there is a context.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

kernel/auditsc.c

@@ -1290,18 +1290,23 @@ void auditsc_get_stamp(struct audit_context *ctx,
  */
 int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
 {
-	if (task->audit_context) {
-		struct audit_buffer *ab;
-
-		ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
-		if (ab) {
-			audit_log_format(ab, "login pid=%d uid=%u "
-				"old auid=%u new auid=%u",
-				task->pid, task->uid, 
-				task->audit_context->loginuid, loginuid);
-			audit_log_end(ab);
+	struct audit_context *context = task->audit_context;
+
+	if (context) {
+		/* Only log if audit is enabled */
+		if (context->in_syscall) {
+			struct audit_buffer *ab;
+
+			ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
+			if (ab) {
+				audit_log_format(ab, "login pid=%d uid=%u "
+					"old auid=%u new auid=%u",
+					task->pid, task->uid,
+					context->loginuid, loginuid);
+				audit_log_end(ab);
+			}
 		}
-		task->audit_context->loginuid = loginuid;
+		context->loginuid = loginuid;
 	}
 	return 0;
 }