+ int ret = 0;
+
+ mutex_lock(&probe_enable_lock);
+
+ if (file) {
+ struct ftrace_event_file **new, **old = tp->files;
+ int n = trace_probe_nr_files(tp);
+ int i, j;
+
+ if (n == 0 || trace_probe_file_index(tp, file) < 0) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ if (n == 1) { /* Remove the last file */
+ tp->flags &= ~TP_FLAG_TRACE;
+ new = NULL;
+ } else {
+ new = kzalloc(n * sizeof(struct ftrace_event_file *),
+ GFP_KERNEL);
+ if (!new) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ /* This copy & check loop copies the NULL stopper too */
+ for (i = 0, j = 0; j < n && i < n + 1; i++)
+ if (old[i] != file)
+ new[j++] = old[i];
+ }
+
+ rcu_assign_pointer(tp->files, new);
+
+ /* Make sure the probe is done with old files */
+ synchronize_sched();
+ kfree(old);
+ } else
+ tp->flags &= ~TP_FLAG_PROFILE;
+