tracing: Add WARN_ON_ONCE when returned value is negative

[linux-2.6-microblaze.git] / kernel / trace / trace_events_hist.c

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index c1abd63..ba03b7d 100644 (file)
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2434,12 +2434,12 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
                      char *subsys_name, char *event_name, char *field_name)
 {
        struct trace_array *tr = target_hist_data->event_file->tr;
-       struct hist_field *event_var = ERR_PTR(-EINVAL);
        struct hist_trigger_data *hist_data;
        unsigned int i, n, first = true;
        struct field_var_hist *var_hist;
        struct trace_event_file *file;
        struct hist_field *key_field;
+       struct hist_field *event_var;
        char *saved_filter;
        char *cmd;
        int ret;
@@ -5232,6 +5232,7 @@ static void unregister_field_var_hists(struct hist_trigger_data *hist_data)
                cmd = hist_data->field_var_hists[i]->cmd;
                ret = event_hist_trigger_func(&trigger_hist_cmd, file,
                                              "!hist", "hist", cmd);
+               WARN_ON_ONCE(ret < 0);
        }
 }