tracing: Don't add flag strings when displaying variable references

Variable references should never have flags appended when displayed -
prevent that from happening.

Before:

  # cat /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
  hist:keys=next_pid:vals=hitcount:wakeup_lat=common_timestamp.usecs-$ts0.usecs:...

After:

  hist:keys=next_pid:vals=hitcount:wakeup_lat=common_timestamp.usecs-$ts0:...

Link: http://lkml.kernel.org/r/913318a5610ef6b24af2522575f671fa6ee19b6b.1522256721.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 4f4792f4c83fd7ae982f491ab7e65a23e8440f8f..d867502a56bafa64585a1e76570c363751ac999a 100644 (file)
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2052,7 +2052,7 @@ static void expr_field_str(struct hist_field *field, char *expr)
 
        strcat(expr, hist_field_name(field, 0));
 
-       if (field->flags) {
+       if (field->flags && !(field->flags & HIST_FIELD_FL_VAR_REF)) {
                const char *flags_str = get_hist_field_flags(field);
 
                if (flags_str) {