[PATCH] perf script: Skip dummy event attr check

[Jiri Olsa <jolsa@kernel.org>]

Hongtao Yu reported problem when displaying uregs in perf script
for system wide perf.data:

  # perf script -F uregs | head -10
  Samples for 'dummy:HG' event do not have UREGS attribute set. Cannot print 'uregs' field.

The problem is the extra dummy event added for system wide,
which does not have proper sample_type setup.

Skipping attr check completely for dummy event as suggested
by Namhyung, because it does not have any samples anyway.

Reported-by: Hongtao Yu <hoy@fb.com>
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/builtin-script.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 13580a9c50b8..304d234d8e84 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -566,6 +566,8 @@ static struct evsel *find_first_output_type(struct evlist *evlist,
 	struct evsel *evsel;
 
 	evlist__for_each_entry(evlist, evsel) {
+		if (evsel__is_dummy_event(evsel))
+			continue;
 		if (output_type(evsel->core.attr.type) == (int)type)
 			return evsel;
 	}
-- 
2.37.2