perf: Fix dynamic field detection

Checking if a tracing field is an array with a dynamic length
requires to check the field type and seek the "__data_loc"
string that prepends the actual type, as can be found in a trace
event format file:

	field:__data_loc char[] name;	offset:16;	size:4;	signed:1;

But we actually use strcmp() to check if the field type fully
matches "__data_loc", which may fail as we trip over the rest of
the type.

To fix this, use strncmp to only check if it starts with
"__data_loc".

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Steven Rostedt <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 17d6d66ed766..d6ef414075a6 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -761,7 +761,7 @@ static int field_is_string(struct format_field *field)
 
 static int field_is_dynamic(struct format_field *field)
 {
-	if (!strcmp(field->type, "__data_loc"))
+	if (!strncmp(field->type, "__data_loc", 10))
 		return 1;
 
 	return 0;