[PATCH 3.16 036/133] perf events parse: Use just one parse events state struct

[Ben Hutchings]

3.16.51-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

commit d17d0878f456c8227345b6c76b918ec068fa0abd upstream.

Andi reported problems when parse errors were detected with vendor
events (json), because in the yyparse/parse_events_parse function we
dereferenced the _data parameter to two different structs, with
different layouts, which ended up making parse_events_evlist->error to
point to random stack addresses.

Fix it by making _data to always be struct parse_events_state, changing
the only place where 'struct parse_events_term' was used in
parse_events.y.

Reported-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-bc27lshz823hxl8n9nkelcgh@xxxxxxxxxxxxxx
Fixes: 90e2b22dee90 ("perf/tool: Add support to reuse event grammar to parse out terms")
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 tools/perf/util/parse-events.c | 2 +-
 tools/perf/util/parse-events.h | 5 +----
 tools/perf/util/parse-events.y | 2 +-
 3 files changed, 3 insertions(+), 6 deletions(-)

--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -908,7 +908,7 @@ static int parse_events__scanner(const c
  */
 int parse_events_terms(struct list_head *terms, const char *str)
 {
-	struct parse_events_terms data = {
+	struct parse_events_state data = {
 		.terms = NULL,
 	};
 	int ret;
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -65,10 +65,7 @@ struct parse_events_state {
 	struct list_head list;
 	int idx;
 	int nr_groups;
-};
-
-struct parse_events_terms {
-	struct list_head *terms;
+	struct list_head	  *terms;
 };
 
 int parse_events__is_hardcoded_term(struct parse_events_term *term);
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -346,7 +346,7 @@ PE_RAW
 
 start_terms: event_config
 {
-	struct parse_events_terms *data = _data;
+	struct parse_events_state *data = _data;
 	data->terms = $1;
 }