perf parse events: Demystify memory allocations

List heads are currently allocated way down the function chain in
__add_event and add_tracepoint and then freed when the scanner code
calls parse_events_update_lists.

Be more explicit with where memory is allocated and who should free it. With
this patch the list_head is allocated in the scanner code and freed when the
scanner code calls parse_events_update_lists.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1372793245-4136-7-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 40 insertions, 22 deletions

diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index afc44c18dfe1..4eb67ec333f1 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -22,6 +22,13 @@ do { \
 		YYABORT; \
 } while (0)
 
+#define ALLOC_LIST(list) \
+do { \
+	list = malloc(sizeof(*list)); \
+	ABORT_ON(!list);              \
+	INIT_LIST_HEAD(list);         \
+} while (0)
+
 static inc_group_count(struct list_head *list,
 		       struct parse_events_evlist *data)
 {
@@ -196,9 +203,10 @@ event_pmu:
 PE_NAME '/' event_config '/'
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 
-	ABORT_ON(parse_events_add_pmu(&list, &data->idx, $1, $3));
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_pmu(list, &data->idx, $1, $3));
 	parse_events__free_terms($3);
 	$$ = list;
 }
@@ -212,11 +220,12 @@ event_legacy_symbol:
 value_sym '/' event_config '/'
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 	int type = $1 >> 16;
 	int config = $1 & 255;
 
-	ABORT_ON(parse_events_add_numeric(&list, &data->idx,
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_numeric(list, &data->idx,
 					  type, config, $3));
 	parse_events__free_terms($3);
 	$$ = list;
@@ -225,11 +234,12 @@ value_sym '/' event_config '/'
 value_sym sep_slash_dc
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 	int type = $1 >> 16;
 	int config = $1 & 255;
 
-	ABORT_ON(parse_events_add_numeric(&list, &data->idx,
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_numeric(list, &data->idx,
 					  type, config, NULL));
 	$$ = list;
 }
@@ -238,27 +248,30 @@ event_legacy_cache:
 PE_NAME_CACHE_TYPE '-' PE_NAME_CACHE_OP_RESULT '-' PE_NAME_CACHE_OP_RESULT
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 
-	ABORT_ON(parse_events_add_cache(&list, &data->idx, $1, $3, $5));
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_cache(list, &data->idx, $1, $3, $5));
 	$$ = list;
 }
 |
 PE_NAME_CACHE_TYPE '-' PE_NAME_CACHE_OP_RESULT
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 
-	ABORT_ON(parse_events_add_cache(&list, &data->idx, $1, $3, NULL));
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_cache(list, &data->idx, $1, $3, NULL));
 	$$ = list;
 }
 |
 PE_NAME_CACHE_TYPE
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 
-	ABORT_ON(parse_events_add_cache(&list, &data->idx, $1, NULL, NULL));
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_cache(list, &data->idx, $1, NULL, NULL));
 	$$ = list;
 }
 
@@ -266,9 +279,10 @@ event_legacy_mem:
 PE_PREFIX_MEM PE_VALUE ':' PE_MODIFIER_BP sep_dc
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 
-	ABORT_ON(parse_events_add_breakpoint(&list, &data->idx,
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_breakpoint(list, &data->idx,
 					     (void *) $2, $4));
 	$$ = list;
 }
@@ -276,9 +290,10 @@ PE_PREFIX_MEM PE_VALUE ':' PE_MODIFIER_BP sep_dc
 PE_PREFIX_MEM PE_VALUE sep_dc
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 
-	ABORT_ON(parse_events_add_breakpoint(&list, &data->idx,
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_breakpoint(list, &data->idx,
 					     (void *) $2, NULL));
 	$$ = list;
 }
@@ -287,9 +302,10 @@ event_legacy_tracepoint:
 PE_NAME ':' PE_NAME
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 
-	ABORT_ON(parse_events_add_tracepoint(&list, &data->idx, $1, $3));
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_tracepoint(list, &data->idx, $1, $3));
 	$$ = list;
 }
 
@@ -297,9 +313,10 @@ event_legacy_numeric:
 PE_VALUE ':' PE_VALUE
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 
-	ABORT_ON(parse_events_add_numeric(&list, &data->idx, (u32)$1, $3, NULL));
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_numeric(list, &data->idx, (u32)$1, $3, NULL));
 	$$ = list;
 }
 
@@ -307,9 +324,10 @@ event_legacy_raw:
 PE_RAW
 {
 	struct parse_events_evlist *data = _data;
-	struct list_head *list = NULL;
+	struct list_head *list;
 
-	ABORT_ON(parse_events_add_numeric(&list, &data->idx,
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_add_numeric(list, &data->idx,
 					  PERF_TYPE_RAW, $1, NULL));
 	$$ = list;
 }