[PATCH v2 2/4] perf dso: Make lock error check and add BUG_ONs

[Ian Rogers]

Make the pthread mutex on dso use the error check type. This allows
deadlock checking via the return type. Assert the returned value from
mutex lock is always 0.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/util/dso.c    | 12 +++++++++---
 tools/perf/util/symbol.c |  2 +-
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 9cc8a1772b4b..6beccffeef7b 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -784,7 +784,7 @@ dso_cache__free(struct dso *dso)
 	struct rb_root *root = &dso->data.cache;
 	struct rb_node *next = rb_first(root);
 
-	pthread_mutex_lock(&dso->lock);
+	BUG_ON(pthread_mutex_lock(&dso->lock) != 0);
 	while (next) {
 		struct dso_cache *cache;
 
@@ -830,7 +830,7 @@ dso_cache__insert(struct dso *dso, struct dso_cache *new)
 	struct dso_cache *cache;
 	u64 offset = new->offset;
 
-	pthread_mutex_lock(&dso->lock);
+	BUG_ON(pthread_mutex_lock(&dso->lock) != 0);
 	while (*p != NULL) {
 		u64 end;
 
@@ -1259,6 +1259,8 @@ struct dso *dso__new_id(const char *name, struct dso_id *id)
 	struct dso *dso = calloc(1, sizeof(*dso) + strlen(name) + 1);
 
 	if (dso != NULL) {
+		pthread_mutexattr_t lock_attr;
+
 		strcpy(dso->name, name);
 		if (id)
 			dso->id = *id;
@@ -1286,8 +1288,12 @@ struct dso *dso__new_id(const char *name, struct dso_id *id)
 		dso->root = NULL;
 		INIT_LIST_HEAD(&dso->node);
 		INIT_LIST_HEAD(&dso->data.open_entry);
-		pthread_mutex_init(&dso->lock, NULL);
+		pthread_mutexattr_init(&lock_attr);
+		pthread_mutexattr_settype(&lock_attr, PTHREAD_MUTEX_ERRORCHECK);
+		pthread_mutex_init(&dso->lock, &lock_attr);
+		pthread_mutexattr_destroy(&lock_attr);
 		refcount_set(&dso->refcnt, 1);
+
 	}
 
 	return dso;
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index b2ed3140a1fa..43f47532696f 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1783,7 +1783,7 @@ int dso__load(struct dso *dso, struct map *map)
 	}
 
 	nsinfo__mountns_enter(dso->nsinfo, &nsc);
-	pthread_mutex_lock(&dso->lock);
+	BUG_ON(pthread_mutex_lock(&dso->lock) != 0);
 
 	/* check again under the dso->lock */
 	if (dso__loaded(dso)) {
-- 
2.35.0.rc0.227.g00780c9af4-goog