[PATCH v1 5/6] perf mutex: Fix thread safety analysis

[Ian Rogers]

Add annotations to describe lock behavior. Add missing unlocks to
perf_sched__replay. Alter hist_iter__top_callback as the thread-safety
analysis cannot follow pointers through local variables.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/builtin-sched.c | 8 ++++++++
 tools/perf/builtin-top.c   | 5 +++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 0f52f73be896..a8a765ed28ce 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -658,6 +658,8 @@ static void *thread_func(void *ctx)
 }
 
 static void create_tasks(struct perf_sched *sched)
+	EXCLUSIVE_LOCK_FUNCTION(sched->start_work_mutex)
+	EXCLUSIVE_LOCK_FUNCTION(sched->work_done_wait_mutex)
 {
 	struct task_desc *task;
 	pthread_attr_t attr;
@@ -687,6 +689,8 @@ static void create_tasks(struct perf_sched *sched)
 }
 
 static void wait_for_tasks(struct perf_sched *sched)
+	EXCLUSIVE_LOCKS_REQUIRED(sched->work_done_wait_mutex)
+	EXCLUSIVE_LOCKS_REQUIRED(sched->start_work_mutex)
 {
 	u64 cpu_usage_0, cpu_usage_1;
 	struct task_desc *task;
@@ -738,6 +742,8 @@ static void wait_for_tasks(struct perf_sched *sched)
 }
 
 static void run_one_test(struct perf_sched *sched)
+	EXCLUSIVE_LOCKS_REQUIRED(sched->work_done_wait_mutex)
+	EXCLUSIVE_LOCKS_REQUIRED(sched->start_work_mutex)
 {
 	u64 T0, T1, delta, avg_delta, fluct;
 
@@ -3314,6 +3320,8 @@ static int perf_sched__replay(struct perf_sched *sched)
 	for (i = 0; i < sched->replay_repeat; i++)
 		run_one_test(sched);
 
+	mutex_unlock(&sched->start_work_mutex);
+	mutex_unlock(&sched->work_done_wait_mutex);
 	return 0;
 }
 
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 3757292bfe86..e832f04e3076 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -196,6 +196,7 @@ static void perf_top__record_precise_ip(struct perf_top *top,
 					struct hist_entry *he,
 					struct perf_sample *sample,
 					struct evsel *evsel, u64 ip)
+	EXCLUSIVE_LOCKS_REQUIRED(he->hists->lock)
 {
 	struct annotation *notes;
 	struct symbol *sym = he->ms.sym;
@@ -724,13 +725,13 @@ static void *display_thread(void *arg)
 static int hist_iter__top_callback(struct hist_entry_iter *iter,
 				   struct addr_location *al, bool single,
 				   void *arg)
+	EXCLUSIVE_LOCKS_REQUIRED(iter->he->hists->lock)
 {
 	struct perf_top *top = arg;
-	struct hist_entry *he = iter->he;
 	struct evsel *evsel = iter->evsel;
 
 	if (perf_hpp_list.sym && single)
-		perf_top__record_precise_ip(top, he, iter->sample, evsel, al->addr);
+		perf_top__record_precise_ip(top, iter->he, iter->sample, evsel, al->addr);
 
 	hist__account_cycles(iter->sample->branch_stack, al, iter->sample,
 		     !(top->record_opts.branch_stack & PERF_SAMPLE_BRANCH_ANY),
-- 
2.37.1.595.g718a3a8f04-goog