3 files changed, 28 insertions, 10 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 414d7210b2ec..bcd93031d042 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -893,7 +893,7 @@ int __trace_bputs(unsigned long ip, const char *str)
 EXPORT_SYMBOL_GPL(__trace_bputs);
 
 #ifdef CONFIG_TRACER_SNAPSHOT
-static void tracing_snapshot_instance(struct trace_array *tr)
+void tracing_snapshot_instance(struct trace_array *tr)
 {
 	struct tracer *tracer = tr->current_trace;
 	unsigned long flags;
@@ -949,7 +949,7 @@ static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,
 					struct trace_buffer *size_buf, int cpu_id);
 static void set_buffer_entries(struct trace_buffer *buf, unsigned long val);
 
-static int alloc_snapshot(struct trace_array *tr)
+int tracing_alloc_snapshot_instance(struct trace_array *tr)
 {
 	int ret;
 
@@ -995,7 +995,7 @@ int tracing_alloc_snapshot(void)
 	struct trace_array *tr = &global_trace;
 	int ret;
 
-	ret = alloc_snapshot(tr);
+	ret = tracing_alloc_snapshot_instance(tr);
 	WARN_ON(ret < 0);
 
 	return ret;
@@ -5408,7 +5408,7 @@ static int tracing_set_tracer(struct trace_array *tr, const char *buf)
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	if (t->use_max_tr && !had_max_tr) {
-		ret = alloc_snapshot(tr);
+		ret = tracing_alloc_snapshot_instance(tr);
 		if (ret < 0)
 			goto out;
 	}
@@ -6451,7 +6451,7 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
 		}
 #endif
 		if (!tr->allocated_snapshot) {
-			ret = alloc_snapshot(tr);
+			ret = tracing_alloc_snapshot_instance(tr);
 			if (ret < 0)
 				break;
 		}
@@ -7179,7 +7179,7 @@ ftrace_trace_snapshot_callback(struct trace_array *tr, struct ftrace_hash *hash,
 		return ret;
 
  out_reg:
-	ret = alloc_snapshot(tr);
+	ret = tracing_alloc_snapshot_instance(tr);
 	if (ret < 0)
 		goto out;
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 6fb46a06c9dc..507954b4e058 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1817,6 +1817,17 @@ static inline void __init trace_event_init(void) { }
 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
 #endif
 
+#ifdef CONFIG_TRACER_SNAPSHOT
+void tracing_snapshot_instance(struct trace_array *tr);
+int tracing_alloc_snapshot_instance(struct trace_array *tr);
+#else
+static inline void tracing_snapshot_instance(struct trace_array *tr) { }
+static inline int tracing_alloc_snapshot_instance(struct trace_array *tr)
+{
+	return 0;
+}
+#endif
+
 extern struct trace_iterator *tracepoint_print_iter;
 
 #endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index d251cabcf69a..8b5bdcf64871 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -483,9 +483,10 @@ clear_event_triggers(struct trace_array *tr)
 	struct trace_event_file *file;
 
 	list_for_each_entry(file, &tr->events, list) {
-		struct event_trigger_data *data;
-		list_for_each_entry_rcu(data, &file->triggers, list) {
+		struct event_trigger_data *data, *n;
+		list_for_each_entry_safe(data, n, &file->triggers, list) {
 			trace_event_trigger_enable_disable(file, 0);
+			list_del_rcu(&data->list);
 			if (data->ops->free)
 				data->ops->free(data->ops, data);
 		}
@@ -642,6 +643,7 @@ event_trigger_callback(struct event_command *cmd_ops,
 	trigger_data->count = -1;
 	trigger_data->ops = trigger_ops;
 	trigger_data->cmd_ops = cmd_ops;
+	trigger_data->private_data = file;
 	INIT_LIST_HEAD(&trigger_data->list);
 	INIT_LIST_HEAD(&trigger_data->named_list);
 
@@ -1053,7 +1055,12 @@ static void
 snapshot_trigger(struct event_trigger_data *data, void *rec,
 		 struct ring_buffer_event *event)
 {
-	tracing_snapshot();
+	struct trace_event_file *file = data->private_data;
+
+	if (file)
+		tracing_snapshot_instance(file->tr);
+	else
+		tracing_snapshot();
 }
 
 static void
@@ -1076,7 +1083,7 @@ register_snapshot_trigger(char *glob, struct event_trigger_ops *ops,
 {
 	int ret = register_trigger(glob, ops, data, file);
 
-	if (ret > 0 && tracing_alloc_snapshot() != 0) {
+	if (ret > 0 && tracing_alloc_snapshot_instance(file->tr) != 0) {
 		unregister_trigger(glob, ops, data, file);
 		ret = 0;
 	}