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Commit d8a30f20 authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt
Browse files

tracing: Fix rcu handling of event_trigger_data filter field 



The filter field of the event_trigger_data structure is protected under
RCU sched locks. It was not annotated as such, and after doing so,
sparse pointed out several locations that required fix ups.

Reported-by: default avatarkbuild test robot <fengguang.wu@intel.com>
Tested-by: default avatarTom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: default avatarTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 098c879e

kernel/trace/trace.h

+1 −1
Original line number Diff line number Diff line
@@ -1057,7 +1057,7 @@ struct event_trigger_data { 
	int				ref;

	struct event_trigger_ops	*ops;

	struct event_command		*cmd_ops;

	struct event_filter		*filter;

	struct event_filter __rcu	*filter;

	char				*filter_str;

	void				*private_data;

	struct list_head		list;

kernel/trace/trace_events_trigger.c

+5 −3
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ event_triggers_call(struct ftrace_event_file *file, void *rec) 
{

	struct event_trigger_data *data;

	enum event_trigger_type tt = ETT_NONE;

	struct event_filter *filter;



	if (list_empty(&file->triggers))

		return tt;
@@ -76,7 +77,8 @@ event_triggers_call(struct ftrace_event_file *file, void *rec) 
			data->ops->func(data);

			continue;

		}

		if (data->filter && !filter_match_preds(data->filter, rec))

		filter = rcu_dereference(data->filter);

		if (filter && !filter_match_preds(filter, rec))

			continue;

		if (data->cmd_ops->post_trigger) {

			tt |= data->cmd_ops->trigger_type;
@@ -703,7 +705,7 @@ static int set_trigger_filter(char *filter_str, 
	if (ret)

		goto out;

 assign:

	tmp = data->filter;

	tmp = rcu_access_pointer(data->filter);



	rcu_assign_pointer(data->filter, filter);
@@ -719,7 +721,7 @@ static int set_trigger_filter(char *filter_str, 
	if (filter_str) {

		data->filter_str = kstrdup(filter_str, GFP_KERNEL);

		if (!data->filter_str) {

			free_event_filter(data->filter);

			free_event_filter(rcu_access_pointer(data->filter));

			data->filter = NULL;

			ret = -ENOMEM;

		}