Commit 549e914c authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt (Google)
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tracing: Add rcu annotation around file->filter accesses 

Running sparse on trace_events_filter.c triggered several warnings about
file->filter being accessed directly even though it's annotated with __rcu.

Add rcu_dereference() around it and shuffle the logic slightly so that
it's always referenced via accessor functions.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250607102821.6c7effbf@gandalf.local.home


Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent de6fdc07

kernel/trace/trace_events_filter.c

+6 −4
Original line number Diff line number Diff line
@@ -1250,7 +1250,9 @@ static void append_filter_err(struct trace_array *tr, 


static inline struct event_filter *event_filter(struct trace_event_file *file)

{

	return file->filter;

	return rcu_dereference_protected(file->filter,

					 lockdep_is_held(&event_mutex));



}



/* caller must hold event_mutex */
@@ -1320,7 +1322,7 @@ void free_event_filter(struct event_filter *filter) 
static inline void __remove_filter(struct trace_event_file *file)

{

	filter_disable(file);

	remove_filter_string(file->filter);

	remove_filter_string(event_filter(file));

}



static void filter_free_subsystem_preds(struct trace_subsystem_dir *dir,
@@ -1405,7 +1407,7 @@ static void try_delay_free_filter(struct event_filter *filter) 


static inline void __free_subsystem_filter(struct trace_event_file *file)

{

	__free_filter(file->filter);

	__free_filter(event_filter(file));

	file->filter = NULL;

}
@@ -1465,7 +1467,7 @@ static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir, 
	list_for_each_entry(file, &tr->events, list) {

		if (file->system != dir || !file->filter)

			continue;

		__free_filter(file->filter);

		__free_subsystem_filter(file);

	}

	__free_filter(filter);

}