From: "Steven Rostedt (Google)" rostedt@goodmis.org
The creation of the trace event directory requires that a TRACE_SYSTEM is defined that the trace event directory is added within the system it was defined in.
The code handled the case where a TRACE_SYSTEM was not added, and would then add the event at the events directory. But nothing should be doing this. This code also prevents the implementation of creating dynamic dentrys for the eventfs system.
As this path has never been hit on correct code, remove it. If it does get hit, issues a WARN_ON_ONCE() and return ENODEV.
Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Ajay Kaher akaher@vmware.com --- kernel/trace/trace_events.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 57e539d47989..12ed71428939 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2426,14 +2426,15 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file)
/* * If the trace point header did not define TRACE_SYSTEM - * then the system would be called "TRACE_SYSTEM". + * then the system would be called "TRACE_SYSTEM". This should + * never happen. */ - if (strcmp(call->class->system, TRACE_SYSTEM) != 0) { - d_events = event_subsystem_dir(tr, call->class->system, file, parent); - if (!d_events) - return -ENOMEM; - } else - d_events = parent; + if (WARN_ON_ONCE(strcmp(call->class->system, TRACE_SYSTEM) == 0)) + return -ENODEV; + + d_events = event_subsystem_dir(tr, call->class->system, file, parent); + if (!d_events) + return -ENOMEM;
name = trace_event_name(call); file->dir = tracefs_create_dir(name, d_events);