From ee41106a12c76f38d0cf82ef17809fa62757151d Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Fri, 28 Jul 2023 23:50:43 +0530 Subject: [PATCH] tracing: Require all trace events to have a TRACE_SYSTEM 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. Link: https://lkml.kernel.org/r/1690568452-46553-2-git-send-email-akaher@vmware.com Signed-off-by: Steven Rostedt (Google) Signed-off-by: Ajay Kaher Signed-off-by: Steven Rostedt (Google) --- 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 578f1f7d49a6..3ecc41f6acd9 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2420,14 +2420,15 @@ 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);