Linux kernel: tracing: Hold trace_types_lock when updating modules in persistent instances

In the Linux kernel, the following vulnerability has been resolved:

tracing: Hold trace_types_lock when updating modules in persistent instances

trace_module_record() walks ftrace_trace_arrays from the module notifier without trace_types_lock. A concurrent rmdir of an instance removes it from the list and frees it under that lock, so a module load or unload can walk into a freed trace_array.