Extern or forward variable declaration at kernel/trace/ftrace_internal.h, line 8 References: kernel/trace/fgraph.c, line 345 kernel/trace/fgraph.c, line 450 kernel/trace/fgraph.c, line 474 kernel/trace/ftrace.c, line 120 kernel/trace/ftrace.c, line 1041 kernel/trace/ftrace.c, line 1045 kernel/trace/ftrace.c, line 1826 kernel/trace/ftrace.c, line 1837 kernel/trace/ftrace.c, line 3634 kernel/trace/ftrace.c, line 3659 kernel/trace/ftrace.c, line 4006 kernel/trace/ftrace.c, line 4010 kernel/trace/ftrace.c, line 5325 kernel/trace/ftrace.c, line 5383 kernel/trace/ftrace.c, line 5399 kernel/trace/ftrace.c, line 5499 kernel/trace/ftrace.c, line 5501 kernel/trace/ftrace.c, line 6039 kernel/trace/ftrace.c, line 6747 kernel/trace/ftrace.c, line 6776