Extern or forward variable declaration at include/linux/ftrace.h, line 86 References: include/linux/ftrace.h, line 86 include/linux/ftrace.h, line 804 include/linux/ftrace.h, line 816 include/linux/ftrace.h, line 817 include/linux/ftrace.h, line 827 kernel/sysctl.c, line 2054 kernel/trace/ftrace.c, line 88 kernel/trace/ftrace.c, line 323 kernel/trace/ftrace.c, line 339 kernel/trace/ftrace.c, line 357 kernel/trace/ftrace.c, line 2851 kernel/trace/ftrace.c, line 2940 kernel/trace/ftrace.c, line 4068 kernel/trace/ftrace.c, line 4758 kernel/trace/ftrace.c, line 6871 kernel/trace/ftrace.c, line 6930 kernel/trace/ftrace.c, line 7523 kernel/trace/ftrace.c, line 7607 kernel/trace/ftrace.c, line 7610 kernel/trace/ftrace.c, line 7621 kernel/trace/ftrace.c, line 7632