DEBUGFS
FS(debugfs, debugfs, DEBUGFS);
has_debugfs = faccessat(AT_FDCWD, DEBUGFS, F_OK, AT_EACCESS) == 0;
return use_debugfs() ? DEBUGFS : TRACEFS;
return use_debugfs() ? DEBUGFS"/kprobe_events" : TRACEFS"/kprobe_events";
return use_debugfs() ? DEBUGFS"/uprobe_events" : TRACEFS"/uprobe_events";
return use_debugfs() ? DEBUGFS"/available_filter_functions"
return use_debugfs() ? DEBUGFS"/available_filter_functions_addrs"
ret = snprintf(buf, PATH_MAX, READ_PATH_FMT, DEBUGFS, cpu_num);