include/linux/tracepoint.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 #ifndef _LINUX_TRACEPOINT_H
   3 #define _LINUX_TRACEPOINT_H
   4
   5 /*
   6  * Kernel Tracepoint API.
   7  *
   8  * See Documentation/trace/tracepoints.rst.
   9  *
  10  * Copyright (C) 2008-2014 Mathieu Desnoyers <[email protected]>
  11  *
  12  * Heavily inspired from the Linux Kernel Markers.
  13  */
  14
  15 #include <linux/smp.h>
  16 #include <linux/srcu.h>
  17 #include <linux/errno.h>
  18 #include <linux/types.h>
  19 #include <linux/rcupdate.h>
  20 #include <linux/tracepoint-defs.h>
  21 #include <linux/static_call.h>
  22
  23 struct module;
  24 struct tracepoint;
  25 struct notifier_block;
  26
  27 struct trace_eval_map {
  28         const char              *system;
  29         const char              *eval_string;
  30         unsigned long           eval_value;
  31 };
  32
  33 #define TRACEPOINT_DEFAULT_PRIO 10
  34
  35 extern struct srcu_struct tracepoint_srcu;
  36
  37 extern int
  38 tracepoint_probe_register(struct tracepoint *tp, void *probe, void *data);
  39 extern int
  40 tracepoint_probe_register_prio(struct tracepoint *tp, void *probe, void *data,
  41                                int prio);
  42 extern int
  43 tracepoint_probe_register_prio_may_exist(struct tracepoint *tp, void *probe, void *data,
  44                                          int prio);
  45 extern int
  46 tracepoint_probe_unregister(struct tracepoint *tp, void *probe, void *data);
  47 static inline int
  48 tracepoint_probe_register_may_exist(struct tracepoint *tp, void *probe,
  49                                     void *data)
  50 {
  51         return tracepoint_probe_register_prio_may_exist(tp, probe, data,
  52                                                         TRACEPOINT_DEFAULT_PRIO);
  53 }
  54 extern void
  55 for_each_kernel_tracepoint(void (*fct)(struct tracepoint *tp, void *priv),
  56                 void *priv);
  57
  58 #ifdef CONFIG_MODULES
  59 struct tp_module {
  60         struct list_head list;
  61         struct module *mod;
  62 };
  63
  64 bool trace_module_has_bad_taint(struct module *mod);
  65 extern int register_tracepoint_module_notifier(struct notifier_block *nb);
  66 extern int unregister_tracepoint_module_notifier(struct notifier_block *nb);
  67 #else
  68 static inline bool trace_module_has_bad_taint(struct module *mod)
  69 {
  70         return false;
  71 }
  72 static inline
  73 int register_tracepoint_module_notifier(struct notifier_block *nb)
  74 {
  75         return 0;
  76 }
  77 static inline
  78 int unregister_tracepoint_module_notifier(struct notifier_block *nb)
  79 {
  80         return 0;
  81 }
  82 #endif /* CONFIG_MODULES */
  83
  84 /*
  85  * tracepoint_synchronize_unregister must be called between the last tracepoint
  86  * probe unregistration and the end of module exit to make sure there is no
  87  * caller executing a probe when it is freed.
  88  */
  89 #ifdef CONFIG_TRACEPOINTS
  90 static inline void tracepoint_synchronize_unregister(void)
  91 {
  92         synchronize_srcu(&tracepoint_srcu);
  93         synchronize_rcu();
  94 }
  95 #else
  96 static inline void tracepoint_synchronize_unregister(void)
  97 { }
  98 #endif
  99
 100 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 101 extern int syscall_regfunc(void);
 102 extern void syscall_unregfunc(void);
 103 #endif /* CONFIG_HAVE_SYSCALL_TRACEPOINTS */
 104
 105 #ifndef PARAMS
 106 #define PARAMS(args...) args
 107 #endif
 108
 109 #define TRACE_DEFINE_ENUM(x)
 110 #define TRACE_DEFINE_SIZEOF(x)
 111
 112 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
 113 static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 114 {
 115         return offset_to_ptr(p);
 116 }
 117
 118 #define __TRACEPOINT_ENTRY(name)                                        \
 119         asm("   .section \"__tracepoints_ptrs\", \"a\"          \n"     \
 120             "   .balign 4                                       \n"     \
 121             "   .long   __tracepoint_" #name " - .              \n"     \
 122             "   .previous                                       \n")
 123 #else
 124 static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 125 {
 126         return *p;
 127 }
 128
 129 #define __TRACEPOINT_ENTRY(name)                                         \
 130         static tracepoint_ptr_t __tracepoint_ptr_##name __used           \
 131         __section("__tracepoints_ptrs") = &__tracepoint_##name
 132 #endif
 133
 134 #endif /* _LINUX_TRACEPOINT_H */
 135
 136 /*
 137  * Note: we keep the TRACE_EVENT and DECLARE_TRACE outside the include
 138  *  file ifdef protection.
 139  *  This is due to the way trace events work. If a file includes two
 140  *  trace event headers under one "CREATE_TRACE_POINTS" the first include
 141  *  will override the TRACE_EVENT and break the second include.
 142  */
 143
 144 #ifndef DECLARE_TRACE
 145
 146 #define TP_PROTO(args...)       args
 147 #define TP_ARGS(args...)        args
 148 #define TP_CONDITION(args...)   args
 149
 150 /*
 151  * Individual subsystem my have a separate configuration to
 152  * enable their tracepoints. By default, this file will create
 153  * the tracepoints if CONFIG_TRACEPOINTS is defined. If a subsystem
 154  * wants to be able to disable its tracepoints from being created
 155  * it can define NOTRACE before including the tracepoint headers.
 156  */
 157 #if defined(CONFIG_TRACEPOINTS) && !defined(NOTRACE)
 158 #define TRACEPOINTS_ENABLED
 159 #endif
 160
 161 #ifdef TRACEPOINTS_ENABLED
 162
 163 #ifdef CONFIG_HAVE_STATIC_CALL
 164 #define __DO_TRACE_CALL(name, args)                                     \
 165         do {                                                            \
 166                 struct tracepoint_func *it_func_ptr;                    \
 167                 void *__data;                                           \
 168                 it_func_ptr =                                           \
 169                         rcu_dereference_raw((&__tracepoint_##name)->funcs); \
 170                 if (it_func_ptr) {                                      \
 171                         __data = (it_func_ptr)->data;                   \
 172                         static_call(tp_func_##name)(__data, args);      \
 173                 }                                                       \
 174         } while (0)
 175 #else
 176 #define __DO_TRACE_CALL(name, args)     __traceiter_##name(NULL, args)
 177 #endif /* CONFIG_HAVE_STATIC_CALL */
 178
 179 /*
 180  * ARCH_WANTS_NO_INSTR archs are expected to have sanitized entry and idle
 181  * code that disallow any/all tracing/instrumentation when RCU isn't watching.
 182  */
 183 #ifdef CONFIG_ARCH_WANTS_NO_INSTR
 184 #define RCUIDLE_COND(rcuidle)   (rcuidle)
 185 #else
 186 /* srcu can't be used from NMI */
 187 #define RCUIDLE_COND(rcuidle)   (rcuidle && in_nmi())
 188 #endif
 189
 190 /*
 191  * it_func[0] is never NULL because there is at least one element in the array
 192  * when the array itself is non NULL.
 193  */
 194 #define __DO_TRACE(name, args, cond, rcuidle)                           \
 195         do {                                                            \
 196                 int __maybe_unused __idx = 0;                           \
 197                                                                         \
 198                 if (!(cond))                                            \
 199                         return;                                         \
 200                                                                         \
 201                 if (WARN_ONCE(RCUIDLE_COND(rcuidle),                    \
 202                               "Bad RCU usage for tracepoint"))          \
 203                         return;                                         \
 204                                                                         \
 205                 /* keep srcu and sched-rcu usage consistent */          \
 206                 preempt_disable_notrace();                              \
 207                                                                         \
 208                 /*                                                      \
 209                  * For rcuidle callers, use srcu since sched-rcu        \
 210                  * doesn't work from the idle path.                     \
 211                  */                                                     \
 212                 if (rcuidle) {                                          \
 213                         __idx = srcu_read_lock_notrace(&tracepoint_srcu);\
 214                         ct_irq_enter_irqson();                          \
 215                 }                                                       \
 216                                                                         \
 217                 __DO_TRACE_CALL(name, TP_ARGS(args));                   \
 218                                                                         \
 219                 if (rcuidle) {                                          \
 220                         ct_irq_exit_irqson();                           \
 221                         srcu_read_unlock_notrace(&tracepoint_srcu, __idx);\
 222                 }                                                       \
 223                                                                         \
 224                 preempt_enable_notrace();                               \
 225         } while (0)
 226
 227 #ifndef MODULE
 228 #define __DECLARE_TRACE_RCU(name, proto, args, cond)                    \
 229         static inline void trace_##name##_rcuidle(proto)                \
 230         {                                                               \
 231                 if (static_key_false(&__tracepoint_##name.key))         \
 232                         __DO_TRACE(name,                                \
 233                                 TP_ARGS(args),                          \
 234                                 TP_CONDITION(cond), 1);                 \
 235         }
 236 #else
 237 #define __DECLARE_TRACE_RCU(name, proto, args, cond)
 238 #endif
 239
 240 /*
 241  * Make sure the alignment of the structure in the __tracepoints section will
 242  * not add unwanted padding between the beginning of the section and the
 243  * structure. Force alignment to the same alignment as the section start.
 244  *
 245  * When lockdep is enabled, we make sure to always test if RCU is
 246  * "watching" regardless if the tracepoint is enabled or not. Tracepoints
 247  * require RCU to be active, and it should always warn at the tracepoint
 248  * site if it is not watching, as it will need to be active when the
 249  * tracepoint is enabled.
 250  */
 251 #define __DECLARE_TRACE(name, proto, args, cond, data_proto)            \
 252         extern int __traceiter_##name(data_proto);                      \
 253         DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name);        \
 254         extern struct tracepoint __tracepoint_##name;                   \
 255         static inline void trace_##name(proto)                          \
 256         {                                                               \
 257                 if (static_key_false(&__tracepoint_##name.key))         \
 258                         __DO_TRACE(name,                                \
 259                                 TP_ARGS(args),                          \
 260                                 TP_CONDITION(cond), 0);                 \
 261                 if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) {             \
 262                         WARN_ONCE(!rcu_is_watching(),                   \
 263                                   "RCU not watching for tracepoint");   \
 264                 }                                                       \
 265         }                                                               \
 266         __DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args),          \
 267                             PARAMS(cond))                               \
 268         static inline int                                               \
 269         register_trace_##name(void (*probe)(data_proto), void *data)    \
 270         {                                                               \
 271                 return tracepoint_probe_register(&__tracepoint_##name,  \
 272                                                 (void *)probe, data);   \
 273         }                                                               \
 274         static inline int                                               \
 275         register_trace_prio_##name(void (*probe)(data_proto), void *data,\
 276                                    int prio)                            \
 277         {                                                               \
 278                 return tracepoint_probe_register_prio(&__tracepoint_##name, \
 279                                               (void *)probe, data, prio); \
 280         }                                                               \
 281         static inline int                                               \
 282         unregister_trace_##name(void (*probe)(data_proto), void *data)  \
 283         {                                                               \
 284                 return tracepoint_probe_unregister(&__tracepoint_##name,\
 285                                                 (void *)probe, data);   \
 286         }                                                               \
 287         static inline void                                              \
 288         check_trace_callback_type_##name(void (*cb)(data_proto))        \
 289         {                                                               \
 290         }                                                               \
 291         static inline bool                                              \
 292         trace_##name##_enabled(void)                                    \
 293         {                                                               \
 294                 return static_key_false(&__tracepoint_##name.key);      \
 295         }
 296
 297 /*
 298  * We have no guarantee that gcc and the linker won't up-align the tracepoint
 299  * structures, so we create an array of pointers that will be used for iteration
 300  * on the tracepoints.
 301  */
 302 #define DEFINE_TRACE_FN(_name, _reg, _unreg, proto, args)               \
 303         static const char __tpstrtab_##_name[]                          \
 304         __section("__tracepoints_strings") = #_name;                    \
 305         extern struct static_call_key STATIC_CALL_KEY(tp_func_##_name); \
 306         int __traceiter_##_name(void *__data, proto);                   \
 307         void __probestub_##_name(void *__data, proto);                  \
 308         struct tracepoint __tracepoint_##_name  __used                  \
 309         __section("__tracepoints") = {                                  \
 310                 .name = __tpstrtab_##_name,                             \
 311                 .key = STATIC_KEY_INIT_FALSE,                           \
 312                 .static_call_key = &STATIC_CALL_KEY(tp_func_##_name),   \
 313                 .static_call_tramp = STATIC_CALL_TRAMP_ADDR(tp_func_##_name), \
 314                 .iterator = &__traceiter_##_name,                       \
 315                 .probestub = &__probestub_##_name,                      \
 316                 .regfunc = _reg,                                        \
 317                 .unregfunc = _unreg,                                    \
 318                 .funcs = NULL };                                        \
 319         __TRACEPOINT_ENTRY(_name);                                      \
 320         int __traceiter_##_name(void *__data, proto)                    \
 321         {                                                               \
 322                 struct tracepoint_func *it_func_ptr;                    \
 323                 void *it_func;                                          \
 324                                                                         \
 325                 it_func_ptr =                                           \
 326                         rcu_dereference_raw((&__tracepoint_##_name)->funcs); \
 327                 if (it_func_ptr) {                                      \
 328                         do {                                            \
 329                                 it_func = READ_ONCE((it_func_ptr)->func); \
 330                                 __data = (it_func_ptr)->data;           \
 331                                 ((void(*)(void *, proto))(it_func))(__data, args); \
 332                         } while ((++it_func_ptr)->func);                \
 333                 }                                                       \
 334                 return 0;                                               \
 335         }                                                               \
 336         void __probestub_##_name(void *__data, proto)                   \
 337         {                                                               \
 338         }                                                               \
 339         DEFINE_STATIC_CALL(tp_func_##_name, __traceiter_##_name);
 340
 341 #define DEFINE_TRACE(name, proto, args)         \
 342         DEFINE_TRACE_FN(name, NULL, NULL, PARAMS(proto), PARAMS(args));
 343
 344 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)                              \
 345         EXPORT_SYMBOL_GPL(__tracepoint_##name);                         \
 346         EXPORT_SYMBOL_GPL(__traceiter_##name);                          \
 347         EXPORT_STATIC_CALL_GPL(tp_func_##name)
 348 #define EXPORT_TRACEPOINT_SYMBOL(name)                                  \
 349         EXPORT_SYMBOL(__tracepoint_##name);                             \
 350         EXPORT_SYMBOL(__traceiter_##name);                              \
 351         EXPORT_STATIC_CALL(tp_func_##name)
 352
 353
 354 #else /* !TRACEPOINTS_ENABLED */
 355 #define __DECLARE_TRACE(name, proto, args, cond, data_proto)            \
 356         static inline void trace_##name(proto)                          \
 357         { }                                                             \
 358         static inline void trace_##name##_rcuidle(proto)                \
 359         { }                                                             \
 360         static inline int                                               \
 361         register_trace_##name(void (*probe)(data_proto),                \
 362                               void *data)                               \
 363         {                                                               \
 364                 return -ENOSYS;                                         \
 365         }                                                               \
 366         static inline int                                               \
 367         unregister_trace_##name(void (*probe)(data_proto),              \
 368                                 void *data)                             \
 369         {                                                               \
 370                 return -ENOSYS;                                         \
 371         }                                                               \
 372         static inline void check_trace_callback_type_##name(void (*cb)(data_proto)) \
 373         {                                                               \
 374         }                                                               \
 375         static inline bool                                              \
 376         trace_##name##_enabled(void)                                    \
 377         {                                                               \
 378                 return false;                                           \
 379         }
 380
 381 #define DEFINE_TRACE_FN(name, reg, unreg, proto, args)
 382 #define DEFINE_TRACE(name, proto, args)
 383 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
 384 #define EXPORT_TRACEPOINT_SYMBOL(name)
 385
 386 #endif /* TRACEPOINTS_ENABLED */
 387
 388 #ifdef CONFIG_TRACING
 389 /**
 390  * tracepoint_string - register constant persistent string to trace system
 391  * @str - a constant persistent string that will be referenced in tracepoints
 392  *
 393  * If constant strings are being used in tracepoints, it is faster and
 394  * more efficient to just save the pointer to the string and reference
 395  * that with a printf "%s" instead of saving the string in the ring buffer
 396  * and wasting space and time.
 397  *
 398  * The problem with the above approach is that userspace tools that read
 399  * the binary output of the trace buffers do not have access to the string.
 400  * Instead they just show the address of the string which is not very
 401  * useful to users.
 402  *
 403  * With tracepoint_string(), the string will be registered to the tracing
 404  * system and exported to userspace via the debugfs/tracing/printk_formats
 405  * file that maps the string address to the string text. This way userspace
 406  * tools that read the binary buffers have a way to map the pointers to
 407  * the ASCII strings they represent.
 408  *
 409  * The @str used must be a constant string and persistent as it would not
 410  * make sense to show a string that no longer exists. But it is still fine
 411  * to be used with modules, because when modules are unloaded, if they
 412  * had tracepoints, the ring buffers are cleared too. As long as the string
 413  * does not change during the life of the module, it is fine to use
 414  * tracepoint_string() within a module.
 415  */
 416 #define tracepoint_string(str)                                          \
 417         ({                                                              \
 418                 static const char *___tp_str __tracepoint_string = str; \
 419                 ___tp_str;                                              \
 420         })
 421 #define __tracepoint_string     __used __section("__tracepoint_str")
 422 #else
 423 /*
 424  * tracepoint_string() is used to save the string address for userspace
 425  * tracing tools. When tracing isn't configured, there's no need to save
 426  * anything.
 427  */
 428 # define tracepoint_string(str) str
 429 # define __tracepoint_string
 430 #endif
 431
 432 #define DECLARE_TRACE(name, proto, args)                                \
 433         __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),              \
 434                         cpu_online(raw_smp_processor_id()),             \
 435                         PARAMS(void *__data, proto))
 436
 437 #define DECLARE_TRACE_CONDITION(name, proto, args, cond)                \
 438         __DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),              \
 439                         cpu_online(raw_smp_processor_id()) && (PARAMS(cond)), \
 440                         PARAMS(void *__data, proto))
 441
 442 #define TRACE_EVENT_FLAGS(event, flag)
 443
 444 #define TRACE_EVENT_PERF_PERM(event, expr...)
 445
 446 #endif /* DECLARE_TRACE */
 447
 448 #ifndef TRACE_EVENT
 449 /*
 450  * For use with the TRACE_EVENT macro:
 451  *
 452  * We define a tracepoint, its arguments, its printk format
 453  * and its 'fast binary record' layout.
 454  *
 455  * Firstly, name your tracepoint via TRACE_EVENT(name : the
 456  * 'subsystem_event' notation is fine.
 457  *
 458  * Think about this whole construct as the
 459  * 'trace_sched_switch() function' from now on.
 460  *
 461  *
 462  *  TRACE_EVENT(sched_switch,
 463  *
 464  *      *
 465  *      * A function has a regular function arguments
 466  *      * prototype, declare it via TP_PROTO():
 467  *      *
 468  *
 469  *      TP_PROTO(struct rq *rq, struct task_struct *prev,
 470  *               struct task_struct *next),
 471  *
 472  *      *
 473  *      * Define the call signature of the 'function'.
 474  *      * (Design sidenote: we use this instead of a
 475  *      *  TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
 476  *      *
 477  *
 478  *      TP_ARGS(rq, prev, next),
 479  *
 480  *      *
 481  *      * Fast binary tracing: define the trace record via
 482  *      * TP_STRUCT__entry(). You can think about it like a
 483  *      * regular C structure local variable definition.
 484  *      *
 485  *      * This is how the trace record is structured and will
 486  *      * be saved into the ring buffer. These are the fields
 487  *      * that will be exposed to user-space in
 488  *      * /sys/kernel/tracing/events/<*>/format.
 489  *      *
 490  *      * The declared 'local variable' is called '__entry'
 491  *      *
 492  *      * __field(pid_t, prev_pid) is equivalent to a standard declaration:
 493  *      *
 494  *      *       pid_t   prev_pid;
 495  *      *
 496  *      * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to:
 497  *      *
 498  *      *       char    prev_comm[TASK_COMM_LEN];
 499  *      *
 500  *
 501  *      TP_STRUCT__entry(
 502  *              __array(        char,   prev_comm,      TASK_COMM_LEN   )
 503  *              __field(        pid_t,  prev_pid                        )
 504  *              __field(        int,    prev_prio                       )
 505  *              __array(        char,   next_comm,      TASK_COMM_LEN   )
 506  *              __field(        pid_t,  next_pid                        )
 507  *              __field(        int,    next_prio                       )
 508  *      ),
 509  *
 510  *      *
 511  *      * Assign the entry into the trace record, by embedding
 512  *      * a full C statement block into TP_fast_assign(). You
 513  *      * can refer to the trace record as '__entry' -
 514  *      * otherwise you can put arbitrary C code in here.
 515  *      *
 516  *      * Note: this C code will execute every time a trace event
 517  *      * happens, on an active tracepoint.
 518  *      *
 519  *
 520  *      TP_fast_assign(
 521  *              memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN);
 522  *              __entry->prev_pid       = prev->pid;
 523  *              __entry->prev_prio      = prev->prio;
 524  *              memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN);
 525  *              __entry->next_pid       = next->pid;
 526  *              __entry->next_prio      = next->prio;
 527  *      ),
 528  *
 529  *      *
 530  *      * Formatted output of a trace record via TP_printk().
 531  *      * This is how the tracepoint will appear under ftrace
 532  *      * plugins that make use of this tracepoint.
 533  *      *
 534  *      * (raw-binary tracing wont actually perform this step.)
 535  *      *
 536  *
 537  *      TP_printk("task %s:%d [%d] ==> %s:%d [%d]",
 538  *              __entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
 539  *              __entry->next_comm, __entry->next_pid, __entry->next_prio),
 540  *
 541  * );
 542  *
 543  * This macro construct is thus used for the regular printk format
 544  * tracing setup, it is used to construct a function pointer based
 545  * tracepoint callback (this is used by programmatic plugins and
 546  * can also by used by generic instrumentation like SystemTap), and
 547  * it is also used to expose a structured trace record in
 548  * /sys/kernel/tracing/events/.
 549  *
 550  * A set of (un)registration functions can be passed to the variant
 551  * TRACE_EVENT_FN to perform any (un)registration work.
 552  */
 553
 554 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
 555 #define DEFINE_EVENT(template, name, proto, args)               \
 556         DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 557 #define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\
 558         DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 559 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
 560         DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 561 #define DEFINE_EVENT_CONDITION(template, name, proto,           \
 562                                args, cond)                      \
 563         DECLARE_TRACE_CONDITION(name, PARAMS(proto),            \
 564                                 PARAMS(args), PARAMS(cond))
 565
 566 #define TRACE_EVENT(name, proto, args, struct, assign, print)   \
 567         DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 568 #define TRACE_EVENT_FN(name, proto, args, struct,               \
 569                 assign, print, reg, unreg)                      \
 570         DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 571 #define TRACE_EVENT_FN_COND(name, proto, args, cond, struct,            \
 572                 assign, print, reg, unreg)                      \
 573         DECLARE_TRACE_CONDITION(name, PARAMS(proto),    \
 574                         PARAMS(args), PARAMS(cond))
 575 #define TRACE_EVENT_CONDITION(name, proto, args, cond,          \
 576                               struct, assign, print)            \
 577         DECLARE_TRACE_CONDITION(name, PARAMS(proto),            \
 578                                 PARAMS(args), PARAMS(cond))
 579
 580 #define TRACE_EVENT_FLAGS(event, flag)
 581
 582 #define TRACE_EVENT_PERF_PERM(event, expr...)
 583
 584 #define DECLARE_EVENT_NOP(name, proto, args)                            \
 585         static inline void trace_##name(proto)                          \
 586         { }                                                             \
 587         static inline bool trace_##name##_enabled(void)                 \
 588         {                                                               \
 589                 return false;                                           \
 590         }
 591
 592 #define TRACE_EVENT_NOP(name, proto, args, struct, assign, print)       \
 593         DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
 594
 595 #define DECLARE_EVENT_CLASS_NOP(name, proto, args, tstruct, assign, print)
 596 #define DEFINE_EVENT_NOP(template, name, proto, args)                   \
 597         DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args))
 598
 599 #endif /* ifdef TRACE_EVENT (see note above) */