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