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