1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * If TRACE_SYSTEM is defined, that will be the directory created
4 * in the ftrace directory under /sys/kernel/tracing/events/<system>
5 *
6 * The define_trace.h below will also look for a file name of
7 * TRACE_SYSTEM.h where TRACE_SYSTEM is what is defined here.
8 * In this case, it would look for sample-trace.h
9 *
10 * If the header name will be different than the system name
11 * (as in this case), then you can override the header name that
12 * define_trace.h will look up by defining TRACE_INCLUDE_FILE
13 *
14 * This file is called trace-events-sample.h but we want the system
15 * to be called "sample-trace". Therefore we must define the name of this
16 * file:
17 *
18 * #define TRACE_INCLUDE_FILE trace-events-sample
19 *
20 * As we do an the bottom of this file.
21 *
22 * Notice that TRACE_SYSTEM should be defined outside of #if
23 * protection, just like TRACE_INCLUDE_FILE.
24 */
25 #undef TRACE_SYSTEM
26 #define TRACE_SYSTEM sample-trace
27
28 /*
29 * TRACE_SYSTEM is expected to be a C valid variable (alpha-numeric
30 * and underscore), although it may start with numbers. If for some
31 * reason it is not, you need to add the following lines:
32 */
33 #undef TRACE_SYSTEM_VAR
34 #define TRACE_SYSTEM_VAR sample_trace
35 /*
36 * But the above is only needed if TRACE_SYSTEM is not alpha-numeric
37 * and underscored. By default, TRACE_SYSTEM_VAR will be equal to
38 * TRACE_SYSTEM. As TRACE_SYSTEM_VAR must be alpha-numeric, if
39 * TRACE_SYSTEM is not, then TRACE_SYSTEM_VAR must be defined with
40 * only alpha-numeric and underscores.
41 *
42 * The TRACE_SYSTEM_VAR is only used internally and not visible to
43 * user space.
44 */
45
46 /*
47 * Notice that this file is not protected like a normal header.
48 * We also must allow for rereading of this file. The
49 *
50 * || defined(TRACE_HEADER_MULTI_READ)
51 *
52 * serves this purpose.
53 */
54 #if !defined(_TRACE_EVENT_SAMPLE_H) || defined(TRACE_HEADER_MULTI_READ)
55 #define _TRACE_EVENT_SAMPLE_H
56
57 /*
58 * All trace headers should include tracepoint.h, until we finally
59 * make it into a standard header.
60 */
61 #include <linux/tracepoint.h>
62
63 /*
64 * The TRACE_EVENT macro is broken up into 5 parts.
65 *
66 * name: name of the trace point. This is also how to enable the tracepoint.
67 * A function called trace_foo_bar() will be created.
68 *
69 * proto: the prototype of the function trace_foo_bar()
70 * Here it is trace_foo_bar(char *foo, int bar).
71 *
72 * args: must match the arguments in the prototype.
73 * Here it is simply "foo, bar".
74 *
75 * struct: This defines the way the data will be stored in the ring buffer.
76 * The items declared here become part of a special structure
77 * called "__entry", which can be used in the fast_assign part of the
78 * TRACE_EVENT macro.
79 *
80 * Here are the currently defined types you can use:
81 *
82 * __field : Is broken up into type and name. Where type can be any
83 * primitive type (integer, long or pointer).
84 *
85 * __field(int, foo)
86 *
87 * __entry->foo = 5;
88 *
89 * __field_struct : This can be any static complex data type (struct, union
90 * but not an array). Be careful using complex types, as each
91 * event is limited in size, and copying large amounts of data
92 * into the ring buffer can slow things down.
93 *
94 * __field_struct(struct bar, foo)
95 *
96 * __entry->bar.x = y;
97
98 * __array: There are three fields (type, name, size). The type is the
99 * type of elements in the array, the name is the name of the array.
100 * size is the number of items in the array (not the total size).
101 *
102 * __array( char, foo, 10) is the same as saying: char foo[10];
103 *
104 * Assigning arrays can be done like any array:
105 *
106 * __entry->foo[0] = 'a';
107 *
108 * memcpy(__entry->foo, bar, 10);
109 *
110 * __dynamic_array: This is similar to array, but can vary its size from
111 * instance to instance of the tracepoint being called.
112 * Like __array, this too has three elements (type, name, size);
113 * type is the type of the element, name is the name of the array.
114 * The size is different than __array. It is not a static number,
115 * but the algorithm to figure out the length of the array for the
116 * specific instance of tracepoint. Again, size is the number of
117 * items in the array, not the total length in bytes.
118 *
119 * __dynamic_array( int, foo, bar) is similar to: int foo[bar];
120 *
121 * Note, unlike arrays, you must use the __get_dynamic_array() macro
122 * to access the array.
123 *
124 * memcpy(__get_dynamic_array(foo), bar, 10);
125 *
126 * Notice, that "__entry" is not needed here.
127 *
128 * __string: This is a special kind of __dynamic_array. It expects to
129 * have a null terminated character array passed to it (it allows
130 * for NULL too, which would be converted into "(null)"). __string
131 * takes two parameter (name, src), where name is the name of
132 * the string saved, and src is the string to copy into the
133 * ring buffer.
134 *
135 * __string(foo, bar) is similar to: strcpy(foo, bar)
136 *
137 * To assign a string, use the helper macro __assign_str().
138 *
139 * __assign_str(foo);
140 *
141 * The __string() macro saves off the string that is passed into
142 * the second parameter, and the __assign_str() will store than
143 * saved string into the "foo" field.
144 *
145 * __vstring: This is similar to __string() but instead of taking a
146 * dynamic length, it takes a variable list va_list 'va' variable.
147 * Some event callers already have a message from parameters saved
148 * in a va_list. Passing in the format and the va_list variable
149 * will save just enough on the ring buffer for that string.
150 * Note, the va variable used is a pointer to a va_list, not
151 * to the va_list directly.
152 *
153 * (va_list *va)
154 *
155 * __vstring(foo, fmt, va) is similar to: vsnprintf(foo, fmt, va)
156 *
157 * To assign the string, use the helper macro __assign_vstr().
158 *
159 * __assign_vstr(foo, fmt, va);
160 *
161 * In most cases, the __assign_vstr() macro will take the same
162 * parameters as the __vstring() macro had to declare the string.
163 * Use __get_str() to retrieve the __vstring() just like it would for
164 * __string().
165 *
166 * __string_len: This is a helper to a __dynamic_array, but it understands
167 * that the array has characters in it, it will allocate 'len' + 1 bytes
168 * in the ring buffer and add a '\0' to the string. This is
169 * useful if the string being saved has no terminating '\0' byte.
170 * It requires that the length of the string is known as it acts
171 * like a memcpy().
172 *
173 * Declared with:
174 *
175 * __string_len(foo, bar, len)
176 *
177 * To assign this string, use the helper macro __assign_str().
178 * The length is saved via the __string_len() and is retrieved in
179 * __assign_str().
180 *
181 * __assign_str(foo);
182 *
183 * Then len + 1 is allocated to the ring buffer, and a nul terminating
184 * byte is added. This is similar to:
185 *
186 * memcpy(__get_str(foo), bar, len);
187 * __get_str(foo)[len] = 0;
188 *
189 * The advantage of using this over __dynamic_array, is that it
190 * takes care of allocating the extra byte on the ring buffer
191 * for the '\0' terminating byte, and __get_str(foo) can be used
192 * in the TP_printk().
193 *
194 * __bitmask: This is another kind of __dynamic_array, but it expects
195 * an array of longs, and the number of bits to parse. It takes
196 * two parameters (name, nr_bits), where name is the name of the
197 * bitmask to save, and the nr_bits is the number of bits to record.
198 *
199 * __bitmask(target_cpu, nr_cpumask_bits)
200 *
201 * To assign a bitmask, use the __assign_bitmask() helper macro.
202 *
203 * __assign_bitmask(target_cpus, cpumask_bits(bar), nr_cpumask_bits);
204 *
205 * __cpumask: This is pretty much the same as __bitmask but is specific for
206 * CPU masks. The type displayed to the user via the format files will
207 * be "cpumaks_t" such that user space may deal with them differently
208 * if they choose to do so, and the bits is always set to nr_cpumask_bits.
209 *
210 * __cpumask(target_cpu)
211 *
212 * To assign a cpumask, use the __assign_cpumask() helper macro.
213 *
214 * __assign_cpumask(target_cpus, cpumask_bits(bar));
215 *
216 * fast_assign: This is a C like function that is used to store the items
217 * into the ring buffer. A special variable called "__entry" will be the
218 * structure that points into the ring buffer and has the same fields as
219 * described by the struct part of TRACE_EVENT above.
220 *
221 * printk: This is a way to print out the data in pretty print. This is
222 * useful if the system crashes and you are logging via a serial line,
223 * the data can be printed to the console using this "printk" method.
224 * This is also used to print out the data from the trace files.
225 * Again, the __entry macro is used to access the data from the ring buffer.
226 *
227 * Note, __dynamic_array, __string, __bitmask and __cpumask require special
228 * helpers to access the data.
229 *
230 * For __dynamic_array(int, foo, bar) use __get_dynamic_array(foo)
231 * Use __get_dynamic_array_len(foo) to get the length of the array
232 * saved. Note, __get_dynamic_array_len() returns the total allocated
233 * length of the dynamic array; __print_array() expects the second
234 * parameter to be the number of elements. To get that, the array length
235 * needs to be divided by the element size.
236 *
237 * For __string(foo, bar) use __get_str(foo)
238 *
239 * For __bitmask(target_cpus, nr_cpumask_bits) use __get_bitmask(target_cpus)
240 *
241 * For __cpumask(target_cpus) use __get_cpumask(target_cpus)
242 *
243 *
244 * Note, that for both the assign and the printk, __entry is the handler
245 * to the data structure in the ring buffer, and is defined by the
246 * TP_STRUCT__entry.
247 */
248
249 /*
250 * It is OK to have helper functions and data structures in the file, but they
251 * need to be protected from being defined more than once. Remember, this file
252 * gets included more than once.
253 */
254 #ifndef __TRACE_EVENT_SAMPLE_HELPER_FUNCTIONS
255 #define __TRACE_EVENT_SAMPLE_HELPER_FUNCTIONS
256 #include <linux/timer.h>
257
__length_of(const int * list)258 static inline int __length_of(const int *list)
259 {
260 int i;
261
262 if (!list)
263 return 0;
264
265 for (i = 0; list[i]; i++)
266 ;
267 return i;
268 }
269
270 enum {
271 TRACE_SAMPLE_FOO = 2,
272 TRACE_SAMPLE_BAR = 4,
273 TRACE_SAMPLE_ZOO = 8,
274 };
275
276 struct foo_timer_data {
277 const char *name;
278 struct timer_list timer;
279 int __percpu *counter;
280 };
281
282 #endif
283
284 /*
285 * If enums are used in the TP_printk(), their names will be shown in
286 * format files and not their values. This can cause problems with user
287 * space programs that parse the format files to know how to translate
288 * the raw binary trace output into human readable text.
289 *
290 * To help out user space programs, any enum that is used in the TP_printk()
291 * should be defined by TRACE_DEFINE_ENUM() macro. All that is needed to
292 * be done is to add this macro with the enum within it in the trace
293 * header file, and it will be converted in the output.
294 */
295
296 TRACE_DEFINE_ENUM(TRACE_SAMPLE_FOO);
297 TRACE_DEFINE_ENUM(TRACE_SAMPLE_BAR);
298 TRACE_DEFINE_ENUM(TRACE_SAMPLE_ZOO);
299
300 TRACE_EVENT(foo_bar,
301
302 TP_PROTO(const char *foo, int bar, const int *lst,
303 const char *string, const struct cpumask *mask,
304 const char *fmt, va_list *va),
305
306 TP_ARGS(foo, bar, lst, string, mask, fmt, va),
307
308 TP_STRUCT__entry(
309 __array( char, foo, 10 )
310 __field( int, bar )
311 __dynamic_array(int, list, __length_of(lst))
312 __string( str, string )
313 __bitmask( cpus, num_possible_cpus() )
314 __cpumask( cpum )
315 __vstring( vstr, fmt, va )
316 __string_len( lstr, foo, bar / 2 < strlen(foo) ? bar / 2 : strlen(foo) )
317 ),
318
319 TP_fast_assign(
320 strscpy(__entry->foo, foo, 10);
321 __entry->bar = bar;
322 memcpy(__get_dynamic_array(list), lst,
323 __length_of(lst) * sizeof(int));
324 __assign_str(str);
325 __assign_str(lstr);
326 __assign_vstr(vstr, fmt, va);
327 __assign_bitmask(cpus, cpumask_bits(mask), num_possible_cpus());
328 __assign_cpumask(cpum, cpumask_bits(mask));
329 ),
330
331 TP_printk("foo %s %d %s %s %s %s %s %s (%s) (%s) %s [%d] %*pbl",
332 __entry->foo, __entry->bar,
333
334 /*
335 * Notice here the use of some helper functions. This includes:
336 *
337 * __print_symbolic( variable, { value, "string" }, ... ),
338 *
339 * The variable is tested against each value of the { } pair. If
340 * the variable matches one of the values, then it will print the
341 * string in that pair. If non are matched, it returns a string
342 * version of the number (if __entry->bar == 7 then "7" is returned).
343 */
344 __print_symbolic(__entry->bar,
345 { 0, "zero" },
346 { TRACE_SAMPLE_FOO, "TWO" },
347 { TRACE_SAMPLE_BAR, "FOUR" },
348 { TRACE_SAMPLE_ZOO, "EIGHT" },
349 { 10, "TEN" }
350 ),
351
352 /*
353 * __print_flags( variable, "delim", { value, "flag" }, ... ),
354 *
355 * This is similar to __print_symbolic, except that it tests the bits
356 * of the value. If ((FLAG & variable) == FLAG) then the string is
357 * printed. If more than one flag matches, then each one that does is
358 * also printed with delim in between them.
359 * If not all bits are accounted for, then the not found bits will be
360 * added in hex format: 0x506 will show BIT2|BIT4|0x500
361 */
362 __print_flags(__entry->bar, "|",
363 { 1, "BIT1" },
364 { 2, "BIT2" },
365 { 4, "BIT3" },
366 { 8, "BIT4" }
367 ),
368 /*
369 * __print_array( array, len, element_size )
370 *
371 * This prints out the array that is defined by __array in a nice format.
372 */
373 __print_array(__get_dynamic_array(list),
374 __get_dynamic_array_len(list) / sizeof(int),
375 sizeof(int)),
376
377 /* A shortcut is to use __print_dynamic_array for dynamic arrays */
378
379 __print_dynamic_array(list, sizeof(int)),
380
381 __get_str(str), __get_str(lstr),
382 __get_bitmask(cpus), __get_cpumask(cpum),
383 __get_str(vstr),
384 __get_dynamic_array_len(cpus),
385 __get_dynamic_array_len(cpus),
386 __get_dynamic_array(cpus))
387 );
388
389 /*
390 * There may be a case where a tracepoint should only be called if
391 * some condition is set. Otherwise the tracepoint should not be called.
392 * But to do something like:
393 *
394 * if (cond)
395 * trace_foo();
396 *
397 * Would cause a little overhead when tracing is not enabled, and that
398 * overhead, even if small, is not something we want. As tracepoints
399 * use static branch (aka jump_labels), where no branch is taken to
400 * skip the tracepoint when not enabled, and a jmp is placed to jump
401 * to the tracepoint code when it is enabled, having a if statement
402 * nullifies that optimization. It would be nice to place that
403 * condition within the static branch. This is where TRACE_EVENT_CONDITION
404 * comes in.
405 *
406 * TRACE_EVENT_CONDITION() is just like TRACE_EVENT, except it adds another
407 * parameter just after args. Where TRACE_EVENT has:
408 *
409 * TRACE_EVENT(name, proto, args, struct, assign, printk)
410 *
411 * the CONDITION version has:
412 *
413 * TRACE_EVENT_CONDITION(name, proto, args, cond, struct, assign, printk)
414 *
415 * Everything is the same as TRACE_EVENT except for the new cond. Think
416 * of the cond variable as:
417 *
418 * if (cond)
419 * trace_foo_bar_with_cond();
420 *
421 * Except that the logic for the if branch is placed after the static branch.
422 * That is, the if statement that processes the condition will not be
423 * executed unless that traecpoint is enabled. Otherwise it still remains
424 * a nop.
425 */
426 TRACE_EVENT_CONDITION(foo_bar_with_cond,
427
428 TP_PROTO(const char *foo, int bar),
429
430 TP_ARGS(foo, bar),
431
432 TP_CONDITION(!(bar % 10)),
433
434 TP_STRUCT__entry(
435 __string( foo, foo )
436 __field( int, bar )
437 ),
438
439 TP_fast_assign(
440 __assign_str(foo);
441 __entry->bar = bar;
442 ),
443
444 TP_printk("foo %s %d", __get_str(foo), __entry->bar)
445 );
446
447 int foo_bar_reg(void);
448 void foo_bar_unreg(void);
449
450 /*
451 * Now in the case that some function needs to be called when the
452 * tracepoint is enabled and/or when it is disabled, the
453 * TRACE_EVENT_FN() serves this purpose. This is just like TRACE_EVENT()
454 * but adds two more parameters at the end:
455 *
456 * TRACE_EVENT_FN( name, proto, args, struct, assign, printk, reg, unreg)
457 *
458 * reg and unreg are functions with the prototype of:
459 *
460 * void reg(void)
461 *
462 * The reg function gets called before the tracepoint is enabled, and
463 * the unreg function gets called after the tracepoint is disabled.
464 *
465 * Note, reg and unreg are allowed to be NULL. If you only need to
466 * call a function before enabling, or after disabling, just set one
467 * function and pass in NULL for the other parameter.
468 */
469 TRACE_EVENT_FN(foo_bar_with_fn,
470
471 TP_PROTO(const char *foo, int bar),
472
473 TP_ARGS(foo, bar),
474
475 TP_STRUCT__entry(
476 __string( foo, foo )
477 __field( int, bar )
478 ),
479
480 TP_fast_assign(
481 __assign_str(foo);
482 __entry->bar = bar;
483 ),
484
485 TP_printk("foo %s %d", __get_str(foo), __entry->bar),
486
487 foo_bar_reg, foo_bar_unreg
488 );
489
490 /*
491 * Each TRACE_EVENT macro creates several helper functions to produce
492 * the code to add the tracepoint, create the files in the trace
493 * directory, hook it to perf, assign the values and to print out
494 * the raw data from the ring buffer. To prevent too much bloat,
495 * if there are more than one tracepoint that uses the same format
496 * for the proto, args, struct, assign and printk, and only the name
497 * is different, it is highly recommended to use the DECLARE_EVENT_CLASS
498 *
499 * DECLARE_EVENT_CLASS() macro creates most of the functions for the
500 * tracepoint. Then DEFINE_EVENT() is use to hook a tracepoint to those
501 * functions. This DEFINE_EVENT() is an instance of the class and can
502 * be enabled and disabled separately from other events (either TRACE_EVENT
503 * or other DEFINE_EVENT()s).
504 *
505 * Note, TRACE_EVENT() itself is simply defined as:
506 *
507 * #define TRACE_EVENT(name, proto, args, tstruct, assign, printk) \
508 * DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, printk); \
509 * DEFINE_EVENT(name, name, proto, args)
510 *
511 * The DEFINE_EVENT() also can be declared with conditions and reg functions:
512 *
513 * DEFINE_EVENT_CONDITION(template, name, proto, args, cond);
514 * DEFINE_EVENT_FN(template, name, proto, args, reg, unreg);
515 */
516 DECLARE_EVENT_CLASS(foo_template,
517
518 TP_PROTO(const char *foo, int bar),
519
520 TP_ARGS(foo, bar),
521
522 TP_STRUCT__entry(
523 __string( foo, foo )
524 __field( int, bar )
525 ),
526
527 TP_fast_assign(
528 __assign_str(foo);
529 __entry->bar = bar;
530 ),
531
532 TP_printk("foo %s %d", __get_str(foo), __entry->bar)
533 );
534
535 /*
536 * Here's a better way for the previous samples (except, the first
537 * example had more fields and could not be used here).
538 */
539 DEFINE_EVENT(foo_template, foo_with_template_simple,
540 TP_PROTO(const char *foo, int bar),
541 TP_ARGS(foo, bar));
542
543 DEFINE_EVENT_CONDITION(foo_template, foo_with_template_cond,
544 TP_PROTO(const char *foo, int bar),
545 TP_ARGS(foo, bar),
546 TP_CONDITION(!(bar % 8)));
547
548
549 DEFINE_EVENT_FN(foo_template, foo_with_template_fn,
550 TP_PROTO(const char *foo, int bar),
551 TP_ARGS(foo, bar),
552 foo_bar_reg, foo_bar_unreg);
553
554 /*
555 * Anytime two events share basically the same values and have
556 * the same output, use the DECLARE_EVENT_CLASS() and DEFINE_EVENT()
557 * when ever possible.
558 */
559
560 /*
561 * If the event is similar to the DECLARE_EVENT_CLASS, but you need
562 * to have a different output, then use DEFINE_EVENT_PRINT() which
563 * lets you override the TP_printk() of the class.
564 */
565
566 DEFINE_EVENT_PRINT(foo_template, foo_with_template_print,
567 TP_PROTO(const char *foo, int bar),
568 TP_ARGS(foo, bar),
569 TP_printk("bar %s %d", __get_str(foo), __entry->bar));
570
571 /*
572 * There are yet another __rel_loc dynamic data attribute. If you
573 * use __rel_dynamic_array() and __rel_string() etc. macros, you
574 * can use this attribute. There is no difference from the viewpoint
575 * of functionality with/without 'rel' but the encoding is a bit
576 * different. This is expected to be used with user-space event,
577 * there is no reason that the kernel event use this, but only for
578 * testing.
579 */
580
581 TRACE_EVENT(foo_rel_loc,
582
583 TP_PROTO(const char *foo, int bar, unsigned long *mask, const cpumask_t *cpus),
584
585 TP_ARGS(foo, bar, mask, cpus),
586
587 TP_STRUCT__entry(
588 __rel_string( foo, foo )
589 __field( int, bar )
590 __rel_bitmask( bitmask,
591 BITS_PER_BYTE * sizeof(unsigned long) )
592 __rel_cpumask( cpumask )
593 ),
594
595 TP_fast_assign(
596 __assign_rel_str(foo);
597 __entry->bar = bar;
598 __assign_rel_bitmask(bitmask, mask,
599 BITS_PER_BYTE * sizeof(unsigned long));
600 __assign_rel_cpumask(cpumask, cpus);
601 ),
602
603 TP_printk("foo_rel_loc %s, %d, %s, %s", __get_rel_str(foo), __entry->bar,
604 __get_rel_bitmask(bitmask),
605 __get_rel_cpumask(cpumask))
606 );
607
608 TRACE_EVENT(foo_timer_fn,
609
610 TP_PROTO(struct foo_timer_data *data),
611
612 TP_ARGS(data),
613
614 TP_STRUCT__entry(
615 __string( name, data->name )
616 __field( int, count )
617 ),
618
619 TP_fast_assign(
620 __assign_str(name);
621 __entry->count = *this_cpu_ptr(data->counter);
622 ),
623
624 TP_printk("name=%s count=%d", __get_str(name), __entry->count)
625 );
626 #endif
627
628 /***** NOTICE! The #if protection ends here. *****/
629
630
631 /*
632 * There are several ways I could have done this. If I left out the
633 * TRACE_INCLUDE_PATH, then it would default to the kernel source
634 * include/trace/events directory.
635 *
636 * I could specify a path from the define_trace.h file back to this
637 * file.
638 *
639 * #define TRACE_INCLUDE_PATH ../../samples/trace_events
640 *
641 * But the safest and easiest way to simply make it use the directory
642 * that the file is in is to add in the Makefile:
643 *
644 * CFLAGS_trace-events-sample.o := -I$(src)
645 *
646 * This will make sure the current path is part of the include
647 * structure for our file so that define_trace.h can find it.
648 *
649 * I could have made only the top level directory the include:
650 *
651 * CFLAGS_trace-events-sample.o := -I$(PWD)
652 *
653 * And then let the path to this directory be the TRACE_INCLUDE_PATH:
654 *
655 * #define TRACE_INCLUDE_PATH samples/trace_events
656 *
657 * But then if something defines "samples" or "trace_events" as a macro
658 * then we could risk that being converted too, and give us an unexpected
659 * result.
660 */
661 #undef TRACE_INCLUDE_PATH
662 #undef TRACE_INCLUDE_FILE
663 #define TRACE_INCLUDE_PATH .
664 /*
665 * TRACE_INCLUDE_FILE is not needed if the filename and TRACE_SYSTEM are equal
666 */
667 #define TRACE_INCLUDE_FILE trace-events-sample
668 #include <trace/define_trace.h>
669