xref: /linux/include/trace/trace_events.h (revision 06afb0f36106ecb839c5e2509905e68c1e2677de)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Stage 1 of the trace events.
4  *
5  * Override the macros in the event tracepoint header <trace/events/XXX.h>
6  * to include the following:
7  *
8  * struct trace_event_raw_<call> {
9  *	struct trace_entry		ent;
10  *	<type>				<item>;
11  *	<type2>				<item2>[<len>];
12  *	[...]
13  * };
14  *
15  * The <type> <item> is created by the __field(type, item) macro or
16  * the __array(type2, item2, len) macro.
17  * We simply do "type item;", and that will create the fields
18  * in the structure.
19  */
20 
21 #include <linux/trace_events.h>
22 
23 #ifndef TRACE_SYSTEM_VAR
24 #define TRACE_SYSTEM_VAR TRACE_SYSTEM
25 #endif
26 
27 #include "stages/init.h"
28 
29 /*
30  * DECLARE_EVENT_CLASS can be used to add a generic function
31  * handlers for events. That is, if all events have the same
32  * parameters and just have distinct trace points.
33  * Each tracepoint can be defined with DEFINE_EVENT and that
34  * will map the DECLARE_EVENT_CLASS to the tracepoint.
35  *
36  * TRACE_EVENT is a one to one mapping between tracepoint and template.
37  */
38 #undef TRACE_EVENT
39 #define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
40 	DECLARE_EVENT_CLASS(name,			       \
41 			     PARAMS(proto),		       \
42 			     PARAMS(args),		       \
43 			     PARAMS(tstruct),		       \
44 			     PARAMS(assign),		       \
45 			     PARAMS(print));		       \
46 	DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
47 
48 #undef TRACE_EVENT_SYSCALL
49 #define TRACE_EVENT_SYSCALL(name, proto, args, tstruct, assign, print, reg, unreg) \
50 	DECLARE_EVENT_SYSCALL_CLASS(name,		       \
51 			     PARAMS(proto),		       \
52 			     PARAMS(args),		       \
53 			     PARAMS(tstruct),		       \
54 			     PARAMS(assign),		       \
55 			     PARAMS(print));		       \
56 	DEFINE_EVENT(name, name, PARAMS(proto), PARAMS(args));
57 
58 #include "stages/stage1_struct_define.h"
59 
60 #undef DECLARE_EVENT_CLASS
61 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)	\
62 	struct trace_event_raw_##name {					\
63 		struct trace_entry	ent;				\
64 		tstruct							\
65 		char			__data[];			\
66 	};								\
67 									\
68 	static struct trace_event_class event_class_##name;
69 
70 #undef DECLARE_EVENT_SYSCALL_CLASS
71 #define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
72 
73 #undef DEFINE_EVENT
74 #define DEFINE_EVENT(template, name, proto, args)	\
75 	static struct trace_event_call	__used		\
76 	__attribute__((__aligned__(4))) event_##name
77 
78 #undef DEFINE_EVENT_FN
79 #define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)	\
80 	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
81 
82 #undef DEFINE_EVENT_PRINT
83 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
84 	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
85 
86 /* Callbacks are meaningless to ftrace. */
87 #undef TRACE_EVENT_FN
88 #define TRACE_EVENT_FN(name, proto, args, tstruct,			\
89 		assign, print, reg, unreg)				\
90 	TRACE_EVENT(name, PARAMS(proto), PARAMS(args),			\
91 		PARAMS(tstruct), PARAMS(assign), PARAMS(print))		\
92 
93 #undef TRACE_EVENT_FN_COND
94 #define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct,	\
95 		assign, print, reg, unreg)				\
96 	TRACE_EVENT_CONDITION(name, PARAMS(proto), PARAMS(args), PARAMS(cond),		\
97 		PARAMS(tstruct), PARAMS(assign), PARAMS(print))		\
98 
99 #undef TRACE_EVENT_FLAGS
100 #define TRACE_EVENT_FLAGS(name, value)					\
101 	__TRACE_EVENT_FLAGS(name, value)
102 
103 #undef TRACE_EVENT_PERF_PERM
104 #define TRACE_EVENT_PERF_PERM(name, expr...)				\
105 	__TRACE_EVENT_PERF_PERM(name, expr)
106 
107 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
108 
109 /*
110  * Stage 2 of the trace events.
111  *
112  * Include the following:
113  *
114  * struct trace_event_data_offsets_<call> {
115  *	u32				<item1>;
116  *	u32				<item2>;
117  *	[...]
118  * };
119  *
120  * The __dynamic_array() macro will create each u32 <item>, this is
121  * to keep the offset of each array from the beginning of the event.
122  * The size of an array is also encoded, in the higher 16 bits of <item>.
123  */
124 
125 #include "stages/stage2_data_offsets.h"
126 
127 #undef DECLARE_EVENT_CLASS
128 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
129 	struct trace_event_data_offsets_##call {			\
130 		tstruct;						\
131 	};
132 
133 #undef DECLARE_EVENT_SYSCALL_CLASS
134 #define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
135 
136 #undef DEFINE_EVENT
137 #define DEFINE_EVENT(template, name, proto, args)
138 
139 #undef DEFINE_EVENT_PRINT
140 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)
141 
142 #undef TRACE_EVENT_FLAGS
143 #define TRACE_EVENT_FLAGS(event, flag)
144 
145 #undef TRACE_EVENT_PERF_PERM
146 #define TRACE_EVENT_PERF_PERM(event, expr...)
147 
148 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
149 
150 /*
151  * Stage 3 of the trace events.
152  *
153  * Override the macros in the event tracepoint header <trace/events/XXX.h>
154  * to include the following:
155  *
156  * enum print_line_t
157  * trace_raw_output_<call>(struct trace_iterator *iter, int flags)
158  * {
159  *	struct trace_seq *s = &iter->seq;
160  *	struct trace_event_raw_<call> *field; <-- defined in stage 1
161  *	struct trace_seq *p = &iter->tmp_seq;
162  *
163  * -------(for event)-------
164  *
165  *	struct trace_entry *entry;
166  *
167  *	entry = iter->ent;
168  *
169  *	if (entry->type != event_<call>->event.type) {
170  *		WARN_ON_ONCE(1);
171  *		return TRACE_TYPE_UNHANDLED;
172  *	}
173  *
174  *	field = (typeof(field))entry;
175  *
176  *	trace_seq_init(p);
177  *	return trace_output_call(iter, <call>, <TP_printk> "\n");
178  *
179  * ------(or, for event class)------
180  *
181  *	int ret;
182  *
183  *	field = (typeof(field))iter->ent;
184  *
185  *	ret = trace_raw_output_prep(iter, trace_event);
186  *	if (ret != TRACE_TYPE_HANDLED)
187  *		return ret;
188  *
189  *	trace_event_printf(iter, <TP_printk> "\n");
190  *
191  *	return trace_handle_return(s);
192  * -------
193  *  }
194  *
195  * This is the method used to print the raw event to the trace
196  * output format. Note, this is not needed if the data is read
197  * in binary.
198  */
199 
200 #include "stages/stage3_trace_output.h"
201 
202 #undef DECLARE_EVENT_CLASS
203 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
204 static notrace enum print_line_t					\
205 trace_raw_output_##call(struct trace_iterator *iter, int flags,		\
206 			struct trace_event *trace_event)		\
207 {									\
208 	struct trace_seq *s = &iter->seq;				\
209 	struct trace_seq __maybe_unused *p = &iter->tmp_seq;		\
210 	struct trace_event_raw_##call *field;				\
211 	int ret;							\
212 									\
213 	field = (typeof(field))iter->ent;				\
214 									\
215 	ret = trace_raw_output_prep(iter, trace_event);			\
216 	if (ret != TRACE_TYPE_HANDLED)					\
217 		return ret;						\
218 									\
219 	trace_event_printf(iter, print);				\
220 									\
221 	return trace_handle_return(s);					\
222 }									\
223 static struct trace_event_functions trace_event_type_funcs_##call = {	\
224 	.trace			= trace_raw_output_##call,		\
225 };
226 
227 #undef DECLARE_EVENT_SYSCALL_CLASS
228 #define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
229 
230 #undef DEFINE_EVENT_PRINT
231 #define DEFINE_EVENT_PRINT(template, call, proto, args, print)		\
232 static notrace enum print_line_t					\
233 trace_raw_output_##call(struct trace_iterator *iter, int flags,		\
234 			 struct trace_event *event)			\
235 {									\
236 	struct trace_event_raw_##template *field;			\
237 	struct trace_entry *entry;					\
238 	struct trace_seq *p = &iter->tmp_seq;				\
239 									\
240 	entry = iter->ent;						\
241 									\
242 	if (entry->type != event_##call.event.type) {			\
243 		WARN_ON_ONCE(1);					\
244 		return TRACE_TYPE_UNHANDLED;				\
245 	}								\
246 									\
247 	field = (typeof(field))entry;					\
248 									\
249 	trace_seq_init(p);						\
250 	return trace_output_call(iter, #call, print);			\
251 }									\
252 static struct trace_event_functions trace_event_type_funcs_##call = {	\
253 	.trace			= trace_raw_output_##call,		\
254 };
255 
256 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
257 
258 #include "stages/stage4_event_fields.h"
259 
260 #undef DECLARE_EVENT_CLASS
261 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print)	\
262 static struct trace_event_fields trace_event_fields_##call[] = {	\
263 	tstruct								\
264 	{} };
265 
266 #undef DECLARE_EVENT_SYSCALL_CLASS
267 #define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
268 
269 #undef DEFINE_EVENT_PRINT
270 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)
271 
272 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
273 
274 #include "stages/stage5_get_offsets.h"
275 
276 #undef DECLARE_EVENT_CLASS
277 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
278 static inline notrace int trace_event_get_offsets_##call(		\
279 	struct trace_event_data_offsets_##call *__data_offsets, proto)	\
280 {									\
281 	int __data_size = 0;						\
282 	int __maybe_unused __item_length;				\
283 	struct trace_event_raw_##call __maybe_unused *entry;		\
284 									\
285 	tstruct;							\
286 									\
287 	return __data_size;						\
288 }
289 
290 #undef DECLARE_EVENT_SYSCALL_CLASS
291 #define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
292 
293 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
294 
295 /*
296  * Stage 4 of the trace events.
297  *
298  * Override the macros in the event tracepoint header <trace/events/XXX.h>
299  * to include the following:
300  *
301  * For those macros defined with TRACE_EVENT:
302  *
303  * static struct trace_event_call event_<call>;
304  *
305  * static void trace_event_raw_event_<call>(void *__data, proto)
306  * {
307  *	struct trace_event_file *trace_file = __data;
308  *	struct trace_event_call *event_call = trace_file->event_call;
309  *	struct trace_event_data_offsets_<call> __maybe_unused __data_offsets;
310  *	unsigned long eflags = trace_file->flags;
311  *	enum event_trigger_type __tt = ETT_NONE;
312  *	struct ring_buffer_event *event;
313  *	struct trace_event_raw_<call> *entry; <-- defined in stage 1
314  *	struct trace_buffer *buffer;
315  *	unsigned long irq_flags;
316  *	int __data_size;
317  *	int pc;
318  *
319  *	if (!(eflags & EVENT_FILE_FL_TRIGGER_COND)) {
320  *		if (eflags & EVENT_FILE_FL_TRIGGER_MODE)
321  *			event_triggers_call(trace_file, NULL);
322  *		if (eflags & EVENT_FILE_FL_SOFT_DISABLED)
323  *			return;
324  *	}
325  *
326  *	local_save_flags(irq_flags);
327  *	pc = preempt_count();
328  *
329  *	__data_size = trace_event_get_offsets_<call>(&__data_offsets, args);
330  *
331  *	event = trace_event_buffer_lock_reserve(&buffer, trace_file,
332  *				  event_<call>->event.type,
333  *				  sizeof(*entry) + __data_size,
334  *				  irq_flags, pc);
335  *	if (!event)
336  *		return;
337  *	entry	= ring_buffer_event_data(event);
338  *
339  *	{ <assign>; }  <-- Here we assign the entries by the __field and
340  *			   __array macros.
341  *
342  *	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
343  *		__tt = event_triggers_call(trace_file, entry);
344  *
345  *	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT,
346  *		     &trace_file->flags))
347  *		ring_buffer_discard_commit(buffer, event);
348  *	else if (!filter_check_discard(trace_file, entry, buffer, event))
349  *		trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
350  *
351  *	if (__tt)
352  *		event_triggers_post_call(trace_file, __tt);
353  * }
354  *
355  * static struct trace_event ftrace_event_type_<call> = {
356  *	.trace			= trace_raw_output_<call>, <-- stage 2
357  * };
358  *
359  * static char print_fmt_<call>[] = <TP_printk>;
360  *
361  * static struct trace_event_class __used event_class_<template> = {
362  *	.system			= "<system>",
363  *	.fields_array		= trace_event_fields_<call>,
364  *	.fields			= LIST_HEAD_INIT(event_class_##call.fields),
365  *	.raw_init		= trace_event_raw_init,
366  *	.probe			= trace_event_raw_event_##call,
367  *	.reg			= trace_event_reg,
368  * };
369  *
370  * static struct trace_event_call event_<call> = {
371  *	.class			= event_class_<template>,
372  *	{
373  *		.tp			= &__tracepoint_<call>,
374  *	},
375  *	.event			= &ftrace_event_type_<call>,
376  *	.print_fmt		= print_fmt_<call>,
377  *	.flags			= TRACE_EVENT_FL_TRACEPOINT,
378  * };
379  * // its only safe to use pointers when doing linker tricks to
380  * // create an array.
381  * static struct trace_event_call __used
382  * __section("_ftrace_events") *__event_<call> = &event_<call>;
383  *
384  */
385 
386 #ifdef CONFIG_PERF_EVENTS
387 
388 #define _TRACE_PERF_PROTO(call, proto)					\
389 	static notrace void						\
390 	perf_trace_##call(void *__data, proto);
391 
392 #define _TRACE_PERF_INIT(call)						\
393 	.perf_probe		= perf_trace_##call,
394 
395 #else
396 #define _TRACE_PERF_PROTO(call, proto)
397 #define _TRACE_PERF_INIT(call)
398 #endif /* CONFIG_PERF_EVENTS */
399 
400 #include "stages/stage6_event_callback.h"
401 
402 
403 #undef __DECLARE_EVENT_CLASS
404 #define __DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
405 static notrace void							\
406 do_trace_event_raw_event_##call(void *__data, proto)			\
407 {									\
408 	struct trace_event_file *trace_file = __data;			\
409 	struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
410 	struct trace_event_buffer fbuffer;				\
411 	struct trace_event_raw_##call *entry;				\
412 	int __data_size;						\
413 									\
414 	if (trace_trigger_soft_disabled(trace_file))			\
415 		return;							\
416 									\
417 	__data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
418 									\
419 	entry = trace_event_buffer_reserve(&fbuffer, trace_file,	\
420 				 sizeof(*entry) + __data_size);		\
421 									\
422 	if (!entry)							\
423 		return;							\
424 									\
425 	tstruct								\
426 									\
427 	{ assign; }							\
428 									\
429 	trace_event_buffer_commit(&fbuffer);				\
430 }
431 
432 #undef DECLARE_EVENT_CLASS
433 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
434 __DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
435 		      PARAMS(assign), PARAMS(print))			\
436 static notrace void							\
437 trace_event_raw_event_##call(void *__data, proto)			\
438 {									\
439 	do_trace_event_raw_event_##call(__data, args);			\
440 }
441 
442 #undef DECLARE_EVENT_SYSCALL_CLASS
443 #define DECLARE_EVENT_SYSCALL_CLASS(call, proto, args, tstruct, assign, print) \
444 __DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
445 		      PARAMS(assign), PARAMS(print))			\
446 static notrace void							\
447 trace_event_raw_event_##call(void *__data, proto)			\
448 {									\
449 	might_fault();							\
450 	preempt_disable_notrace();					\
451 	do_trace_event_raw_event_##call(__data, args);			\
452 	preempt_enable_notrace();					\
453 }
454 
455 /*
456  * The ftrace_test_probe is compiled out, it is only here as a build time check
457  * to make sure that if the tracepoint handling changes, the ftrace probe will
458  * fail to compile unless it too is updated.
459  */
460 
461 #undef DEFINE_EVENT
462 #define DEFINE_EVENT(template, call, proto, args)			\
463 static inline void ftrace_test_probe_##call(void)			\
464 {									\
465 	check_trace_callback_type_##call(trace_event_raw_event_##template); \
466 }
467 
468 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
469 
470 #undef __DECLARE_EVENT_CLASS
471 
472 #include "stages/stage7_class_define.h"
473 
474 #undef DECLARE_EVENT_CLASS
475 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
476 _TRACE_PERF_PROTO(call, PARAMS(proto));					\
477 static char print_fmt_##call[] = print;					\
478 static struct trace_event_class __used __refdata event_class_##call = { \
479 	.system			= TRACE_SYSTEM_STRING,			\
480 	.fields_array		= trace_event_fields_##call,		\
481 	.fields			= LIST_HEAD_INIT(event_class_##call.fields),\
482 	.raw_init		= trace_event_raw_init,			\
483 	.probe			= trace_event_raw_event_##call,		\
484 	.reg			= trace_event_reg,			\
485 	_TRACE_PERF_INIT(call)						\
486 };
487 
488 #undef DECLARE_EVENT_SYSCALL_CLASS
489 #define DECLARE_EVENT_SYSCALL_CLASS DECLARE_EVENT_CLASS
490 
491 #undef DEFINE_EVENT
492 #define DEFINE_EVENT(template, call, proto, args)			\
493 									\
494 static struct trace_event_call __used event_##call = {			\
495 	.class			= &event_class_##template,		\
496 	{								\
497 		.tp			= &__tracepoint_##call,		\
498 	},								\
499 	.event.funcs		= &trace_event_type_funcs_##template,	\
500 	.print_fmt		= print_fmt_##template,			\
501 	.flags			= TRACE_EVENT_FL_TRACEPOINT,		\
502 };									\
503 static struct trace_event_call __used					\
504 __section("_ftrace_events") *__event_##call = &event_##call
505 
506 #undef DEFINE_EVENT_PRINT
507 #define DEFINE_EVENT_PRINT(template, call, proto, args, print)		\
508 									\
509 static char print_fmt_##call[] = print;					\
510 									\
511 static struct trace_event_call __used event_##call = {			\
512 	.class			= &event_class_##template,		\
513 	{								\
514 		.tp			= &__tracepoint_##call,		\
515 	},								\
516 	.event.funcs		= &trace_event_type_funcs_##call,	\
517 	.print_fmt		= print_fmt_##call,			\
518 	.flags			= TRACE_EVENT_FL_TRACEPOINT,		\
519 };									\
520 static struct trace_event_call __used					\
521 __section("_ftrace_events") *__event_##call = &event_##call
522 
523 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
524