xref: /linux/include/trace/trace_events.h (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
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 #include "stages/stage1_struct_define.h"
49 
50 #undef DECLARE_EVENT_CLASS
51 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)	\
52 	struct trace_event_raw_##name {					\
53 		struct trace_entry	ent;				\
54 		tstruct							\
55 		char			__data[];			\
56 	};								\
57 									\
58 	static struct trace_event_class event_class_##name;
59 
60 #undef DEFINE_EVENT
61 #define DEFINE_EVENT(template, name, proto, args)	\
62 	static struct trace_event_call	__used		\
63 	__attribute__((__aligned__(4))) event_##name
64 
65 #undef DEFINE_EVENT_FN
66 #define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)	\
67 	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
68 
69 #undef DEFINE_EVENT_PRINT
70 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
71 	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
72 
73 /* Callbacks are meaningless to ftrace. */
74 #undef TRACE_EVENT_FN
75 #define TRACE_EVENT_FN(name, proto, args, tstruct,			\
76 		assign, print, reg, unreg)				\
77 	TRACE_EVENT(name, PARAMS(proto), PARAMS(args),			\
78 		PARAMS(tstruct), PARAMS(assign), PARAMS(print))		\
79 
80 #undef TRACE_EVENT_FN_COND
81 #define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct,	\
82 		assign, print, reg, unreg)				\
83 	TRACE_EVENT_CONDITION(name, PARAMS(proto), PARAMS(args), PARAMS(cond),		\
84 		PARAMS(tstruct), PARAMS(assign), PARAMS(print))		\
85 
86 #undef TRACE_EVENT_FLAGS
87 #define TRACE_EVENT_FLAGS(name, value)					\
88 	__TRACE_EVENT_FLAGS(name, value)
89 
90 #undef TRACE_EVENT_PERF_PERM
91 #define TRACE_EVENT_PERF_PERM(name, expr...)				\
92 	__TRACE_EVENT_PERF_PERM(name, expr)
93 
94 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
95 
96 /*
97  * Stage 2 of the trace events.
98  *
99  * Include the following:
100  *
101  * struct trace_event_data_offsets_<call> {
102  *	u32				<item1>;
103  *	u32				<item2>;
104  *	[...]
105  * };
106  *
107  * The __dynamic_array() macro will create each u32 <item>, this is
108  * to keep the offset of each array from the beginning of the event.
109  * The size of an array is also encoded, in the higher 16 bits of <item>.
110  */
111 
112 #include "stages/stage2_data_offsets.h"
113 
114 #undef DECLARE_EVENT_CLASS
115 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
116 	struct trace_event_data_offsets_##call {			\
117 		tstruct;						\
118 	};
119 
120 #undef DEFINE_EVENT
121 #define DEFINE_EVENT(template, name, proto, args)
122 
123 #undef DEFINE_EVENT_PRINT
124 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)
125 
126 #undef TRACE_EVENT_FLAGS
127 #define TRACE_EVENT_FLAGS(event, flag)
128 
129 #undef TRACE_EVENT_PERF_PERM
130 #define TRACE_EVENT_PERF_PERM(event, expr...)
131 
132 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
133 
134 /*
135  * Stage 3 of the trace events.
136  *
137  * Override the macros in the event tracepoint header <trace/events/XXX.h>
138  * to include the following:
139  *
140  * enum print_line_t
141  * trace_raw_output_<call>(struct trace_iterator *iter, int flags)
142  * {
143  *	struct trace_seq *s = &iter->seq;
144  *	struct trace_event_raw_<call> *field; <-- defined in stage 1
145  *	struct trace_seq *p = &iter->tmp_seq;
146  *
147  * -------(for event)-------
148  *
149  *	struct trace_entry *entry;
150  *
151  *	entry = iter->ent;
152  *
153  *	if (entry->type != event_<call>->event.type) {
154  *		WARN_ON_ONCE(1);
155  *		return TRACE_TYPE_UNHANDLED;
156  *	}
157  *
158  *	field = (typeof(field))entry;
159  *
160  *	trace_seq_init(p);
161  *	return trace_output_call(iter, <call>, <TP_printk> "\n");
162  *
163  * ------(or, for event class)------
164  *
165  *	int ret;
166  *
167  *	field = (typeof(field))iter->ent;
168  *
169  *	ret = trace_raw_output_prep(iter, trace_event);
170  *	if (ret != TRACE_TYPE_HANDLED)
171  *		return ret;
172  *
173  *	trace_event_printf(iter, <TP_printk> "\n");
174  *
175  *	return trace_handle_return(s);
176  * -------
177  *  }
178  *
179  * This is the method used to print the raw event to the trace
180  * output format. Note, this is not needed if the data is read
181  * in binary.
182  */
183 
184 #include "stages/stage3_trace_output.h"
185 
186 #undef DECLARE_EVENT_CLASS
187 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
188 static notrace enum print_line_t					\
189 trace_raw_output_##call(struct trace_iterator *iter, int flags,		\
190 			struct trace_event *trace_event)		\
191 {									\
192 	struct trace_seq *s = &iter->seq;				\
193 	struct trace_seq __maybe_unused *p = &iter->tmp_seq;		\
194 	struct trace_event_raw_##call *field;				\
195 	int ret;							\
196 									\
197 	field = (typeof(field))iter->ent;				\
198 									\
199 	ret = trace_raw_output_prep(iter, trace_event);			\
200 	if (ret != TRACE_TYPE_HANDLED)					\
201 		return ret;						\
202 									\
203 	trace_event_printf(iter, print);				\
204 									\
205 	return trace_handle_return(s);					\
206 }									\
207 static struct trace_event_functions trace_event_type_funcs_##call = {	\
208 	.trace			= trace_raw_output_##call,		\
209 };
210 
211 #undef DEFINE_EVENT_PRINT
212 #define DEFINE_EVENT_PRINT(template, call, proto, args, print)		\
213 static notrace enum print_line_t					\
214 trace_raw_output_##call(struct trace_iterator *iter, int flags,		\
215 			 struct trace_event *event)			\
216 {									\
217 	struct trace_event_raw_##template *field;			\
218 	struct trace_entry *entry;					\
219 	struct trace_seq *p = &iter->tmp_seq;				\
220 									\
221 	entry = iter->ent;						\
222 									\
223 	if (entry->type != event_##call.event.type) {			\
224 		WARN_ON_ONCE(1);					\
225 		return TRACE_TYPE_UNHANDLED;				\
226 	}								\
227 									\
228 	field = (typeof(field))entry;					\
229 									\
230 	trace_seq_init(p);						\
231 	return trace_output_call(iter, #call, print);			\
232 }									\
233 static struct trace_event_functions trace_event_type_funcs_##call = {	\
234 	.trace			= trace_raw_output_##call,		\
235 };
236 
237 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
238 
239 #include "stages/stage4_event_fields.h"
240 
241 #undef DECLARE_EVENT_CLASS
242 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print)	\
243 static struct trace_event_fields trace_event_fields_##call[] = {	\
244 	tstruct								\
245 	{} };
246 
247 #undef DEFINE_EVENT_PRINT
248 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)
249 
250 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
251 
252 #include "stages/stage5_get_offsets.h"
253 
254 #undef DECLARE_EVENT_CLASS
255 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
256 static inline notrace int trace_event_get_offsets_##call(		\
257 	struct trace_event_data_offsets_##call *__data_offsets, proto)	\
258 {									\
259 	int __data_size = 0;						\
260 	int __maybe_unused __item_length;				\
261 	struct trace_event_raw_##call __maybe_unused *entry;		\
262 									\
263 	tstruct;							\
264 									\
265 	return __data_size;						\
266 }
267 
268 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
269 
270 /*
271  * Stage 4 of the trace events.
272  *
273  * Override the macros in the event tracepoint header <trace/events/XXX.h>
274  * to include the following:
275  *
276  * For those macros defined with TRACE_EVENT:
277  *
278  * static struct trace_event_call event_<call>;
279  *
280  * static void trace_event_raw_event_<call>(void *__data, proto)
281  * {
282  *	struct trace_event_file *trace_file = __data;
283  *	struct trace_event_call *event_call = trace_file->event_call;
284  *	struct trace_event_data_offsets_<call> __maybe_unused __data_offsets;
285  *	unsigned long eflags = trace_file->flags;
286  *	enum event_trigger_type __tt = ETT_NONE;
287  *	struct ring_buffer_event *event;
288  *	struct trace_event_raw_<call> *entry; <-- defined in stage 1
289  *	struct trace_buffer *buffer;
290  *	unsigned long irq_flags;
291  *	int __data_size;
292  *	int pc;
293  *
294  *	if (!(eflags & EVENT_FILE_FL_TRIGGER_COND)) {
295  *		if (eflags & EVENT_FILE_FL_TRIGGER_MODE)
296  *			event_triggers_call(trace_file, NULL);
297  *		if (eflags & EVENT_FILE_FL_SOFT_DISABLED)
298  *			return;
299  *	}
300  *
301  *	local_save_flags(irq_flags);
302  *	pc = preempt_count();
303  *
304  *	__data_size = trace_event_get_offsets_<call>(&__data_offsets, args);
305  *
306  *	event = trace_event_buffer_lock_reserve(&buffer, trace_file,
307  *				  event_<call>->event.type,
308  *				  sizeof(*entry) + __data_size,
309  *				  irq_flags, pc);
310  *	if (!event)
311  *		return;
312  *	entry	= ring_buffer_event_data(event);
313  *
314  *	{ <assign>; }  <-- Here we assign the entries by the __field and
315  *			   __array macros.
316  *
317  *	if (eflags & EVENT_FILE_FL_TRIGGER_COND)
318  *		__tt = event_triggers_call(trace_file, entry);
319  *
320  *	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT,
321  *		     &trace_file->flags))
322  *		ring_buffer_discard_commit(buffer, event);
323  *	else if (!filter_check_discard(trace_file, entry, buffer, event))
324  *		trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
325  *
326  *	if (__tt)
327  *		event_triggers_post_call(trace_file, __tt);
328  * }
329  *
330  * static struct trace_event ftrace_event_type_<call> = {
331  *	.trace			= trace_raw_output_<call>, <-- stage 2
332  * };
333  *
334  * static char print_fmt_<call>[] = <TP_printk>;
335  *
336  * static struct trace_event_class __used event_class_<template> = {
337  *	.system			= "<system>",
338  *	.fields_array		= trace_event_fields_<call>,
339  *	.fields			= LIST_HEAD_INIT(event_class_##call.fields),
340  *	.raw_init		= trace_event_raw_init,
341  *	.probe			= trace_event_raw_event_##call,
342  *	.reg			= trace_event_reg,
343  * };
344  *
345  * static struct trace_event_call event_<call> = {
346  *	.class			= event_class_<template>,
347  *	{
348  *		.tp			= &__tracepoint_<call>,
349  *	},
350  *	.event			= &ftrace_event_type_<call>,
351  *	.print_fmt		= print_fmt_<call>,
352  *	.flags			= TRACE_EVENT_FL_TRACEPOINT,
353  * };
354  * // its only safe to use pointers when doing linker tricks to
355  * // create an array.
356  * static struct trace_event_call __used
357  * __section("_ftrace_events") *__event_<call> = &event_<call>;
358  *
359  */
360 
361 #ifdef CONFIG_PERF_EVENTS
362 
363 #define _TRACE_PERF_PROTO(call, proto)					\
364 	static notrace void						\
365 	perf_trace_##call(void *__data, proto);
366 
367 #define _TRACE_PERF_INIT(call)						\
368 	.perf_probe		= perf_trace_##call,
369 
370 #else
371 #define _TRACE_PERF_PROTO(call, proto)
372 #define _TRACE_PERF_INIT(call)
373 #endif /* CONFIG_PERF_EVENTS */
374 
375 #include "stages/stage6_event_callback.h"
376 
377 #undef DECLARE_EVENT_CLASS
378 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
379 									\
380 static notrace void							\
381 trace_event_raw_event_##call(void *__data, proto)			\
382 {									\
383 	struct trace_event_file *trace_file = __data;			\
384 	struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
385 	struct trace_event_buffer fbuffer;				\
386 	struct trace_event_raw_##call *entry;				\
387 	int __data_size;						\
388 									\
389 	if (trace_trigger_soft_disabled(trace_file))			\
390 		return;							\
391 									\
392 	__data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
393 									\
394 	entry = trace_event_buffer_reserve(&fbuffer, trace_file,	\
395 				 sizeof(*entry) + __data_size);		\
396 									\
397 	if (!entry)							\
398 		return;							\
399 									\
400 	tstruct								\
401 									\
402 	{ assign; }							\
403 									\
404 	trace_event_buffer_commit(&fbuffer);				\
405 }
406 /*
407  * The ftrace_test_probe is compiled out, it is only here as a build time check
408  * to make sure that if the tracepoint handling changes, the ftrace probe will
409  * fail to compile unless it too is updated.
410  */
411 
412 #undef DEFINE_EVENT
413 #define DEFINE_EVENT(template, call, proto, args)			\
414 static inline void ftrace_test_probe_##call(void)			\
415 {									\
416 	check_trace_callback_type_##call(trace_event_raw_event_##template); \
417 }
418 
419 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
420 
421 #include "stages/stage7_class_define.h"
422 
423 #undef DECLARE_EVENT_CLASS
424 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
425 _TRACE_PERF_PROTO(call, PARAMS(proto));					\
426 static char print_fmt_##call[] = print;					\
427 static struct trace_event_class __used __refdata event_class_##call = { \
428 	.system			= TRACE_SYSTEM_STRING,			\
429 	.fields_array		= trace_event_fields_##call,		\
430 	.fields			= LIST_HEAD_INIT(event_class_##call.fields),\
431 	.raw_init		= trace_event_raw_init,			\
432 	.probe			= trace_event_raw_event_##call,		\
433 	.reg			= trace_event_reg,			\
434 	_TRACE_PERF_INIT(call)						\
435 };
436 
437 #undef DEFINE_EVENT
438 #define DEFINE_EVENT(template, call, proto, args)			\
439 									\
440 static struct trace_event_call __used event_##call = {			\
441 	.class			= &event_class_##template,		\
442 	{								\
443 		.tp			= &__tracepoint_##call,		\
444 	},								\
445 	.event.funcs		= &trace_event_type_funcs_##template,	\
446 	.print_fmt		= print_fmt_##template,			\
447 	.flags			= TRACE_EVENT_FL_TRACEPOINT,		\
448 };									\
449 static struct trace_event_call __used					\
450 __section("_ftrace_events") *__event_##call = &event_##call
451 
452 #undef DEFINE_EVENT_PRINT
453 #define DEFINE_EVENT_PRINT(template, call, proto, args, print)		\
454 									\
455 static char print_fmt_##call[] = print;					\
456 									\
457 static struct trace_event_call __used event_##call = {			\
458 	.class			= &event_class_##template,		\
459 	{								\
460 		.tp			= &__tracepoint_##call,		\
461 	},								\
462 	.event.funcs		= &trace_event_type_funcs_##call,	\
463 	.print_fmt		= print_fmt_##call,			\
464 	.flags			= TRACE_EVENT_FL_TRACEPOINT,		\
465 };									\
466 static struct trace_event_call __used					\
467 __section("_ftrace_events") *__event_##call = &event_##call
468 
469 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
470