aboutsummaryrefslogtreecommitdiff
path: root/include/trace/ftrace.h
blob: 22c94719c5695cf782c5ddbdc68d5533aba4ac9c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
/*
 * Stage 1 of the trace events.
 *
 * Override the macros in <trace/trace_events.h> to include the following:
 *
 * struct ftrace_raw_<call> {
 *	struct trace_entry		ent;
 *	<type>				<item>;
 *	<type2>				<item2>[<len>];
 *	[...]
 * };
 *
 * The <type> <item> is created by the __field(type, item) macro or
 * the __array(type2, item2, len) macro.
 * We simply do "type item;", and that will create the fields
 * in the structure.
 */

#include <linux/ftrace_event.h>

#undef __array
#define __array(type, item, len)	type	item[len];

#undef __field
#define __field(type, item)		type	item;

#undef __string
#define __string(item, src)		unsigned short	__str_loc_##item;

#undef TP_STRUCT__entry
#define TP_STRUCT__entry(args...) args

#undef TRACE_EVENT
#define TRACE_EVENT(name, proto, args, tstruct, assign, print)	\
	struct ftrace_raw_##name {				\
		struct trace_entry	ent;			\
		tstruct						\
		char			__str_data[0];		\
	};							\
	static struct ftrace_event_call event_##name

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)


/*
 * Stage 2 of the trace events.
 *
 * Include the following:
 *
 * struct ftrace_str_offsets_<call> {
 *	int				<str1>;
 *	int				<str2>;
 *	[...]
 * };
 *
 * The __string() macro will create each int <str>, this is to
 * keep the offset of each string from the beggining of the event
 * once we perform the strlen() of the src strings.
 *
 */

#undef __array
#define __array(type, item, len)

#undef __field
#define __field(type, item);

#undef __string
#define __string(item, src)	int item;

#undef TRACE_EVENT
#define TRACE_EVENT(call, proto, args, tstruct, assign, print)		\
	struct ftrace_str_offsets_##call {				\
		tstruct;						\
	};

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

/*
 * Stage 3 of the trace events.
 *
 * Override the macros in <trace/trace_events.h> to include the following:
 *
 * enum print_line_t
 * ftrace_raw_output_<call>(struct trace_iterator *iter, int flags)
 * {
 *	struct trace_seq *s = &iter->seq;
 *	struct ftrace_raw_<call> *field; <-- defined in stage 1
 *	struct trace_entry *entry;
 *	struct trace_seq *p;
 *	int ret;
 *
 *	entry = iter->ent;
 *
 *	if (entry->type != event_<call>.id) {
 *		WARN_ON_ONCE(1);
 *		return TRACE_TYPE_UNHANDLED;
 *	}
 *
 *	field = (typeof(field))entry;
 *
 *	p = get_cpu_var(ftrace_event_seq);
 *	ret = trace_seq_printf(s, <TP_printk> "\n");
 *	put_cpu();
 *	if (!ret)
 *		return TRACE_TYPE_PARTIAL_LINE;
 *
 *	return TRACE_TYPE_HANDLED;
 * }
 *
 * This is the method used to print the raw event to the trace
 * output format. Note, this is not needed if the data is read
 * in binary.
 */

#undef __entry
#define __entry field

#undef TP_printk
#define TP_printk(fmt, args...) fmt "\n", args

#undef __get_str
#define __get_str(field)	((char *)__entry + __entry->__str_loc_##field)

#undef __print_flags
#define __print_flags(flag, delim, flag_array...)			\
	({								\
		static const struct trace_print_flags flags[] =		\
			{ flag_array, { -1, NULL }};			\
		ftrace_print_flags_seq(p, delim, flag, flags);		\
	})

#undef TRACE_EVENT
#define TRACE_EVENT(call, proto, args, tstruct, assign, print)		\
enum print_line_t							\
ftrace_raw_output_##call(struct trace_iterator *iter, int flags)	\
{									\
	struct trace_seq *s = &iter->seq;				\
	struct ftrace_raw_##call *field;				\
	struct trace_entry *entry;					\
	struct trace_seq *p;						\
	int ret;							\
									\
	entry = iter->ent;						\
									\
	if (entry->type != event_##call.id) {				\
		WARN_ON_ONCE(1);					\
		return TRACE_TYPE_UNHANDLED;				\
	}								\
									\
	field = (typeof(field))entry;					\
									\
	p = &get_cpu_var(ftrace_event_seq);				\
	ret = trace_seq_printf(s, #call ": " print);			\
	put_cpu();							\
	if (!ret)							\
		return TRACE_TYPE_PARTIAL_LINE;				\
									\
	return TRACE_TYPE_HANDLED;					\
}
	
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

/*
 * Setup the showing format of trace point.
 *
 * int
 * ftrace_format_##call(struct trace_seq *s)
 * {
 *	struct ftrace_raw_##call field;
 *	int ret;
 *
 *	ret = trace_seq_printf(s, #type " " #item ";"
 *			       " offset:%u; size:%u;\n",
 *			       offsetof(struct ftrace_raw_##call, item),
 *			       sizeof(field.type));
 *
 * }
 */

#undef TP_STRUCT__entry
#define TP_STRUCT__entry(args...) args

#undef __field
#define __field(type, item)					\
	ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"	\
			       "offset:%u;\tsize:%u;\n",		\
			       (unsigned int)offsetof(typeof(field), item), \
			       (unsigned int)sizeof(field.item));	\
	if (!ret)							\
		return 0;

#undef __array
#define __array(type, item, len)						\
	ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t"	\
			       "offset:%u;\tsize:%u;\n",		\
			       (unsigned int)offsetof(typeof(field), item), \
			       (unsigned int)sizeof(field.item));	\
	if (!ret)							\
		return 0;

#undef __string
#define __string(item, src)						       \
	ret = trace_seq_printf(s, "\tfield: __str_loc " #item ";\t"	       \
			       "offset:%u;tsize:%u;\n",			       \
			       (unsigned int)offsetof(typeof(field),	       \
					__str_loc_##item),		       \
			       (unsigned int)sizeof(field.__str_loc_##item));  \
	if (!ret)							       \
		return 0;

#undef __entry
#define __entry REC

#undef TP_printk
#define TP_printk(fmt, args...) "%s, %s\n", #fmt, __stringify(args)

#undef TP_fast_assign
#define TP_fast_assign(args...) args

#undef TRACE_EVENT
#define TRACE_EVENT(call, proto, args, tstruct, func, print)		\
static int								\
ftrace_format_##call(struct trace_seq *s)				\
{									\
	struct ftrace_raw_##call field __attribute__((unused));		\
	int ret = 0;							\
									\
	tstruct;							\
									\
	trace_seq_printf(s, "\nprint fmt: " print);			\
									\
	return ret;							\
}

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

#undef __field
#define __field(type, item)						\
	ret = trace_define_field(event_call, #type, #item,		\
				 offsetof(typeof(field), item),		\
				 sizeof(field.item), is_signed_type(type));	\
	if (ret)							\
		return ret;

#undef __array
#define __array(type, item, len)					\
	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
				 offsetof(typeof(field), item),		\
				 sizeof(field.item), 0);		\
	if (ret)							\
		return ret;

#undef __string
#define __string(item, src)						       \
	ret = trace_define_field(event_call, "__str_loc", #item,	       \
				offsetof(typeof(field), __str_loc_##item),     \
				 sizeof(field.__str_loc_##item), 0);

#undef TRACE_EVENT
#define TRACE_EVENT(call, proto, args, tstruct, func, print)		\
int									\
ftrace_define_fields_##call(void)					\
{									\
	struct ftrace_raw_##call field;					\
	struct ftrace_event_call *event_call = &event_##call;		\
	int ret;							\
									\
	__common_field(int, type, 1);					\
	__common_field(unsigned char, flags, 0);			\
	__common_field(unsigned char, preempt_count, 0);		\
	__common_field(int, pid, 1);					\
	__common_field(int, tgid, 1);					\
									\
	tstruct;							\
									\
	return ret;							\
}

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

/*
 * Stage 4 of the trace events.
 *
 * Override the macros in <trace/trace_events.h> to include the following:
 *
 * static void ftrace_event_<call>(proto)
 * {
 *	event_trace_printk(_RET_IP_, "<call>: " <fmt>);
 * }
 *
 * static int ftrace_reg_event_<call>(void)
 * {
 *	int ret;
 *
 *	ret = register_trace_<call>(ftrace_event_<call>);
 *	if (!ret)
 *		pr_info("event trace: Could not activate trace point "
 *			"probe to  <call>");
 *	return ret;
 * }
 *
 * static void ftrace_unreg_event_<call>(void)
 * {
 *	unregister_trace_<call>(ftrace_event_<call>);
 * }
 *
 *
 * For those macros defined with TRACE_EVENT:
 *
 * static struct ftrace_event_call event_<call>;
 *
 * static void ftrace_raw_event_<call>(proto)
 * {
 *	struct ring_buffer_event *event;
 *	struct ftrace_raw_<call> *entry; <-- defined in stage 1
 *	unsigned long irq_flags;
 *	int pc;
 *
 *	local_save_flags(irq_flags);
 *	pc = preempt_count();
 *
 *	event = trace_current_buffer_lock_reserve(event_<call>.id,
 *				  sizeof(struct ftrace_raw_<call>),
 *				  irq_flags, pc);
 *	if (!event)
 *		return;
 *	entry	= ring_buffer_event_data(event);
 *
 *	<assign>;  <-- Here we assign the entries by the __field and
 *			__array macros.
 *
 *	trace_current_buffer_unlock_commit(event, irq_flags, pc);
 * }
 *
 * static int ftrace_raw_reg_event_<call>(void)
 * {
 *	int ret;
 *
 *	ret = register_trace_<call>(ftrace_raw_event_<call>);
 *	if (!ret)
 *		pr_info("event trace: Could not activate trace point "
 *			"probe to <call>");
 *	return ret;
 * }
 *
 * static void ftrace_unreg_event_<call>(void)
 * {
 *	unregister_trace_<call>(ftrace_raw_event_<call>);
 * }
 *
 * static struct trace_event ftrace_event_type_<call> = {
 *	.trace			= ftrace_raw_output_<call>, <-- stage 2
 * };
 *
 * static int ftrace_raw_init_event_<call>(void)
 * {
 *	int id;
 *
 *	id = register_ftrace_event(&ftrace_event_type_<call>);
 *	if (!id)
 *		return -ENODEV;
 *	event_<call>.id = id;
 *	return 0;
 * }
 *
 * static struct ftrace_event_call __used
 * __attribute__((__aligned__(4)))
 * __attribute__((section("_ftrace_events"))) event_<call> = {
 *	.name			= "<call>",
 *	.system			= "<system>",
 *	.raw_init		= ftrace_raw_init_event_<call>,
 *	.regfunc		= ftrace_reg_event_<call>,
 *	.unregfunc		= ftrace_unreg_event_<call>,
 *	.show_format		= ftrace_format_<call>,
 * }
 *
 */

#undef TP_FMT
#define TP_FMT(fmt, args...)	fmt "\n", ##args

#ifdef CONFIG_EVENT_PROFILE
#define _TRACE_PROFILE(call, proto, args)				\
static void ftrace_profile_##call(proto)				\
{									\
	extern void perf_tpcounter_event(int);				\
	perf_tpcounter_event(event_##call.id);				\
}									\
									\
static int ftrace_profile_enable_##call(struct ftrace_event_call *call) \
{									\
	int ret = 0;							\
									\
	if (!atomic_inc_return(&call->profile_count))			\
		ret = register_trace_##call(ftrace_profile_##call);	\
									\
	return ret;							\
}									\
									\
static void ftrace_profile_disable_##call(struct ftrace_event_call *call) \
{									\
	if (atomic_add_negative(-1, &call->profile_count))		\
		unregister_trace_##call(ftrace_profile_##call);		\
}

#define _TRACE_PROFILE_INIT(call)					\
	.profile_count = ATOMIC_INIT(-1),				\
	.profile_enable = ftrace_profile_enable_##call,			\
	.profile_disable = ftrace_profile_disable_##call,

#else
#define _TRACE_PROFILE(call, proto, args)
#define _TRACE_PROFILE_INIT(call)
#endif

#undef __entry
#define __entry entry

#undef __field
#define __field(type, item)

#undef __array
#define __array(type, item, len)

#undef __string
#define __string(item, src)						       \
	__str_offsets.item = __str_size +				       \
			     offsetof(typeof(*entry), __str_data);	       \
	__str_size += strlen(src) + 1;

#undef __assign_str
#define __assign_str(dst, src)						\
	__entry->__str_loc_##dst = __str_offsets.dst;			\
	strcpy(__get_str(dst), src);

#undef TRACE_EVENT
#define TRACE_EVENT(call, proto, args, tstruct, assign, print)		\
_TRACE_PROFILE(call, PARAMS(proto), PARAMS(args))			\
									\
static struct ftrace_event_call event_##call;				\
									\
static void ftrace_raw_event_##call(proto)				\
{									\
	struct ftrace_str_offsets_##call __maybe_unused __str_offsets;  \
	struct ftrace_event_call *call = &event_##call;			\
	struct ring_buffer_event *event;				\
	struct ftrace_raw_##call *entry;				\
	unsigned long irq_flags;					\
	int __str_size = 0;						\
	int pc;								\
									\
	local_save_flags(irq_flags);					\
	pc = preempt_count();						\
									\
	tstruct;							\
									\
	event = trace_current_buffer_lock_reserve(event_##call.id,	\
				 sizeof(struct ftrace_raw_##call) + __str_size,\
				 irq_flags, pc);			\
	if (!event)							\
		return;							\
	entry	= ring_buffer_event_data(event);			\
									\
	assign;								\
									\
	if (!filter_current_check_discard(call, entry, event))		\
		trace_nowake_buffer_unlock_commit(event, irq_flags, pc); \
}									\
									\
static int ftrace_raw_reg_event_##call(void)				\
{									\
	int ret;							\
									\
	ret = register_trace_##call(ftrace_raw_event_##call);		\
	if (ret)							\
		pr_info("event trace: Could not activate trace point "	\
			"probe to " #call "\n");			\
	return ret;							\
}									\
									\
static void ftrace_raw_unreg_event_##call(void)				\
{									\
	unregister_trace_##call(ftrace_raw_event_##call);		\
}									\
									\
static struct trace_event ftrace_event_type_##call = {			\
	.trace			= ftrace_raw_output_##call,		\
};									\
									\
static int ftrace_raw_init_event_##call(void)				\
{									\
	int id;								\
									\
	id = register_ftrace_event(&ftrace_event_type_##call);		\
	if (!id)							\
		return -ENODEV;						\
	event_##call.id = id;						\
	INIT_LIST_HEAD(&event_##call.fields);				\
	init_preds(&event_##call);					\
	return 0;							\
}									\
									\
static struct ftrace_event_call __used					\
__attribute__((__aligned__(4)))						\
__attribute__((section("_ftrace_events"))) event_##call = {		\
	.name			= #call,				\
	.system			= __stringify(TRACE_SYSTEM),		\
	.event			= &ftrace_event_type_##call,		\
	.raw_init		= ftrace_raw_init_event_##call,		\
	.regfunc		= ftrace_raw_reg_event_##call,		\
	.unregfunc		= ftrace_raw_unreg_event_##call,	\
	.show_format		= ftrace_format_##call,			\
	.define_fields		= ftrace_define_fields_##call,		\
	_TRACE_PROFILE_INIT(call)					\
}

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

#undef _TRACE_PROFILE
#undef _TRACE_PROFILE_INIT