summaryrefslogtreecommitdiff
path: root/include/trace/trace_custom_events.h
blob: 6e492dba96bfcbf03039ba51b9becf08ae9c6c10 (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
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * This is similar to the trace_events.h file, but is to only
 * create custom trace events to be attached to existing tracepoints.
 * Where as the TRACE_EVENT() macro (from trace_events.h) will create
 * both the trace event and the tracepoint it will attach the event to,
 * TRACE_CUSTOM_EVENT() is to create only a custom version of an existing
 * trace event (created by TRACE_EVENT() or DEFINE_EVENT()), and will
 * be placed in the "custom" system.
 */

#include <linux/trace_events.h>

/* All custom events are placed in the custom group */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM custom

#ifndef TRACE_SYSTEM_VAR
#define TRACE_SYSTEM_VAR TRACE_SYSTEM
#endif

/* The init stage creates the system string and enum mappings */

#include "stages/init.h"

#undef TRACE_CUSTOM_EVENT
#define TRACE_CUSTOM_EVENT(name, proto, args, tstruct, assign, print) \
	DECLARE_CUSTOM_EVENT_CLASS(name,			      \
			     PARAMS(proto),		       \
			     PARAMS(args),		       \
			     PARAMS(tstruct),		       \
			     PARAMS(assign),		       \
			     PARAMS(print));		       \
	DEFINE_CUSTOM_EVENT(name, name, PARAMS(proto), PARAMS(args));

/* Stage 1 creates the structure of the recorded event layout */

#include "stages/stage1_struct_define.h"

#undef DECLARE_CUSTOM_EVENT_CLASS
#define DECLARE_CUSTOM_EVENT_CLASS(name, proto, args, tstruct, assign, print) \
	struct trace_custom_event_raw_##name {				\
		struct trace_entry	ent;				\
		tstruct							\
		char			__data[];			\
	};								\
									\
	static struct trace_event_class custom_event_class_##name;

#undef DEFINE_CUSTOM_EVENT
#define DEFINE_CUSTOM_EVENT(template, name, proto, args)	\
	static struct trace_event_call	__used			\
	__attribute__((__aligned__(4))) custom_event_##name

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

/* Stage 2 creates the custom class */

#include "stages/stage2_data_offsets.h"

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

#undef DEFINE_CUSTOM_EVENT
#define DEFINE_CUSTOM_EVENT(template, name, proto, args)

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

/* Stage 3 create the way to print the custom event */

#include "stages/stage3_trace_output.h"

#undef DECLARE_CUSTOM_EVENT_CLASS
#define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static notrace enum print_line_t					\
trace_custom_raw_output_##call(struct trace_iterator *iter, int flags,	\
			struct trace_event *trace_event)		\
{									\
	struct trace_seq *s = &iter->seq;				\
	struct trace_seq __maybe_unused *p = &iter->tmp_seq;		\
	struct trace_custom_event_raw_##call *field;			\
	int ret;							\
									\
	field = (typeof(field))iter->ent;				\
									\
	ret = trace_raw_output_prep(iter, trace_event);			\
	if (ret != TRACE_TYPE_HANDLED)					\
		return ret;						\
									\
	trace_event_printf(iter, print);				\
									\
	return trace_handle_return(s);					\
}									\
static struct trace_event_functions trace_custom_event_type_funcs_##call = { \
	.trace			= trace_custom_raw_output_##call,	\
};

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

/* Stage 4 creates the offset layout for the fields */

#include "stages/stage4_event_fields.h"

#undef DECLARE_CUSTOM_EVENT_CLASS
#define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, func, print)	\
static struct trace_event_fields trace_custom_event_fields_##call[] = {	\
	tstruct								\
	{} };

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

/* Stage 5 creates the helper function for dynamic fields */

#include "stages/stage5_get_offsets.h"

#undef DECLARE_CUSTOM_EVENT_CLASS
#define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static inline notrace int trace_custom_event_get_offsets_##call(	\
	struct trace_custom_event_data_offsets_##call *__data_offsets, proto) \
{									\
	int __data_size = 0;						\
	int __maybe_unused __item_length;				\
	struct trace_custom_event_raw_##call __maybe_unused *entry;	\
									\
	tstruct;							\
									\
	return __data_size;						\
}

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

/* Stage 6 creates the probe function that records the event */

#include "stages/stage6_event_callback.h"

#undef DECLARE_CUSTOM_EVENT_CLASS
#define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
									\
static notrace void							\
trace_custom_event_raw_event_##call(void *__data, proto)		\
{									\
	struct trace_event_file *trace_file = __data;			\
	struct trace_custom_event_data_offsets_##call __maybe_unused __data_offsets; \
	struct trace_event_buffer fbuffer;				\
	struct trace_custom_event_raw_##call *entry;			\
	int __data_size;						\
									\
	if (trace_trigger_soft_disabled(trace_file))			\
		return;							\
									\
	__data_size = trace_custom_event_get_offsets_##call(&__data_offsets, args); \
									\
	entry = trace_event_buffer_reserve(&fbuffer, trace_file,	\
				 sizeof(*entry) + __data_size);		\
									\
	if (!entry)							\
		return;							\
									\
	tstruct								\
									\
	{ assign; }							\
									\
	trace_event_buffer_commit(&fbuffer);				\
}
/*
 * The ftrace_test_custom_probe is compiled out, it is only here as a build time check
 * to make sure that if the tracepoint handling changes, the ftrace probe will
 * fail to compile unless it too is updated.
 */

#undef DEFINE_CUSTOM_EVENT
#define DEFINE_CUSTOM_EVENT(template, call, proto, args)		\
static inline void ftrace_test_custom_probe_##call(void)		\
{									\
	check_trace_callback_type_##call(trace_custom_event_raw_event_##template); \
}

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)

/* Stage 7 creates the actual class and event structure for the custom event */

#include "stages/stage7_class_define.h"

#undef DECLARE_CUSTOM_EVENT_CLASS
#define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
static char custom_print_fmt_##call[] = print;					\
static struct trace_event_class __used __refdata custom_event_class_##call = { \
	.system			= TRACE_SYSTEM_STRING,			\
	.fields_array		= trace_custom_event_fields_##call,		\
	.fields			= LIST_HEAD_INIT(custom_event_class_##call.fields),\
	.raw_init		= trace_event_raw_init,			\
	.probe			= trace_custom_event_raw_event_##call,	\
	.reg			= trace_event_reg,			\
};

#undef DEFINE_CUSTOM_EVENT
#define DEFINE_CUSTOM_EVENT(template, call, proto, args)		\
									\
static struct trace_event_call __used custom_event_##call = {		\
	.name			= #call,				\
	.class			= &custom_event_class_##template,	\
	.event.funcs		= &trace_custom_event_type_funcs_##template, \
	.print_fmt		= custom_print_fmt_##template,		\
	.flags			= TRACE_EVENT_FL_CUSTOM,		\
};									\
static inline int trace_custom_event_##call##_update(struct tracepoint *tp) \
{									\
	if (tp->name && strcmp(tp->name, #call) == 0) {			\
		custom_event_##call.tp = tp;				\
		custom_event_##call.flags = TRACE_EVENT_FL_TRACEPOINT;	\
		return 1;						\
	}								\
	return 0;							\
}									\
static struct trace_event_call __used					\
__section("_ftrace_events") *__custom_event_##call = &custom_event_##call

#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)