trace_export.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * trace_export.c - export basic ftrace utilities to user space
  4 *
  5 * Copyright (C) 2009 Steven Rostedt <srostedt@redhat.com>
  6 */
  7#include <linux/stringify.h>
  8#include <linux/kallsyms.h>
  9#include <linux/seq_file.h>
 10#include <linux/uaccess.h>
 11#include <linux/ftrace.h>
 12#include <linux/module.h>
 13#include <linux/init.h>
 14
 15#include "trace_output.h"
 16
 17/* Stub function for events with triggers */
 18static int ftrace_event_register(struct trace_event_call *call,
 19				 enum trace_reg type, void *data)
 20{
 21	return 0;
 22}
 23
 24#undef TRACE_SYSTEM
 25#define TRACE_SYSTEM	ftrace
 26
 27/*
 28 * The FTRACE_ENTRY_REG macro allows ftrace entry to define register
 29 * function and thus become accessible via perf.
 30 */
 31#undef FTRACE_ENTRY_REG
 32#define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, regfn) \
 33	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
 34
 35/* not needed for this file */
 36#undef __field_struct
 37#define __field_struct(type, item)
 38
 39#undef __field
 40#define __field(type, item)				type item;
 41
 42#undef __field_fn
 43#define __field_fn(type, item)				type item;
 44
 45#undef __field_packed
 46#define __field_packed(type, item)			type item;
 47
 48#undef __field_desc
 49#define __field_desc(type, container, item)		type item;
 50
 51#undef __field_desc_packed
 52#define __field_desc_packed(type, container, item)	type item;
 53
 54#undef __array
 55#define __array(type, item, size)			type item[size];
 56
 57#undef __stack_array
 58#define __stack_array(type, item, size, field)		__array(type, item, size)
 59
 60#undef __array_desc
 61#define __array_desc(type, container, item, size)	type item[size];
 62
 63#undef __dynamic_array
 64#define __dynamic_array(type, item)			type item[];
 65
 66#undef F_STRUCT
 67#define F_STRUCT(args...)				args
 68
 69#undef F_printk
 70#define F_printk(fmt, args...) fmt, args
 71
 72#undef FTRACE_ENTRY
 73#define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
 74struct ____ftrace_##name {						\
 75	tstruct								\
 76};									\
 77static void __always_unused ____ftrace_check_##name(void)		\
 78{									\
 79	struct ____ftrace_##name *__entry = NULL;			\
 80									\
 81	/* force compile-time check on F_printk() */			\
 82	printk(print);							\
 83}
 84
 85#undef FTRACE_ENTRY_DUP
 86#define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print)		\
 87	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
 88
 89#include "trace_entries.h"
 90
 91#undef __field_ext
 92#define __field_ext(_type, _item, _filter_type) {			\
 93	.type = #_type, .name = #_item,					\
 94	.size = sizeof(_type), .align = __alignof__(_type),		\
 95	is_signed_type(_type), .filter_type = _filter_type },
 96
 97
 98#undef __field_ext_packed
 99#define __field_ext_packed(_type, _item, _filter_type) {	\
100	.type = #_type, .name = #_item,				\
101	.size = sizeof(_type), .align = 1,			\
102	is_signed_type(_type), .filter_type = _filter_type },
103
104#undef __field
105#define __field(_type, _item) __field_ext(_type, _item, FILTER_OTHER)
106
107#undef __field_fn
108#define __field_fn(_type, _item) __field_ext(_type, _item, FILTER_TRACE_FN)
109
110#undef __field_packed
111#define __field_packed(_type, _item) __field_ext_packed(_type, _item, FILTER_OTHER)
112
113#undef __field_desc
114#define __field_desc(_type, _container, _item) __field_ext(_type, _item, FILTER_OTHER)
115
116#undef __field_desc_packed
117#define __field_desc_packed(_type, _container, _item) __field_ext_packed(_type, _item, FILTER_OTHER)
118
119#undef __array
120#define __array(_type, _item, _len) {					\
121	.type = #_type"["__stringify(_len)"]", .name = #_item,		\
122	.size = sizeof(_type[_len]), .align = __alignof__(_type),	\
123	is_signed_type(_type), .filter_type = FILTER_OTHER,			\
124	.len = _len },
125
126#undef __stack_array
127#define __stack_array(_type, _item, _len, _field) __array(_type, _item, _len)
128
129#undef __array_desc
130#define __array_desc(_type, _container, _item, _len) __array(_type, _item, _len)
131
132#undef __dynamic_array
133#define __dynamic_array(_type, _item) {					\
134	.type = #_type "[]", .name = #_item,				\
135	.size = 0, .align = __alignof__(_type),				\
136	is_signed_type(_type), .filter_type = FILTER_OTHER },
137
138#undef FTRACE_ENTRY
139#define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
140static struct trace_event_fields ftrace_event_fields_##name[] = {	\
141	tstruct								\
142	{} };
143
144#include "trace_entries.h"
145
146#undef __entry
147#define __entry REC
148
149#undef __field
150#define __field(type, item)
151
152#undef __field_fn
153#define __field_fn(type, item)
154
155#undef __field_packed
156#define __field_packed(type, item)
157
158#undef __field_desc
159#define __field_desc(type, container, item)
160
161#undef __field_desc_packed
162#define __field_desc_packed(type, container, item)
163
164#undef __array
165#define __array(type, item, len)
166
167#undef __stack_array
168#define __stack_array(type, item, len, field)
169
170#undef __array_desc
171#define __array_desc(type, container, item, len)
172
173#undef __dynamic_array
174#define __dynamic_array(type, item)
175
176#undef F_printk
177#define F_printk(fmt, args...) __stringify(fmt) ", "  __stringify(args)
178
179#undef FTRACE_ENTRY_REG
180#define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, regfn) \
181static struct trace_event_class __refdata event_class_ftrace_##call = {	\
182	.system			= __stringify(TRACE_SYSTEM),		\
183	.fields_array		= ftrace_event_fields_##call,		\
184	.fields			= LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
185	.reg			= regfn,				\
186};									\
187									\
188struct trace_event_call __used event_##call = {				\
189	.class			= &event_class_ftrace_##call,		\
190	{								\
191		.name			= #call,			\
192	},								\
193	.event.type		= etype,				\
194	.print_fmt		= print,				\
195	.flags			= TRACE_EVENT_FL_IGNORE_ENABLE,		\
196};									\
197static struct trace_event_call __used						\
198__section("_ftrace_events") *__event_##call = &event_##call;
199
200#undef FTRACE_ENTRY
201#define FTRACE_ENTRY(call, struct_name, etype, tstruct, print)		\
202	FTRACE_ENTRY_REG(call, struct_name, etype,			\
203			 PARAMS(tstruct), PARAMS(print), NULL)
204
205bool ftrace_event_is_function(struct trace_event_call *call)
206{
207	return call == &event_function;
208}
209
210#include "trace_entries.h"