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 */
ftrace_event_register(struct trace_event_call * call,enum trace_reg type,void * data)18 static 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_desc
46 #define __field_desc(type, container, item)		type item;
47 
48 #undef __field_packed
49 #define __field_packed(type, container, item)		type item;
50 
51 #undef __array
52 #define __array(type, item, size)			type item[size];
53 
54 #undef __stack_array
55 #define __stack_array(type, item, size, field)		__array(type, item, size)
56 
57 #undef __array_desc
58 #define __array_desc(type, container, item, size)	type item[size];
59 
60 #undef __dynamic_array
61 #define __dynamic_array(type, item)			type item[];
62 
63 #undef F_STRUCT
64 #define F_STRUCT(args...)				args
65 
66 #undef F_printk
67 #define F_printk(fmt, args...) fmt, args
68 
69 #undef FTRACE_ENTRY
70 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
71 struct ____ftrace_##name {						\
72 	tstruct								\
73 };									\
74 static void __always_unused ____ftrace_check_##name(void)		\
75 {									\
76 	struct ____ftrace_##name *__entry = NULL;			\
77 									\
78 	/* force compile-time check on F_printk() */			\
79 	printk(print);							\
80 }
81 
82 #undef FTRACE_ENTRY_DUP
83 #define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print)		\
84 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
85 
86 #include "trace_entries.h"
87 
88 #undef __field_ext
89 #define __field_ext(_type, _item, _filter_type) {			\
90 	.type = #_type, .name = #_item,					\
91 	.size = sizeof(_type), .align = __alignof__(_type),		\
92 	is_signed_type(_type), .filter_type = _filter_type },
93 
94 
95 #undef __field_ext_packed
96 #define __field_ext_packed(_type, _item, _filter_type) {	\
97 	.type = #_type, .name = #_item,				\
98 	.size = sizeof(_type), .align = 1,			\
99 	is_signed_type(_type), .filter_type = _filter_type },
100 
101 #undef __field
102 #define __field(_type, _item) __field_ext(_type, _item, FILTER_OTHER)
103 
104 #undef __field_fn
105 #define __field_fn(_type, _item) __field_ext(_type, _item, FILTER_TRACE_FN)
106 
107 #undef __field_desc
108 #define __field_desc(_type, _container, _item) __field_ext(_type, _item, FILTER_OTHER)
109 
110 #undef __field_packed
111 #define __field_packed(_type, _container, _item) __field_ext_packed(_type, _item, FILTER_OTHER)
112 
113 #undef __array
114 #define __array(_type, _item, _len) {					\
115 	.type = #_type"["__stringify(_len)"]", .name = #_item,		\
116 	.size = sizeof(_type[_len]), .align = __alignof__(_type),	\
117 	is_signed_type(_type), .filter_type = FILTER_OTHER,			\
118 	.len = _len },
119 
120 #undef __stack_array
121 #define __stack_array(_type, _item, _len, _field) __array(_type, _item, _len)
122 
123 #undef __array_desc
124 #define __array_desc(_type, _container, _item, _len) __array(_type, _item, _len)
125 
126 #undef __dynamic_array
127 #define __dynamic_array(_type, _item) {					\
128 	.type = #_type "[]", .name = #_item,				\
129 	.size = 0, .align = __alignof__(_type),				\
130 	is_signed_type(_type), .filter_type = FILTER_OTHER },
131 
132 #undef FTRACE_ENTRY
133 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
134 static struct trace_event_fields ftrace_event_fields_##name[] = {	\
135 	tstruct								\
136 	{} };
137 
138 #include "trace_entries.h"
139 
140 #undef __entry
141 #define __entry REC
142 
143 #undef __field
144 #define __field(type, item)
145 
146 #undef __field_fn
147 #define __field_fn(type, item)
148 
149 #undef __field_desc
150 #define __field_desc(type, container, item)
151 
152 #undef __field_packed
153 #define __field_packed(type, container, item)
154 
155 #undef __array
156 #define __array(type, item, len)
157 
158 #undef __stack_array
159 #define __stack_array(type, item, len, field)
160 
161 #undef __array_desc
162 #define __array_desc(type, container, item, len)
163 
164 #undef __dynamic_array
165 #define __dynamic_array(type, item)
166 
167 #undef F_printk
168 #define F_printk(fmt, args...) __stringify(fmt) ", "  __stringify(args)
169 
170 #undef FTRACE_ENTRY_REG
171 #define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, regfn) \
172 static struct trace_event_class __refdata event_class_ftrace_##call = {	\
173 	.system			= __stringify(TRACE_SYSTEM),		\
174 	.fields_array		= ftrace_event_fields_##call,		\
175 	.fields			= LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
176 	.reg			= regfn,				\
177 };									\
178 									\
179 struct trace_event_call __used event_##call = {				\
180 	.class			= &event_class_ftrace_##call,		\
181 	{								\
182 		.name			= #call,			\
183 	},								\
184 	.event.type		= etype,				\
185 	.print_fmt		= print,				\
186 	.flags			= TRACE_EVENT_FL_IGNORE_ENABLE,		\
187 };									\
188 static struct trace_event_call __used						\
189 __section("_ftrace_events") *__event_##call = &event_##call;
190 
191 #undef FTRACE_ENTRY
192 #define FTRACE_ENTRY(call, struct_name, etype, tstruct, print)		\
193 	FTRACE_ENTRY_REG(call, struct_name, etype,			\
194 			 PARAMS(tstruct), PARAMS(print), NULL)
195 
ftrace_event_is_function(struct trace_event_call * call)196 bool ftrace_event_is_function(struct trace_event_call *call)
197 {
198 	return call == &event_function;
199 }
200 
201 #include "trace_entries.h"
202