xref: /openbmc/linux/kernel/trace/trace_export.c (revision 2d700715)
1 /*
2  * trace_export.c - export basic ftrace utilities to user space
3  *
4  * Copyright (C) 2009 Steven Rostedt <srostedt@redhat.com>
5  */
6 #include <linux/stringify.h>
7 #include <linux/kallsyms.h>
8 #include <linux/seq_file.h>
9 #include <linux/uaccess.h>
10 #include <linux/ftrace.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 
14 #include "trace_output.h"
15 
16 #undef TRACE_SYSTEM
17 #define TRACE_SYSTEM	ftrace
18 
19 /*
20  * The FTRACE_ENTRY_REG macro allows ftrace entry to define register
21  * function and thus become accesible via perf.
22  */
23 #undef FTRACE_ENTRY_REG
24 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
25 			 filter, regfn) \
26 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
27 		     filter)
28 
29 /* not needed for this file */
30 #undef __field_struct
31 #define __field_struct(type, item)
32 
33 #undef __field
34 #define __field(type, item)				type item;
35 
36 #undef __field_desc
37 #define __field_desc(type, container, item)		type item;
38 
39 #undef __array
40 #define __array(type, item, size)			type item[size];
41 
42 #undef __array_desc
43 #define __array_desc(type, container, item, size)	type item[size];
44 
45 #undef __dynamic_array
46 #define __dynamic_array(type, item)			type item[];
47 
48 #undef F_STRUCT
49 #define F_STRUCT(args...)				args
50 
51 #undef F_printk
52 #define F_printk(fmt, args...) fmt, args
53 
54 #undef FTRACE_ENTRY
55 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
56 struct ____ftrace_##name {						\
57 	tstruct								\
58 };									\
59 static void __always_unused ____ftrace_check_##name(void)		\
60 {									\
61 	struct ____ftrace_##name *__entry = NULL;			\
62 									\
63 	/* force compile-time check on F_printk() */			\
64 	printk(print);							\
65 }
66 
67 #undef FTRACE_ENTRY_DUP
68 #define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print, filter)	\
69 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
70 		     filter)
71 
72 #include "trace_entries.h"
73 
74 #undef __field
75 #define __field(type, item)						\
76 	ret = trace_define_field(event_call, #type, #item,		\
77 				 offsetof(typeof(field), item),		\
78 				 sizeof(field.item),			\
79 				 is_signed_type(type), filter_type);	\
80 	if (ret)							\
81 		return ret;
82 
83 #undef __field_desc
84 #define __field_desc(type, container, item)	\
85 	ret = trace_define_field(event_call, #type, #item,		\
86 				 offsetof(typeof(field),		\
87 					  container.item),		\
88 				 sizeof(field.container.item),		\
89 				 is_signed_type(type), filter_type);	\
90 	if (ret)							\
91 		return ret;
92 
93 #undef __array
94 #define __array(type, item, len)					\
95 	do {								\
96 		char *type_str = #type"["__stringify(len)"]";		\
97 		BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);			\
98 		ret = trace_define_field(event_call, type_str, #item,	\
99 				 offsetof(typeof(field), item),		\
100 				 sizeof(field.item),			\
101 				 is_signed_type(type), filter_type);	\
102 		if (ret)						\
103 			return ret;					\
104 	} while (0);
105 
106 #undef __array_desc
107 #define __array_desc(type, container, item, len)			\
108 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
109 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
110 				 offsetof(typeof(field),		\
111 					  container.item),		\
112 				 sizeof(field.container.item),		\
113 				 is_signed_type(type), filter_type);	\
114 	if (ret)							\
115 		return ret;
116 
117 #undef __dynamic_array
118 #define __dynamic_array(type, item)					\
119 	ret = trace_define_field(event_call, #type, #item,		\
120 				 offsetof(typeof(field), item),		\
121 				 0, is_signed_type(type), filter_type);\
122 	if (ret)							\
123 		return ret;
124 
125 #undef FTRACE_ENTRY
126 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
127 static int __init							\
128 ftrace_define_fields_##name(struct trace_event_call *event_call)	\
129 {									\
130 	struct struct_name field;					\
131 	int ret;							\
132 	int filter_type = filter;					\
133 									\
134 	tstruct;							\
135 									\
136 	return ret;							\
137 }
138 
139 #include "trace_entries.h"
140 
141 #undef __entry
142 #define __entry REC
143 
144 #undef __field
145 #define __field(type, item)
146 
147 #undef __field_desc
148 #define __field_desc(type, container, item)
149 
150 #undef __array
151 #define __array(type, item, len)
152 
153 #undef __array_desc
154 #define __array_desc(type, container, item, len)
155 
156 #undef __dynamic_array
157 #define __dynamic_array(type, item)
158 
159 #undef F_printk
160 #define F_printk(fmt, args...) __stringify(fmt) ", "  __stringify(args)
161 
162 #undef FTRACE_ENTRY_REG
163 #define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, filter,\
164 			 regfn)						\
165 									\
166 struct trace_event_class __refdata event_class_ftrace_##call = {	\
167 	.system			= __stringify(TRACE_SYSTEM),		\
168 	.define_fields		= ftrace_define_fields_##call,		\
169 	.fields			= LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
170 	.reg			= regfn,				\
171 };									\
172 									\
173 struct trace_event_call __used event_##call = {				\
174 	.class			= &event_class_ftrace_##call,		\
175 	{								\
176 		.name			= #call,			\
177 	},								\
178 	.event.type		= etype,				\
179 	.print_fmt		= print,				\
180 	.flags			= TRACE_EVENT_FL_IGNORE_ENABLE,		\
181 };									\
182 struct trace_event_call __used						\
183 __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call;
184 
185 #undef FTRACE_ENTRY
186 #define FTRACE_ENTRY(call, struct_name, etype, tstruct, print, filter)	\
187 	FTRACE_ENTRY_REG(call, struct_name, etype,			\
188 			 PARAMS(tstruct), PARAMS(print), filter, NULL)
189 
190 int ftrace_event_is_function(struct trace_event_call *call)
191 {
192 	return call == &event_function;
193 }
194 
195 #include "trace_entries.h"
196