xref: /openbmc/linux/kernel/trace/trace_export.c (revision 7dd65feb)
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/debugfs.h>
10 #include <linux/uaccess.h>
11 #include <linux/ftrace.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/fs.h>
15 
16 #include "trace_output.h"
17 
18 #undef TRACE_SYSTEM
19 #define TRACE_SYSTEM	ftrace
20 
21 /* not needed for this file */
22 #undef __field_struct
23 #define __field_struct(type, item)
24 
25 #undef __field
26 #define __field(type, item)				type item;
27 
28 #undef __field_desc
29 #define __field_desc(type, container, item)		type item;
30 
31 #undef __array
32 #define __array(type, item, size)			type item[size];
33 
34 #undef __array_desc
35 #define __array_desc(type, container, item, size)	type item[size];
36 
37 #undef __dynamic_array
38 #define __dynamic_array(type, item)			type item[];
39 
40 #undef F_STRUCT
41 #define F_STRUCT(args...)				args
42 
43 #undef F_printk
44 #define F_printk(fmt, args...) fmt, args
45 
46 #undef FTRACE_ENTRY
47 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)	\
48 struct ____ftrace_##name {					\
49 	tstruct							\
50 };								\
51 static void __always_unused ____ftrace_check_##name(void)	\
52 {								\
53 	struct ____ftrace_##name *__entry = NULL;		\
54 								\
55 	/* force compile-time check on F_printk() */		\
56 	printk(print);						\
57 }
58 
59 #undef FTRACE_ENTRY_DUP
60 #define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print)	\
61 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print))
62 
63 #include "trace_entries.h"
64 
65 
66 #undef __field
67 #define __field(type, item)						\
68 	ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"	\
69 			       "offset:%zu;\tsize:%zu;\tsigned:%u;\n",	\
70 			       offsetof(typeof(field), item),		\
71 			       sizeof(field.item), is_signed_type(type)); \
72 	if (!ret)							\
73 		return 0;
74 
75 #undef __field_desc
76 #define __field_desc(type, container, item)				\
77 	ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"	\
78 			       "offset:%zu;\tsize:%zu;\tsigned:%u;\n",	\
79 			       offsetof(typeof(field), container.item),	\
80 			       sizeof(field.container.item),		\
81 			       is_signed_type(type));			\
82 	if (!ret)							\
83 		return 0;
84 
85 #undef __array
86 #define __array(type, item, len)					\
87 	ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \
88 			       "offset:%zu;\tsize:%zu;\tsigned:%u;\n",	\
89 			       offsetof(typeof(field), item),		\
90 			       sizeof(field.item), is_signed_type(type)); \
91 	if (!ret)							\
92 		return 0;
93 
94 #undef __array_desc
95 #define __array_desc(type, container, item, len)			\
96 	ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \
97 			       "offset:%zu;\tsize:%zu;\tsigned:%u;\n",	\
98 			       offsetof(typeof(field), container.item),	\
99 			       sizeof(field.container.item),		\
100 			       is_signed_type(type));			\
101 	if (!ret)							\
102 		return 0;
103 
104 #undef __dynamic_array
105 #define __dynamic_array(type, item)					\
106 	ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"	\
107 			       "offset:%zu;\tsize:0;\tsigned:%u;\n",	\
108 			       offsetof(typeof(field), item),		\
109 			       is_signed_type(type));			\
110 	if (!ret)							\
111 		return 0;
112 
113 #undef F_printk
114 #define F_printk(fmt, args...) "%s, %s\n", #fmt, __stringify(args)
115 
116 #undef __entry
117 #define __entry REC
118 
119 #undef FTRACE_ENTRY
120 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
121 static int								\
122 ftrace_format_##name(struct ftrace_event_call *unused,			\
123 		     struct trace_seq *s)				\
124 {									\
125 	struct struct_name field __attribute__((unused));		\
126 	int ret = 0;							\
127 									\
128 	tstruct;							\
129 									\
130 	trace_seq_printf(s, "\nprint fmt: " print);			\
131 									\
132 	return ret;							\
133 }
134 
135 #include "trace_entries.h"
136 
137 #undef __field
138 #define __field(type, item)						\
139 	ret = trace_define_field(event_call, #type, #item,		\
140 				 offsetof(typeof(field), item),		\
141 				 sizeof(field.item),			\
142 				 is_signed_type(type), FILTER_OTHER);	\
143 	if (ret)							\
144 		return ret;
145 
146 #undef __field_desc
147 #define __field_desc(type, container, item)	\
148 	ret = trace_define_field(event_call, #type, #item,		\
149 				 offsetof(typeof(field),		\
150 					  container.item),		\
151 				 sizeof(field.container.item),		\
152 				 is_signed_type(type), FILTER_OTHER);	\
153 	if (ret)							\
154 		return ret;
155 
156 #undef __array
157 #define __array(type, item, len)					\
158 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
159 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
160 				 offsetof(typeof(field), item),		\
161 				 sizeof(field.item),			\
162 				 is_signed_type(type), FILTER_OTHER);	\
163 	if (ret)							\
164 		return ret;
165 
166 #undef __array_desc
167 #define __array_desc(type, container, item, len)			\
168 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
169 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
170 				 offsetof(typeof(field),		\
171 					  container.item),		\
172 				 sizeof(field.container.item),		\
173 				 is_signed_type(type), FILTER_OTHER);	\
174 	if (ret)							\
175 		return ret;
176 
177 #undef __dynamic_array
178 #define __dynamic_array(type, item)
179 
180 #undef FTRACE_ENTRY
181 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
182 int									\
183 ftrace_define_fields_##name(struct ftrace_event_call *event_call)	\
184 {									\
185 	struct struct_name field;					\
186 	int ret;							\
187 									\
188 	tstruct;							\
189 									\
190 	return ret;							\
191 }
192 
193 #include "trace_entries.h"
194 
195 static int ftrace_raw_init_event(struct ftrace_event_call *call)
196 {
197 	INIT_LIST_HEAD(&call->fields);
198 	return 0;
199 }
200 
201 #undef __field
202 #define __field(type, item)
203 
204 #undef __field_desc
205 #define __field_desc(type, container, item)
206 
207 #undef __array
208 #define __array(type, item, len)
209 
210 #undef __array_desc
211 #define __array_desc(type, container, item, len)
212 
213 #undef __dynamic_array
214 #define __dynamic_array(type, item)
215 
216 #undef FTRACE_ENTRY
217 #define FTRACE_ENTRY(call, struct_name, type, tstruct, print)		\
218 									\
219 struct ftrace_event_call __used						\
220 __attribute__((__aligned__(4)))						\
221 __attribute__((section("_ftrace_events"))) event_##call = {		\
222 	.name			= #call,				\
223 	.id			= type,					\
224 	.system			= __stringify(TRACE_SYSTEM),		\
225 	.raw_init		= ftrace_raw_init_event,		\
226 	.show_format		= ftrace_format_##call,			\
227 	.define_fields		= ftrace_define_fields_##call,		\
228 };									\
229 
230 #include "trace_entries.h"
231