xref: /openbmc/linux/kernel/trace/trace_export.c (revision fd589a8f)
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 __used ____ftrace_check_##name(void)		\
52 {								\
53 	struct ____ftrace_##name *__entry = NULL;		\
54 								\
55 	/* force cmpile-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;\n",		\
70 			       offsetof(typeof(field), item),		\
71 			       sizeof(field.item));			\
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;\n",		\
79 			       offsetof(typeof(field), container.item),	\
80 			       sizeof(field.container.item));		\
81 	if (!ret)							\
82 		return 0;
83 
84 #undef __array
85 #define __array(type, item, len)					\
86 	ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \
87 			       "offset:%zu;\tsize:%zu;\n",		\
88 			       offsetof(typeof(field), item),	\
89 			       sizeof(field.item));		\
90 	if (!ret)							\
91 		return 0;
92 
93 #undef __array_desc
94 #define __array_desc(type, container, item, len)			\
95 	ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \
96 			       "offset:%zu;\tsize:%zu;\n",		\
97 			       offsetof(typeof(field), container.item),	\
98 			       sizeof(field.container.item));		\
99 	if (!ret)							\
100 		return 0;
101 
102 #undef __dynamic_array
103 #define __dynamic_array(type, item)					\
104 	ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"	\
105 			       "offset:%zu;\tsize:0;\n",		\
106 			       offsetof(typeof(field), item));		\
107 	if (!ret)							\
108 		return 0;
109 
110 #undef F_printk
111 #define F_printk(fmt, args...) "%s, %s\n", #fmt, __stringify(args)
112 
113 #undef __entry
114 #define __entry REC
115 
116 #undef FTRACE_ENTRY
117 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
118 static int								\
119 ftrace_format_##name(struct ftrace_event_call *unused,			\
120 		     struct trace_seq *s)				\
121 {									\
122 	struct struct_name field __attribute__((unused));		\
123 	int ret = 0;							\
124 									\
125 	tstruct;							\
126 									\
127 	trace_seq_printf(s, "\nprint fmt: " print);			\
128 									\
129 	return ret;							\
130 }
131 
132 #include "trace_entries.h"
133 
134 
135 #undef __field
136 #define __field(type, item)						\
137 	ret = trace_define_field(event_call, #type, #item,		\
138 				 offsetof(typeof(field), item),		\
139 				 sizeof(field.item),			\
140 				 is_signed_type(type), FILTER_OTHER);	\
141 	if (ret)							\
142 		return ret;
143 
144 #undef __field_desc
145 #define __field_desc(type, container, item)	\
146 	ret = trace_define_field(event_call, #type, #item,		\
147 				 offsetof(typeof(field),		\
148 					  container.item),		\
149 				 sizeof(field.container.item),		\
150 				 is_signed_type(type), FILTER_OTHER);	\
151 	if (ret)							\
152 		return ret;
153 
154 #undef __array
155 #define __array(type, item, len)					\
156 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
157 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
158 				 offsetof(typeof(field), item),		\
159 				 sizeof(field.item), 0, FILTER_OTHER);	\
160 	if (ret)							\
161 		return ret;
162 
163 #undef __array_desc
164 #define __array_desc(type, container, item, len)			\
165 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
166 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
167 				 offsetof(typeof(field),		\
168 					  container.item),		\
169 				 sizeof(field.container.item), 0,	\
170 				 FILTER_OTHER);				\
171 	if (ret)							\
172 		return ret;
173 
174 #undef __dynamic_array
175 #define __dynamic_array(type, item)
176 
177 #undef FTRACE_ENTRY
178 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
179 int									\
180 ftrace_define_fields_##name(struct ftrace_event_call *event_call)	\
181 {									\
182 	struct struct_name field;					\
183 	int ret;							\
184 									\
185 	ret = trace_define_common_fields(event_call);			\
186 	if (ret)							\
187 		return ret;						\
188 									\
189 	tstruct;							\
190 									\
191 	return ret;							\
192 }
193 
194 #include "trace_entries.h"
195 
196 
197 #undef __field
198 #define __field(type, item)
199 
200 #undef __field_desc
201 #define __field_desc(type, container, item)
202 
203 #undef __array
204 #define __array(type, item, len)
205 
206 #undef __array_desc
207 #define __array_desc(type, container, item, len)
208 
209 #undef __dynamic_array
210 #define __dynamic_array(type, item)
211 
212 #undef FTRACE_ENTRY
213 #define FTRACE_ENTRY(call, struct_name, type, tstruct, print)		\
214 static int ftrace_raw_init_event_##call(void);				\
215 									\
216 struct ftrace_event_call __used						\
217 __attribute__((__aligned__(4)))						\
218 __attribute__((section("_ftrace_events"))) event_##call = {		\
219 	.name			= #call,				\
220 	.id			= type,					\
221 	.system			= __stringify(TRACE_SYSTEM),		\
222 	.raw_init		= ftrace_raw_init_event_##call,		\
223 	.show_format		= ftrace_format_##call,			\
224 	.define_fields		= ftrace_define_fields_##call,		\
225 };									\
226 static int ftrace_raw_init_event_##call(void)				\
227 {									\
228 	INIT_LIST_HEAD(&event_##call.fields);				\
229 	return 0;							\
230 }									\
231 
232 #include "trace_entries.h"
233