xref: /linux/kernel/trace/trace_export.c (revision 98b8788ae91694499d1995035625bea16a4db0c4)
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), 0, FILTER_OTHER);	\
162 	if (ret)							\
163 		return ret;
164 
165 #undef __array_desc
166 #define __array_desc(type, container, item, len)			\
167 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
168 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
169 				 offsetof(typeof(field),		\
170 					  container.item),		\
171 				 sizeof(field.container.item), 0,	\
172 				 FILTER_OTHER);				\
173 	if (ret)							\
174 		return ret;
175 
176 #undef __dynamic_array
177 #define __dynamic_array(type, item)
178 
179 #undef FTRACE_ENTRY
180 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
181 int									\
182 ftrace_define_fields_##name(struct ftrace_event_call *event_call)	\
183 {									\
184 	struct struct_name field;					\
185 	int ret;							\
186 									\
187 	ret = trace_define_common_fields(event_call);			\
188 	if (ret)							\
189 		return ret;						\
190 									\
191 	tstruct;							\
192 									\
193 	return ret;							\
194 }
195 
196 #include "trace_entries.h"
197 
198 static int ftrace_raw_init_event(struct ftrace_event_call *call)
199 {
200 	INIT_LIST_HEAD(&call->fields);
201 	return 0;
202 }
203 
204 #undef __field
205 #define __field(type, item)
206 
207 #undef __field_desc
208 #define __field_desc(type, container, item)
209 
210 #undef __array
211 #define __array(type, item, len)
212 
213 #undef __array_desc
214 #define __array_desc(type, container, item, len)
215 
216 #undef __dynamic_array
217 #define __dynamic_array(type, item)
218 
219 #undef FTRACE_ENTRY
220 #define FTRACE_ENTRY(call, struct_name, type, tstruct, print)		\
221 									\
222 struct ftrace_event_call __used						\
223 __attribute__((__aligned__(4)))						\
224 __attribute__((section("_ftrace_events"))) event_##call = {		\
225 	.name			= #call,				\
226 	.id			= type,					\
227 	.system			= __stringify(TRACE_SYSTEM),		\
228 	.raw_init		= ftrace_raw_init_event,		\
229 	.show_format		= ftrace_format_##call,			\
230 	.define_fields		= ftrace_define_fields_##call,		\
231 };									\
232 
233 #include "trace_entries.h"
234