xref: /linux/kernel/trace/trace_export.c (revision a0b54e256d513ed99e456bea6e4e188ff92e7c46)
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 
19 #undef TRACE_STRUCT
20 #define TRACE_STRUCT(args...) args
21 
22 extern void __bad_type_size(void);
23 
24 #undef TRACE_FIELD
25 #define TRACE_FIELD(type, item, assign)					\
26 	if (sizeof(type) != sizeof(field.item))				\
27 		__bad_type_size();					\
28 	ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t"	\
29 			       "offset:%u;\tsize:%u;\n",		\
30 			       (unsigned int)offsetof(typeof(field), item), \
31 			       (unsigned int)sizeof(field.item));	\
32 	if (!ret)							\
33 		return 0;
34 
35 
36 #undef TRACE_FIELD_SPECIAL
37 #define TRACE_FIELD_SPECIAL(type_item, item, len, cmd)			\
38 	ret = trace_seq_printf(s, "\tfield special:" #type_item ";\t"	\
39 			       "offset:%u;\tsize:%u;\n",		\
40 			       (unsigned int)offsetof(typeof(field), item), \
41 			       (unsigned int)sizeof(field.item));	\
42 	if (!ret)							\
43 		return 0;
44 
45 #undef TRACE_FIELD_ZERO_CHAR
46 #define TRACE_FIELD_ZERO_CHAR(item)					\
47 	ret = trace_seq_printf(s, "\tfield:char " #item ";\t"		\
48 			       "offset:%u;\tsize:0;\n",			\
49 			       (unsigned int)offsetof(typeof(field), item)); \
50 	if (!ret)							\
51 		return 0;
52 
53 #undef TRACE_FIELD_SIGN
54 #define TRACE_FIELD_SIGN(type, item, assign, is_signed)	\
55 	TRACE_FIELD(type, item, assign)
56 
57 #undef TP_RAW_FMT
58 #define TP_RAW_FMT(args...) args
59 
60 #undef TRACE_EVENT_FORMAT
61 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)	\
62 static int								\
63 ftrace_format_##call(struct ftrace_event_call *unused,			\
64 		      struct trace_seq *s)				\
65 {									\
66 	struct args field;						\
67 	int ret;							\
68 									\
69 	tstruct;							\
70 									\
71 	trace_seq_printf(s, "\nprint fmt: \"%s\"\n", tpfmt);		\
72 									\
73 	return ret;							\
74 }
75 
76 #undef TRACE_EVENT_FORMAT_NOFILTER
77 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct,	\
78 				    tpfmt)				\
79 static int								\
80 ftrace_format_##call(struct ftrace_event_call *unused,			\
81 		      struct trace_seq *s)				\
82 {									\
83 	struct args field;						\
84 	int ret;							\
85 									\
86 	tstruct;							\
87 									\
88 	trace_seq_printf(s, "\nprint fmt: \"%s\"\n", tpfmt);		\
89 									\
90 	return ret;							\
91 }
92 
93 #include "trace_event_types.h"
94 
95 #undef TRACE_ZERO_CHAR
96 #define TRACE_ZERO_CHAR(arg)
97 
98 #undef TRACE_FIELD
99 #define TRACE_FIELD(type, item, assign)\
100 	entry->item = assign;
101 
102 #undef TRACE_FIELD
103 #define TRACE_FIELD(type, item, assign)\
104 	entry->item = assign;
105 
106 #undef TRACE_FIELD_SIGN
107 #define TRACE_FIELD_SIGN(type, item, assign, is_signed)	\
108 	TRACE_FIELD(type, item, assign)
109 
110 #undef TP_CMD
111 #define TP_CMD(cmd...)	cmd
112 
113 #undef TRACE_ENTRY
114 #define TRACE_ENTRY	entry
115 
116 #undef TRACE_FIELD_SPECIAL
117 #define TRACE_FIELD_SPECIAL(type_item, item, len, cmd)	\
118 	cmd;
119 
120 #undef TRACE_EVENT_FORMAT
121 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)	\
122 int ftrace_define_fields_##call(struct ftrace_event_call *event_call);	\
123 static int ftrace_raw_init_event_##call(void);				\
124 									\
125 struct ftrace_event_call __used						\
126 __attribute__((__aligned__(4)))						\
127 __attribute__((section("_ftrace_events"))) event_##call = {		\
128 	.name			= #call,				\
129 	.id			= proto,				\
130 	.system			= __stringify(TRACE_SYSTEM),		\
131 	.raw_init		= ftrace_raw_init_event_##call,		\
132 	.show_format		= ftrace_format_##call,			\
133 	.define_fields		= ftrace_define_fields_##call,		\
134 };									\
135 static int ftrace_raw_init_event_##call(void)				\
136 {									\
137 	INIT_LIST_HEAD(&event_##call.fields);				\
138 	return 0;							\
139 }									\
140 
141 #undef TRACE_EVENT_FORMAT_NOFILTER
142 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct,	\
143 				    tpfmt)				\
144 									\
145 struct ftrace_event_call __used						\
146 __attribute__((__aligned__(4)))						\
147 __attribute__((section("_ftrace_events"))) event_##call = {		\
148 	.name			= #call,				\
149 	.id			= proto,				\
150 	.system			= __stringify(TRACE_SYSTEM),		\
151 	.show_format		= ftrace_format_##call,			\
152 };
153 
154 #include "trace_event_types.h"
155 
156 #undef TRACE_FIELD
157 #define TRACE_FIELD(type, item, assign)					\
158 	ret = trace_define_field(event_call, #type, #item,		\
159 				 offsetof(typeof(field), item),		\
160 				 sizeof(field.item),			\
161 				 is_signed_type(type), FILTER_OTHER);	\
162 	if (ret)							\
163 		return ret;
164 
165 #undef TRACE_FIELD_SPECIAL
166 #define TRACE_FIELD_SPECIAL(type, item, len, cmd)			\
167 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
168 				 offsetof(typeof(field), item),		\
169 				 sizeof(field.item), 0, FILTER_OTHER);	\
170 	if (ret)							\
171 		return ret;
172 
173 #undef TRACE_FIELD_SIGN
174 #define TRACE_FIELD_SIGN(type, item, assign, is_signed)			\
175 	ret = trace_define_field(event_call, #type, #item,		\
176 				 offsetof(typeof(field), item),		\
177 				 sizeof(field.item), is_signed,		\
178 				 FILTER_OTHER);				\
179 	if (ret)							\
180 		return ret;
181 
182 #undef TRACE_FIELD_ZERO_CHAR
183 #define TRACE_FIELD_ZERO_CHAR(item)
184 
185 #undef TRACE_EVENT_FORMAT
186 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)	\
187 int									\
188 ftrace_define_fields_##call(struct ftrace_event_call *event_call)	\
189 {									\
190 	struct args field;						\
191 	int ret;							\
192 									\
193 	ret = trace_define_common_fields(event_call);			\
194 	if (ret)							\
195 		return ret;						\
196 									\
197 	tstruct;							\
198 									\
199 	return ret;							\
200 }
201 
202 #undef TRACE_EVENT_FORMAT_NOFILTER
203 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct,	\
204 				    tpfmt)
205 
206 #include "trace_event_types.h"
207