xref: /linux/kernel/trace/trace_export.c (revision cc4589ebfae6f8dbb5cf880a0a67eedab3416492)
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 #undef __field
66 #define __field(type, item)						\
67 	ret = trace_define_field(event_call, #type, #item,		\
68 				 offsetof(typeof(field), item),		\
69 				 sizeof(field.item),			\
70 				 is_signed_type(type), FILTER_OTHER);	\
71 	if (ret)							\
72 		return ret;
73 
74 #undef __field_desc
75 #define __field_desc(type, container, item)	\
76 	ret = trace_define_field(event_call, #type, #item,		\
77 				 offsetof(typeof(field),		\
78 					  container.item),		\
79 				 sizeof(field.container.item),		\
80 				 is_signed_type(type), FILTER_OTHER);	\
81 	if (ret)							\
82 		return ret;
83 
84 #undef __array
85 #define __array(type, item, len)					\
86 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
87 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
88 				 offsetof(typeof(field), item),		\
89 				 sizeof(field.item),			\
90 				 is_signed_type(type), FILTER_OTHER);	\
91 	if (ret)							\
92 		return ret;
93 
94 #undef __array_desc
95 #define __array_desc(type, container, item, len)			\
96 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
97 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
98 				 offsetof(typeof(field),		\
99 					  container.item),		\
100 				 sizeof(field.container.item),		\
101 				 is_signed_type(type), FILTER_OTHER);	\
102 	if (ret)							\
103 		return ret;
104 
105 #undef __dynamic_array
106 #define __dynamic_array(type, item)					\
107 	ret = trace_define_field(event_call, #type, #item,		\
108 				 offsetof(typeof(field), item),		\
109 				 0, is_signed_type(type), FILTER_OTHER);\
110 	if (ret)							\
111 		return ret;
112 
113 #undef FTRACE_ENTRY
114 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
115 int									\
116 ftrace_define_fields_##name(struct ftrace_event_call *event_call)	\
117 {									\
118 	struct struct_name field;					\
119 	int ret;							\
120 									\
121 	tstruct;							\
122 									\
123 	return ret;							\
124 }
125 
126 #include "trace_entries.h"
127 
128 #undef __entry
129 #define __entry REC
130 
131 #undef __field
132 #define __field(type, item)
133 
134 #undef __field_desc
135 #define __field_desc(type, container, item)
136 
137 #undef __array
138 #define __array(type, item, len)
139 
140 #undef __array_desc
141 #define __array_desc(type, container, item, len)
142 
143 #undef __dynamic_array
144 #define __dynamic_array(type, item)
145 
146 #undef F_printk
147 #define F_printk(fmt, args...) #fmt ", "  __stringify(args)
148 
149 #undef FTRACE_ENTRY
150 #define FTRACE_ENTRY(call, struct_name, etype, tstruct, print)		\
151 									\
152 struct ftrace_event_class event_class_ftrace_##call = {			\
153 	.system			= __stringify(TRACE_SYSTEM),		\
154 	.define_fields		= ftrace_define_fields_##call,		\
155 	.fields			= LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
156 };									\
157 									\
158 struct ftrace_event_call __used						\
159 __attribute__((__aligned__(4)))						\
160 __attribute__((section("_ftrace_events"))) event_##call = {		\
161 	.name			= #call,				\
162 	.event.type		= etype,				\
163 	.class			= &event_class_ftrace_##call,		\
164 	.print_fmt		= print,				\
165 };									\
166 
167 #include "trace_entries.h"
168