xref: /openbmc/linux/kernel/trace/trace_export.c (revision 35bb4399)
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 /*
22  * The FTRACE_ENTRY_REG macro allows ftrace entry to define register
23  * function and thus become accesible via perf.
24  */
25 #undef FTRACE_ENTRY_REG
26 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
27 			 filter, regfn) \
28 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
29 		     filter)
30 
31 /* not needed for this file */
32 #undef __field_struct
33 #define __field_struct(type, item)
34 
35 #undef __field
36 #define __field(type, item)				type item;
37 
38 #undef __field_desc
39 #define __field_desc(type, container, item)		type item;
40 
41 #undef __array
42 #define __array(type, item, size)			type item[size];
43 
44 #undef __array_desc
45 #define __array_desc(type, container, item, size)	type item[size];
46 
47 #undef __dynamic_array
48 #define __dynamic_array(type, item)			type item[];
49 
50 #undef F_STRUCT
51 #define F_STRUCT(args...)				args
52 
53 #undef F_printk
54 #define F_printk(fmt, args...) fmt, args
55 
56 #undef FTRACE_ENTRY
57 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
58 struct ____ftrace_##name {						\
59 	tstruct								\
60 };									\
61 static void __always_unused ____ftrace_check_##name(void)		\
62 {									\
63 	struct ____ftrace_##name *__entry = NULL;			\
64 									\
65 	/* force compile-time check on F_printk() */			\
66 	printk(print);							\
67 }
68 
69 #undef FTRACE_ENTRY_DUP
70 #define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print, filter)	\
71 	FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
72 		     filter)
73 
74 #include "trace_entries.h"
75 
76 #undef __field
77 #define __field(type, item)						\
78 	ret = trace_define_field(event_call, #type, #item,		\
79 				 offsetof(typeof(field), item),		\
80 				 sizeof(field.item),			\
81 				 is_signed_type(type), filter_type);	\
82 	if (ret)							\
83 		return ret;
84 
85 #undef __field_desc
86 #define __field_desc(type, container, item)	\
87 	ret = trace_define_field(event_call, #type, #item,		\
88 				 offsetof(typeof(field),		\
89 					  container.item),		\
90 				 sizeof(field.container.item),		\
91 				 is_signed_type(type), filter_type);	\
92 	if (ret)							\
93 		return ret;
94 
95 #undef __array
96 #define __array(type, item, len)					\
97 	do {								\
98 		BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);			\
99 		ret = ftrace_event_define_field(event_call, #type, len,	\
100 				#item, offsetof(typeof(field), item),   \
101 				sizeof(field.item),			\
102 			 	is_signed_type(type), filter_type);	\
103 		if (ret)						\
104 			return ret;					\
105 	} while (0);
106 
107 #undef __array_desc
108 #define __array_desc(type, container, item, len)			\
109 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
110 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
111 				 offsetof(typeof(field),		\
112 					  container.item),		\
113 				 sizeof(field.container.item),		\
114 				 is_signed_type(type), filter_type);	\
115 	if (ret)							\
116 		return ret;
117 
118 #undef __dynamic_array
119 #define __dynamic_array(type, item)					\
120 	ret = trace_define_field(event_call, #type, #item,		\
121 				 offsetof(typeof(field), item),		\
122 				 0, is_signed_type(type), filter_type);\
123 	if (ret)							\
124 		return ret;
125 
126 #undef FTRACE_ENTRY
127 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
128 static int __init							\
129 ftrace_define_fields_##name(struct ftrace_event_call *event_call)	\
130 {									\
131 	struct struct_name field;					\
132 	int ret;							\
133 	int filter_type = filter;					\
134 									\
135 	tstruct;							\
136 									\
137 	return ret;							\
138 }
139 
140 #include "trace_entries.h"
141 
142 #undef __entry
143 #define __entry REC
144 
145 #undef __field
146 #define __field(type, item)
147 
148 #undef __field_desc
149 #define __field_desc(type, container, item)
150 
151 #undef __array
152 #define __array(type, item, len)
153 
154 #undef __array_desc
155 #define __array_desc(type, container, item, len)
156 
157 #undef __dynamic_array
158 #define __dynamic_array(type, item)
159 
160 #undef F_printk
161 #define F_printk(fmt, args...) __stringify(fmt) ", "  __stringify(args)
162 
163 #undef FTRACE_ENTRY_REG
164 #define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, filter,\
165 			 regfn)						\
166 									\
167 struct ftrace_event_class __refdata event_class_ftrace_##call = {	\
168 	.system			= __stringify(TRACE_SYSTEM),		\
169 	.define_fields		= ftrace_define_fields_##call,		\
170 	.fields			= LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
171 	.reg			= regfn,				\
172 };									\
173 									\
174 struct ftrace_event_call __used event_##call = {			\
175 	.name			= #call,				\
176 	.event.type		= etype,				\
177 	.class			= &event_class_ftrace_##call,		\
178 	.print_fmt		= print,				\
179 	.flags			= TRACE_EVENT_FL_IGNORE_ENABLE | TRACE_EVENT_FL_USE_CALL_FILTER, \
180 };									\
181 struct ftrace_event_call __used						\
182 __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call;
183 
184 #undef FTRACE_ENTRY
185 #define FTRACE_ENTRY(call, struct_name, etype, tstruct, print, filter)	\
186 	FTRACE_ENTRY_REG(call, struct_name, etype,			\
187 			 PARAMS(tstruct), PARAMS(print), filter, NULL)
188 
189 int ftrace_event_is_function(struct ftrace_event_call *call)
190 {
191 	return call == &event_function;
192 }
193 
194 #include "trace_entries.h"
195