xref: /openbmc/linux/kernel/trace/trace_export.c (revision 2223cbec)
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 		mutex_lock(&event_storage_mutex);			\
100 		snprintf(event_storage, sizeof(event_storage),		\
101 			 "%s[%d]", #type, len);				\
102 		ret = trace_define_field(event_call, event_storage, #item, \
103 				 offsetof(typeof(field), item),		\
104 				 sizeof(field.item),			\
105 				 is_signed_type(type), filter_type);	\
106 		mutex_unlock(&event_storage_mutex);			\
107 		if (ret)						\
108 			return ret;					\
109 	} while (0);
110 
111 #undef __array_desc
112 #define __array_desc(type, container, item, len)			\
113 	BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);				\
114 	ret = trace_define_field(event_call, #type "[" #len "]", #item,	\
115 				 offsetof(typeof(field),		\
116 					  container.item),		\
117 				 sizeof(field.container.item),		\
118 				 is_signed_type(type), filter_type);	\
119 	if (ret)							\
120 		return ret;
121 
122 #undef __dynamic_array
123 #define __dynamic_array(type, item)					\
124 	ret = trace_define_field(event_call, #type, #item,		\
125 				 offsetof(typeof(field), item),		\
126 				 0, is_signed_type(type), filter_type);\
127 	if (ret)							\
128 		return ret;
129 
130 #undef FTRACE_ENTRY
131 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter)	\
132 int									\
133 ftrace_define_fields_##name(struct ftrace_event_call *event_call)	\
134 {									\
135 	struct struct_name field;					\
136 	int ret;							\
137 	int filter_type = filter;					\
138 									\
139 	tstruct;							\
140 									\
141 	return ret;							\
142 }
143 
144 #include "trace_entries.h"
145 
146 #undef __entry
147 #define __entry REC
148 
149 #undef __field
150 #define __field(type, item)
151 
152 #undef __field_desc
153 #define __field_desc(type, container, item)
154 
155 #undef __array
156 #define __array(type, item, len)
157 
158 #undef __array_desc
159 #define __array_desc(type, container, item, len)
160 
161 #undef __dynamic_array
162 #define __dynamic_array(type, item)
163 
164 #undef F_printk
165 #define F_printk(fmt, args...) __stringify(fmt) ", "  __stringify(args)
166 
167 #undef FTRACE_ENTRY_REG
168 #define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, filter,\
169 			 regfn)						\
170 									\
171 struct ftrace_event_class event_class_ftrace_##call = {			\
172 	.system			= __stringify(TRACE_SYSTEM),		\
173 	.define_fields		= ftrace_define_fields_##call,		\
174 	.fields			= LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
175 	.reg			= regfn,				\
176 };									\
177 									\
178 struct ftrace_event_call __used event_##call = {			\
179 	.name			= #call,				\
180 	.event.type		= etype,				\
181 	.class			= &event_class_ftrace_##call,		\
182 	.print_fmt		= print,				\
183 	.flags			= TRACE_EVENT_FL_IGNORE_ENABLE,		\
184 };									\
185 struct ftrace_event_call __used						\
186 __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call;
187 
188 #undef FTRACE_ENTRY
189 #define FTRACE_ENTRY(call, struct_name, etype, tstruct, print, filter)	\
190 	FTRACE_ENTRY_REG(call, struct_name, etype,			\
191 			 PARAMS(tstruct), PARAMS(print), filter, NULL)
192 
193 int ftrace_event_is_function(struct ftrace_event_call *call)
194 {
195 	return call == &event_function;
196 }
197 
198 #include "trace_entries.h"
199