1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * trace_export.c - export basic ftrace utilities to user space
4 *
5 * Copyright (C) 2009 Steven Rostedt <srostedt@redhat.com>
6 */
7 #include <linux/stringify.h>
8 #include <linux/kallsyms.h>
9 #include <linux/seq_file.h>
10 #include <linux/uaccess.h>
11 #include <linux/ftrace.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14
15 #include "trace_output.h"
16
17 /* Stub function for events with triggers */
ftrace_event_register(struct trace_event_call * call,enum trace_reg type,void * data)18 static int ftrace_event_register(struct trace_event_call *call,
19 enum trace_reg type, void *data)
20 {
21 return 0;
22 }
23
24 #undef TRACE_SYSTEM
25 #define TRACE_SYSTEM ftrace
26
27 /*
28 * The FTRACE_ENTRY_REG macro allows ftrace entry to define register
29 * function and thus become accesible via perf.
30 */
31 #undef FTRACE_ENTRY_REG
32 #define FTRACE_ENTRY_REG(name, struct_name, id, tstruct, print, \
33 filter, regfn) \
34 FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
35 filter)
36
37 /* not needed for this file */
38 #undef __field_struct
39 #define __field_struct(type, item)
40
41 #undef __field
42 #define __field(type, item) type item;
43
44 #undef __field_desc
45 #define __field_desc(type, container, item) type item;
46
47 #undef __array
48 #define __array(type, item, size) type item[size];
49
50 #undef __array_desc
51 #define __array_desc(type, container, item, size) type item[size];
52
53 #undef __dynamic_array
54 #define __dynamic_array(type, item) type item[];
55
56 #undef F_STRUCT
57 #define F_STRUCT(args...) args
58
59 #undef F_printk
60 #define F_printk(fmt, args...) fmt, args
61
62 #undef FTRACE_ENTRY
63 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter) \
64 struct ____ftrace_##name { \
65 tstruct \
66 }; \
67 static void __always_unused ____ftrace_check_##name(void) \
68 { \
69 struct ____ftrace_##name *__entry = NULL; \
70 \
71 /* force compile-time check on F_printk() */ \
72 printk(print); \
73 }
74
75 #undef FTRACE_ENTRY_DUP
76 #define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print, filter) \
77 FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print), \
78 filter)
79
80 #include "trace_entries.h"
81
82 #undef __field
83 #define __field(type, item) \
84 ret = trace_define_field(event_call, #type, #item, \
85 offsetof(typeof(field), item), \
86 sizeof(field.item), \
87 is_signed_type(type), filter_type); \
88 if (ret) \
89 return ret;
90
91 #undef __field_desc
92 #define __field_desc(type, container, item) \
93 ret = trace_define_field(event_call, #type, #item, \
94 offsetof(typeof(field), \
95 container.item), \
96 sizeof(field.container.item), \
97 is_signed_type(type), filter_type); \
98 if (ret) \
99 return ret;
100
101 #undef __array
102 #define __array(type, item, len) \
103 do { \
104 char *type_str = #type"["__stringify(len)"]"; \
105 BUILD_BUG_ON(len > MAX_FILTER_STR_VAL); \
106 ret = trace_define_field(event_call, type_str, #item, \
107 offsetof(typeof(field), item), \
108 sizeof(field.item), \
109 is_signed_type(type), filter_type); \
110 if (ret) \
111 return ret; \
112 } while (0);
113
114 #undef __array_desc
115 #define __array_desc(type, container, item, len) \
116 BUILD_BUG_ON(len > MAX_FILTER_STR_VAL); \
117 ret = trace_define_field(event_call, #type "[" #len "]", #item, \
118 offsetof(typeof(field), \
119 container.item), \
120 sizeof(field.container.item), \
121 is_signed_type(type), filter_type); \
122 if (ret) \
123 return ret;
124
125 #undef __dynamic_array
126 #define __dynamic_array(type, item) \
127 ret = trace_define_field(event_call, #type "[]", #item, \
128 offsetof(typeof(field), item), \
129 0, is_signed_type(type), filter_type);\
130 if (ret) \
131 return ret;
132
133 #undef FTRACE_ENTRY
134 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print, filter) \
135 static int __init \
136 ftrace_define_fields_##name(struct trace_event_call *event_call) \
137 { \
138 struct struct_name field; \
139 int ret; \
140 int filter_type = filter; \
141 \
142 tstruct; \
143 \
144 return ret; \
145 }
146
147 #include "trace_entries.h"
148
149 #undef __entry
150 #define __entry REC
151
152 #undef __field
153 #define __field(type, item)
154
155 #undef __field_desc
156 #define __field_desc(type, container, item)
157
158 #undef __array
159 #define __array(type, item, len)
160
161 #undef __array_desc
162 #define __array_desc(type, container, item, len)
163
164 #undef __dynamic_array
165 #define __dynamic_array(type, item)
166
167 #undef F_printk
168 #define F_printk(fmt, args...) __stringify(fmt) ", " __stringify(args)
169
170 #undef FTRACE_ENTRY_REG
171 #define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, filter,\
172 regfn) \
173 \
174 struct trace_event_class __refdata event_class_ftrace_##call = { \
175 .system = __stringify(TRACE_SYSTEM), \
176 .define_fields = ftrace_define_fields_##call, \
177 .fields = LIST_HEAD_INIT(event_class_ftrace_##call.fields),\
178 .reg = regfn, \
179 }; \
180 \
181 struct trace_event_call __used event_##call = { \
182 .class = &event_class_ftrace_##call, \
183 { \
184 .name = #call, \
185 }, \
186 .event.type = etype, \
187 .print_fmt = print, \
188 .flags = TRACE_EVENT_FL_IGNORE_ENABLE, \
189 }; \
190 struct trace_event_call __used \
191 __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call;
192
193 #undef FTRACE_ENTRY
194 #define FTRACE_ENTRY(call, struct_name, etype, tstruct, print, filter) \
195 FTRACE_ENTRY_REG(call, struct_name, etype, \
196 PARAMS(tstruct), PARAMS(print), filter, NULL)
197
ftrace_event_is_function(struct trace_event_call * call)198 bool ftrace_event_is_function(struct trace_event_call *call)
199 {
200 return call == &event_function;
201 }
202
203 #include "trace_entries.h"
204