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8256e47c MD |
1 | #ifndef _LINUX_MARKER_H |
2 | #define _LINUX_MARKER_H | |
3 | ||
4 | /* | |
5 | * Code markup for dynamic and static tracing. | |
6 | * | |
7 | * See Documentation/marker.txt. | |
8 | * | |
9 | * (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | |
10 | * | |
11 | * This file is released under the GPLv2. | |
12 | * See the file COPYING for more details. | |
13 | */ | |
14 | ||
e3f8c4b9 | 15 | #include <stdarg.h> |
8256e47c MD |
16 | #include <linux/types.h> |
17 | ||
18 | struct module; | |
19 | struct marker; | |
20 | ||
21 | /** | |
22 | * marker_probe_func - Type of a marker probe function | |
fb40bd78 MD |
23 | * @probe_private: probe private data |
24 | * @call_private: call site private data | |
8256e47c | 25 | * @fmt: format string |
fb40bd78 MD |
26 | * @args: variable argument list pointer. Use a pointer to overcome C's |
27 | * inability to pass this around as a pointer in a portable manner in | |
28 | * the callee otherwise. | |
8256e47c MD |
29 | * |
30 | * Type of marker probe functions. They receive the mdata and need to parse the | |
31 | * format string to recover the variable argument list. | |
32 | */ | |
fb40bd78 MD |
33 | typedef void marker_probe_func(void *probe_private, void *call_private, |
34 | const char *fmt, va_list *args); | |
35 | ||
36 | struct marker_probe_closure { | |
37 | marker_probe_func *func; /* Callback */ | |
38 | void *probe_private; /* Private probe data */ | |
39 | }; | |
8256e47c MD |
40 | |
41 | struct marker { | |
42 | const char *name; /* Marker name */ | |
43 | const char *format; /* Marker format string, describing the | |
44 | * variable argument list. | |
45 | */ | |
46 | char state; /* Marker state. */ | |
fb40bd78 | 47 | char ptype; /* probe type : 0 : single, 1 : multi */ |
dc102a8f MD |
48 | /* Probe wrapper */ |
49 | void (*call)(const struct marker *mdata, void *call_private, ...); | |
fb40bd78 MD |
50 | struct marker_probe_closure single; |
51 | struct marker_probe_closure *multi; | |
c1df1bd2 MD |
52 | const char *tp_name; /* Optional tracepoint name */ |
53 | void *tp_cb; /* Optional tracepoint callback */ | |
8256e47c MD |
54 | } __attribute__((aligned(8))); |
55 | ||
56 | #ifdef CONFIG_MARKERS | |
57 | ||
a0bca6a5 MD |
58 | #define _DEFINE_MARKER(name, tp_name_str, tp_cb, format) \ |
59 | static const char __mstrtab_##name[] \ | |
60 | __attribute__((section("__markers_strings"))) \ | |
61 | = #name "\0" format; \ | |
62 | static struct marker __mark_##name \ | |
63 | __attribute__((section("__markers"), aligned(8))) = \ | |
64 | { __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \ | |
65 | 0, 0, marker_probe_cb, { __mark_empty_function, NULL},\ | |
66 | NULL, tp_name_str, tp_cb } | |
67 | ||
68 | #define DEFINE_MARKER(name, format) \ | |
69 | _DEFINE_MARKER(name, NULL, NULL, format) | |
70 | ||
71 | #define DEFINE_MARKER_TP(name, tp_name, tp_cb, format) \ | |
72 | _DEFINE_MARKER(name, #tp_name, tp_cb, format) | |
73 | ||
8256e47c MD |
74 | /* |
75 | * Note : the empty asm volatile with read constraint is used here instead of a | |
76 | * "used" attribute to fix a gcc 4.1.x bug. | |
77 | * Make sure the alignment of the structure in the __markers section will | |
78 | * not add unwanted padding between the beginning of the section and the | |
79 | * structure. Force alignment to the same alignment as the section start. | |
0aa977f5 MD |
80 | * |
81 | * The "generic" argument controls which marker enabling mechanism must be used. | |
82 | * If generic is true, a variable read is used. | |
83 | * If generic is false, immediate values are used. | |
8256e47c | 84 | */ |
0aa977f5 | 85 | #define __trace_mark(generic, name, call_private, format, args...) \ |
8256e47c | 86 | do { \ |
a0bca6a5 | 87 | DEFINE_MARKER(name, format); \ |
8256e47c MD |
88 | __mark_check_format(format, ## args); \ |
89 | if (unlikely(__mark_##name.state)) { \ | |
8256e47c | 90 | (*__mark_##name.call) \ |
dc102a8f | 91 | (&__mark_##name, call_private, ## args);\ |
8256e47c MD |
92 | } \ |
93 | } while (0) | |
94 | ||
c1df1bd2 MD |
95 | #define __trace_mark_tp(name, call_private, tp_name, tp_cb, format, args...) \ |
96 | do { \ | |
97 | void __check_tp_type(void) \ | |
98 | { \ | |
99 | register_trace_##tp_name(tp_cb); \ | |
100 | } \ | |
a0bca6a5 | 101 | DEFINE_MARKER_TP(name, tp_name, tp_cb, format); \ |
c1df1bd2 MD |
102 | __mark_check_format(format, ## args); \ |
103 | (*__mark_##name.call)(&__mark_##name, call_private, \ | |
104 | ## args); \ | |
105 | } while (0) | |
106 | ||
8256e47c | 107 | extern void marker_update_probe_range(struct marker *begin, |
fb40bd78 | 108 | struct marker *end); |
a0bca6a5 MD |
109 | |
110 | #define GET_MARKER(name) (__mark_##name) | |
111 | ||
8256e47c | 112 | #else /* !CONFIG_MARKERS */ |
a0bca6a5 | 113 | #define DEFINE_MARKER(name, tp_name, tp_cb, format) |
0aa977f5 | 114 | #define __trace_mark(generic, name, call_private, format, args...) \ |
8256e47c | 115 | __mark_check_format(format, ## args) |
c1df1bd2 MD |
116 | #define __trace_mark_tp(name, call_private, tp_name, tp_cb, format, args...) \ |
117 | do { \ | |
118 | void __check_tp_type(void) \ | |
119 | { \ | |
120 | register_trace_##tp_name(tp_cb); \ | |
121 | } \ | |
122 | __mark_check_format(format, ## args); \ | |
123 | } while (0) | |
8256e47c | 124 | static inline void marker_update_probe_range(struct marker *begin, |
fb40bd78 | 125 | struct marker *end) |
8256e47c | 126 | { } |
a0bca6a5 | 127 | #define GET_MARKER(name) |
8256e47c MD |
128 | #endif /* CONFIG_MARKERS */ |
129 | ||
130 | /** | |
0aa977f5 | 131 | * trace_mark - Marker using code patching |
8256e47c MD |
132 | * @name: marker name, not quoted. |
133 | * @format: format string | |
134 | * @args...: variable argument list | |
135 | * | |
0aa977f5 MD |
136 | * Places a marker using optimized code patching technique (imv_read()) |
137 | * to be enabled when immediate values are present. | |
8256e47c MD |
138 | */ |
139 | #define trace_mark(name, format, args...) \ | |
0aa977f5 MD |
140 | __trace_mark(0, name, NULL, format, ## args) |
141 | ||
142 | /** | |
143 | * _trace_mark - Marker using variable read | |
144 | * @name: marker name, not quoted. | |
145 | * @format: format string | |
146 | * @args...: variable argument list | |
147 | * | |
148 | * Places a marker using a standard memory read (_imv_read()) to be | |
149 | * enabled. Should be used for markers in code paths where instruction | |
150 | * modification based enabling is not welcome. (__init and __exit functions, | |
151 | * lockdep, some traps, printk). | |
152 | */ | |
153 | #define _trace_mark(name, format, args...) \ | |
154 | __trace_mark(1, name, NULL, format, ## args) | |
8256e47c | 155 | |
c1df1bd2 MD |
156 | /** |
157 | * trace_mark_tp - Marker in a tracepoint callback | |
158 | * @name: marker name, not quoted. | |
159 | * @tp_name: tracepoint name, not quoted. | |
160 | * @tp_cb: tracepoint callback. Should have an associated global symbol so it | |
161 | * is not optimized away by the compiler (should not be static). | |
162 | * @format: format string | |
163 | * @args...: variable argument list | |
164 | * | |
165 | * Places a marker in a tracepoint callback. | |
166 | */ | |
167 | #define trace_mark_tp(name, tp_name, tp_cb, format, args...) \ | |
168 | __trace_mark_tp(name, NULL, tp_name, tp_cb, format, ## args) | |
169 | ||
8256e47c MD |
170 | /** |
171 | * MARK_NOARGS - Format string for a marker with no argument. | |
172 | */ | |
173 | #define MARK_NOARGS " " | |
174 | ||
175 | /* To be used for string format validity checking with gcc */ | |
acc4988b | 176 | static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...) |
8256e47c MD |
177 | { |
178 | } | |
179 | ||
acc4988b MD |
180 | #define __mark_check_format(format, args...) \ |
181 | do { \ | |
182 | if (0) \ | |
183 | ___mark_check_format(format, ## args); \ | |
184 | } while (0) | |
185 | ||
8256e47c MD |
186 | extern marker_probe_func __mark_empty_function; |
187 | ||
fb40bd78 | 188 | extern void marker_probe_cb(const struct marker *mdata, |
dc102a8f | 189 | void *call_private, ...); |
fb40bd78 | 190 | |
8256e47c MD |
191 | /* |
192 | * Connect a probe to a marker. | |
193 | * private data pointer must be a valid allocated memory address, or NULL. | |
194 | */ | |
195 | extern int marker_probe_register(const char *name, const char *format, | |
fb40bd78 | 196 | marker_probe_func *probe, void *probe_private); |
8256e47c MD |
197 | |
198 | /* | |
199 | * Returns the private data given to marker_probe_register. | |
200 | */ | |
fb40bd78 MD |
201 | extern int marker_probe_unregister(const char *name, |
202 | marker_probe_func *probe, void *probe_private); | |
8256e47c MD |
203 | /* |
204 | * Unregister a marker by providing the registered private data. | |
205 | */ | |
fb40bd78 MD |
206 | extern int marker_probe_unregister_private_data(marker_probe_func *probe, |
207 | void *probe_private); | |
8256e47c | 208 | |
fb40bd78 MD |
209 | extern void *marker_get_private_data(const char *name, marker_probe_func *probe, |
210 | int num); | |
8256e47c | 211 | |
e98d0eab MD |
212 | /* |
213 | * marker_synchronize_unregister must be called between the last marker probe | |
a838c2ec WF |
214 | * unregistration and the first one of |
215 | * - the end of module exit function | |
216 | * - the free of any resource used by the probes | |
217 | * to ensure the code and data are valid for any possibly running probes. | |
e98d0eab | 218 | */ |
bfadadfc | 219 | #define marker_synchronize_unregister() synchronize_sched() |
e98d0eab | 220 | |
8256e47c | 221 | #endif |