| 1 | #ifndef _UST_MARKER_H |
| 2 | #define _UST_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 | * (C) Copyright 2009 Pierre-Marc Fournier <pierre-marc dot fournier at polymtl dot ca> |
| 11 | * (C) Copyright 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 12 | * |
| 13 | * This library is free software; you can redistribute it and/or |
| 14 | * modify it under the terms of the GNU Lesser General Public |
| 15 | * License as published by the Free Software Foundation; |
| 16 | * version 2.1 of the License. |
| 17 | * |
| 18 | * This library is distributed in the hope that it will be useful, |
| 19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 21 | * Lesser General Public License for more details. |
| 22 | * |
| 23 | * You should have received a copy of the GNU Lesser General Public |
| 24 | * License along with this library; if not, write to the Free Software |
| 25 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 26 | */ |
| 27 | |
| 28 | #include <stdarg.h> |
| 29 | #include <stdint.h> |
| 30 | #include <stddef.h> |
| 31 | #include <bits/wordsize.h> |
| 32 | #include <urcu/list.h> |
| 33 | |
| 34 | #ifdef __cplusplus |
| 35 | extern "C" { |
| 36 | #endif |
| 37 | |
| 38 | struct ust_marker; |
| 39 | struct ust_marker_probe_array; |
| 40 | |
| 41 | /** |
| 42 | * ust_marker_probe_func - Type of a marker probe function |
| 43 | * @mdata: marker data |
| 44 | * @probe_private: probe private data |
| 45 | * @call_private: call site private data |
| 46 | * @fmt: format string |
| 47 | * @args: variable argument list pointer. Use a pointer to overcome C's |
| 48 | * inability to pass this around as a pointer in a portable manner in |
| 49 | * the callee otherwise. |
| 50 | * |
| 51 | * Type of marker probe functions. They receive the mdata and need to parse the |
| 52 | * format string to recover the variable argument list. |
| 53 | */ |
| 54 | typedef void ust_marker_probe_func(const struct ust_marker *mdata, |
| 55 | void *probe_private, void *call_private, |
| 56 | const char *fmt, va_list *args); |
| 57 | |
| 58 | struct ust_marker_probe_closure { |
| 59 | ust_marker_probe_func *func; /* Callback */ |
| 60 | void *probe_private; /* Private probe data */ |
| 61 | }; |
| 62 | |
| 63 | struct ust_marker { |
| 64 | const char *channel; /* Name of channel where to send data */ |
| 65 | const char *name; /* Marker name */ |
| 66 | const char *format; /* Marker format string, describing the |
| 67 | * variable argument list. |
| 68 | */ |
| 69 | char state; /* State. */ |
| 70 | char ptype; /* probe type : 0 : single, 1 : multi */ |
| 71 | /* Probe wrapper */ |
| 72 | uint16_t channel_id; /* Numeric channel identifier, dynamic */ |
| 73 | uint16_t event_id; /* Numeric event identifier, dynamic */ |
| 74 | void (*call)(const struct ust_marker *mdata, void *call_private, ...); |
| 75 | struct ust_marker_probe_closure single; |
| 76 | struct ust_marker_probe_array *multi; |
| 77 | const char *tp_name; /* Optional tracepoint name */ |
| 78 | void *tp_cb; /* Optional tracepoint callback */ |
| 79 | }; |
| 80 | |
| 81 | /* |
| 82 | * We keep the "channel" as internal field for marker.c *only*. It will be |
| 83 | * removed soon. |
| 84 | */ |
| 85 | |
| 86 | /* |
| 87 | * __ust_marker_ptrs section is not const (read-only) because it needs to be |
| 88 | * read-write to let the linker apply relocations and keep the object PIC. |
| 89 | */ |
| 90 | #define _DEFINE_UST_MARKER(channel, name, tp_name_str, tp_cb, format) \ |
| 91 | static const char __mstrtab_##channel##_##name[] \ |
| 92 | __attribute__((section("__ust_markers_strings"))) \ |
| 93 | = #channel "\0" #name "\0" format; \ |
| 94 | static struct ust_marker __ust_marker_def_##name \ |
| 95 | __attribute__((section("__ust_markers"))) = \ |
| 96 | { __mstrtab_##channel##_##name, \ |
| 97 | &__mstrtab_##channel##_##name[sizeof(#channel)], \ |
| 98 | &__mstrtab_##channel##_##name[sizeof(#channel) + \ |
| 99 | sizeof(#name)], \ |
| 100 | 0, 0, 0, 0, ust_marker_probe_cb, \ |
| 101 | { __ust_marker_empty_function, NULL}, \ |
| 102 | NULL, tp_name_str, tp_cb }; \ |
| 103 | static struct ust_marker * __ust_marker_ptr_##name \ |
| 104 | __attribute__((used, section("__ust_marker_ptrs"))) = \ |
| 105 | &__ust_marker_def_##name |
| 106 | |
| 107 | /* |
| 108 | * Make sure the alignment of the structure in the __ust_marker section will |
| 109 | * not add unwanted padding between the beginning of the section and the |
| 110 | * structure. Force alignment to the same alignment as the section start. |
| 111 | */ |
| 112 | |
| 113 | #define __ust_marker(channel, name, call_private, format, args...) \ |
| 114 | do { \ |
| 115 | _DEFINE_UST_MARKER(channel, name, NULL, NULL, format); \ |
| 116 | __ust_marker_check_format(format, ## args); \ |
| 117 | if (__builtin_expect(!!(__ust_marker_def_##name.state), 0)) \ |
| 118 | (__ust_marker_def_##name.call) \ |
| 119 | (&__ust_marker_def_##name, call_private,\ |
| 120 | ## args); \ |
| 121 | } while (0) |
| 122 | |
| 123 | /** |
| 124 | * ust_marker - Marker using code patching |
| 125 | * @name: marker name, not quoted. |
| 126 | * @format: format string |
| 127 | * @args...: variable argument list |
| 128 | * |
| 129 | * Places a marker at caller site. |
| 130 | */ |
| 131 | #define ust_marker(name, format, args...) \ |
| 132 | __ust_marker(ust, name, NULL, format, ## args) |
| 133 | |
| 134 | static inline __attribute__((deprecated)) |
| 135 | void __trace_mark_is_deprecated() |
| 136 | { |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * UST_MARKER_NOARGS - Format string for a marker with no argument. |
| 141 | */ |
| 142 | #define UST_MARKER_NOARGS " " |
| 143 | |
| 144 | /* To be used for string format validity checking with gcc */ |
| 145 | static inline |
| 146 | void __attribute__((format(printf, 1, 2))) |
| 147 | ___ust_marker_check_format(const char *fmt, ...) |
| 148 | { |
| 149 | } |
| 150 | |
| 151 | #define __ust_marker_check_format(format, args...) \ |
| 152 | do { \ |
| 153 | if (0) \ |
| 154 | ___ust_marker_check_format(format, ## args); \ |
| 155 | } while (0) |
| 156 | |
| 157 | extern ust_marker_probe_func __ust_marker_empty_function; |
| 158 | |
| 159 | extern void ust_marker_probe_cb(const struct ust_marker *mdata, |
| 160 | void *call_private, ...); |
| 161 | |
| 162 | struct ust_marker_lib { |
| 163 | struct ust_marker * const *ust_marker_start; |
| 164 | int ust_marker_count; |
| 165 | struct cds_list_head list; |
| 166 | }; |
| 167 | |
| 168 | #define UST_MARKER_LIB \ |
| 169 | extern struct ust_marker * const __start___ust_marker_ptrs[] __attribute__((weak, visibility("hidden"))); \ |
| 170 | extern struct ust_marker * const __stop___ust_marker_ptrs[] __attribute__((weak, visibility("hidden"))); \ |
| 171 | static struct ust_marker * __ust_marker_ptr_dummy \ |
| 172 | __attribute__((used, section("__ust_marker_ptrs"))); \ |
| 173 | \ |
| 174 | static void __attribute__((constructor)) __ust_marker__init(void) \ |
| 175 | { \ |
| 176 | ust_marker_register_lib(__start___ust_marker_ptrs, \ |
| 177 | __stop___ust_marker_ptrs \ |
| 178 | - __start___ust_marker_ptrs); \ |
| 179 | } \ |
| 180 | \ |
| 181 | static void __attribute__((destructor)) __ust_marker__destroy(void) \ |
| 182 | { \ |
| 183 | ust_marker_unregister_lib(__start___ust_marker_ptrs); \ |
| 184 | } |
| 185 | |
| 186 | extern |
| 187 | int ust_marker_register_lib(struct ust_marker * const *ust_marker_start, |
| 188 | int ust_marker_count); |
| 189 | extern |
| 190 | int ust_marker_unregister_lib(struct ust_marker * const *ust_marker_start); |
| 191 | |
| 192 | /* |
| 193 | * trace_mark() -- DEPRECATED |
| 194 | * @channel: name prefix, not quoted. Ignored. |
| 195 | * @name: marker name, not quoted. |
| 196 | * @format: format string |
| 197 | * @args...: variable argument list |
| 198 | * |
| 199 | * Kept as a compatibility API and is *DEPRECATED* in favor of |
| 200 | * ust_marker(). |
| 201 | */ |
| 202 | #define trace_mark(channel, name, format, args...) \ |
| 203 | __trace_mark_is_deprecated(); \ |
| 204 | ust_marker(name, format, ## args) |
| 205 | |
| 206 | static inline __attribute__((deprecated)) |
| 207 | void __MARKER_LIB_IS_DEPRECATED() |
| 208 | { |
| 209 | } |
| 210 | |
| 211 | /* |
| 212 | * MARKER_LIB is kept for backward compatibility and is *DEPRECATED*. |
| 213 | * Use UST_MARKER_LIB instead. |
| 214 | */ |
| 215 | #define MARKER_LIB \ |
| 216 | __MARKER_LIB_IS_DEPRECATED(); \ |
| 217 | UST_MARKER_LIB |
| 218 | |
| 219 | /** |
| 220 | * MARKER_NOARGS - Compatibility API. *DEPRECATED*. Use |
| 221 | * UST_MARKER_NOARGS instead. |
| 222 | */ |
| 223 | #define MARK_NOARGS UST_MARKER_NOARGS |
| 224 | |
| 225 | #ifdef __cplusplus |
| 226 | } |
| 227 | #endif |
| 228 | |
| 229 | #endif /* _UST_MARKER_H */ |