libmarkers/marker.h

   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  * (C) Copyright 2009 Pierre-Marc Fournier <pierre-marc dot fournier at polymtl dot ca>
  11  *
  12  * This file is released under the GPLv2.
  13  * See the file COPYING for more details.
  14  */
  15
  16 #include <stdarg.h>
  17 //ust// #include <linux/types.h>
  18 #include "immediate.h"
  19 //ust// #include <linux/ltt-channels.h>
  20 #include "kernelcompat.h"
  21 #include "compiler.h"
  22
  23 //ust// struct module;
  24 //ust// struct task_struct;
  25 struct marker;
  26
  27 /**
  28  * marker_probe_func - Type of a marker probe function
  29  * @mdata: marker data
  30  * @probe_private: probe private data
  31  * @call_private: call site private data
  32  * @fmt: format string
  33  * @args: variable argument list pointer. Use a pointer to overcome C's
  34  *        inability to pass this around as a pointer in a portable manner in
  35  *        the callee otherwise.
  36  *
  37  * Type of marker probe functions. They receive the mdata and need to parse the
  38  * format string to recover the variable argument list.
  39  */
  40 typedef void marker_probe_func(const struct marker *mdata,
  41                 void *probe_private, void *call_private,
  42                 const char *fmt, va_list *args);
  43
  44 struct marker_probe_closure {
  45         marker_probe_func *func;        /* Callback */
  46         void *probe_private;            /* Private probe data */
  47 };
  48
  49 struct marker {
  50         const char *channel;    /* Name of channel where to send data */
  51         const char *name;       /* Marker name */
  52         const char *format;     /* Marker format string, describing the
  53                                  * variable argument list.
  54                                  */
  55         DEFINE_IMV(char, state);/* Immediate value state. */
  56         char ptype;             /* probe type : 0 : single, 1 : multi */
  57                                 /* Probe wrapper */
  58         u16 channel_id;         /* Numeric channel identifier, dynamic */
  59         u16 event_id;           /* Numeric event identifier, dynamic */
  60         void (*call)(const struct marker *mdata, void *call_private, ...);
  61         struct marker_probe_closure single;
  62         struct marker_probe_closure *multi;
  63         const char *tp_name;    /* Optional tracepoint name */
  64         void *tp_cb;            /* Optional tracepoint callback */
  65 } __attribute__((aligned(8)));
  66
  67 //ust// #ifdef CONFIG_MARKERS
  68
  69 #define _DEFINE_MARKER(channel, name, tp_name_str, tp_cb, format)       \
  70                 static const char __mstrtab_##channel##_##name[]        \
  71                 __attribute__((section("__markers_strings")))           \
  72                 = #channel "\0" #name "\0" format;                      \
  73                 static struct marker __mark_##channel##_##name          \
  74                 __attribute__((section("__markers"), aligned(8))) =     \
  75                 { __mstrtab_##channel##_##name,                         \
  76                   &__mstrtab_##channel##_##name[sizeof(#channel)],      \
  77                   &__mstrtab_##channel##_##name[sizeof(#channel) +      \
  78                                                 sizeof(#name)],         \
  79                   0, 0, 0, 0, marker_probe_cb,                          \
  80                   { __mark_empty_function, NULL},                       \
  81                   NULL, tp_name_str, tp_cb }
  82
  83 #define DEFINE_MARKER(channel, name, format)                            \
  84                 _DEFINE_MARKER(channel, name, NULL, NULL, format)
  85
  86 #define DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format)         \
  87                 _DEFINE_MARKER(channel, name, #tp_name, tp_cb, format)
  88
  89 /*
  90  * Make sure the alignment of the structure in the __markers section will
  91  * not add unwanted padding between the beginning of the section and the
  92  * structure. Force alignment to the same alignment as the section start.
  93  *
  94  * The "generic" argument controls which marker enabling mechanism must be used.
  95  * If generic is true, a variable read is used.
  96  * If generic is false, immediate values are used.
  97  */
  98 #define __trace_mark(generic, channel, name, call_private, format, args...) \
  99         do {                                                            \
 100                 DEFINE_MARKER(channel, name, format);                   \
 101                 __mark_check_format(format, ## args);                   \
 102                 if (!generic) {                                         \
 103                         if (unlikely(imv_read(                          \
 104                                         __mark_##channel##_##name.state))) \
 105                                 (*__mark_##channel##_##name.call)       \
 106                                         (&__mark_##channel##_##name,    \
 107                                         call_private, ## args);         \
 108                 } else {                                                \
 109                         if (unlikely(_imv_read(                         \
 110                                         __mark_##channel##_##name.state))) \
 111                                 (*__mark_##channel##_##name.call)       \
 112                                         (&__mark_##channel##_##name,    \
 113                                         call_private, ## args);         \
 114                 }                                                       \
 115         } while (0)
 116
 117 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb,    \
 118                         format, args...)                                \
 119         do {                                                            \
 120                 void __check_tp_type(void)                              \
 121                 {                                                       \
 122                         register_trace_##tp_name(tp_cb);                \
 123                 }                                                       \
 124                 DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format);\
 125                 __mark_check_format(format, ## args);                   \
 126                 (*__mark_##channel##_##name.call)(&__mark_##channel##_##name, \
 127                         call_private, ## args);                         \
 128         } while (0)
 129
 130 extern void marker_update_probe_range(struct marker *begin,
 131         struct marker *end);
 132
 133 #define GET_MARKER(channel, name)       (__mark_##channel##_##name)
 134
 135 //ust// #else /* !CONFIG_MARKERS */
 136 //ust// #define DEFINE_MARKER(channel, name, tp_name, tp_cb, format)
 137 //ust// #define __trace_mark(generic, channel, name, call_private, format, args...) \
 138 //ust//                 __mark_check_format(format, ## args)
 139 //ust// #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb,    \
 140 //ust//                 format, args...)                                        \
 141 //ust//         do {                                                            \
 142 //ust//                 void __check_tp_type(void)                              \
 143 //ust//                 {                                                       \
 144 //ust//                         register_trace_##tp_name(tp_cb);                \
 145 //ust//                 }                                                       \
 146 //ust//                 __mark_check_format(format, ## args);                   \
 147 //ust//         } while (0)
 148 //ust// static inline void marker_update_probe_range(struct marker *begin,
 149 //ust//         struct marker *end)
 150 //ust// { }
 151 //ust// #define GET_MARKER(channel, name)
 152 //ust// #endif /* CONFIG_MARKERS */
 153
 154 /**
 155  * trace_mark - Marker using code patching
 156  * @channel: marker channel (where to send the data), not quoted.
 157  * @name: marker name, not quoted.
 158  * @format: format string
 159  * @args...: variable argument list
 160  *
 161  * Places a marker using optimized code patching technique (imv_read())
 162  * to be enabled when immediate values are present.
 163  */
 164 #define trace_mark(channel, name, format, args...) \
 165         __trace_mark(0, channel, name, NULL, format, ## args)
 166
 167 /**
 168  * _trace_mark - Marker using variable read
 169  * @channel: marker channel (where to send the data), not quoted.
 170  * @name: marker name, not quoted.
 171  * @format: format string
 172  * @args...: variable argument list
 173  *
 174  * Places a marker using a standard memory read (_imv_read()) to be
 175  * enabled. Should be used for markers in code paths where instruction
 176  * modification based enabling is not welcome. (__init and __exit functions,
 177  * lockdep, some traps, printk).
 178  */
 179 #define _trace_mark(channel, name, format, args...) \
 180         __trace_mark(1, channel, name, NULL, format, ## args)
 181
 182 /**
 183  * trace_mark_tp - Marker in a tracepoint callback
 184  * @channel: marker channel (where to send the data), not quoted.
 185  * @name: marker name, not quoted.
 186  * @tp_name: tracepoint name, not quoted.
 187  * @tp_cb: tracepoint callback. Should have an associated global symbol so it
 188  *         is not optimized away by the compiler (should not be static).
 189  * @format: format string
 190  * @args...: variable argument list
 191  *
 192  * Places a marker in a tracepoint callback.
 193  */
 194 #define trace_mark_tp(channel, name, tp_name, tp_cb, format, args...)   \
 195         __trace_mark_tp(channel, name, NULL, tp_name, tp_cb, format, ## args)
 196
 197 /**
 198  * MARK_NOARGS - Format string for a marker with no argument.
 199  */
 200 #define MARK_NOARGS " "
 201
 202 extern void lock_markers(void);
 203 extern void unlock_markers(void);
 204
 205 extern void markers_compact_event_ids(void);
 206
 207 /* To be used for string format validity checking with gcc */
 208 static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
 209 {
 210 }
 211
 212 #define __mark_check_format(format, args...)                            \
 213         do {                                                            \
 214                 if (0)                                                  \
 215                         ___mark_check_format(format, ## args);          \
 216         } while (0)
 217
 218 extern marker_probe_func __mark_empty_function;
 219
 220 extern void marker_probe_cb(const struct marker *mdata,
 221         void *call_private, ...);
 222
 223 /*
 224  * Connect a probe to a marker.
 225  * private data pointer must be a valid allocated memory address, or NULL.
 226  */
 227 extern int marker_probe_register(const char *channel, const char *name,
 228         const char *format, marker_probe_func *probe, void *probe_private);
 229
 230 /*
 231  * Returns the private data given to marker_probe_register.
 232  */
 233 extern int marker_probe_unregister(const char *channel, const char *name,
 234         marker_probe_func *probe, void *probe_private);
 235 /*
 236  * Unregister a marker by providing the registered private data.
 237  */
 238 extern int marker_probe_unregister_private_data(marker_probe_func *probe,
 239         void *probe_private);
 240
 241 extern void *marker_get_private_data(const char *channel, const char *name,
 242         marker_probe_func *probe, int num);
 243
 244 /*
 245  * marker_synchronize_unregister must be called between the last marker probe
 246  * unregistration and the first one of
 247  * - the end of module exit function
 248  * - the free of any resource used by the probes
 249  * to ensure the code and data are valid for any possibly running probes.
 250  */
 251 #define marker_synchronize_unregister() synchronize_sched()
 252
 253 struct marker_iter {
 254         struct module *module;
 255         struct marker *marker;
 256 };
 257
 258 extern void marker_iter_start(struct marker_iter *iter);
 259 extern void marker_iter_next(struct marker_iter *iter);
 260 extern void marker_iter_stop(struct marker_iter *iter);
 261 extern void marker_iter_reset(struct marker_iter *iter);
 262 extern int marker_get_iter_range(struct marker **marker, struct marker *begin,
 263         struct marker *end);
 264
 265 extern void marker_update_process(void);
 266 extern int is_marker_enabled(const char *channel, const char *name);
 267
 268 //ust// #ifdef CONFIG_MARKERS_USERSPACE
 269 //ust// extern void exit_user_markers(struct task_struct *p);
 270 //ust// #else
 271 //ust// static inline void exit_user_markers(struct task_struct *p)
 272 //ust// {
 273 //ust// }
 274 //ust// #endif
 275
 276 #endif