libust/marker.h

   1 /*
   2  * Code markup for dynamic and static tracing.
   3  *
   4  * See Documentation/marker.txt.
   5  *
   6  * (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   7  * (C) Copyright 2009 Pierre-Marc Fournier <pierre-marc dot fournier at polymtl dot ca>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  22  */
  23
  24 #ifndef _LINUX_MARKER_H
  25 #define _LINUX_MARKER_H
  26
  27 #include <stdarg.h>
  28 //ust// #include <linux/types.h>
  29 #include "immediate.h"
  30 //ust// #include <linux/ltt-channels.h>
  31 #include "kernelcompat.h"
  32 #include <kcompat/list.h>
  33 #include "usterr.h"
  34
  35 //ust// struct module;
  36 //ust// struct task_struct;
  37 struct marker;
  38
  39 /**
  40  * marker_probe_func - Type of a marker probe function
  41  * @mdata: marker data
  42  * @probe_private: probe private data
  43  * @call_private: call site private data
  44  * @fmt: format string
  45  * @args: variable argument list pointer. Use a pointer to overcome C's
  46  *        inability to pass this around as a pointer in a portable manner in
  47  *        the callee otherwise.
  48  *
  49  * Type of marker probe functions. They receive the mdata and need to parse the
  50  * format string to recover the variable argument list.
  51  */
  52 typedef void marker_probe_func(const struct marker *mdata,
  53                 void *probe_private, void *call_private,
  54                 const char *fmt, va_list *args);
  55
  56 struct marker_probe_closure {
  57         marker_probe_func *func;        /* Callback */
  58         void *probe_private;            /* Private probe data */
  59 };
  60
  61 struct marker {
  62         const char *channel;    /* Name of channel where to send data */
  63         const char *name;       /* Marker name */
  64         const char *format;     /* Marker format string, describing the
  65                                  * variable argument list.
  66                                  */
  67         DEFINE_IMV(char, state);/* Immediate value state. */
  68         char ptype;             /* probe type : 0 : single, 1 : multi */
  69                                 /* Probe wrapper */
  70         u16 channel_id;         /* Numeric channel identifier, dynamic */
  71         u16 event_id;           /* Numeric event identifier, dynamic */
  72         void (*call)(const struct marker *mdata, void *call_private, ...);
  73         struct marker_probe_closure single;
  74         struct marker_probe_closure *multi;
  75         const char *tp_name;    /* Optional tracepoint name */
  76         void *tp_cb;            /* Optional tracepoint callback */
  77 } __attribute__((aligned(8)));
  78
  79 #define CONFIG_MARKERS
  80 #ifdef CONFIG_MARKERS
  81
  82 #define _DEFINE_MARKER(channel, name, tp_name_str, tp_cb, format)       \
  83                 static const char __mstrtab_##channel##_##name[]        \
  84                 __attribute__((section("__markers_strings")))           \
  85                 = #channel "\0" #name "\0" format;                      \
  86                 static struct marker __mark_##channel##_##name          \
  87                 __attribute__((section("__markers"), aligned(8))) =     \
  88                 { __mstrtab_##channel##_##name,                         \
  89                   &__mstrtab_##channel##_##name[sizeof(#channel)],      \
  90                   &__mstrtab_##channel##_##name[sizeof(#channel) +      \
  91                                                 sizeof(#name)],         \
  92                   0, 0, 0, 0, marker_probe_cb,                          \
  93                   { __mark_empty_function, NULL},                       \
  94                   NULL, tp_name_str, tp_cb }
  95
  96 #define DEFINE_MARKER(channel, name, format)                            \
  97                 _DEFINE_MARKER(channel, name, NULL, NULL, format)
  98
  99 #define DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format)         \
 100                 _DEFINE_MARKER(channel, name, #tp_name, tp_cb, format)
 101
 102 /*
 103  * Make sure the alignment of the structure in the __markers section will
 104  * not add unwanted padding between the beginning of the section and the
 105  * structure. Force alignment to the same alignment as the section start.
 106  *
 107  * The "generic" argument controls which marker enabling mechanism must be used.
 108  * If generic is true, a variable read is used.
 109  * If generic is false, immediate values are used.
 110  */
 111 #define __trace_mark(generic, channel, name, call_private, format, args...) \
 112         do {                                                            \
 113                 DEFINE_MARKER(channel, name, format);                   \
 114                 __mark_check_format(format, ## args);                   \
 115                 if (!generic) {                                         \
 116                         if (unlikely(imv_read(                          \
 117                                         __mark_##channel##_##name.state))) \
 118                                 (*__mark_##channel##_##name.call)       \
 119                                         (&__mark_##channel##_##name,    \
 120                                         call_private, ## args);         \
 121                 } else {                                                \
 122                         if (unlikely(_imv_read(                         \
 123                                         __mark_##channel##_##name.state))) \
 124                                 (*__mark_##channel##_##name.call)       \
 125                                         (&__mark_##channel##_##name,    \
 126                                         call_private, ## args);         \
 127                 }                                                       \
 128         } while (0)
 129
 130 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb,    \
 131                         format, args...)                                \
 132         do {                                                            \
 133                 void __check_tp_type(void)                              \
 134                 {                                                       \
 135                         register_trace_##tp_name(tp_cb);                \
 136                 }                                                       \
 137                 DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format);\
 138                 __mark_check_format(format, ## args);                   \
 139                 (*__mark_##channel##_##name.call)(&__mark_##channel##_##name, \
 140                         call_private, ## args);                         \
 141         } while (0)
 142
 143 extern void marker_update_probe_range(struct marker *begin,
 144         struct marker *end);
 145
 146 #define GET_MARKER(channel, name)       (__mark_##channel##_##name)
 147
 148 #else /* !CONFIG_MARKERS */
 149 #define DEFINE_MARKER(channel, name, tp_name, tp_cb, format)
 150 #define __trace_mark(generic, channel, name, call_private, format, args...) \
 151                 __mark_check_format(format, ## args)
 152 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb,    \
 153                 format, args...)                                        \
 154         do {                                                            \
 155                 void __check_tp_type(void)                              \
 156                 {                                                       \
 157                         register_trace_##tp_name(tp_cb);                \
 158                 }                                                       \
 159                 __mark_check_format(format, ## args);                   \
 160         } while (0)
 161 static inline void marker_update_probe_range(struct marker *begin,
 162         struct marker *end)
 163 { }
 164 #define GET_MARKER(channel, name)
 165 #endif /* CONFIG_MARKERS */
 166
 167 /**
 168  * trace_mark - Marker using code patching
 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 optimized code patching technique (imv_read())
 175  * to be enabled when immediate values are present.
 176  */
 177 #define trace_mark(channel, name, format, args...) \
 178         __trace_mark(0, channel, name, NULL, format, ## args)
 179
 180 /**
 181  * _trace_mark - Marker using variable read
 182  * @channel: marker channel (where to send the data), not quoted.
 183  * @name: marker name, not quoted.
 184  * @format: format string
 185  * @args...: variable argument list
 186  *
 187  * Places a marker using a standard memory read (_imv_read()) to be
 188  * enabled. Should be used for markers in code paths where instruction
 189  * modification based enabling is not welcome. (__init and __exit functions,
 190  * lockdep, some traps, printk).
 191  */
 192 #define _trace_mark(channel, name, format, args...) \
 193         __trace_mark(1, channel, name, NULL, format, ## args)
 194
 195 /**
 196  * trace_mark_tp - Marker in a tracepoint callback
 197  * @channel: marker channel (where to send the data), not quoted.
 198  * @name: marker name, not quoted.
 199  * @tp_name: tracepoint name, not quoted.
 200  * @tp_cb: tracepoint callback. Should have an associated global symbol so it
 201  *         is not optimized away by the compiler (should not be static).
 202  * @format: format string
 203  * @args...: variable argument list
 204  *
 205  * Places a marker in a tracepoint callback.
 206  */
 207 #define trace_mark_tp(channel, name, tp_name, tp_cb, format, args...)   \
 208         __trace_mark_tp(channel, name, NULL, tp_name, tp_cb, format, ## args)
 209
 210 /**
 211  * MARK_NOARGS - Format string for a marker with no argument.
 212  */
 213 #define MARK_NOARGS " "
 214
 215 extern void lock_markers(void);
 216 extern void unlock_markers(void);
 217
 218 extern void markers_compact_event_ids(void);
 219
 220 /* To be used for string format validity checking with gcc */
 221 static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
 222 {
 223 }
 224
 225 #define __mark_check_format(format, args...)                            \
 226         do {                                                            \
 227                 if (0)                                                  \
 228                         ___mark_check_format(format, ## args);          \
 229         } while (0)
 230
 231 extern marker_probe_func __mark_empty_function;
 232
 233 extern void marker_probe_cb(const struct marker *mdata,
 234         void *call_private, ...);
 235
 236 /*
 237  * Connect a probe to a marker.
 238  * private data pointer must be a valid allocated memory address, or NULL.
 239  */
 240 extern int marker_probe_register(const char *channel, const char *name,
 241         const char *format, marker_probe_func *probe, void *probe_private);
 242
 243 /*
 244  * Returns the private data given to marker_probe_register.
 245  */
 246 extern int marker_probe_unregister(const char *channel, const char *name,
 247         marker_probe_func *probe, void *probe_private);
 248 /*
 249  * Unregister a marker by providing the registered private data.
 250  */
 251 extern int marker_probe_unregister_private_data(marker_probe_func *probe,
 252         void *probe_private);
 253
 254 extern void *marker_get_private_data(const char *channel, const char *name,
 255         marker_probe_func *probe, int num);
 256
 257 /*
 258  * marker_synchronize_unregister must be called between the last marker probe
 259  * unregistration and the first one of
 260  * - the end of module exit function
 261  * - the free of any resource used by the probes
 262  * to ensure the code and data are valid for any possibly running probes.
 263  */
 264 #define marker_synchronize_unregister() synchronize_sched()
 265
 266 struct marker_iter {
 267 //ust// struct module *module;
 268         struct lib *lib;
 269         struct marker *marker;
 270 };
 271
 272 extern void marker_iter_start(struct marker_iter *iter);
 273 extern void marker_iter_next(struct marker_iter *iter);
 274 extern void marker_iter_stop(struct marker_iter *iter);
 275 extern void marker_iter_reset(struct marker_iter *iter);
 276 extern int marker_get_iter_range(struct marker **marker, struct marker *begin,
 277         struct marker *end);
 278
 279 extern void marker_update_process(void);
 280 extern int is_marker_enabled(const char *channel, const char *name);
 281
 282 //ust// #ifdef CONFIG_MARKERS_USERSPACE
 283 //ust// extern void exit_user_markers(struct task_struct *p);
 284 //ust// #else
 285 //ust// static inline void exit_user_markers(struct task_struct *p)
 286 //ust// {
 287 //ust// }
 288 //ust// #endif
 289
 290
 291 struct lib {
 292         struct marker *markers_start;
 293         int markers_count;
 294         struct list_head list;
 295 };
 296
 297 extern int marker_register_lib(struct marker *markers_start,
 298                                int markers_count);
 299
 300 #define MARKER_LIB                                                      \
 301 extern struct marker __start___markers[] __attribute__((visibility("hidden"))); \
 302 extern struct marker __stop___markers[] __attribute__((visibility("hidden")));          \
 303                                                                                         \
 304 static void __attribute__((constructor)) __markers__init(void)                          \
 305 {                                                                                       \
 306         DBG("next registration in "__FILE__"\n");\
 307         marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker));\
 308 }
 309
 310 extern void marker_set_new_marker_cb(void (*cb)(struct marker *));
 311 extern void init_markers(void);
 312
 313 #endif