include/ust/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 _UST_MARKER_H
  25 #define _UST_MARKER_H
  26
  27 #include <stdarg.h>
  28 #include <ust/immediate.h>
  29 #include <ust/core.h>
  30 #include <urcu/list.h>
  31 #include <ust/processor.h>
  32 #include <ust/kcompat/kcompat.h>
  33
  34 #include <bits/wordsize.h>
  35
  36 struct marker;
  37
  38 /* To stringify the expansion of a define */
  39 #define XSTR(d) STR(d)
  40 #define STR(s) #s
  41
  42 /**
  43  * marker_probe_func - Type of a marker probe function
  44  * @mdata: marker data
  45  * @probe_private: probe private data
  46  * @call_private: call site private data
  47  * @fmt: format string
  48  * @args: variable argument list pointer. Use a pointer to overcome C's
  49  *        inability to pass this around as a pointer in a portable manner in
  50  *        the callee otherwise.
  51  *
  52  * Type of marker probe functions. They receive the mdata and need to parse the
  53  * format string to recover the variable argument list.
  54  */
  55 typedef void marker_probe_func(const struct marker *mdata,
  56                 void *probe_private, struct registers *regs, void *call_private,
  57                 const char *fmt, va_list *args);
  58
  59 struct marker_probe_closure {
  60         marker_probe_func *func;        /* Callback */
  61         void *probe_private;            /* Private probe data */
  62 };
  63
  64 struct marker {
  65         const char *channel;    /* Name of channel where to send data */
  66         const char *name;       /* Marker name */
  67         const char *format;     /* Marker format string, describing the
  68                                  * variable argument list.
  69                                  */
  70         DEFINE_IMV(char, state);/* Immediate value state. */
  71         char ptype;             /* probe type : 0 : single, 1 : multi */
  72                                 /* Probe wrapper */
  73         u16 channel_id;         /* Numeric channel identifier, dynamic */
  74         u16 event_id;           /* Numeric event identifier, dynamic */
  75         void (*call)(const struct marker *mdata, void *call_private, struct registers *regs, ...);
  76         struct marker_probe_closure single;
  77         struct marker_probe_closure *multi;
  78         const char *tp_name;    /* Optional tracepoint name */
  79         void *tp_cb;            /* Optional tracepoint callback */
  80         void *location;         /* Address of marker in code */
  81 } __attribute__((aligned(8)));
  82
  83 #define CONFIG_MARKERS
  84 #ifdef CONFIG_MARKERS
  85
  86 #define _DEFINE_MARKER(channel, name, tp_name_str, tp_cb, format, unique, m)                    \
  87                 struct registers regs;                                                          \
  88                                                                                                 \
  89                 /* This next asm has to be a basic inline asm (no input/output/clobber),        \
  90                  * because it must not require %-sign escaping, as we most certainly            \
  91                  * have some %-signs in the format string.                                      \
  92                  */                                                                             \
  93                 asm volatile (                                                                  \
  94                      /* We only define these symbols if they have not yet been defined. Indeed, \
  95                       * if two markers with the same channel/name are on the same line, they    \
  96                       * will try to create the same symbols, resulting in a conflict. This      \
  97                       * is not unusual as it can be the result of function inlining.            \
  98                       */                                                                        \
  99                      ".ifndef __mstrtab_" XSTR(channel) "_" XSTR(name) "_channel_" XSTR(unique) "\n\t"  \
 100                      /*".section __markers_strings\n\t"*/                                       \
 101                      ".section __markers_strings,\"aw\",@progbits\n\t"                          \
 102                      "__mstrtab_" XSTR(channel) "_" XSTR(name) "_channel_" XSTR(unique) ":\n\t" \
 103                      ".string \"" XSTR(channel) "\"\n\t"                                        \
 104                      "__mstrtab_" XSTR(channel) "_" XSTR(name) "_name_" XSTR(unique) ":\n\t"    \
 105                      ".string \"" XSTR(name) "\"\n\t"                                           \
 106                      "__mstrtab_" XSTR(channel) "_" XSTR(name) "_format_" XSTR(unique) ":\n\t"  \
 107                      ".string " "\"" format "\"" "\n\t"                                         \
 108                      ".previous\n\t"                                                            \
 109                      ".endif\n\t"                                                               \
 110                 );                                                                              \
 111                 asm volatile (                                                                  \
 112                      /*".section __markers\n\t"*/ \
 113                      ".section __markers,\"aw\",@progbits\n\t"                                  \
 114                      ".balign 8\n\t"                                                            \
 115                      "2:\n\t" \
 116                      _ASM_PTR "(__mstrtab_" XSTR(channel) "_" XSTR(name) "_channel_" XSTR(unique) ")\n\t" /* channel string */ \
 117                      _ASM_PTR "(__mstrtab_" XSTR(channel) "_" XSTR(name) "_name_" XSTR(unique) ")\n\t" /* name string */ \
 118                      _ASM_PTR "(__mstrtab_" XSTR(channel) "_" XSTR(name) "_format_" XSTR(unique) ")\n\t" /* format string */ \
 119                      ".byte 0\n\t" /* state imv */                                              \
 120                      ".byte 0\n\t" /* ptype */                                                  \
 121                      ".word 0\n\t" /* channel_id */                                             \
 122                      ".word 0\n\t" /* event_id */                                               \
 123                      ".balign " XSTR(__WORDSIZE) " / 8\n\t" /* alignment */                     \
 124                      _ASM_PTR "(marker_probe_cb)\n\t" /* call */                                \
 125                      _ASM_PTR "(__mark_empty_function)\n\t" /* marker_probe_closure single.field1 */ \
 126                      _ASM_PTR "0\n\t" /* marker_probe_closure single.field2 */                  \
 127                      _ASM_PTR "0\n\t" /* marker_probe_closure *multi */                         \
 128                      _ASM_PTR "0\n\t" /* tp_name */                                             \
 129                      _ASM_PTR "0\n\t" /* tp_cb */                                               \
 130                      _ASM_PTR "(1f)\n\t" /* location */                                         \
 131                      ".previous\n\t"                                                            \
 132                      "1:\n\t"                                                                   \
 133                      ARCH_COPY_ADDR("%[outptr]")                                                \
 134                 : [outptr] "=r" (m) );                                                          \
 135                                                                                                 \
 136                 save_registers(&regs)
 137
 138
 139 #define DEFINE_MARKER(channel, name, format, unique, m)                         \
 140                 _DEFINE_MARKER(channel, name, NULL, NULL, format, unique, m)
 141
 142 #define DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format)         \
 143                 _DEFINE_MARKER_TP(channel, name, #tp_name, tp_cb, format)
 144
 145 #define _DEFINE_MARKER_TP(channel, name, tp_name_str, tp_cb, format) \
 146                 static const char __mstrtab_##channel##_##name[]        \
 147                 __attribute__((section("__markers_strings")))           \
 148                 = #channel "\0" #name "\0" format;                      \
 149                 static struct marker __mark_##channel##_##name          \
 150                 __attribute__((section("__markers"), aligned(8))) =     \
 151                 { __mstrtab_##channel##_##name,                         \
 152                   &__mstrtab_##channel##_##name[sizeof(#channel)],      \
 153                   &__mstrtab_##channel##_##name[sizeof(#channel) +      \
 154                                                 sizeof(#name)],         \
 155                   0, 0, 0, 0, marker_probe_cb,                          \
 156                   { __mark_empty_function, NULL},                       \
 157                   NULL, tp_name_str, tp_cb }
 158
 159 /*
 160  * Make sure the alignment of the structure in the __markers section will
 161  * not add unwanted padding between the beginning of the section and the
 162  * structure. Force alignment to the same alignment as the section start.
 163  *
 164  * The "generic" argument controls which marker enabling mechanism must be used.
 165  * If generic is true, a variable read is used.
 166  * If generic is false, immediate values are used.
 167  */
 168
 169 #define __trace_mark(generic, channel, name, call_private, format, args...) \
 170         __trace_mark_counter(generic, channel, name, __LINE__, call_private, format, ## args)
 171
 172 #define __trace_mark_counter(generic, channel, name, unique, call_private, format, args...) \
 173         do {                                                            \
 174                 struct marker *m;                                       \
 175                 DEFINE_MARKER(channel, name, format, unique, m);                        \
 176                 __mark_check_format(format, ## args);                   \
 177                 if (!generic) {                                         \
 178                         if (unlikely(imv_read(m->state))) \
 179                                 (m->call)(m, call_private, &regs, ## args);             \
 180                 } else {                                                \
 181                         if (unlikely(_imv_read(m->state))) \
 182                                 (m->call)(m, call_private, &regs, ## args);             \
 183                 }                                                       \
 184         } while (0)
 185
 186 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb, format, args...) \
 187         __trace_mark_tp_counter(channel, name, __LINE__, call_private, tp_name, tp_cb, format, ## args)
 188
 189 #define __trace_mark_tp_counter(channel, name, unique, call_private, tp_name, tp_cb, format, args...) \
 190         do {                                                            \
 191                 struct registers regs;                                                          \
 192                 void __check_tp_type(void)                              \
 193                 {                                                       \
 194                         register_trace_##tp_name(tp_cb, call_private);          \
 195                 }                                                       \
 196                 DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format);\
 197                 __mark_check_format(format, ## args);                   \
 198                 (*__mark_##channel##_##name.call)(&__mark_##channel##_##name, \
 199                         call_private, &regs, ## args);                          \
 200         } while (0)
 201
 202 extern void marker_update_probe_range(struct marker *begin,
 203         struct marker *end);
 204
 205 #define GET_MARKER(channel, name)       (__mark_##channel##_##name)
 206
 207 #else /* !CONFIG_MARKERS */
 208 #define DEFINE_MARKER(channel, name, tp_name, tp_cb, format, m)
 209 #define __trace_mark(generic, channel, name, call_private, format, args...) \
 210                 __mark_check_format(format, ## args)
 211 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb,    \
 212                 format, args...)                                        \
 213         do {                                                            \
 214                 void __check_tp_type(void)                              \
 215                 {                                                       \
 216                         register_trace_##tp_name(tp_cb, call_private);          \
 217                 }                                                       \
 218                 __mark_check_format(format, ## args);                   \
 219         } while (0)
 220 static inline void marker_update_probe_range(struct marker *begin,
 221         struct marker *end)
 222 { }
 223 #define GET_MARKER(channel, name)
 224 #endif /* CONFIG_MARKERS */
 225
 226 /**
 227  * trace_mark - Marker using code patching
 228  * @channel: marker channel (where to send the data), not quoted.
 229  * @name: marker name, not quoted.
 230  * @format: format string
 231  * @args...: variable argument list
 232  *
 233  * Places a marker using optimized code patching technique (imv_read())
 234  * to be enabled when immediate values are present.
 235  */
 236 #define trace_mark(channel, name, format, args...) \
 237         __trace_mark(0, channel, name, NULL, format, ## args)
 238
 239 /**
 240  * _trace_mark - Marker using variable read
 241  * @channel: marker channel (where to send the data), not quoted.
 242  * @name: marker name, not quoted.
 243  * @format: format string
 244  * @args...: variable argument list
 245  *
 246  * Places a marker using a standard memory read (_imv_read()) to be
 247  * enabled. Should be used for markers in code paths where instruction
 248  * modification based enabling is not welcome.
 249  */
 250 #define _trace_mark(channel, name, format, args...) \
 251         __trace_mark(1, channel, name, NULL, format, ## args)
 252
 253 /**
 254  * trace_mark_tp - Marker in a tracepoint callback
 255  * @channel: marker channel (where to send the data), not quoted.
 256  * @name: marker name, not quoted.
 257  * @tp_name: tracepoint name, not quoted.
 258  * @tp_cb: tracepoint callback. Should have an associated global symbol so it
 259  *         is not optimized away by the compiler (should not be static).
 260  * @format: format string
 261  * @args...: variable argument list
 262  *
 263  * Places a marker in a tracepoint callback.
 264  */
 265 #define trace_mark_tp(channel, name, tp_name, tp_cb, format, args...)   \
 266         __trace_mark_tp(channel, name, NULL, tp_name, tp_cb, format, ## args)
 267
 268 /**
 269  * MARK_NOARGS - Format string for a marker with no argument.
 270  */
 271 #define MARK_NOARGS " "
 272
 273 extern void lock_markers(void);
 274 extern void unlock_markers(void);
 275
 276 extern void markers_compact_event_ids(void);
 277
 278 /* To be used for string format validity checking with gcc */
 279 static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
 280 {
 281 }
 282
 283 #define __mark_check_format(format, args...)                            \
 284         do {                                                            \
 285                 if (0)                                                  \
 286                         ___mark_check_format(format, ## args);          \
 287         } while (0)
 288
 289 extern marker_probe_func __mark_empty_function;
 290
 291 extern void marker_probe_cb(const struct marker *mdata,
 292         void *call_private, struct registers *regs, ...);
 293
 294 /*
 295  * Connect a probe to a marker.
 296  * private data pointer must be a valid allocated memory address, or NULL.
 297  */
 298 extern int marker_probe_register(const char *channel, const char *name,
 299         const char *format, marker_probe_func *probe, void *probe_private);
 300
 301 /*
 302  * Returns the private data given to marker_probe_register.
 303  */
 304 extern int marker_probe_unregister(const char *channel, const char *name,
 305         marker_probe_func *probe, void *probe_private);
 306 /*
 307  * Unregister a marker by providing the registered private data.
 308  */
 309 extern int marker_probe_unregister_private_data(marker_probe_func *probe,
 310         void *probe_private);
 311
 312 extern void *marker_get_private_data(const char *channel, const char *name,
 313         marker_probe_func *probe, int num);
 314
 315 /*
 316  * marker_synchronize_unregister must be called between the last marker probe
 317  * unregistration and the first one of
 318  * - the end of module exit function
 319  * - the free of any resource used by the probes
 320  * to ensure the code and data are valid for any possibly running probes.
 321  */
 322 #define marker_synchronize_unregister() synchronize_sched()
 323
 324 struct marker_iter {
 325 //ust// struct module *module;
 326         struct lib *lib;
 327         struct marker *marker;
 328 };
 329
 330 extern void marker_iter_start(struct marker_iter *iter);
 331 extern void marker_iter_next(struct marker_iter *iter);
 332 extern void marker_iter_stop(struct marker_iter *iter);
 333 extern void marker_iter_reset(struct marker_iter *iter);
 334 extern int marker_get_iter_range(struct marker **marker, struct marker *begin,
 335         struct marker *end);
 336
 337 extern void marker_update_process(void);
 338 extern int is_marker_enabled(const char *channel, const char *name);
 339
 340 //ust// #ifdef CONFIG_MARKERS_USERSPACE
 341 //ust// extern void exit_user_markers(struct task_struct *p);
 342 //ust// #else
 343 //ust// static inline void exit_user_markers(struct task_struct *p)
 344 //ust// {
 345 //ust// }
 346 //ust// #endif
 347
 348 struct marker_addr {
 349         struct marker *marker;
 350         void *addr;
 351 };
 352
 353 struct lib {
 354         struct marker *markers_start;
 355 #ifdef CONFIG_UST_GDB_INTEGRATION
 356         struct marker_addr *markers_addr_start;
 357 #endif
 358         int markers_count;
 359         struct list_head list;
 360 };
 361
 362 extern int marker_register_lib(struct marker *markers_start, int markers_count);
 363 extern int marker_unregister_lib(struct marker *markers_start);
 364
 365 #define MARKER_LIB                                                      \
 366         extern struct marker __start___markers[] __attribute__((weak, visibility("hidden"))); \
 367         extern struct marker __stop___markers[] __attribute__((weak, visibility("hidden"))); \
 368                                                                         \
 369         static void __attribute__((constructor)) __markers__init(void)  \
 370         {                                                               \
 371                 marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker)); \
 372         } \
 373         \
 374         static void __attribute__((destructor)) __markers__destroy(void)        \
 375         {                                                               \
 376                 marker_unregister_lib(__start___markers); \
 377         }
 378
 379 extern void marker_set_new_marker_cb(void (*cb)(struct marker *));
 380 extern void init_markers(void);
 381
 382 #endif /* _UST_MARKER_H */