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