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 <kcompat/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)                       \
  90                 struct registers regs;                                                          \
  91                 /* make asm label visible to C */                                               \
  92                 extern struct marker make_mark_struct_name(channel, name, unique);              \
  93                                                                                                 \
  94                 /* This next asm has to be a basic inline asm (no input/output/clobber),        \
  95                    because it must not require %-sign escaping, as we most certainly            \
  96                    have some %-signs in the format string. */                                   \
  97                 asm volatile (                                                                  \
  98                      ".section __markers_strings,\"aw\",@progbits\n\t"                          \
  99                      "__mstrtab_" XSTR(channel) "_" XSTR(name) "_channel_" XSTR(unique) ":\n\t" \
 100                      ".string \"" XSTR(channel) "\"\n\t"                                        \
 101                      "__mstrtab_" XSTR(channel) "_" XSTR(name) "_name_" XSTR(unique) ":\n\t"    \
 102                      ".string \"" XSTR(name) "\"\n\t"                                           \
 103                      "__mstrtab_" XSTR(channel) "_" XSTR(name) "_format_" XSTR(unique) ":\n\t"  \
 104                      ".string " "\"" format "\"" "\n\t"                                         \
 105                      ".previous\n\t"                                                            \
 106                      ".section __markers,\"aw\",@progbits\n\t"                                  \
 107                      ".align 8\n\t"                                                             \
 108                      XSTR(make_mark_struct_name(channel, name, unique)) ":\n\t"                 \
 109                      ".global " XSTR(make_mark_struct_name(channel, name, unique)) "\n\t"       \
 110                      ".local " XSTR(make_mark_struct_name(channel, name, unique)) "\n\t"        \
 111                      _ASM_PTR "(__mstrtab_" XSTR(channel) "_" XSTR(name) "_channel_" XSTR(unique) ")\n\t" /* channel string */ \
 112                      _ASM_PTR "(__mstrtab_" XSTR(channel) "_" XSTR(name) "_name_" XSTR(unique) ")\n\t" /* name string */ \
 113                      _ASM_PTR "(__mstrtab_" XSTR(channel) "_" XSTR(name) "_format_" XSTR(unique) ")\n\t" /* format string */ \
 114                      ".byte 0\n\t" /* state imv */                                              \
 115                      ".byte 0\n\t" /* ptype */                                                  \
 116                      ".word 0\n\t" /* channel_id */                                             \
 117                      ".word 0\n\t" /* event_id */                                               \
 118                      ".align " XSTR(__WORDSIZE) " / 8\n\t" /* alignment */                      \
 119                      _ASM_PTR "(marker_probe_cb)\n\t" /* call */                                \
 120                      _ASM_PTR "(__mark_empty_function)\n\t" /* marker_probe_closure single.field1 */ \
 121                      _ASM_PTR "0\n\t" /* marker_probe_closure single.field2 */                  \
 122                      _ASM_PTR "0\n\t" /* marker_probe_closure *multi */                         \
 123                      _ASM_PTR "0\n\t" /* tp_name */                                             \
 124                      _ASM_PTR "0\n\t" /* tp_cb */                                               \
 125                      "__mark_location_" XSTR(unique) ":\n\t"                                    \
 126                      _ASM_PTR "(1f)\n\t" /* location */                                         \
 127                      ".previous\n\t"                                                            \
 128                      "1:\n\t"                                                                   \
 129                 );                                                                              \
 130                                                                                                 \
 131                 save_registers(&regs)
 132
 133
 134 #define DEFINE_MARKER(channel, name, format, unique)                            \
 135                 _DEFINE_MARKER(channel, name, NULL, NULL, format, unique)
 136
 137 #define DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format, unique)         \
 138                 _DEFINE_MARKER(channel, name, #tp_name, tp_cb, format, unique)
 139
 140 /*
 141  * Make sure the alignment of the structure in the __markers section will
 142  * not add unwanted padding between the beginning of the section and the
 143  * structure. Force alignment to the same alignment as the section start.
 144  *
 145  * The "generic" argument controls which marker enabling mechanism must be used.
 146  * If generic is true, a variable read is used.
 147  * If generic is false, immediate values are used.
 148  */
 149
 150 #define make_mark_struct_name(channel, name, unique) \
 151         make_mark_struct_name2(channel, name, unique)
 152
 153 #define make_mark_struct_name2(channel, name, unique) \
 154         __mark_struct_##channel##_##name##_##unique
 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                 DEFINE_MARKER(channel, name, format, unique);                   \
 162                 __mark_check_format(format, ## args);                   \
 163                 if (!generic) {                                         \
 164                         if (unlikely(imv_read(                          \
 165                                         make_mark_struct_name(channel, name, unique).state))) \
 166                                 (make_mark_struct_name(channel, name, unique).call)     \
 167                                         (&make_mark_struct_name(channel, name, unique), \
 168                                         call_private, &regs, ## args);          \
 169                 } else {                                                \
 170                         if (unlikely(_imv_read(                         \
 171                                         make_mark_struct_name(channel, name, unique).state))) \
 172                                 (make_mark_struct_name(channel, name, unique).call)     \
 173                                         (&make_mark_struct_name(channel, name, unique), \
 174                                         call_private, &regs, ## args);          \
 175                 }                                                       \
 176         } while (0)
 177
 178 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb, format, args...) \
 179         __trace_mark_tp_counter(channel, name, __LINE__, call_private, tp_name, tp_cb, format, ## args)
 180
 181 #define __trace_mark_tp_counter(channel, name, unique, call_private, tp_name, tp_cb, format, args...) \
 182         do {                                                            \
 183                 void __check_tp_type(void)                              \
 184                 {                                                       \
 185                         register_trace_##tp_name(tp_cb);                \
 186                 }                                                       \
 187                 DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format, unique);\
 188                 __mark_check_format(format, ## args);                   \
 189                 (*__mark_##channel##_##name.call)(&__mark_##channel##_##name, \
 190                         call_private, &regs, ## args);                          \
 191         } while (0)
 192
 193 extern void marker_update_probe_range(struct marker *begin,
 194         struct marker *end);
 195
 196 #define GET_MARKER(channel, name)       (__mark_##channel##_##name)
 197
 198 #else /* !CONFIG_MARKERS */
 199 #define DEFINE_MARKER(channel, name, tp_name, tp_cb, format)
 200 #define __trace_mark(generic, channel, name, call_private, format, args...) \
 201                 __mark_check_format(format, ## args)
 202 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb,    \
 203                 format, args...)                                        \
 204         do {                                                            \
 205                 void __check_tp_type(void)                              \
 206                 {                                                       \
 207                         register_trace_##tp_name(tp_cb);                \
 208                 }                                                       \
 209                 __mark_check_format(format, ## args);                   \
 210         } while (0)
 211 static inline void marker_update_probe_range(struct marker *begin,
 212         struct marker *end)
 213 { }
 214 #define GET_MARKER(channel, name)
 215 #endif /* CONFIG_MARKERS */
 216
 217 /**
 218  * trace_mark - Marker using code patching
 219  * @channel: marker channel (where to send the data), not quoted.
 220  * @name: marker name, not quoted.
 221  * @format: format string
 222  * @args...: variable argument list
 223  *
 224  * Places a marker using optimized code patching technique (imv_read())
 225  * to be enabled when immediate values are present.
 226  */
 227 #define trace_mark(channel, name, format, args...) \
 228         __trace_mark(0, channel, name, NULL, format, ## args)
 229
 230 /**
 231  * _trace_mark - Marker using variable read
 232  * @channel: marker channel (where to send the data), not quoted.
 233  * @name: marker name, not quoted.
 234  * @format: format string
 235  * @args...: variable argument list
 236  *
 237  * Places a marker using a standard memory read (_imv_read()) to be
 238  * enabled. Should be used for markers in code paths where instruction
 239  * modification based enabling is not welcome. (__init and __exit functions,
 240  * lockdep, some traps, printk).
 241  */
 242 #define _trace_mark(channel, name, format, args...) \
 243         __trace_mark(1, channel, name, NULL, format, ## args)
 244
 245 /**
 246  * trace_mark_tp - Marker in a tracepoint callback
 247  * @channel: marker channel (where to send the data), not quoted.
 248  * @name: marker name, not quoted.
 249  * @tp_name: tracepoint name, not quoted.
 250  * @tp_cb: tracepoint callback. Should have an associated global symbol so it
 251  *         is not optimized away by the compiler (should not be static).
 252  * @format: format string
 253  * @args...: variable argument list
 254  *
 255  * Places a marker in a tracepoint callback.
 256  */
 257 #define trace_mark_tp(channel, name, tp_name, tp_cb, format, args...)   \
 258         __trace_mark_tp(channel, name, NULL, tp_name, tp_cb, format, ## args)
 259
 260 /**
 261  * MARK_NOARGS - Format string for a marker with no argument.
 262  */
 263 #define MARK_NOARGS " "
 264
 265 extern void lock_markers(void);
 266 extern void unlock_markers(void);
 267
 268 extern void markers_compact_event_ids(void);
 269
 270 /* To be used for string format validity checking with gcc */
 271 static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
 272 {
 273 }
 274
 275 #define __mark_check_format(format, args...)                            \
 276         do {                                                            \
 277                 if (0)                                                  \
 278                         ___mark_check_format(format, ## args);          \
 279         } while (0)
 280
 281 extern marker_probe_func __mark_empty_function;
 282
 283 extern void marker_probe_cb(const struct marker *mdata,
 284         void *call_private, struct registers *regs, ...);
 285
 286 /*
 287  * Connect a probe to a marker.
 288  * private data pointer must be a valid allocated memory address, or NULL.
 289  */
 290 extern int marker_probe_register(const char *channel, const char *name,
 291         const char *format, marker_probe_func *probe, void *probe_private);
 292
 293 /*
 294  * Returns the private data given to marker_probe_register.
 295  */
 296 extern int marker_probe_unregister(const char *channel, const char *name,
 297         marker_probe_func *probe, void *probe_private);
 298 /*
 299  * Unregister a marker by providing the registered private data.
 300  */
 301 extern int marker_probe_unregister_private_data(marker_probe_func *probe,
 302         void *probe_private);
 303
 304 extern void *marker_get_private_data(const char *channel, const char *name,
 305         marker_probe_func *probe, int num);
 306
 307 /*
 308  * marker_synchronize_unregister must be called between the last marker probe
 309  * unregistration and the first one of
 310  * - the end of module exit function
 311  * - the free of any resource used by the probes
 312  * to ensure the code and data are valid for any possibly running probes.
 313  */
 314 #define marker_synchronize_unregister() synchronize_sched()
 315
 316 struct marker_iter {
 317 //ust// struct module *module;
 318         struct lib *lib;
 319         struct marker *marker;
 320 };
 321
 322 extern void marker_iter_start(struct marker_iter *iter);
 323 extern void marker_iter_next(struct marker_iter *iter);
 324 extern void marker_iter_stop(struct marker_iter *iter);
 325 extern void marker_iter_reset(struct marker_iter *iter);
 326 extern int marker_get_iter_range(struct marker **marker, struct marker *begin,
 327         struct marker *end);
 328
 329 extern void marker_update_process(void);
 330 extern int is_marker_enabled(const char *channel, const char *name);
 331
 332 //ust// #ifdef CONFIG_MARKERS_USERSPACE
 333 //ust// extern void exit_user_markers(struct task_struct *p);
 334 //ust// #else
 335 //ust// static inline void exit_user_markers(struct task_struct *p)
 336 //ust// {
 337 //ust// }
 338 //ust// #endif
 339
 340 struct marker_addr {
 341         struct marker *marker;
 342         void *addr;
 343 };
 344
 345 struct lib {
 346         struct marker *markers_start;
 347 #ifdef CONFIG_UST_GDB_INTEGRATION
 348         struct marker_addr *markers_addr_start;
 349 #endif
 350         int markers_count;
 351         struct list_head list;
 352 };
 353
 354 extern int marker_register_lib(struct marker *markers_start, int markers_count);
 355
 356 #define MARKER_LIB                                                      \
 357         extern struct marker __start___markers[] __attribute__((weak, visibility("hidden"))); \
 358         extern struct marker __stop___markers[] __attribute__((weak, visibility("hidden"))); \
 359                                                                         \
 360         static void __attribute__((constructor)) __markers__init(void)  \
 361         {                                                               \
 362                 marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker)); \
 363         }
 364
 365 extern void marker_set_new_marker_cb(void (*cb)(struct marker *));
 366 extern void init_markers(void);
 367
 368 #endif /* _UST_MARKER_H */