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