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;
  12  * version 2.1 of the License.
  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/core.h>
  29 #include <urcu/list.h>
  30 #include <ust/processor.h>
  31 #include <ust/kcompat/kcompat.h>
  32 #include <ust/kcompat/stringify.h>
  33
  34 #include <bits/wordsize.h>
  35
  36 struct ust_marker;
  37
  38 /**
  39  * ust_marker_probe_func - Type of a marker probe function
  40  * @mdata: marker data
  41  * @probe_private: probe private data
  42  * @call_private: call site private data
  43  * @fmt: format string
  44  * @args: variable argument list pointer. Use a pointer to overcome C's
  45  *        inability to pass this around as a pointer in a portable manner in
  46  *        the callee otherwise.
  47  *
  48  * Type of marker probe functions. They receive the mdata and need to parse the
  49  * format string to recover the variable argument list.
  50  */
  51 typedef void ust_marker_probe_func(const struct ust_marker *mdata,
  52                 void *probe_private, struct registers *regs, void *call_private,
  53                 const char *fmt, va_list *args);
  54
  55 struct ust_marker_probe_closure {
  56         ust_marker_probe_func *func;    /* Callback */
  57         void *probe_private;            /* Private probe data */
  58 };
  59
  60 struct ust_marker {
  61         const char *channel;    /* Name of channel where to send data */
  62         const char *name;       /* Marker name */
  63         const char *format;     /* Marker format string, describing the
  64                                  * variable argument list.
  65                                  */
  66         char state;             /* State. */
  67         char ptype;             /* probe type : 0 : single, 1 : multi */
  68                                 /* Probe wrapper */
  69         u16 channel_id;         /* Numeric channel identifier, dynamic */
  70         u16 event_id;           /* Numeric event identifier, dynamic */
  71         void (*call)(const struct ust_marker *mdata, void *call_private, struct registers *regs, ...);
  72         struct ust_marker_probe_closure single;
  73         struct ust_marker_probe_closure *multi;
  74         const char *tp_name;    /* Optional tracepoint name */
  75         void *tp_cb;            /* Optional tracepoint callback */
  76         void *location;         /* Address of marker in code */
  77 };
  78
  79 #define GET_UST_MARKER(name)            (__ust_marker_ust_##name)
  80
  81 #define _DEFINE_UST_MARKER(channel, name, tp_name_str, tp_cb, format, unique, m)                        \
  82                 struct registers __ust_marker_regs;                                                     \
  83                                                                                                 \
  84                 /* This next asm has to be a basic inline asm (no input/output/clobber),        \
  85                  * because it must not require %-sign escaping, as we most certainly            \
  86                  * have some %-signs in the format string.                                      \
  87                  */                                                                             \
  88                 asm volatile (                                                                  \
  89                         /* We only define these symbols if they have not yet been defined. Indeed, \
  90                          * if two markers with the same channel/name are on the same line, they \
  91                          * will try to create the same symbols, resulting in a conflict. This   \
  92                          * is not unusual as it can be the result of function inlining.         \
  93                          */                                                                     \
  94                         ".ifndef __mstrtab_" __stringify(channel) "_" __stringify(name) "_channel_" __stringify(unique) "\n\t"  \
  95                         /*".section __ust_marker_strings\n\t"*/                                 \
  96                         ".section __ust_marker_strings,\"aw\"\n\t"                                      \
  97                         "__mstrtab_" __stringify(channel) "_" __stringify(name) "_channel_" __stringify(unique) ":\n\t" \
  98                         ".string \"" __stringify(channel) "\"\n\t"                                      \
  99                         "__mstrtab_" __stringify(channel) "_" __stringify(name) "_name_" __stringify(unique) ":\n\t"    \
 100                         ".string \"" __stringify(name) "\"\n\t"                                         \
 101                         "__mstrtab_" __stringify(channel) "_" __stringify(name) "_format_" __stringify(unique) ":\n\t"  \
 102                         ".string " "\"" format "\"" "\n\t"                                              \
 103                         ".previous\n\t"                                                         \
 104                         ".endif\n\t"                                                            \
 105                 );                                                                              \
 106                 asm volatile (                                                                  \
 107                         /*".section __ust_marker\n\t"*/ \
 108                         ".section __ust_marker,\"aw\"\n\t"                                              \
 109                         "2:\n\t" \
 110                         _ASM_PTR "(__mstrtab_" __stringify(channel) "_" __stringify(name) "_channel_" __stringify(unique) ")\n\t" /* channel string */ \
 111                         _ASM_PTR "(__mstrtab_" __stringify(channel) "_" __stringify(name) "_name_" __stringify(unique) ")\n\t" /* name string */ \
 112                         _ASM_PTR "(__mstrtab_" __stringify(channel) "_" __stringify(name) "_format_" __stringify(unique) ")\n\t" /* format string */ \
 113                         ".byte 0\n\t" /* state imv */                                           \
 114                         ".byte 0\n\t" /* ptype */                                                       \
 115                         ".hword 0\n\t" /* channel_id */                                         \
 116                         ".hword 0\n\t" /* event_id */                                           \
 117                         ".balign " __stringify(__WORDSIZE) " / 8\n\t" /* alignment */                   \
 118                         _ASM_PTR "(ust_marker_probe_cb)\n\t" /* call */                         \
 119                         _ASM_PTR "(__ust_marker_empty_function)\n\t" /* ust_marker_probe_closure single.field1 */ \
 120                         _ASM_PTR "0\n\t" /* ust_marker_probe_closure single.field2 */                   \
 121                         _ASM_PTR "0\n\t" /* ust_marker_probe_closure *multi */                          \
 122                         _ASM_PTR "0\n\t" /* tp_name */                                          \
 123                         _ASM_PTR "0\n\t" /* tp_cb */                                            \
 124                         _ASM_PTR "(1f)\n\t" /* location */                                              \
 125                         ".previous\n\t"                                                         \
 126                         /*".section __ust_marker_ptrs\n\t"*/ \
 127                         ".section __ust_marker_ptrs,\"a\"\n\t"                                  \
 128                         _ASM_PTR "(2b)\n\t"                                                     \
 129                         ".previous\n\t"                                                         \
 130                         "1:\n\t"                                                                \
 131                         ARCH_COPY_ADDR("%[outptr]")                                             \
 132                 : [outptr] "=r" (m) );                                                          \
 133                                                                                                 \
 134                 save_registers(&__ust_marker_regs)
 135
 136
 137 #define DEFINE_UST_MARKER(name, format, unique, m)                      \
 138                 _DEFINE_UST_MARKER(ust, name, NULL, NULL, format, unique, m)
 139
 140 #define DEFINE_UST_MARKER_TP(name, tp_name, tp_cb, format)              \
 141                 _DEFINE_UST_MARKER_TP(ust, name, #tp_name, tp_cb, format)
 142
 143 #define _DEFINE_UST_MARKER_TP(channel, name, tp_name_str, tp_cb, format)\
 144                 static const char __mstrtab_##channel##_##name[]        \
 145                 __attribute__((section("__ust_marker_strings")))        \
 146                 = #channel "\0" #name "\0" format;                      \
 147                 static struct ust_marker __ust_marker_##channel##_##name\
 148                 __attribute__((section("__ust_marker"))) =              \
 149                 { __mstrtab_##channel##_##name,                         \
 150                         &__mstrtab_##channel##_##name[sizeof(#channel)],\
 151                         &__mstrtab_##channel##_##name[sizeof(#channel) + sizeof(#name)],                \
 152                         0, 0, 0, 0, ust_marker_probe_cb,                \
 153                         { __ust_marker_empty_function, NULL},           \
 154                         NULL, tp_name_str, tp_cb };                     \
 155                 static struct ust_marker * const __ust_marker_ptr_##channel##_##name    \
 156                         __attribute__((used, section("__ust_marker_ptrs"))) =   \
 157                         &__ust_marker_##channel##_##name;
 158
 159 /*
 160  * Make sure the alignment of the structure in the __ust_marker 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
 165 #define __ust_marker(channel, name, call_private, format, args...) \
 166         __ust_marker_counter(channel, name, __LINE__, call_private, format, ## args)
 167
 168 #define __ust_marker_counter(channel, name, unique, call_private, format, args...) \
 169         do {                                                            \
 170                 struct ust_marker *__ust_marker_counter_ptr;                    \
 171                 _DEFINE_UST_MARKER(channel, name, NULL, NULL, format, unique, __ust_marker_counter_ptr);        \
 172                 __ust_marker_check_format(format, ## args);             \
 173                 if (unlikely(__ust_marker_counter_ptr->state)) \
 174                         (__ust_marker_counter_ptr->call)(__ust_marker_counter_ptr, call_private, &__ust_marker_regs, ## args);          \
 175         } while (0)
 176
 177 #define __ust_marker_tp(channel, name, call_private, tp_name, tp_cb, format, args...) \
 178         __ust_marker_tp_counter(channel, name, __LINE__, call_private, tp_name, tp_cb, format, ## args)
 179
 180 #define __ust_marker_tp_counter(channel, name, unique, call_private, tp_name, tp_cb, format, args...) \
 181         do {                                                            \
 182                 struct registers __ust_marker_regs;                             \
 183                 void __check_tp_type(void)                              \
 184                 {                                                       \
 185                         register_trace_##tp_name(tp_cb, call_private);          \
 186                 }                                                       \
 187                 _DEFINE_UST_MARKER_TP(channel, name, #tp_name, tp_cb, format);  \
 188                 __ust_marker_check_format(format, ## args);             \
 189                 (*__ust_marker_##channel##_##name.call)(&__ust_marker_##channel##_##name,       \
 190                         call_private, &__ust_marker_regs, ## args);                             \
 191         } while (0)
 192
 193 extern void ust_marker_update_probe_range(struct ust_marker * const *begin,
 194         struct ust_marker * const *end);
 195
 196 /**
 197  * ust_marker - Marker using code patching
 198  * @name: marker name, not quoted.
 199  * @format: format string
 200  * @args...: variable argument list
 201  *
 202  * Places a marker at caller site.
 203  */
 204 #define ust_marker(name, format, args...) \
 205         __ust_marker(ust, name, NULL, format, ## args)
 206
 207 /**
 208  * ust_marker_tp - Marker in a tracepoint callback
 209  * @name: marker name, not quoted.
 210  * @tp_name: tracepoint name, not quoted.
 211  * @tp_cb: tracepoint callback. Should have an associated global symbol so it
 212  *         is not optimized away by the compiler (should not be static).
 213  * @format: format string
 214  * @args...: variable argument list
 215  *
 216  * Places a marker in a tracepoint callback.
 217  */
 218 #define ust_marker_tp(name, tp_name, tp_cb, format, args...)    \
 219         __ust_marker_tp(ust, name, NULL, tp_name, tp_cb, format, ## args)
 220
 221 /**
 222  * UST_MARKER_NOARGS - Format string for a marker with no argument.
 223  */
 224 #define UST_MARKER_NOARGS " "
 225
 226 extern void lock_ust_marker(void);
 227 extern void unlock_ust_marker(void);
 228
 229 extern void ust_marker_compact_event_ids(void);
 230
 231 /* To be used for string format validity checking with gcc */
 232 static inline void __printf(1, 2) ___ust_marker_check_format(const char *fmt, ...)
 233 {
 234 }
 235
 236 #define __ust_marker_check_format(format, args...)                      \
 237         do {                                                            \
 238                 if (0)                                                  \
 239                         ___ust_marker_check_format(format, ## args);    \
 240         } while (0)
 241
 242 extern ust_marker_probe_func __ust_marker_empty_function;
 243
 244 extern void ust_marker_probe_cb(const struct ust_marker *mdata,
 245         void *call_private, struct registers *regs, ...);
 246
 247 /*
 248  * Connect a probe to a marker.
 249  * private data pointer must be a valid allocated memory address, or NULL.
 250  */
 251 extern int ust_marker_probe_register(const char *channel, const char *name,
 252         const char *format, ust_marker_probe_func *probe, void *probe_private);
 253
 254 /*
 255  * Returns the private data given to ust_marker_probe_register.
 256  */
 257 extern int ust_marker_probe_unregister(const char *channel, const char *name,
 258         ust_marker_probe_func *probe, void *probe_private);
 259 /*
 260  * Unregister a marker by providing the registered private data.
 261  */
 262 extern int ust_marker_probe_unregister_private_data(ust_marker_probe_func *probe,
 263         void *probe_private);
 264
 265 extern void *ust_marker_get_private_data(const char *channel, const char *name,
 266         ust_marker_probe_func *probe, int num);
 267
 268 /*
 269  * ust_marker_synchronize_unregister must be called between the last marker probe
 270  * unregistration and the first one of
 271  * - the end of module exit function
 272  * - the free of any resource used by the probes
 273  * to ensure the code and data are valid for any possibly running probes.
 274  */
 275 #define ust_marker_synchronize_unregister() synchronize_sched()
 276
 277 struct ust_marker_iter {
 278 //ust// struct module *module;
 279         struct ust_marker_lib *lib;
 280         struct ust_marker * const *ust_marker;
 281 };
 282
 283 extern void ust_marker_iter_start(struct ust_marker_iter *iter);
 284 extern void ust_marker_iter_next(struct ust_marker_iter *iter);
 285 extern void ust_marker_iter_stop(struct ust_marker_iter *iter);
 286 extern void ust_marker_iter_reset(struct ust_marker_iter *iter);
 287 extern int ust_marker_get_iter_range(struct ust_marker * const **marker, struct ust_marker * const *begin,
 288         struct ust_marker * const *end);
 289
 290 extern void ust_marker_update_process(void);
 291 extern int is_ust_marker_enabled(const char *channel, const char *name);
 292
 293 //ust// #ifdef CONFIG_UST_MARKER_USERSPACE
 294 //ust// extern void exit_user_ust_marker(struct task_struct *p);
 295 //ust// #else
 296 //ust// static inline void exit_user_ust_marker(struct task_struct *p)
 297 //ust// {
 298 //ust// }
 299 //ust// #endif
 300
 301 struct ust_marker_addr {
 302         struct ust_marker *marker;
 303         void *addr;
 304 };
 305
 306 struct ust_marker_lib {
 307         struct ust_marker * const *ust_marker_start;
 308 #ifdef CONFIG_UST_GDB_INTEGRATION
 309         struct ust_marker_addr *ust_marker_addr_start;
 310 #endif
 311         int ust_marker_count;
 312         struct cds_list_head list;
 313 };
 314
 315 extern int ust_marker_register_lib(struct ust_marker * const *ust_marker_start, int ust_marker_count);
 316 extern int ust_marker_unregister_lib(struct ust_marker * const *ust_marker_start);
 317
 318 #define UST_MARKER_LIB                                                  \
 319         extern struct ust_marker * const __start___ust_marker_ptrs[] __attribute__((weak, visibility("hidden"))); \
 320         extern struct ust_marker * const __stop___ust_marker_ptrs[] __attribute__((weak, visibility("hidden"))); \
 321         static struct ust_marker * const __ust_marker_ptr_dummy                 \
 322                 __attribute__((used, section("__ust_marker_ptrs"))) = NULL;\
 323                                                                         \
 324         static void __attribute__((constructor)) __ust_marker__init(void)       \
 325         {                                                               \
 326                 ust_marker_register_lib(__start___ust_marker_ptrs,      \
 327                                     __stop___ust_marker_ptrs            \
 328                                     - __start___ust_marker_ptrs);               \
 329         }                                                               \
 330                                                                         \
 331         static void __attribute__((destructor)) __ust_marker__destroy(void)\
 332         {                                                               \
 333                 ust_marker_unregister_lib(__start___ust_marker_ptrs);   \
 334         }
 335
 336 extern void ust_marker_set_new_ust_marker_cb(void (*cb)(struct ust_marker *));
 337 extern void init_ust_marker(void);
 338
 339 #endif /* _UST_MARKER_H */