libust/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 _LINUX_MARKER_H
  25 #define _LINUX_MARKER_H
  26
  27 #include <stdarg.h>
  28 //ust// #include <linux/types.h>
  29 #include "immediate.h"
  30 //ust// #include <linux/ltt-channels.h>
  31 #include "kernelcompat.h"
  32 #include <kcompat/list.h>
  33 #include "localerr.h"
  34 #include "registers.h"
  35
  36 //ust// struct module;
  37 //ust// struct task_struct;
  38 struct marker;
  39
  40 /**
  41  * marker_probe_func - Type of a marker probe function
  42  * @mdata: marker data
  43  * @probe_private: probe private data
  44  * @call_private: call site private data
  45  * @fmt: format string
  46  * @args: variable argument list pointer. Use a pointer to overcome C's
  47  *        inability to pass this around as a pointer in a portable manner in
  48  *        the callee otherwise.
  49  *
  50  * Type of marker probe functions. They receive the mdata and need to parse the
  51  * format string to recover the variable argument list.
  52  */
  53 typedef void marker_probe_func(const struct marker *mdata,
  54                 void *probe_private, void *call_private,
  55                 const char *fmt, va_list *args);
  56
  57 struct marker_probe_closure {
  58         marker_probe_func *func;        /* Callback */
  59         void *probe_private;            /* Private probe data */
  60 };
  61
  62 struct marker {
  63         const char *channel;    /* Name of channel where to send data */
  64         const char *name;       /* Marker name */
  65         const char *format;     /* Marker format string, describing the
  66                                  * variable argument list.
  67                                  */
  68         DEFINE_IMV(char, state);/* Immediate value state. */
  69         char ptype;             /* probe type : 0 : single, 1 : multi */
  70                                 /* Probe wrapper */
  71         u16 channel_id;         /* Numeric channel identifier, dynamic */
  72         u16 event_id;           /* Numeric event identifier, dynamic */
  73         void (*call)(const struct marker *mdata, void *call_private, ...);
  74         struct marker_probe_closure single;
  75         struct marker_probe_closure *multi;
  76         const char *tp_name;    /* Optional tracepoint name */
  77         void *tp_cb;            /* Optional tracepoint callback */
  78         void *location;         /* Address of marker in code */
  79 } __attribute__((aligned(8)));
  80
  81 #define CONFIG_MARKERS
  82 #ifdef CONFIG_MARKERS
  83
  84 #define _DEFINE_MARKER(channel, name, tp_name_str, tp_cb, format)       \
  85                 static const char __mstrtab_##channel##_##name[]        \
  86                 __attribute__((section("__markers_strings")))           \
  87                 = #channel "\0" #name "\0" format;                      \
  88                 static struct marker __mark_##channel##_##name          \
  89                 __attribute__((section("__markers"), aligned(8))) =     \
  90                 { __mstrtab_##channel##_##name,                         \
  91                   &__mstrtab_##channel##_##name[sizeof(#channel)],      \
  92                   &__mstrtab_##channel##_##name[sizeof(#channel) +      \
  93                                                 sizeof(#name)],         \
  94                   0, 0, 0, 0, marker_probe_cb,                          \
  95                   { __mark_empty_function, NULL},                       \
  96                   NULL, tp_name_str, tp_cb };                           \
  97                 asm (".section __marker_addr,\"aw\",@progbits\n\t"      \
  98                        _ASM_PTR "%c[marker_struct], (1f)\n\t"           \
  99                        ".previous\n\t"                                  \
 100                        "\n\t"                                           \
 101                        "1:\n\t"                                         \
 102                         :: [marker_struct] "i" (&__mark_##channel##_##name));\
 103                 save_registers(&regs)
 104
 105
 106
 107 #define DEFINE_MARKER(channel, name, format)                            \
 108                 _DEFINE_MARKER(channel, name, NULL, NULL, format)
 109
 110 #define DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format)         \
 111                 _DEFINE_MARKER(channel, name, #tp_name, tp_cb, format)
 112
 113 /*
 114  * Make sure the alignment of the structure in the __markers section will
 115  * not add unwanted padding between the beginning of the section and the
 116  * structure. Force alignment to the same alignment as the section start.
 117  *
 118  * The "generic" argument controls which marker enabling mechanism must be used.
 119  * If generic is true, a variable read is used.
 120  * If generic is false, immediate values are used.
 121  */
 122 #define __trace_mark(generic, channel, name, call_private, format, args...) \
 123         do {                                                            \
 124                 DEFINE_MARKER(channel, name, format);                   \
 125                 __mark_check_format(format, ## args);                   \
 126                 if (!generic) {                                         \
 127                         if (unlikely(imv_read(                          \
 128                                         __mark_##channel##_##name.state))) \
 129                                 (*__mark_##channel##_##name.call)       \
 130                                         (&__mark_##channel##_##name,    \
 131                                         call_private, ## args);         \
 132                 } else {                                                \
 133                         if (unlikely(_imv_read(                         \
 134                                         __mark_##channel##_##name.state))) \
 135                                 (*__mark_##channel##_##name.call)       \
 136                                         (&__mark_##channel##_##name,    \
 137                                         call_private, ## args);         \
 138                 }                                                       \
 139         } while (0)
 140
 141 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb,    \
 142                         format, args...)                                \
 143         do {                                                            \
 144                 void __check_tp_type(void)                              \
 145                 {                                                       \
 146                         register_trace_##tp_name(tp_cb);                \
 147                 }                                                       \
 148                 DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format);\
 149                 __mark_check_format(format, ## args);                   \
 150                 (*__mark_##channel##_##name.call)(&__mark_##channel##_##name, \
 151                         call_private, ## args);                         \
 152         } while (0)
 153
 154 extern void marker_update_probe_range(struct marker *begin,
 155         struct marker *end);
 156
 157 #define GET_MARKER(channel, name)       (__mark_##channel##_##name)
 158
 159 #else /* !CONFIG_MARKERS */
 160 #define DEFINE_MARKER(channel, name, tp_name, tp_cb, format)
 161 #define __trace_mark(generic, channel, name, call_private, format, args...) \
 162                 __mark_check_format(format, ## args)
 163 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb,    \
 164                 format, args...)                                        \
 165         do {                                                            \
 166                 void __check_tp_type(void)                              \
 167                 {                                                       \
 168                         register_trace_##tp_name(tp_cb);                \
 169                 }                                                       \
 170                 __mark_check_format(format, ## args);                   \
 171         } while (0)
 172 static inline void marker_update_probe_range(struct marker *begin,
 173         struct marker *end)
 174 { }
 175 #define GET_MARKER(channel, name)
 176 #endif /* CONFIG_MARKERS */
 177
 178 /**
 179  * trace_mark - Marker using code patching
 180  * @channel: marker channel (where to send the data), not quoted.
 181  * @name: marker name, not quoted.
 182  * @format: format string
 183  * @args...: variable argument list
 184  *
 185  * Places a marker using optimized code patching technique (imv_read())
 186  * to be enabled when immediate values are present.
 187  */
 188 #define trace_mark(channel, name, format, args...) \
 189         __trace_mark(0, channel, name, NULL, format, ## args)
 190
 191 /**
 192  * _trace_mark - Marker using variable read
 193  * @channel: marker channel (where to send the data), not quoted.
 194  * @name: marker name, not quoted.
 195  * @format: format string
 196  * @args...: variable argument list
 197  *
 198  * Places a marker using a standard memory read (_imv_read()) to be
 199  * enabled. Should be used for markers in code paths where instruction
 200  * modification based enabling is not welcome. (__init and __exit functions,
 201  * lockdep, some traps, printk).
 202  */
 203 #define _trace_mark(channel, name, format, args...) \
 204         __trace_mark(1, channel, name, NULL, format, ## args)
 205
 206 /**
 207  * trace_mark_tp - Marker in a tracepoint callback
 208  * @channel: marker channel (where to send the data), not quoted.
 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 trace_mark_tp(channel, name, tp_name, tp_cb, format, args...)   \
 219         __trace_mark_tp(channel, name, NULL, tp_name, tp_cb, format, ## args)
 220
 221 /**
 222  * MARK_NOARGS - Format string for a marker with no argument.
 223  */
 224 #define MARK_NOARGS " "
 225
 226 extern void lock_markers(void);
 227 extern void unlock_markers(void);
 228
 229 extern void markers_compact_event_ids(void);
 230
 231 /* To be used for string format validity checking with gcc */
 232 static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
 233 {
 234 }
 235
 236 #define __mark_check_format(format, args...)                            \
 237         do {                                                            \
 238                 if (0)                                                  \
 239                         ___mark_check_format(format, ## args);          \
 240         } while (0)
 241
 242 extern marker_probe_func __mark_empty_function;
 243
 244 extern void marker_probe_cb(const struct marker *mdata,
 245         void *call_private, ...);
 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 marker_probe_register(const char *channel, const char *name,
 252         const char *format, marker_probe_func *probe, void *probe_private);
 253
 254 /*
 255  * Returns the private data given to marker_probe_register.
 256  */
 257 extern int marker_probe_unregister(const char *channel, const char *name,
 258         marker_probe_func *probe, void *probe_private);
 259 /*
 260  * Unregister a marker by providing the registered private data.
 261  */
 262 extern int marker_probe_unregister_private_data(marker_probe_func *probe,
 263         void *probe_private);
 264
 265 extern void *marker_get_private_data(const char *channel, const char *name,
 266         marker_probe_func *probe, int num);
 267
 268 /*
 269  * 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 marker_synchronize_unregister() synchronize_sched()
 276
 277 struct marker_iter {
 278 //ust// struct module *module;
 279         struct lib *lib;
 280         struct marker *marker;
 281 };
 282
 283 extern void marker_iter_start(struct marker_iter *iter);
 284 extern void marker_iter_next(struct marker_iter *iter);
 285 extern void marker_iter_stop(struct marker_iter *iter);
 286 extern void marker_iter_reset(struct marker_iter *iter);
 287 extern int marker_get_iter_range(struct marker **marker, struct marker *begin,
 288         struct marker *end);
 289
 290 extern void marker_update_process(void);
 291 extern int is_marker_enabled(const char *channel, const char *name);
 292
 293 //ust// #ifdef CONFIG_MARKERS_USERSPACE
 294 //ust// extern void exit_user_markers(struct task_struct *p);
 295 //ust// #else
 296 //ust// static inline void exit_user_markers(struct task_struct *p)
 297 //ust// {
 298 //ust// }
 299 //ust// #endif
 300
 301 struct marker_addr {
 302         struct marker *marker;
 303         void *addr;
 304 };
 305
 306 struct lib {
 307         struct marker *markers_start;
 308         struct marker_addr *markers_addr_start;
 309         int markers_count;
 310         struct list_head list;
 311 };
 312
 313 extern int marker_register_lib(struct marker *markers_start, struct marker_addr *marker_addr_start, int markers_count);
 314
 315 #define MARKER_LIB                                                                              \
 316 extern struct marker __start___markers[] __attribute__((visibility("hidden")));                 \
 317 extern struct marker __stop___markers[] __attribute__((visibility("hidden")));                  \
 318 extern struct marker_addr __start___marker_addr[] __attribute__((visibility("hidden")));        \
 319 extern struct marker_addr __stop___marker_addr[] __attribute__((visibility("hidden")));         \
 320                                                                                                 \
 321 static void __attribute__((constructor)) __markers__init(void)                                  \
 322 {                                                                                               \
 323         DBG("next registration in "__FILE__"\n");                                               \
 324         marker_register_lib(__start___markers, __start___marker_addr, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker)); \
 325 }
 326
 327 extern void marker_set_new_marker_cb(void (*cb)(struct marker *));
 328 extern void init_markers(void);
 329
 330 #endif