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, struct registers *regs, 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, struct registers *regs, ...);
  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                 struct registers regs;                                  \
  89                 static struct marker __mark_##channel##_##name          \
  90                 __attribute__((section("__markers"), aligned(8))) =     \
  91                 { __mstrtab_##channel##_##name,                         \
  92                   &__mstrtab_##channel##_##name[sizeof(#channel)],      \
  93                   &__mstrtab_##channel##_##name[sizeof(#channel) +      \
  94                                                 sizeof(#name)],         \
  95                   0, 0, 0, 0, marker_probe_cb,                          \
  96                   { __mark_empty_function, NULL},                       \
  97                   NULL, tp_name_str, tp_cb };                           \
  98                 asm (".section __marker_addr,\"aw\",@progbits\n\t"      \
  99                        _ASM_PTR "%c[marker_struct], (1f)\n\t"           \
 100                        ".previous\n\t"                                  \
 101                        "\n\t"                                           \
 102                        "1:\n\t"                                         \
 103                         :: [marker_struct] "i" (&__mark_##channel##_##name));\
 104                 save_registers(&regs)
 105
 106
 107
 108 #define DEFINE_MARKER(channel, name, format)                            \
 109                 _DEFINE_MARKER(channel, name, NULL, NULL, format)
 110
 111 #define DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format)         \
 112                 _DEFINE_MARKER(channel, name, #tp_name, tp_cb, format)
 113
 114 /*
 115  * Make sure the alignment of the structure in the __markers section will
 116  * not add unwanted padding between the beginning of the section and the
 117  * structure. Force alignment to the same alignment as the section start.
 118  *
 119  * The "generic" argument controls which marker enabling mechanism must be used.
 120  * If generic is true, a variable read is used.
 121  * If generic is false, immediate values are used.
 122  */
 123 #define __trace_mark(generic, channel, name, call_private, format, args...) \
 124         do {                                                            \
 125                 DEFINE_MARKER(channel, name, format);                   \
 126                 __mark_check_format(format, ## args);                   \
 127                 if (!generic) {                                         \
 128                         if (unlikely(imv_read(                          \
 129                                         __mark_##channel##_##name.state))) \
 130                                 (*__mark_##channel##_##name.call)       \
 131                                         (&__mark_##channel##_##name,    \
 132                                         call_private, &regs, ## args);          \
 133                 } else {                                                \
 134                         if (unlikely(_imv_read(                         \
 135                                         __mark_##channel##_##name.state))) \
 136                                 (*__mark_##channel##_##name.call)       \
 137                                         (&__mark_##channel##_##name,    \
 138                                         call_private, &regs, ## args);          \
 139                 }                                                       \
 140         } while (0)
 141
 142 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb,    \
 143                         format, args...)                                \
 144         do {                                                            \
 145                 void __check_tp_type(void)                              \
 146                 {                                                       \
 147                         register_trace_##tp_name(tp_cb);                \
 148                 }                                                       \
 149                 DEFINE_MARKER_TP(channel, name, tp_name, tp_cb, format);\
 150                 __mark_check_format(format, ## args);                   \
 151                 (*__mark_##channel##_##name.call)(&__mark_##channel##_##name, \
 152                         call_private, &regs, ## args);                          \
 153         } while (0)
 154
 155 extern void marker_update_probe_range(struct marker *begin,
 156         struct marker *end);
 157
 158 #define GET_MARKER(channel, name)       (__mark_##channel##_##name)
 159
 160 #else /* !CONFIG_MARKERS */
 161 #define DEFINE_MARKER(channel, name, tp_name, tp_cb, format)
 162 #define __trace_mark(generic, channel, name, call_private, format, args...) \
 163                 __mark_check_format(format, ## args)
 164 #define __trace_mark_tp(channel, name, call_private, tp_name, tp_cb,    \
 165                 format, args...)                                        \
 166         do {                                                            \
 167                 void __check_tp_type(void)                              \
 168                 {                                                       \
 169                         register_trace_##tp_name(tp_cb);                \
 170                 }                                                       \
 171                 __mark_check_format(format, ## args);                   \
 172         } while (0)
 173 static inline void marker_update_probe_range(struct marker *begin,
 174         struct marker *end)
 175 { }
 176 #define GET_MARKER(channel, name)
 177 #endif /* CONFIG_MARKERS */
 178
 179 /**
 180  * trace_mark - Marker using code patching
 181  * @channel: marker channel (where to send the data), not quoted.
 182  * @name: marker name, not quoted.
 183  * @format: format string
 184  * @args...: variable argument list
 185  *
 186  * Places a marker using optimized code patching technique (imv_read())
 187  * to be enabled when immediate values are present.
 188  */
 189 #define trace_mark(channel, name, format, args...) \
 190         __trace_mark(0, channel, name, NULL, format, ## args)
 191
 192 /**
 193  * _trace_mark - Marker using variable read
 194  * @channel: marker channel (where to send the data), not quoted.
 195  * @name: marker name, not quoted.
 196  * @format: format string
 197  * @args...: variable argument list
 198  *
 199  * Places a marker using a standard memory read (_imv_read()) to be
 200  * enabled. Should be used for markers in code paths where instruction
 201  * modification based enabling is not welcome. (__init and __exit functions,
 202  * lockdep, some traps, printk).
 203  */
 204 #define _trace_mark(channel, name, format, args...) \
 205         __trace_mark(1, channel, name, NULL, format, ## args)
 206
 207 /**
 208  * trace_mark_tp - Marker in a tracepoint callback
 209  * @channel: marker channel (where to send the data), not quoted.
 210  * @name: marker name, not quoted.
 211  * @tp_name: tracepoint name, not quoted.
 212  * @tp_cb: tracepoint callback. Should have an associated global symbol so it
 213  *         is not optimized away by the compiler (should not be static).
 214  * @format: format string
 215  * @args...: variable argument list
 216  *
 217  * Places a marker in a tracepoint callback.
 218  */
 219 #define trace_mark_tp(channel, name, tp_name, tp_cb, format, args...)   \
 220         __trace_mark_tp(channel, name, NULL, tp_name, tp_cb, format, ## args)
 221
 222 /**
 223  * MARK_NOARGS - Format string for a marker with no argument.
 224  */
 225 #define MARK_NOARGS " "
 226
 227 extern void lock_markers(void);
 228 extern void unlock_markers(void);
 229
 230 extern void markers_compact_event_ids(void);
 231
 232 /* To be used for string format validity checking with gcc */
 233 static inline void __printf(1, 2) ___mark_check_format(const char *fmt, ...)
 234 {
 235 }
 236
 237 #define __mark_check_format(format, args...)                            \
 238         do {                                                            \
 239                 if (0)                                                  \
 240                         ___mark_check_format(format, ## args);          \
 241         } while (0)
 242
 243 extern marker_probe_func __mark_empty_function;
 244
 245 extern void marker_probe_cb(const struct marker *mdata,
 246         void *call_private, struct registers *regs, ...);
 247
 248 /*
 249  * Connect a probe to a marker.
 250  * private data pointer must be a valid allocated memory address, or NULL.
 251  */
 252 extern int marker_probe_register(const char *channel, const char *name,
 253         const char *format, marker_probe_func *probe, void *probe_private);
 254
 255 /*
 256  * Returns the private data given to marker_probe_register.
 257  */
 258 extern int marker_probe_unregister(const char *channel, const char *name,
 259         marker_probe_func *probe, void *probe_private);
 260 /*
 261  * Unregister a marker by providing the registered private data.
 262  */
 263 extern int marker_probe_unregister_private_data(marker_probe_func *probe,
 264         void *probe_private);
 265
 266 extern void *marker_get_private_data(const char *channel, const char *name,
 267         marker_probe_func *probe, int num);
 268
 269 /*
 270  * marker_synchronize_unregister must be called between the last marker probe
 271  * unregistration and the first one of
 272  * - the end of module exit function
 273  * - the free of any resource used by the probes
 274  * to ensure the code and data are valid for any possibly running probes.
 275  */
 276 #define marker_synchronize_unregister() synchronize_sched()
 277
 278 struct marker_iter {
 279 //ust// struct module *module;
 280         struct lib *lib;
 281         struct marker *marker;
 282 };
 283
 284 extern void marker_iter_start(struct marker_iter *iter);
 285 extern void marker_iter_next(struct marker_iter *iter);
 286 extern void marker_iter_stop(struct marker_iter *iter);
 287 extern void marker_iter_reset(struct marker_iter *iter);
 288 extern int marker_get_iter_range(struct marker **marker, struct marker *begin,
 289         struct marker *end);
 290
 291 extern void marker_update_process(void);
 292 extern int is_marker_enabled(const char *channel, const char *name);
 293
 294 //ust// #ifdef CONFIG_MARKERS_USERSPACE
 295 //ust// extern void exit_user_markers(struct task_struct *p);
 296 //ust// #else
 297 //ust// static inline void exit_user_markers(struct task_struct *p)
 298 //ust// {
 299 //ust// }
 300 //ust// #endif
 301
 302 struct marker_addr {
 303         struct marker *marker;
 304         void *addr;
 305 };
 306
 307 struct lib {
 308         struct marker *markers_start;
 309         struct marker_addr *markers_addr_start;
 310         int markers_count;
 311         struct list_head list;
 312 };
 313
 314 extern int marker_register_lib(struct marker *markers_start, struct marker_addr *marker_addr_start, int markers_count);
 315
 316 #define MARKER_LIB                                                                              \
 317 extern struct marker __start___markers[] __attribute__((visibility("hidden")));                 \
 318 extern struct marker __stop___markers[] __attribute__((visibility("hidden")));                  \
 319 extern struct marker_addr __start___marker_addr[] __attribute__((visibility("hidden")));        \
 320 extern struct marker_addr __stop___marker_addr[] __attribute__((visibility("hidden")));         \
 321                                                                                                 \
 322 static void __attribute__((constructor)) __markers__init(void)                                  \
 323 {                                                                                               \
 324         DBG("next registration in "__FILE__"\n");                                               \
 325         marker_register_lib(__start___markers, __start___marker_addr, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker)); \
 326 }
 327
 328 extern void marker_set_new_marker_cb(void (*cb)(struct marker *));
 329 extern void init_markers(void);
 330
 331 #endif