include/linux/trace_events.h

   1
   2 #ifndef _LINUX_TRACE_EVENT_H
   3 #define _LINUX_TRACE_EVENT_H
   4
   5 #include <linux/ring_buffer.h>
   6 #include <linux/trace_seq.h>
   7 #include <linux/percpu.h>
   8 #include <linux/hardirq.h>
   9 #include <linux/perf_event.h>
  10 #include <linux/tracepoint.h>
  11
  12 struct trace_array;
  13 struct trace_buffer;
  14 struct tracer;
  15 struct dentry;
  16 struct bpf_prog;
  17
  18 struct trace_print_flags {
  19         unsigned long           mask;
  20         const char              *name;
  21 };
  22
  23 struct trace_print_flags_u64 {
  24         unsigned long long      mask;
  25         const char              *name;
  26 };
  27
  28 const char *trace_print_flags_seq(struct trace_seq *p, const char *delim,
  29                                   unsigned long flags,
  30                                   const struct trace_print_flags *flag_array);
  31
  32 const char *trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
  33                                     const struct trace_print_flags *symbol_array);
  34
  35 #if BITS_PER_LONG == 32
  36 const char *trace_print_symbols_seq_u64(struct trace_seq *p,
  37                                         unsigned long long val,
  38                                         const struct trace_print_flags_u64
  39                                                                  *symbol_array);
  40 #endif
  41
  42 const char *trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
  43                                     unsigned int bitmask_size);
  44
  45 const char *trace_print_hex_seq(struct trace_seq *p,
  46                                 const unsigned char *buf, int len);
  47
  48 const char *trace_print_array_seq(struct trace_seq *p,
  49                                    const void *buf, int count,
  50                                    size_t el_size);
  51
  52 struct trace_iterator;
  53 struct trace_event;
  54
  55 int trace_raw_output_prep(struct trace_iterator *iter,
  56                           struct trace_event *event);
  57
  58 /*
  59  * The trace entry - the most basic unit of tracing. This is what
  60  * is printed in the end as a single line in the trace output, such as:
  61  *
  62  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  63  */
  64 struct trace_entry {
  65         unsigned short          type;
  66         unsigned char           flags;
  67         unsigned char           preempt_count;
  68         int                     pid;
  69 };
  70
  71 #define TRACE_EVENT_TYPE_MAX                                            \
  72         ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  73
  74 /*
  75  * Trace iterator - used by printout routines who present trace
  76  * results to users and which routines might sleep, etc:
  77  */
  78 struct trace_iterator {
  79         struct trace_array      *tr;
  80         struct tracer           *trace;
  81         struct trace_buffer     *trace_buffer;
  82         void                    *private;
  83         int                     cpu_file;
  84         struct mutex            mutex;
  85         struct ring_buffer_iter **buffer_iter;
  86         unsigned long           iter_flags;
  87
  88         /* trace_seq for __print_flags() and __print_symbolic() etc. */
  89         struct trace_seq        tmp_seq;
  90
  91         cpumask_var_t           started;
  92
  93         /* it's true when current open file is snapshot */
  94         bool                    snapshot;
  95
  96         /* The below is zeroed out in pipe_read */
  97         struct trace_seq        seq;
  98         struct trace_entry      *ent;
  99         unsigned long           lost_events;
 100         int                     leftover;
 101         int                     ent_size;
 102         int                     cpu;
 103         u64                     ts;
 104
 105         loff_t                  pos;
 106         long                    idx;
 107
 108         /* All new field here will be zeroed out in pipe_read */
 109 };
 110
 111 enum trace_iter_flags {
 112         TRACE_FILE_LAT_FMT      = 1,
 113         TRACE_FILE_ANNOTATE     = 2,
 114         TRACE_FILE_TIME_IN_NS   = 4,
 115 };
 116
 117
 118 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
 119                                       int flags, struct trace_event *event);
 120
 121 struct trace_event_functions {
 122         trace_print_func        trace;
 123         trace_print_func        raw;
 124         trace_print_func        hex;
 125         trace_print_func        binary;
 126 };
 127
 128 struct trace_event {
 129         struct hlist_node               node;
 130         struct list_head                list;
 131         int                             type;
 132         struct trace_event_functions    *funcs;
 133 };
 134
 135 extern int register_trace_event(struct trace_event *event);
 136 extern int unregister_trace_event(struct trace_event *event);
 137
 138 /* Return values for print_line callback */
 139 enum print_line_t {
 140         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 141         TRACE_TYPE_HANDLED      = 1,
 142         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 143         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 144 };
 145
 146 /*
 147  * Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq
 148  * overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function
 149  * simplifies those functions and keeps them in sync.
 150  */
 151 static inline enum print_line_t trace_handle_return(struct trace_seq *s)
 152 {
 153         return trace_seq_has_overflowed(s) ?
 154                 TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
 155 }
 156
 157 void tracing_generic_entry_update(struct trace_entry *entry,
 158                                   unsigned long flags,
 159                                   int pc);
 160 struct trace_event_file;
 161
 162 struct ring_buffer_event *
 163 trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer,
 164                                 struct trace_event_file *trace_file,
 165                                 int type, unsigned long len,
 166                                 unsigned long flags, int pc);
 167 struct ring_buffer_event *
 168 trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer,
 169                                   int type, unsigned long len,
 170                                   unsigned long flags, int pc);
 171 void trace_buffer_unlock_commit(struct trace_array *tr,
 172                                 struct ring_buffer *buffer,
 173                                 struct ring_buffer_event *event,
 174                                 unsigned long flags, int pc);
 175 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
 176                                      struct ring_buffer *buffer,
 177                                      struct ring_buffer_event *event,
 178                                      unsigned long flags, int pc,
 179                                      struct pt_regs *regs);
 180 void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
 181                                          struct ring_buffer_event *event);
 182
 183 void tracing_record_cmdline(struct task_struct *tsk);
 184
 185 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...);
 186
 187 struct event_filter;
 188
 189 enum trace_reg {
 190         TRACE_REG_REGISTER,
 191         TRACE_REG_UNREGISTER,
 192 #ifdef CONFIG_PERF_EVENTS
 193         TRACE_REG_PERF_REGISTER,
 194         TRACE_REG_PERF_UNREGISTER,
 195         TRACE_REG_PERF_OPEN,
 196         TRACE_REG_PERF_CLOSE,
 197         TRACE_REG_PERF_ADD,
 198         TRACE_REG_PERF_DEL,
 199 #endif
 200 };
 201
 202 struct trace_event_call;
 203
 204 struct trace_event_class {
 205         const char              *system;
 206         void                    *probe;
 207 #ifdef CONFIG_PERF_EVENTS
 208         void                    *perf_probe;
 209 #endif
 210         int                     (*reg)(struct trace_event_call *event,
 211                                        enum trace_reg type, void *data);
 212         int                     (*define_fields)(struct trace_event_call *);
 213         struct list_head        *(*get_fields)(struct trace_event_call *);
 214         struct list_head        fields;
 215         int                     (*raw_init)(struct trace_event_call *);
 216 };
 217
 218 extern int trace_event_reg(struct trace_event_call *event,
 219                             enum trace_reg type, void *data);
 220
 221 struct trace_event_buffer {
 222         struct ring_buffer              *buffer;
 223         struct ring_buffer_event        *event;
 224         struct trace_event_file         *trace_file;
 225         void                            *entry;
 226         unsigned long                   flags;
 227         int                             pc;
 228 };
 229
 230 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
 231                                   struct trace_event_file *trace_file,
 232                                   unsigned long len);
 233
 234 void trace_event_buffer_commit(struct trace_event_buffer *fbuffer);
 235
 236 enum {
 237         TRACE_EVENT_FL_FILTERED_BIT,
 238         TRACE_EVENT_FL_CAP_ANY_BIT,
 239         TRACE_EVENT_FL_NO_SET_FILTER_BIT,
 240         TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
 241         TRACE_EVENT_FL_WAS_ENABLED_BIT,
 242         TRACE_EVENT_FL_USE_CALL_FILTER_BIT,
 243         TRACE_EVENT_FL_TRACEPOINT_BIT,
 244         TRACE_EVENT_FL_KPROBE_BIT,
 245         TRACE_EVENT_FL_UPROBE_BIT,
 246 };
 247
 248 /*
 249  * Event flags:
 250  *  FILTERED      - The event has a filter attached
 251  *  CAP_ANY       - Any user can enable for perf
 252  *  NO_SET_FILTER - Set when filter has error and is to be ignored
 253  *  IGNORE_ENABLE - For trace internal events, do not enable with debugfs file
 254  *  WAS_ENABLED   - Set and stays set when an event was ever enabled
 255  *                    (used for module unloading, if a module event is enabled,
 256  *                     it is best to clear the buffers that used it).
 257  *  USE_CALL_FILTER - For trace internal events, don't use file filter
 258  *  TRACEPOINT    - Event is a tracepoint
 259  *  KPROBE        - Event is a kprobe
 260  *  UPROBE        - Event is a uprobe
 261  */
 262 enum {
 263         TRACE_EVENT_FL_FILTERED         = (1 << TRACE_EVENT_FL_FILTERED_BIT),
 264         TRACE_EVENT_FL_CAP_ANY          = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
 265         TRACE_EVENT_FL_NO_SET_FILTER    = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
 266         TRACE_EVENT_FL_IGNORE_ENABLE    = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
 267         TRACE_EVENT_FL_WAS_ENABLED      = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT),
 268         TRACE_EVENT_FL_USE_CALL_FILTER  = (1 << TRACE_EVENT_FL_USE_CALL_FILTER_BIT),
 269         TRACE_EVENT_FL_TRACEPOINT       = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT),
 270         TRACE_EVENT_FL_KPROBE           = (1 << TRACE_EVENT_FL_KPROBE_BIT),
 271         TRACE_EVENT_FL_UPROBE           = (1 << TRACE_EVENT_FL_UPROBE_BIT),
 272 };
 273
 274 #define TRACE_EVENT_FL_UKPROBE (TRACE_EVENT_FL_KPROBE | TRACE_EVENT_FL_UPROBE)
 275
 276 struct trace_event_call {
 277         struct list_head        list;
 278         struct trace_event_class *class;
 279         union {
 280                 char                    *name;
 281                 /* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */
 282                 struct tracepoint       *tp;
 283         };
 284         struct trace_event      event;
 285         char                    *print_fmt;
 286         struct event_filter     *filter;
 287         void                    *mod;
 288         void                    *data;
 289         /*
 290          *   bit 0:             filter_active
 291          *   bit 1:             allow trace by non root (cap any)
 292          *   bit 2:             failed to apply filter
 293          *   bit 3:             trace internal event (do not enable)
 294          *   bit 4:             Event was enabled by module
 295          *   bit 5:             use call filter rather than file filter
 296          *   bit 6:             Event is a tracepoint
 297          */
 298         int                     flags; /* static flags of different events */
 299
 300 #ifdef CONFIG_PERF_EVENTS
 301         int                             perf_refcount;
 302         struct hlist_head __percpu      *perf_events;
 303         struct bpf_prog                 *prog;
 304
 305         int     (*perf_perm)(struct trace_event_call *,
 306                              struct perf_event *);
 307 #endif
 308 };
 309
 310 static inline const char *
 311 trace_event_name(struct trace_event_call *call)
 312 {
 313         if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
 314                 return call->tp ? call->tp->name : NULL;
 315         else
 316                 return call->name;
 317 }
 318
 319 struct trace_array;
 320 struct trace_subsystem_dir;
 321
 322 enum {
 323         EVENT_FILE_FL_ENABLED_BIT,
 324         EVENT_FILE_FL_RECORDED_CMD_BIT,
 325         EVENT_FILE_FL_FILTERED_BIT,
 326         EVENT_FILE_FL_NO_SET_FILTER_BIT,
 327         EVENT_FILE_FL_SOFT_MODE_BIT,
 328         EVENT_FILE_FL_SOFT_DISABLED_BIT,
 329         EVENT_FILE_FL_TRIGGER_MODE_BIT,
 330         EVENT_FILE_FL_TRIGGER_COND_BIT,
 331         EVENT_FILE_FL_PID_FILTER_BIT,
 332 };
 333
 334 /*
 335  * Event file flags:
 336  *  ENABLED       - The event is enabled
 337  *  RECORDED_CMD  - The comms should be recorded at sched_switch
 338  *  FILTERED      - The event has a filter attached
 339  *  NO_SET_FILTER - Set when filter has error and is to be ignored
 340  *  SOFT_MODE     - The event is enabled/disabled by SOFT_DISABLED
 341  *  SOFT_DISABLED - When set, do not trace the event (even though its
 342  *                   tracepoint may be enabled)
 343  *  TRIGGER_MODE  - When set, invoke the triggers associated with the event
 344  *  TRIGGER_COND  - When set, one or more triggers has an associated filter
 345  *  PID_FILTER    - When set, the event is filtered based on pid
 346  */
 347 enum {
 348         EVENT_FILE_FL_ENABLED           = (1 << EVENT_FILE_FL_ENABLED_BIT),
 349         EVENT_FILE_FL_RECORDED_CMD      = (1 << EVENT_FILE_FL_RECORDED_CMD_BIT),
 350         EVENT_FILE_FL_FILTERED          = (1 << EVENT_FILE_FL_FILTERED_BIT),
 351         EVENT_FILE_FL_NO_SET_FILTER     = (1 << EVENT_FILE_FL_NO_SET_FILTER_BIT),
 352         EVENT_FILE_FL_SOFT_MODE         = (1 << EVENT_FILE_FL_SOFT_MODE_BIT),
 353         EVENT_FILE_FL_SOFT_DISABLED     = (1 << EVENT_FILE_FL_SOFT_DISABLED_BIT),
 354         EVENT_FILE_FL_TRIGGER_MODE      = (1 << EVENT_FILE_FL_TRIGGER_MODE_BIT),
 355         EVENT_FILE_FL_TRIGGER_COND      = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT),
 356         EVENT_FILE_FL_PID_FILTER        = (1 << EVENT_FILE_FL_PID_FILTER_BIT),
 357 };
 358
 359 struct trace_event_file {
 360         struct list_head                list;
 361         struct trace_event_call         *event_call;
 362         struct event_filter             *filter;
 363         struct dentry                   *dir;
 364         struct trace_array              *tr;
 365         struct trace_subsystem_dir      *system;
 366         struct list_head                triggers;
 367
 368         /*
 369          * 32 bit flags:
 370          *   bit 0:             enabled
 371          *   bit 1:             enabled cmd record
 372          *   bit 2:             enable/disable with the soft disable bit
 373          *   bit 3:             soft disabled
 374          *   bit 4:             trigger enabled
 375          *
 376          * Note: The bits must be set atomically to prevent races
 377          * from other writers. Reads of flags do not need to be in
 378          * sync as they occur in critical sections. But the way flags
 379          * is currently used, these changes do not affect the code
 380          * except that when a change is made, it may have a slight
 381          * delay in propagating the changes to other CPUs due to
 382          * caching and such. Which is mostly OK ;-)
 383          */
 384         unsigned long           flags;
 385         atomic_t                sm_ref; /* soft-mode reference counter */
 386         atomic_t                tm_ref; /* trigger-mode reference counter */
 387 };
 388
 389 #define __TRACE_EVENT_FLAGS(name, value)                                \
 390         static int __init trace_init_flags_##name(void)                 \
 391         {                                                               \
 392                 event_##name.flags |= value;                            \
 393                 return 0;                                               \
 394         }                                                               \
 395         early_initcall(trace_init_flags_##name);
 396
 397 #define __TRACE_EVENT_PERF_PERM(name, expr...)                          \
 398         static int perf_perm_##name(struct trace_event_call *tp_event, \
 399                                     struct perf_event *p_event)         \
 400         {                                                               \
 401                 return ({ expr; });                                     \
 402         }                                                               \
 403         static int __init trace_init_perf_perm_##name(void)             \
 404         {                                                               \
 405                 event_##name.perf_perm = &perf_perm_##name;             \
 406                 return 0;                                               \
 407         }                                                               \
 408         early_initcall(trace_init_perf_perm_##name);
 409
 410 #define PERF_MAX_TRACE_SIZE     2048
 411
 412 #define MAX_FILTER_STR_VAL      256     /* Should handle KSYM_SYMBOL_LEN */
 413
 414 enum event_trigger_type {
 415         ETT_NONE                = (0),
 416         ETT_TRACE_ONOFF         = (1 << 0),
 417         ETT_SNAPSHOT            = (1 << 1),
 418         ETT_STACKTRACE          = (1 << 2),
 419         ETT_EVENT_ENABLE        = (1 << 3),
 420 };
 421
 422 extern int filter_match_preds(struct event_filter *filter, void *rec);
 423
 424 extern int filter_check_discard(struct trace_event_file *file, void *rec,
 425                                 struct ring_buffer *buffer,
 426                                 struct ring_buffer_event *event);
 427 extern int call_filter_check_discard(struct trace_event_call *call, void *rec,
 428                                      struct ring_buffer *buffer,
 429                                      struct ring_buffer_event *event);
 430 extern enum event_trigger_type event_triggers_call(struct trace_event_file *file,
 431                                                    void *rec);
 432 extern void event_triggers_post_call(struct trace_event_file *file,
 433                                      enum event_trigger_type tt);
 434
 435 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file);
 436
 437 /**
 438  * trace_trigger_soft_disabled - do triggers and test if soft disabled
 439  * @file: The file pointer of the event to test
 440  *
 441  * If any triggers without filters are attached to this event, they
 442  * will be called here. If the event is soft disabled and has no
 443  * triggers that require testing the fields, it will return true,
 444  * otherwise false.
 445  */
 446 static inline bool
 447 trace_trigger_soft_disabled(struct trace_event_file *file)
 448 {
 449         unsigned long eflags = file->flags;
 450
 451         if (!(eflags & EVENT_FILE_FL_TRIGGER_COND)) {
 452                 if (eflags & EVENT_FILE_FL_TRIGGER_MODE)
 453                         event_triggers_call(file, NULL);
 454                 if (eflags & EVENT_FILE_FL_SOFT_DISABLED)
 455                         return true;
 456                 if (eflags & EVENT_FILE_FL_PID_FILTER)
 457                         return trace_event_ignore_this_pid(file);
 458         }
 459         return false;
 460 }
 461
 462 /*
 463  * Helper function for event_trigger_unlock_commit{_regs}().
 464  * If there are event triggers attached to this event that requires
 465  * filtering against its fields, then they wil be called as the
 466  * entry already holds the field information of the current event.
 467  *
 468  * It also checks if the event should be discarded or not.
 469  * It is to be discarded if the event is soft disabled and the
 470  * event was only recorded to process triggers, or if the event
 471  * filter is active and this event did not match the filters.
 472  *
 473  * Returns true if the event is discarded, false otherwise.
 474  */
 475 static inline bool
 476 __event_trigger_test_discard(struct trace_event_file *file,
 477                              struct ring_buffer *buffer,
 478                              struct ring_buffer_event *event,
 479                              void *entry,
 480                              enum event_trigger_type *tt)
 481 {
 482         unsigned long eflags = file->flags;
 483
 484         if (eflags & EVENT_FILE_FL_TRIGGER_COND)
 485                 *tt = event_triggers_call(file, entry);
 486
 487         if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags))
 488                 ring_buffer_discard_commit(buffer, event);
 489         else if (!filter_check_discard(file, entry, buffer, event))
 490                 return false;
 491
 492         return true;
 493 }
 494
 495 /**
 496  * event_trigger_unlock_commit - handle triggers and finish event commit
 497  * @file: The file pointer assoctiated to the event
 498  * @buffer: The ring buffer that the event is being written to
 499  * @event: The event meta data in the ring buffer
 500  * @entry: The event itself
 501  * @irq_flags: The state of the interrupts at the start of the event
 502  * @pc: The state of the preempt count at the start of the event.
 503  *
 504  * This is a helper function to handle triggers that require data
 505  * from the event itself. It also tests the event against filters and
 506  * if the event is soft disabled and should be discarded.
 507  */
 508 static inline void
 509 event_trigger_unlock_commit(struct trace_event_file *file,
 510                             struct ring_buffer *buffer,
 511                             struct ring_buffer_event *event,
 512                             void *entry, unsigned long irq_flags, int pc)
 513 {
 514         enum event_trigger_type tt = ETT_NONE;
 515
 516         if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
 517                 trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
 518
 519         if (tt)
 520                 event_triggers_post_call(file, tt);
 521 }
 522
 523 /**
 524  * event_trigger_unlock_commit_regs - handle triggers and finish event commit
 525  * @file: The file pointer assoctiated to the event
 526  * @buffer: The ring buffer that the event is being written to
 527  * @event: The event meta data in the ring buffer
 528  * @entry: The event itself
 529  * @irq_flags: The state of the interrupts at the start of the event
 530  * @pc: The state of the preempt count at the start of the event.
 531  *
 532  * This is a helper function to handle triggers that require data
 533  * from the event itself. It also tests the event against filters and
 534  * if the event is soft disabled and should be discarded.
 535  *
 536  * Same as event_trigger_unlock_commit() but calls
 537  * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit().
 538  */
 539 static inline void
 540 event_trigger_unlock_commit_regs(struct trace_event_file *file,
 541                                  struct ring_buffer *buffer,
 542                                  struct ring_buffer_event *event,
 543                                  void *entry, unsigned long irq_flags, int pc,
 544                                  struct pt_regs *regs)
 545 {
 546         enum event_trigger_type tt = ETT_NONE;
 547
 548         if (!__event_trigger_test_discard(file, buffer, event, entry, &tt))
 549                 trace_buffer_unlock_commit_regs(file->tr, buffer, event,
 550                                                 irq_flags, pc, regs);
 551
 552         if (tt)
 553                 event_triggers_post_call(file, tt);
 554 }
 555
 556 #ifdef CONFIG_BPF_EVENTS
 557 unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx);
 558 #else
 559 static inline unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx)
 560 {
 561         return 1;
 562 }
 563 #endif
 564
 565 enum {
 566         FILTER_OTHER = 0,
 567         FILTER_STATIC_STRING,
 568         FILTER_DYN_STRING,
 569         FILTER_PTR_STRING,
 570         FILTER_TRACE_FN,
 571 };
 572
 573 extern int trace_event_raw_init(struct trace_event_call *call);
 574 extern int trace_define_field(struct trace_event_call *call, const char *type,
 575                               const char *name, int offset, int size,
 576                               int is_signed, int filter_type);
 577 extern int trace_add_event_call(struct trace_event_call *call);
 578 extern int trace_remove_event_call(struct trace_event_call *call);
 579
 580 #define is_signed_type(type)    (((type)(-1)) < (type)1)
 581
 582 int trace_set_clr_event(const char *system, const char *event, int set);
 583
 584 /*
 585  * The double __builtin_constant_p is because gcc will give us an error
 586  * if we try to allocate the static variable to fmt if it is not a
 587  * constant. Even with the outer if statement optimizing out.
 588  */
 589 #define event_trace_printk(ip, fmt, args...)                            \
 590 do {                                                                    \
 591         __trace_printk_check_format(fmt, ##args);                       \
 592         tracing_record_cmdline(current);                                \
 593         if (__builtin_constant_p(fmt)) {                                \
 594                 static const char *trace_printk_fmt                     \
 595                   __attribute__((section("__trace_printk_fmt"))) =      \
 596                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 597                                                                         \
 598                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 599         } else                                                          \
 600                 __trace_printk(ip, fmt, ##args);                        \
 601 } while (0)
 602
 603 #ifdef CONFIG_PERF_EVENTS
 604 struct perf_event;
 605
 606 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 607
 608 extern int  perf_trace_init(struct perf_event *event);
 609 extern void perf_trace_destroy(struct perf_event *event);
 610 extern int  perf_trace_add(struct perf_event *event, int flags);
 611 extern void perf_trace_del(struct perf_event *event, int flags);
 612 extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 613                                      char *filter_str);
 614 extern void ftrace_profile_free_filter(struct perf_event *event);
 615 extern void *perf_trace_buf_prepare(int size, unsigned short type,
 616                                     struct pt_regs **regs, int *rctxp);
 617
 618 static inline void
 619 perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
 620                        u64 count, struct pt_regs *regs, void *head,
 621                        struct task_struct *task)
 622 {
 623         perf_tp_event(addr, count, raw_data, size, regs, head, rctx, task);
 624 }
 625 #endif
 626
 627 #endif /* _LINUX_TRACE_EVENT_H */