include/linux/trace_events.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #ifndef _LINUX_TRACE_EVENT_H
   4 #define _LINUX_TRACE_EVENT_H
   5
   6 #include <linux/ring_buffer.h>
   7 #include <linux/trace_seq.h>
   8 #include <linux/percpu.h>
   9 #include <linux/hardirq.h>
  10 #include <linux/perf_event.h>
  11 #include <linux/tracepoint.h>
  12
  13 struct trace_array;
  14 struct array_buffer;
  15 struct tracer;
  16 struct dentry;
  17 struct bpf_prog;
  18 union bpf_attr;
  19
  20 /* Used for event string fields when they are NULL */
  21 #define EVENT_NULL_STR          "(null)"
  22
  23 const char *trace_print_flags_seq(struct trace_seq *p, const char *delim,
  24                                   unsigned long flags,
  25                                   const struct trace_print_flags *flag_array);
  26
  27 const char *trace_print_symbols_seq(struct trace_seq *p, unsigned long val,
  28                                     const struct trace_print_flags *symbol_array);
  29
  30 #if BITS_PER_LONG == 32
  31 const char *trace_print_flags_seq_u64(struct trace_seq *p, const char *delim,
  32                       unsigned long long flags,
  33                       const struct trace_print_flags_u64 *flag_array);
  34
  35 const char *trace_print_symbols_seq_u64(struct trace_seq *p,
  36                                         unsigned long long val,
  37                                         const struct trace_print_flags_u64
  38                                                                  *symbol_array);
  39 #endif
  40
  41 const char *trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
  42                                     unsigned int bitmask_size);
  43
  44 const char *trace_print_hex_seq(struct trace_seq *p,
  45                                 const unsigned char *buf, int len,
  46                                 bool concatenate);
  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 const char *
  53 trace_print_hex_dump_seq(struct trace_seq *p, const char *prefix_str,
  54                          int prefix_type, int rowsize, int groupsize,
  55                          const void *buf, size_t len, bool ascii);
  56
  57 struct trace_iterator;
  58 struct trace_event;
  59
  60 int trace_raw_output_prep(struct trace_iterator *iter,
  61                           struct trace_event *event);
  62 extern __printf(2, 3)
  63 void trace_event_printf(struct trace_iterator *iter, const char *fmt, ...);
  64
  65 /* Used to find the offset and length of dynamic fields in trace events */
  66 struct trace_dynamic_info {
  67 #ifdef CONFIG_CPU_BIG_ENDIAN
  68         u16     len;
  69         u16     offset;
  70 #else
  71         u16     offset;
  72         u16     len;
  73 #endif
  74 } __packed;
  75
  76 /*
  77  * The trace entry - the most basic unit of tracing. This is what
  78  * is printed in the end as a single line in the trace output, such as:
  79  *
  80  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  81  */
  82 struct trace_entry {
  83         unsigned short          type;
  84         unsigned char           flags;
  85         unsigned char           preempt_count;
  86         int                     pid;
  87 };
  88
  89 #define TRACE_EVENT_TYPE_MAX                                            \
  90         ((1 << (sizeof(((struct trace_entry *)0)->type) * 8)) - 1)
  91
  92 /*
  93  * Trace iterator - used by printout routines who present trace
  94  * results to users and which routines might sleep, etc:
  95  */
  96 struct trace_iterator {
  97         struct trace_array      *tr;
  98         struct tracer           *trace;
  99         struct array_buffer     *array_buffer;
 100         void                    *private;
 101         int                     cpu_file;
 102         struct mutex            mutex;
 103         struct ring_buffer_iter **buffer_iter;
 104         unsigned long           iter_flags;
 105         void                    *temp;  /* temp holder */
 106         unsigned int            temp_size;
 107         char                    *fmt;   /* modified format holder */
 108         unsigned int            fmt_size;
 109         atomic_t                wait_index;
 110
 111         /* trace_seq for __print_flags() and __print_symbolic() etc. */
 112         struct trace_seq        tmp_seq;
 113
 114         cpumask_var_t           started;
 115
 116         /* Set when the file is closed to prevent new waiters */
 117         bool                    closed;
 118
 119         /* it's true when current open file is snapshot */
 120         bool                    snapshot;
 121
 122         /* The below is zeroed out in pipe_read */
 123         struct trace_seq        seq;
 124         struct trace_entry      *ent;
 125         unsigned long           lost_events;
 126         int                     leftover;
 127         int                     ent_size;
 128         int                     cpu;
 129         u64                     ts;
 130
 131         loff_t                  pos;
 132         long                    idx;
 133
 134         /* All new field here will be zeroed out in pipe_read */
 135 };
 136
 137 enum trace_iter_flags {
 138         TRACE_FILE_LAT_FMT      = 1,
 139         TRACE_FILE_ANNOTATE     = 2,
 140         TRACE_FILE_TIME_IN_NS   = 4,
 141 };
 142
 143
 144 typedef enum print_line_t (*trace_print_func)(struct trace_iterator *iter,
 145                                       int flags, struct trace_event *event);
 146
 147 struct trace_event_functions {
 148         trace_print_func        trace;
 149         trace_print_func        raw;
 150         trace_print_func        hex;
 151         trace_print_func        binary;
 152 };
 153
 154 struct trace_event {
 155         struct hlist_node               node;
 156         int                             type;
 157         struct trace_event_functions    *funcs;
 158 };
 159
 160 extern int register_trace_event(struct trace_event *event);
 161 extern int unregister_trace_event(struct trace_event *event);
 162
 163 /* Return values for print_line callback */
 164 enum print_line_t {
 165         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 166         TRACE_TYPE_HANDLED      = 1,
 167         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 168         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 169 };
 170
 171 enum print_line_t trace_handle_return(struct trace_seq *s);
 172
 173 static inline void tracing_generic_entry_update(struct trace_entry *entry,
 174                                                 unsigned short type,
 175                                                 unsigned int trace_ctx)
 176 {
 177         entry->preempt_count            = trace_ctx & 0xff;
 178         entry->pid                      = current->pid;
 179         entry->type                     = type;
 180         entry->flags =                  trace_ctx >> 16;
 181 }
 182
 183 unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status);
 184
 185 enum trace_flag_type {
 186         TRACE_FLAG_IRQS_OFF             = 0x01,
 187         TRACE_FLAG_NEED_RESCHED_LAZY    = 0x02,
 188         TRACE_FLAG_NEED_RESCHED         = 0x04,
 189         TRACE_FLAG_HARDIRQ              = 0x08,
 190         TRACE_FLAG_SOFTIRQ              = 0x10,
 191         TRACE_FLAG_PREEMPT_RESCHED      = 0x20,
 192         TRACE_FLAG_NMI                  = 0x40,
 193         TRACE_FLAG_BH_OFF               = 0x80,
 194 };
 195
 196 static inline unsigned int tracing_gen_ctx_flags(unsigned long irqflags)
 197 {
 198         unsigned int irq_status = irqs_disabled_flags(irqflags) ?
 199                 TRACE_FLAG_IRQS_OFF : 0;
 200         return tracing_gen_ctx_irq_test(irq_status);
 201 }
 202 static inline unsigned int tracing_gen_ctx(void)
 203 {
 204         unsigned long irqflags;
 205
 206         local_save_flags(irqflags);
 207         return tracing_gen_ctx_flags(irqflags);
 208 }
 209
 210 static inline unsigned int tracing_gen_ctx_dec(void)
 211 {
 212         unsigned int trace_ctx;
 213
 214         trace_ctx = tracing_gen_ctx();
 215         /*
 216          * Subtract one from the preemption counter if preemption is enabled,
 217          * see trace_event_buffer_reserve()for details.
 218          */
 219         if (IS_ENABLED(CONFIG_PREEMPTION))
 220                 trace_ctx--;
 221         return trace_ctx;
 222 }
 223
 224 struct trace_event_file;
 225
 226 struct ring_buffer_event *
 227 trace_event_buffer_lock_reserve(struct trace_buffer **current_buffer,
 228                                 struct trace_event_file *trace_file,
 229                                 int type, unsigned long len,
 230                                 unsigned int trace_ctx);
 231
 232 #define TRACE_RECORD_CMDLINE    BIT(0)
 233 #define TRACE_RECORD_TGID       BIT(1)
 234
 235 void tracing_record_taskinfo(struct task_struct *task, int flags);
 236 void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
 237                                           struct task_struct *next, int flags);
 238
 239 void tracing_record_cmdline(struct task_struct *task);
 240 void tracing_record_tgid(struct task_struct *task);
 241
 242 int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
 243          __printf(3, 4);
 244
 245 struct event_filter;
 246
 247 enum trace_reg {
 248         TRACE_REG_REGISTER,
 249         TRACE_REG_UNREGISTER,
 250 #ifdef CONFIG_PERF_EVENTS
 251         TRACE_REG_PERF_REGISTER,
 252         TRACE_REG_PERF_UNREGISTER,
 253         TRACE_REG_PERF_OPEN,
 254         TRACE_REG_PERF_CLOSE,
 255         /*
 256          * These (ADD/DEL) use a 'boolean' return value, where 1 (true) means a
 257          * custom action was taken and the default action is not to be
 258          * performed.
 259          */
 260         TRACE_REG_PERF_ADD,
 261         TRACE_REG_PERF_DEL,
 262 #endif
 263 };
 264
 265 struct trace_event_call;
 266
 267 #define TRACE_FUNCTION_TYPE ((const char *)~0UL)
 268
 269 struct trace_event_fields {
 270         const char *type;
 271         union {
 272                 struct {
 273                         const char *name;
 274                         const int  size;
 275                         const int  align;
 276                         const int  is_signed;
 277                         const int  filter_type;
 278                         const int  len;
 279                 };
 280                 int (*define_fields)(struct trace_event_call *);
 281         };
 282 };
 283
 284 struct trace_event_class {
 285         const char              *system;
 286         void                    *probe;
 287 #ifdef CONFIG_PERF_EVENTS
 288         void                    *perf_probe;
 289 #endif
 290         int                     (*reg)(struct trace_event_call *event,
 291                                        enum trace_reg type, void *data);
 292         struct trace_event_fields *fields_array;
 293         struct list_head        *(*get_fields)(struct trace_event_call *);
 294         struct list_head        fields;
 295         int                     (*raw_init)(struct trace_event_call *);
 296 };
 297
 298 extern int trace_event_reg(struct trace_event_call *event,
 299                             enum trace_reg type, void *data);
 300
 301 struct trace_event_buffer {
 302         struct trace_buffer             *buffer;
 303         struct ring_buffer_event        *event;
 304         struct trace_event_file         *trace_file;
 305         void                            *entry;
 306         unsigned int                    trace_ctx;
 307         struct pt_regs                  *regs;
 308 };
 309
 310 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
 311                                   struct trace_event_file *trace_file,
 312                                   unsigned long len);
 313
 314 void trace_event_buffer_commit(struct trace_event_buffer *fbuffer);
 315
 316 enum {
 317         TRACE_EVENT_FL_CAP_ANY_BIT,
 318         TRACE_EVENT_FL_NO_SET_FILTER_BIT,
 319         TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
 320         TRACE_EVENT_FL_TRACEPOINT_BIT,
 321         TRACE_EVENT_FL_DYNAMIC_BIT,
 322         TRACE_EVENT_FL_KPROBE_BIT,
 323         TRACE_EVENT_FL_UPROBE_BIT,
 324         TRACE_EVENT_FL_EPROBE_BIT,
 325         TRACE_EVENT_FL_FPROBE_BIT,
 326         TRACE_EVENT_FL_CUSTOM_BIT,
 327 };
 328
 329 /*
 330  * Event flags:
 331  *  CAP_ANY       - Any user can enable for perf
 332  *  NO_SET_FILTER - Set when filter has error and is to be ignored
 333  *  IGNORE_ENABLE - For trace internal events, do not enable with debugfs file
 334  *  TRACEPOINT    - Event is a tracepoint
 335  *  DYNAMIC       - Event is a dynamic event (created at run time)
 336  *  KPROBE        - Event is a kprobe
 337  *  UPROBE        - Event is a uprobe
 338  *  EPROBE        - Event is an event probe
 339  *  FPROBE        - Event is an function probe
 340  *  CUSTOM        - Event is a custom event (to be attached to an exsiting tracepoint)
 341  *                   This is set when the custom event has not been attached
 342  *                   to a tracepoint yet, then it is cleared when it is.
 343  */
 344 enum {
 345         TRACE_EVENT_FL_CAP_ANY          = (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
 346         TRACE_EVENT_FL_NO_SET_FILTER    = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
 347         TRACE_EVENT_FL_IGNORE_ENABLE    = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
 348         TRACE_EVENT_FL_TRACEPOINT       = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT),
 349         TRACE_EVENT_FL_DYNAMIC          = (1 << TRACE_EVENT_FL_DYNAMIC_BIT),
 350         TRACE_EVENT_FL_KPROBE           = (1 << TRACE_EVENT_FL_KPROBE_BIT),
 351         TRACE_EVENT_FL_UPROBE           = (1 << TRACE_EVENT_FL_UPROBE_BIT),
 352         TRACE_EVENT_FL_EPROBE           = (1 << TRACE_EVENT_FL_EPROBE_BIT),
 353         TRACE_EVENT_FL_FPROBE           = (1 << TRACE_EVENT_FL_FPROBE_BIT),
 354         TRACE_EVENT_FL_CUSTOM           = (1 << TRACE_EVENT_FL_CUSTOM_BIT),
 355 };
 356
 357 #define TRACE_EVENT_FL_UKPROBE (TRACE_EVENT_FL_KPROBE | TRACE_EVENT_FL_UPROBE)
 358
 359 struct trace_event_call {
 360         struct list_head        list;
 361         struct trace_event_class *class;
 362         union {
 363                 char                    *name;
 364                 /* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */
 365                 struct tracepoint       *tp;
 366         };
 367         struct trace_event      event;
 368         char                    *print_fmt;
 369         /*
 370          * Static events can disappear with modules,
 371          * where as dynamic ones need their own ref count.
 372          */
 373         union {
 374                 void                            *module;
 375                 atomic_t                        refcnt;
 376         };
 377         void                    *data;
 378
 379         /* See the TRACE_EVENT_FL_* flags above */
 380         int                     flags; /* static flags of different events */
 381
 382 #ifdef CONFIG_PERF_EVENTS
 383         int                             perf_refcount;
 384         struct hlist_head __percpu      *perf_events;
 385         struct bpf_prog_array __rcu     *prog_array;
 386
 387         int     (*perf_perm)(struct trace_event_call *,
 388                              struct perf_event *);
 389 #endif
 390 };
 391
 392 #ifdef CONFIG_DYNAMIC_EVENTS
 393 bool trace_event_dyn_try_get_ref(struct trace_event_call *call);
 394 void trace_event_dyn_put_ref(struct trace_event_call *call);
 395 bool trace_event_dyn_busy(struct trace_event_call *call);
 396 #else
 397 static inline bool trace_event_dyn_try_get_ref(struct trace_event_call *call)
 398 {
 399         /* Without DYNAMIC_EVENTS configured, nothing should be calling this */
 400         return false;
 401 }
 402 static inline void trace_event_dyn_put_ref(struct trace_event_call *call)
 403 {
 404 }
 405 static inline bool trace_event_dyn_busy(struct trace_event_call *call)
 406 {
 407         /* Nothing should call this without DYNAIMIC_EVENTS configured. */
 408         return true;
 409 }
 410 #endif
 411
 412 static inline bool trace_event_try_get_ref(struct trace_event_call *call)
 413 {
 414         if (call->flags & TRACE_EVENT_FL_DYNAMIC)
 415                 return trace_event_dyn_try_get_ref(call);
 416         else
 417                 return try_module_get(call->module);
 418 }
 419
 420 static inline void trace_event_put_ref(struct trace_event_call *call)
 421 {
 422         if (call->flags & TRACE_EVENT_FL_DYNAMIC)
 423                 trace_event_dyn_put_ref(call);
 424         else
 425                 module_put(call->module);
 426 }
 427
 428 #ifdef CONFIG_PERF_EVENTS
 429 static inline bool bpf_prog_array_valid(struct trace_event_call *call)
 430 {
 431         /*
 432          * This inline function checks whether call->prog_array
 433          * is valid or not. The function is called in various places,
 434          * outside rcu_read_lock/unlock, as a heuristic to speed up execution.
 435          *
 436          * If this function returns true, and later call->prog_array
 437          * becomes false inside rcu_read_lock/unlock region,
 438          * we bail out then. If this function return false,
 439          * there is a risk that we might miss a few events if the checking
 440          * were delayed until inside rcu_read_lock/unlock region and
 441          * call->prog_array happened to become non-NULL then.
 442          *
 443          * Here, READ_ONCE() is used instead of rcu_access_pointer().
 444          * rcu_access_pointer() requires the actual definition of
 445          * "struct bpf_prog_array" while READ_ONCE() only needs
 446          * a declaration of the same type.
 447          */
 448         return !!READ_ONCE(call->prog_array);
 449 }
 450 #endif
 451
 452 static inline const char *
 453 trace_event_name(struct trace_event_call *call)
 454 {
 455         if (call->flags & TRACE_EVENT_FL_CUSTOM)
 456                 return call->name;
 457         else if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
 458                 return call->tp ? call->tp->name : NULL;
 459         else
 460                 return call->name;
 461 }
 462
 463 static inline struct list_head *
 464 trace_get_fields(struct trace_event_call *event_call)
 465 {
 466         if (!event_call->class->get_fields)
 467                 return &event_call->class->fields;
 468         return event_call->class->get_fields(event_call);
 469 }
 470
 471 struct trace_subsystem_dir;
 472
 473 enum {
 474         EVENT_FILE_FL_ENABLED_BIT,
 475         EVENT_FILE_FL_RECORDED_CMD_BIT,
 476         EVENT_FILE_FL_RECORDED_TGID_BIT,
 477         EVENT_FILE_FL_FILTERED_BIT,
 478         EVENT_FILE_FL_NO_SET_FILTER_BIT,
 479         EVENT_FILE_FL_SOFT_MODE_BIT,
 480         EVENT_FILE_FL_SOFT_DISABLED_BIT,
 481         EVENT_FILE_FL_TRIGGER_MODE_BIT,
 482         EVENT_FILE_FL_TRIGGER_COND_BIT,
 483         EVENT_FILE_FL_PID_FILTER_BIT,
 484         EVENT_FILE_FL_WAS_ENABLED_BIT,
 485         EVENT_FILE_FL_FREED_BIT,
 486 };
 487
 488 extern struct trace_event_file *trace_get_event_file(const char *instance,
 489                                                      const char *system,
 490                                                      const char *event);
 491 extern void trace_put_event_file(struct trace_event_file *file);
 492
 493 #define MAX_DYNEVENT_CMD_LEN    (2048)
 494
 495 enum dynevent_type {
 496         DYNEVENT_TYPE_SYNTH = 1,
 497         DYNEVENT_TYPE_KPROBE,
 498         DYNEVENT_TYPE_NONE,
 499 };
 500
 501 struct dynevent_cmd;
 502
 503 typedef int (*dynevent_create_fn_t)(struct dynevent_cmd *cmd);
 504
 505 struct dynevent_cmd {
 506         struct seq_buf          seq;
 507         const char              *event_name;
 508         unsigned int            n_fields;
 509         enum dynevent_type      type;
 510         dynevent_create_fn_t    run_command;
 511         void                    *private_data;
 512 };
 513
 514 extern int dynevent_create(struct dynevent_cmd *cmd);
 515
 516 extern int synth_event_delete(const char *name);
 517
 518 extern void synth_event_cmd_init(struct dynevent_cmd *cmd,
 519                                  char *buf, int maxlen);
 520
 521 extern int __synth_event_gen_cmd_start(struct dynevent_cmd *cmd,
 522                                        const char *name,
 523                                        struct module *mod, ...);
 524
 525 #define synth_event_gen_cmd_start(cmd, name, mod, ...)  \
 526         __synth_event_gen_cmd_start(cmd, name, mod, ## __VA_ARGS__, NULL)
 527
 528 struct synth_field_desc {
 529         const char *type;
 530         const char *name;
 531 };
 532
 533 extern int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd,
 534                                            const char *name,
 535                                            struct module *mod,
 536                                            struct synth_field_desc *fields,
 537                                            unsigned int n_fields);
 538 extern int synth_event_create(const char *name,
 539                               struct synth_field_desc *fields,
 540                               unsigned int n_fields, struct module *mod);
 541
 542 extern int synth_event_add_field(struct dynevent_cmd *cmd,
 543                                  const char *type,
 544                                  const char *name);
 545 extern int synth_event_add_field_str(struct dynevent_cmd *cmd,
 546                                      const char *type_name);
 547 extern int synth_event_add_fields(struct dynevent_cmd *cmd,
 548                                   struct synth_field_desc *fields,
 549                                   unsigned int n_fields);
 550
 551 #define synth_event_gen_cmd_end(cmd)    \
 552         dynevent_create(cmd)
 553
 554 struct synth_event;
 555
 556 struct synth_event_trace_state {
 557         struct trace_event_buffer fbuffer;
 558         struct synth_trace_event *entry;
 559         struct trace_buffer *buffer;
 560         struct synth_event *event;
 561         unsigned int cur_field;
 562         unsigned int n_u64;
 563         bool disabled;
 564         bool add_next;
 565         bool add_name;
 566 };
 567
 568 extern int synth_event_trace(struct trace_event_file *file,
 569                              unsigned int n_vals, ...);
 570 extern int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
 571                                    unsigned int n_vals);
 572 extern int synth_event_trace_start(struct trace_event_file *file,
 573                                    struct synth_event_trace_state *trace_state);
 574 extern int synth_event_add_next_val(u64 val,
 575                                     struct synth_event_trace_state *trace_state);
 576 extern int synth_event_add_val(const char *field_name, u64 val,
 577                                struct synth_event_trace_state *trace_state);
 578 extern int synth_event_trace_end(struct synth_event_trace_state *trace_state);
 579
 580 extern int kprobe_event_delete(const char *name);
 581
 582 extern void kprobe_event_cmd_init(struct dynevent_cmd *cmd,
 583                                   char *buf, int maxlen);
 584
 585 #define kprobe_event_gen_cmd_start(cmd, name, loc, ...)                 \
 586         __kprobe_event_gen_cmd_start(cmd, false, name, loc, ## __VA_ARGS__, NULL)
 587
 588 #define kretprobe_event_gen_cmd_start(cmd, name, loc, ...)              \
 589         __kprobe_event_gen_cmd_start(cmd, true, name, loc, ## __VA_ARGS__, NULL)
 590
 591 extern int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd,
 592                                         bool kretprobe,
 593                                         const char *name,
 594                                         const char *loc, ...);
 595
 596 #define kprobe_event_add_fields(cmd, ...)       \
 597         __kprobe_event_add_fields(cmd, ## __VA_ARGS__, NULL)
 598
 599 #define kprobe_event_add_field(cmd, field)      \
 600         __kprobe_event_add_fields(cmd, field, NULL)
 601
 602 extern int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...);
 603
 604 #define kprobe_event_gen_cmd_end(cmd)           \
 605         dynevent_create(cmd)
 606
 607 #define kretprobe_event_gen_cmd_end(cmd)        \
 608         dynevent_create(cmd)
 609
 610 /*
 611  * Event file flags:
 612  *  ENABLED       - The event is enabled
 613  *  RECORDED_CMD  - The comms should be recorded at sched_switch
 614  *  RECORDED_TGID - The tgids should be recorded at sched_switch
 615  *  FILTERED      - The event has a filter attached
 616  *  NO_SET_FILTER - Set when filter has error and is to be ignored
 617  *  SOFT_MODE     - The event is enabled/disabled by SOFT_DISABLED
 618  *  SOFT_DISABLED - When set, do not trace the event (even though its
 619  *                   tracepoint may be enabled)
 620  *  TRIGGER_MODE  - When set, invoke the triggers associated with the event
 621  *  TRIGGER_COND  - When set, one or more triggers has an associated filter
 622  *  PID_FILTER    - When set, the event is filtered based on pid
 623  *  WAS_ENABLED   - Set when enabled to know to clear trace on module removal
 624  *  FREED         - File descriptor is freed, all fields should be considered invalid
 625  */
 626 enum {
 627         EVENT_FILE_FL_ENABLED           = (1 << EVENT_FILE_FL_ENABLED_BIT),
 628         EVENT_FILE_FL_RECORDED_CMD      = (1 << EVENT_FILE_FL_RECORDED_CMD_BIT),
 629         EVENT_FILE_FL_RECORDED_TGID     = (1 << EVENT_FILE_FL_RECORDED_TGID_BIT),
 630         EVENT_FILE_FL_FILTERED          = (1 << EVENT_FILE_FL_FILTERED_BIT),
 631         EVENT_FILE_FL_NO_SET_FILTER     = (1 << EVENT_FILE_FL_NO_SET_FILTER_BIT),
 632         EVENT_FILE_FL_SOFT_MODE         = (1 << EVENT_FILE_FL_SOFT_MODE_BIT),
 633         EVENT_FILE_FL_SOFT_DISABLED     = (1 << EVENT_FILE_FL_SOFT_DISABLED_BIT),
 634         EVENT_FILE_FL_TRIGGER_MODE      = (1 << EVENT_FILE_FL_TRIGGER_MODE_BIT),
 635         EVENT_FILE_FL_TRIGGER_COND      = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT),
 636         EVENT_FILE_FL_PID_FILTER        = (1 << EVENT_FILE_FL_PID_FILTER_BIT),
 637         EVENT_FILE_FL_WAS_ENABLED       = (1 << EVENT_FILE_FL_WAS_ENABLED_BIT),
 638         EVENT_FILE_FL_FREED             = (1 << EVENT_FILE_FL_FREED_BIT),
 639 };
 640
 641 struct trace_event_file {
 642         struct list_head                list;
 643         struct trace_event_call         *event_call;
 644         struct event_filter __rcu       *filter;
 645         struct eventfs_inode            *ei;
 646         struct trace_array              *tr;
 647         struct trace_subsystem_dir      *system;
 648         struct list_head                triggers;
 649
 650         /*
 651          * 32 bit flags:
 652          *   bit 0:             enabled
 653          *   bit 1:             enabled cmd record
 654          *   bit 2:             enable/disable with the soft disable bit
 655          *   bit 3:             soft disabled
 656          *   bit 4:             trigger enabled
 657          *
 658          * Note: The bits must be set atomically to prevent races
 659          * from other writers. Reads of flags do not need to be in
 660          * sync as they occur in critical sections. But the way flags
 661          * is currently used, these changes do not affect the code
 662          * except that when a change is made, it may have a slight
 663          * delay in propagating the changes to other CPUs due to
 664          * caching and such. Which is mostly OK ;-)
 665          */
 666         unsigned long           flags;
 667         refcount_t              ref;    /* ref count for opened files */
 668         atomic_t                sm_ref; /* soft-mode reference counter */
 669         atomic_t                tm_ref; /* trigger-mode reference counter */
 670 };
 671
 672 #define __TRACE_EVENT_FLAGS(name, value)                                \
 673         static int __init trace_init_flags_##name(void)                 \
 674         {                                                               \
 675                 event_##name.flags |= value;                            \
 676                 return 0;                                               \
 677         }                                                               \
 678         early_initcall(trace_init_flags_##name);
 679
 680 #define __TRACE_EVENT_PERF_PERM(name, expr...)                          \
 681         static int perf_perm_##name(struct trace_event_call *tp_event, \
 682                                     struct perf_event *p_event)         \
 683         {                                                               \
 684                 return ({ expr; });                                     \
 685         }                                                               \
 686         static int __init trace_init_perf_perm_##name(void)             \
 687         {                                                               \
 688                 event_##name.perf_perm = &perf_perm_##name;             \
 689                 return 0;                                               \
 690         }                                                               \
 691         early_initcall(trace_init_perf_perm_##name);
 692
 693 #define PERF_MAX_TRACE_SIZE     8192
 694
 695 #define MAX_FILTER_STR_VAL      256U    /* Should handle KSYM_SYMBOL_LEN */
 696
 697 enum event_trigger_type {
 698         ETT_NONE                = (0),
 699         ETT_TRACE_ONOFF         = (1 << 0),
 700         ETT_SNAPSHOT            = (1 << 1),
 701         ETT_STACKTRACE          = (1 << 2),
 702         ETT_EVENT_ENABLE        = (1 << 3),
 703         ETT_EVENT_HIST          = (1 << 4),
 704         ETT_HIST_ENABLE         = (1 << 5),
 705         ETT_EVENT_EPROBE        = (1 << 6),
 706 };
 707
 708 extern int filter_match_preds(struct event_filter *filter, void *rec);
 709
 710 extern enum event_trigger_type
 711 event_triggers_call(struct trace_event_file *file,
 712                     struct trace_buffer *buffer, void *rec,
 713                     struct ring_buffer_event *event);
 714 extern void
 715 event_triggers_post_call(struct trace_event_file *file,
 716                          enum event_trigger_type tt);
 717
 718 bool trace_event_ignore_this_pid(struct trace_event_file *trace_file);
 719
 720 bool __trace_trigger_soft_disabled(struct trace_event_file *file);
 721
 722 /**
 723  * trace_trigger_soft_disabled - do triggers and test if soft disabled
 724  * @file: The file pointer of the event to test
 725  *
 726  * If any triggers without filters are attached to this event, they
 727  * will be called here. If the event is soft disabled and has no
 728  * triggers that require testing the fields, it will return true,
 729  * otherwise false.
 730  */
 731 static __always_inline bool
 732 trace_trigger_soft_disabled(struct trace_event_file *file)
 733 {
 734         unsigned long eflags = file->flags;
 735
 736         if (likely(!(eflags & (EVENT_FILE_FL_TRIGGER_MODE |
 737                                EVENT_FILE_FL_SOFT_DISABLED |
 738                                EVENT_FILE_FL_PID_FILTER))))
 739                 return false;
 740
 741         if (likely(eflags & EVENT_FILE_FL_TRIGGER_COND))
 742                 return false;
 743
 744         return __trace_trigger_soft_disabled(file);
 745 }
 746
 747 #ifdef CONFIG_BPF_EVENTS
 748 unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx);
 749 int perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie);
 750 void perf_event_detach_bpf_prog(struct perf_event *event);
 751 int perf_event_query_prog_array(struct perf_event *event, void __user *info);
 752
 753 struct bpf_raw_tp_link;
 754 int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link);
 755 int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link);
 756
 757 struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name);
 758 void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp);
 759 int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
 760                             u32 *fd_type, const char **buf,
 761                             u64 *probe_offset, u64 *probe_addr,
 762                             unsigned long *missed);
 763 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
 764 int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
 765 #else
 766 static inline unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
 767 {
 768         return 1;
 769 }
 770
 771 static inline int
 772 perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie)
 773 {
 774         return -EOPNOTSUPP;
 775 }
 776
 777 static inline void perf_event_detach_bpf_prog(struct perf_event *event) { }
 778
 779 static inline int
 780 perf_event_query_prog_array(struct perf_event *event, void __user *info)
 781 {
 782         return -EOPNOTSUPP;
 783 }
 784 struct bpf_raw_tp_link;
 785 static inline int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
 786 {
 787         return -EOPNOTSUPP;
 788 }
 789 static inline int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_raw_tp_link *link)
 790 {
 791         return -EOPNOTSUPP;
 792 }
 793 static inline struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
 794 {
 795         return NULL;
 796 }
 797 static inline void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
 798 {
 799 }
 800 static inline int bpf_get_perf_event_info(const struct perf_event *event,
 801                                           u32 *prog_id, u32 *fd_type,
 802                                           const char **buf, u64 *probe_offset,
 803                                           u64 *probe_addr, unsigned long *missed)
 804 {
 805         return -EOPNOTSUPP;
 806 }
 807 static inline int
 808 bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
 809 {
 810         return -EOPNOTSUPP;
 811 }
 812 static inline int
 813 bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
 814 {
 815         return -EOPNOTSUPP;
 816 }
 817 #endif
 818
 819 enum {
 820         FILTER_OTHER = 0,
 821         FILTER_STATIC_STRING,
 822         FILTER_DYN_STRING,
 823         FILTER_RDYN_STRING,
 824         FILTER_PTR_STRING,
 825         FILTER_TRACE_FN,
 826         FILTER_CPUMASK,
 827         FILTER_COMM,
 828         FILTER_CPU,
 829         FILTER_STACKTRACE,
 830 };
 831
 832 extern int trace_event_raw_init(struct trace_event_call *call);
 833 extern int trace_define_field(struct trace_event_call *call, const char *type,
 834                               const char *name, int offset, int size,
 835                               int is_signed, int filter_type);
 836 extern int trace_add_event_call(struct trace_event_call *call);
 837 extern int trace_remove_event_call(struct trace_event_call *call);
 838 extern int trace_event_get_offsets(struct trace_event_call *call);
 839
 840 int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
 841 int trace_set_clr_event(const char *system, const char *event, int set);
 842 int trace_array_set_clr_event(struct trace_array *tr, const char *system,
 843                 const char *event, bool enable);
 844 /*
 845  * The double __builtin_constant_p is because gcc will give us an error
 846  * if we try to allocate the static variable to fmt if it is not a
 847  * constant. Even with the outer if statement optimizing out.
 848  */
 849 #define event_trace_printk(ip, fmt, args...)                            \
 850 do {                                                                    \
 851         __trace_printk_check_format(fmt, ##args);                       \
 852         tracing_record_cmdline(current);                                \
 853         if (__builtin_constant_p(fmt)) {                                \
 854                 static const char *trace_printk_fmt                     \
 855                   __section("__trace_printk_fmt") =                     \
 856                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 857                                                                         \
 858                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 859         } else                                                          \
 860                 __trace_printk(ip, fmt, ##args);                        \
 861 } while (0)
 862
 863 #ifdef CONFIG_PERF_EVENTS
 864 struct perf_event;
 865
 866 DECLARE_PER_CPU(struct pt_regs, perf_trace_regs);
 867
 868 extern int  perf_trace_init(struct perf_event *event);
 869 extern void perf_trace_destroy(struct perf_event *event);
 870 extern int  perf_trace_add(struct perf_event *event, int flags);
 871 extern void perf_trace_del(struct perf_event *event, int flags);
 872 #ifdef CONFIG_KPROBE_EVENTS
 873 extern int  perf_kprobe_init(struct perf_event *event, bool is_retprobe);
 874 extern void perf_kprobe_destroy(struct perf_event *event);
 875 extern int bpf_get_kprobe_info(const struct perf_event *event,
 876                                u32 *fd_type, const char **symbol,
 877                                u64 *probe_offset, u64 *probe_addr,
 878                                unsigned long *missed,
 879                                bool perf_type_tracepoint);
 880 #endif
 881 #ifdef CONFIG_UPROBE_EVENTS
 882 extern int  perf_uprobe_init(struct perf_event *event,
 883                              unsigned long ref_ctr_offset, bool is_retprobe);
 884 extern void perf_uprobe_destroy(struct perf_event *event);
 885 extern int bpf_get_uprobe_info(const struct perf_event *event,
 886                                u32 *fd_type, const char **filename,
 887                                u64 *probe_offset, u64 *probe_addr,
 888                                bool perf_type_tracepoint);
 889 #endif
 890 extern int  ftrace_profile_set_filter(struct perf_event *event, int event_id,
 891                                      char *filter_str);
 892 extern void ftrace_profile_free_filter(struct perf_event *event);
 893 void perf_trace_buf_update(void *record, u16 type);
 894 void *perf_trace_buf_alloc(int size, struct pt_regs **regs, int *rctxp);
 895
 896 int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, u64 bpf_cookie);
 897 void perf_event_free_bpf_prog(struct perf_event *event);
 898
 899 void bpf_trace_run1(struct bpf_raw_tp_link *link, u64 arg1);
 900 void bpf_trace_run2(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2);
 901 void bpf_trace_run3(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2,
 902                     u64 arg3);
 903 void bpf_trace_run4(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2,
 904                     u64 arg3, u64 arg4);
 905 void bpf_trace_run5(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2,
 906                     u64 arg3, u64 arg4, u64 arg5);
 907 void bpf_trace_run6(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2,
 908                     u64 arg3, u64 arg4, u64 arg5, u64 arg6);
 909 void bpf_trace_run7(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2,
 910                     u64 arg3, u64 arg4, u64 arg5, u64 arg6, u64 arg7);
 911 void bpf_trace_run8(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2,
 912                     u64 arg3, u64 arg4, u64 arg5, u64 arg6, u64 arg7,
 913                     u64 arg8);
 914 void bpf_trace_run9(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2,
 915                     u64 arg3, u64 arg4, u64 arg5, u64 arg6, u64 arg7,
 916                     u64 arg8, u64 arg9);
 917 void bpf_trace_run10(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2,
 918                      u64 arg3, u64 arg4, u64 arg5, u64 arg6, u64 arg7,
 919                      u64 arg8, u64 arg9, u64 arg10);
 920 void bpf_trace_run11(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2,
 921                      u64 arg3, u64 arg4, u64 arg5, u64 arg6, u64 arg7,
 922                      u64 arg8, u64 arg9, u64 arg10, u64 arg11);
 923 void bpf_trace_run12(struct bpf_raw_tp_link *link, u64 arg1, u64 arg2,
 924                      u64 arg3, u64 arg4, u64 arg5, u64 arg6, u64 arg7,
 925                      u64 arg8, u64 arg9, u64 arg10, u64 arg11, u64 arg12);
 926 void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx,
 927                                struct trace_event_call *call, u64 count,
 928                                struct pt_regs *regs, struct hlist_head *head,
 929                                struct task_struct *task);
 930
 931 static inline void
 932 perf_trace_buf_submit(void *raw_data, int size, int rctx, u16 type,
 933                        u64 count, struct pt_regs *regs, void *head,
 934                        struct task_struct *task)
 935 {
 936         perf_tp_event(type, count, raw_data, size, regs, head, rctx, task);
 937 }
 938
 939 #endif
 940
 941 #define TRACE_EVENT_STR_MAX     512
 942
 943 /*
 944  * gcc warns that you can not use a va_list in an inlined
 945  * function. But lets me make it into a macro :-/
 946  */
 947 #define __trace_event_vstr_len(fmt, va)                 \
 948 ({                                                      \
 949         va_list __ap;                                   \
 950         int __ret;                                      \
 951                                                         \
 952         va_copy(__ap, *(va));                           \
 953         __ret = vsnprintf(NULL, 0, fmt, __ap) + 1;      \
 954         va_end(__ap);                                   \
 955                                                         \
 956         min(__ret, TRACE_EVENT_STR_MAX);                \
 957 })
 958
 959 #endif /* _LINUX_TRACE_EVENT_H */
 960
 961 /*
 962  * Note: we keep the TRACE_CUSTOM_EVENT outside the include file ifdef protection.
 963  *  This is due to the way trace custom events work. If a file includes two
 964  *  trace event headers under one "CREATE_CUSTOM_TRACE_EVENTS" the first include
 965  *  will override the TRACE_CUSTOM_EVENT and break the second include.
 966  */
 967
 968 #ifndef TRACE_CUSTOM_EVENT
 969
 970 #define DECLARE_CUSTOM_EVENT_CLASS(name, proto, args, tstruct, assign, print)
 971 #define DEFINE_CUSTOM_EVENT(template, name, proto, args)
 972 #define TRACE_CUSTOM_EVENT(name, proto, args, struct, assign, print)
 973
 974 #endif /* ifdef TRACE_CUSTOM_EVENT (see note above) */