kernel/trace/trace.h

   1 #ifndef _LINUX_KERNEL_TRACE_H
   2 #define _LINUX_KERNEL_TRACE_H
   3
   4 #include <linux/fs.h>
   5 #include <asm/atomic.h>
   6 #include <linux/sched.h>
   7 #include <linux/clocksource.h>
   8 #include <linux/ring_buffer.h>
   9 #include <linux/mmiotrace.h>
  10 #include <linux/ftrace.h>
  11 #include <trace/boot.h>
  12 #include <linux/kmemtrace.h>
  13 #include <trace/power.h>
  14
  15 #include <linux/trace_seq.h>
  16 #include <linux/ftrace_event.h>
  17
  18 enum trace_type {
  19         __TRACE_FIRST_TYPE = 0,
  20
  21         TRACE_FN,
  22         TRACE_CTX,
  23         TRACE_WAKE,
  24         TRACE_STACK,
  25         TRACE_PRINT,
  26         TRACE_BPRINT,
  27         TRACE_SPECIAL,
  28         TRACE_MMIO_RW,
  29         TRACE_MMIO_MAP,
  30         TRACE_BRANCH,
  31         TRACE_BOOT_CALL,
  32         TRACE_BOOT_RET,
  33         TRACE_GRAPH_RET,
  34         TRACE_GRAPH_ENT,
  35         TRACE_USER_STACK,
  36         TRACE_HW_BRANCHES,
  37         TRACE_KMEM_ALLOC,
  38         TRACE_KMEM_FREE,
  39         TRACE_POWER,
  40         TRACE_BLK,
  41
  42         __TRACE_LAST_TYPE,
  43 };
  44
  45 /*
  46  * Function trace entry - function address and parent function addres:
  47  */
  48 struct ftrace_entry {
  49         struct trace_entry      ent;
  50         unsigned long           ip;
  51         unsigned long           parent_ip;
  52 };
  53
  54 /* Function call entry */
  55 struct ftrace_graph_ent_entry {
  56         struct trace_entry              ent;
  57         struct ftrace_graph_ent         graph_ent;
  58 };
  59
  60 /* Function return entry */
  61 struct ftrace_graph_ret_entry {
  62         struct trace_entry              ent;
  63         struct ftrace_graph_ret         ret;
  64 };
  65 extern struct tracer boot_tracer;
  66
  67 /*
  68  * Context switch trace entry - which task (and prio) we switched from/to:
  69  */
  70 struct ctx_switch_entry {
  71         struct trace_entry      ent;
  72         unsigned int            prev_pid;
  73         unsigned char           prev_prio;
  74         unsigned char           prev_state;
  75         unsigned int            next_pid;
  76         unsigned char           next_prio;
  77         unsigned char           next_state;
  78         unsigned int            next_cpu;
  79 };
  80
  81 /*
  82  * Special (free-form) trace entry:
  83  */
  84 struct special_entry {
  85         struct trace_entry      ent;
  86         unsigned long           arg1;
  87         unsigned long           arg2;
  88         unsigned long           arg3;
  89 };
  90
  91 /*
  92  * Stack-trace entry:
  93  */
  94
  95 #define FTRACE_STACK_ENTRIES    8
  96
  97 struct stack_entry {
  98         struct trace_entry      ent;
  99         unsigned long           caller[FTRACE_STACK_ENTRIES];
 100 };
 101
 102 struct userstack_entry {
 103         struct trace_entry      ent;
 104         unsigned int            tgid;
 105         unsigned long           caller[FTRACE_STACK_ENTRIES];
 106 };
 107
 108 /*
 109  * trace_printk entry:
 110  */
 111 struct bprint_entry {
 112         struct trace_entry      ent;
 113         unsigned long           ip;
 114         const char              *fmt;
 115         u32                     buf[];
 116 };
 117
 118 struct print_entry {
 119         struct trace_entry      ent;
 120         unsigned long           ip;
 121         char                    buf[];
 122 };
 123
 124 struct trace_mmiotrace_rw {
 125         struct trace_entry      ent;
 126         struct mmiotrace_rw     rw;
 127 };
 128
 129 struct trace_mmiotrace_map {
 130         struct trace_entry      ent;
 131         struct mmiotrace_map    map;
 132 };
 133
 134 struct trace_boot_call {
 135         struct trace_entry      ent;
 136         struct boot_trace_call boot_call;
 137 };
 138
 139 struct trace_boot_ret {
 140         struct trace_entry      ent;
 141         struct boot_trace_ret boot_ret;
 142 };
 143
 144 #define TRACE_FUNC_SIZE 30
 145 #define TRACE_FILE_SIZE 20
 146 struct trace_branch {
 147         struct trace_entry      ent;
 148         unsigned                line;
 149         char                    func[TRACE_FUNC_SIZE+1];
 150         char                    file[TRACE_FILE_SIZE+1];
 151         char                    correct;
 152 };
 153
 154 struct hw_branch_entry {
 155         struct trace_entry      ent;
 156         u64                     from;
 157         u64                     to;
 158 };
 159
 160 struct trace_power {
 161         struct trace_entry      ent;
 162         struct power_trace      state_data;
 163 };
 164
 165 enum kmemtrace_type_id {
 166         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
 167         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
 168         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
 169 };
 170
 171 struct kmemtrace_alloc_entry {
 172         struct trace_entry      ent;
 173         enum kmemtrace_type_id  type_id;
 174         unsigned long           call_site;
 175         const void              *ptr;
 176         size_t                  bytes_req;
 177         size_t                  bytes_alloc;
 178         gfp_t                   gfp_flags;
 179         int                     node;
 180 };
 181
 182 struct kmemtrace_free_entry {
 183         struct trace_entry      ent;
 184         enum kmemtrace_type_id  type_id;
 185         unsigned long           call_site;
 186         const void              *ptr;
 187 };
 188
 189 struct syscall_trace_enter {
 190         struct trace_entry      ent;
 191         int                     nr;
 192         unsigned long           args[];
 193 };
 194
 195 struct syscall_trace_exit {
 196         struct trace_entry      ent;
 197         int                     nr;
 198         unsigned long           ret;
 199 };
 200
 201
 202 /*
 203  * trace_flag_type is an enumeration that holds different
 204  * states when a trace occurs. These are:
 205  *  IRQS_OFF            - interrupts were disabled
 206  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 207  *  NEED_RESCHED        - reschedule is requested
 208  *  HARDIRQ             - inside an interrupt handler
 209  *  SOFTIRQ             - inside a softirq handler
 210  */
 211 enum trace_flag_type {
 212         TRACE_FLAG_IRQS_OFF             = 0x01,
 213         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 214         TRACE_FLAG_NEED_RESCHED         = 0x04,
 215         TRACE_FLAG_HARDIRQ              = 0x08,
 216         TRACE_FLAG_SOFTIRQ              = 0x10,
 217 };
 218
 219 #define TRACE_BUF_SIZE          1024
 220
 221 /*
 222  * The CPU trace array - it consists of thousands of trace entries
 223  * plus some other descriptor data: (for example which task started
 224  * the trace, etc.)
 225  */
 226 struct trace_array_cpu {
 227         atomic_t                disabled;
 228         void                    *buffer_page;   /* ring buffer spare */
 229
 230         unsigned long           saved_latency;
 231         unsigned long           critical_start;
 232         unsigned long           critical_end;
 233         unsigned long           critical_sequence;
 234         unsigned long           nice;
 235         unsigned long           policy;
 236         unsigned long           rt_priority;
 237         unsigned long           skipped_entries;
 238         cycle_t                 preempt_timestamp;
 239         pid_t                   pid;
 240         uid_t                   uid;
 241         char                    comm[TASK_COMM_LEN];
 242 };
 243
 244 /*
 245  * The trace array - an array of per-CPU trace arrays. This is the
 246  * highest level data structure that individual tracers deal with.
 247  * They have on/off state as well:
 248  */
 249 struct trace_array {
 250         struct ring_buffer      *buffer;
 251         unsigned long           entries;
 252         int                     cpu;
 253         cycle_t                 time_start;
 254         struct task_struct      *waiter;
 255         struct trace_array_cpu  *data[NR_CPUS];
 256 };
 257
 258 #define FTRACE_CMP_TYPE(var, type) \
 259         __builtin_types_compatible_p(typeof(var), type *)
 260
 261 #undef IF_ASSIGN
 262 #define IF_ASSIGN(var, entry, etype, id)                \
 263         if (FTRACE_CMP_TYPE(var, etype)) {              \
 264                 var = (typeof(var))(entry);             \
 265                 WARN_ON(id && (entry)->type != id);     \
 266                 break;                                  \
 267         }
 268
 269 /* Will cause compile errors if type is not found. */
 270 extern void __ftrace_bad_type(void);
 271
 272 /*
 273  * The trace_assign_type is a verifier that the entry type is
 274  * the same as the type being assigned. To add new types simply
 275  * add a line with the following format:
 276  *
 277  * IF_ASSIGN(var, ent, type, id);
 278  *
 279  *  Where "type" is the trace type that includes the trace_entry
 280  *  as the "ent" item. And "id" is the trace identifier that is
 281  *  used in the trace_type enum.
 282  *
 283  *  If the type can have more than one id, then use zero.
 284  */
 285 #define trace_assign_type(var, ent)                                     \
 286         do {                                                            \
 287                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 288                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 289                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 290                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 291                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 292                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 293                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 294                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 295                           TRACE_MMIO_RW);                               \
 296                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 297                           TRACE_MMIO_MAP);                              \
 298                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 299                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 300                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 301                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 302                           TRACE_GRAPH_ENT);             \
 303                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 304                           TRACE_GRAPH_RET);             \
 305                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 306                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 307                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 308                           TRACE_KMEM_ALLOC);    \
 309                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 310                           TRACE_KMEM_FREE);     \
 311                 __ftrace_bad_type();                                    \
 312         } while (0)
 313
 314 /*
 315  * An option specific to a tracer. This is a boolean value.
 316  * The bit is the bit index that sets its value on the
 317  * flags value in struct tracer_flags.
 318  */
 319 struct tracer_opt {
 320         const char      *name; /* Will appear on the trace_options file */
 321         u32             bit; /* Mask assigned in val field in tracer_flags */
 322 };
 323
 324 /*
 325  * The set of specific options for a tracer. Your tracer
 326  * have to set the initial value of the flags val.
 327  */
 328 struct tracer_flags {
 329         u32                     val;
 330         struct tracer_opt       *opts;
 331 };
 332
 333 /* Makes more easy to define a tracer opt */
 334 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 335
 336
 337 /**
 338  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 339  * @name: the name chosen to select it on the available_tracers file
 340  * @init: called when one switches to this tracer (echo name > current_tracer)
 341  * @reset: called when one switches to another tracer
 342  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 343  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 344  * @open: called when the trace file is opened
 345  * @pipe_open: called when the trace_pipe file is opened
 346  * @wait_pipe: override how the user waits for traces on trace_pipe
 347  * @close: called when the trace file is released
 348  * @read: override the default read callback on trace_pipe
 349  * @splice_read: override the default splice_read callback on trace_pipe
 350  * @selftest: selftest to run on boot (see trace_selftest.c)
 351  * @print_headers: override the first lines that describe your columns
 352  * @print_line: callback that prints a trace
 353  * @set_flag: signals one of your private flags changed (trace_options file)
 354  * @flags: your private flags
 355  */
 356 struct tracer {
 357         const char              *name;
 358         int                     (*init)(struct trace_array *tr);
 359         void                    (*reset)(struct trace_array *tr);
 360         void                    (*start)(struct trace_array *tr);
 361         void                    (*stop)(struct trace_array *tr);
 362         void                    (*open)(struct trace_iterator *iter);
 363         void                    (*pipe_open)(struct trace_iterator *iter);
 364         void                    (*wait_pipe)(struct trace_iterator *iter);
 365         void                    (*close)(struct trace_iterator *iter);
 366         ssize_t                 (*read)(struct trace_iterator *iter,
 367                                         struct file *filp, char __user *ubuf,
 368                                         size_t cnt, loff_t *ppos);
 369         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 370                                                struct file *filp,
 371                                                loff_t *ppos,
 372                                                struct pipe_inode_info *pipe,
 373                                                size_t len,
 374                                                unsigned int flags);
 375 #ifdef CONFIG_FTRACE_STARTUP_TEST
 376         int                     (*selftest)(struct tracer *trace,
 377                                             struct trace_array *tr);
 378 #endif
 379         void                    (*print_header)(struct seq_file *m);
 380         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 381         /* If you handled the flag setting, return 0 */
 382         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 383         struct tracer           *next;
 384         int                     print_max;
 385         struct tracer_flags     *flags;
 386 };
 387
 388
 389 #define TRACE_PIPE_ALL_CPU      -1
 390
 391 int tracer_init(struct tracer *t, struct trace_array *tr);
 392 int tracing_is_enabled(void);
 393 void trace_wake_up(void);
 394 void tracing_reset(struct trace_array *tr, int cpu);
 395 void tracing_reset_online_cpus(struct trace_array *tr);
 396 void tracing_reset_current(int cpu);
 397 void tracing_reset_current_online_cpus(void);
 398 int tracing_open_generic(struct inode *inode, struct file *filp);
 399 struct dentry *trace_create_file(const char *name,
 400                                  mode_t mode,
 401                                  struct dentry *parent,
 402                                  void *data,
 403                                  const struct file_operations *fops);
 404
 405 struct dentry *tracing_init_dentry(void);
 406 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 407
 408 struct ring_buffer_event;
 409
 410 struct ring_buffer_event *
 411 trace_buffer_lock_reserve(struct ring_buffer *buffer,
 412                           int type,
 413                           unsigned long len,
 414                           unsigned long flags,
 415                           int pc);
 416 void trace_buffer_unlock_commit(struct ring_buffer *buffer,
 417                                 struct ring_buffer_event *event,
 418                                 unsigned long flags, int pc);
 419
 420 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 421                                                 struct trace_array_cpu *data);
 422
 423 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 424                                           int *ent_cpu, u64 *ent_ts);
 425
 426 void default_wait_pipe(struct trace_iterator *iter);
 427 void poll_wait_pipe(struct trace_iterator *iter);
 428
 429 void ftrace(struct trace_array *tr,
 430                             struct trace_array_cpu *data,
 431                             unsigned long ip,
 432                             unsigned long parent_ip,
 433                             unsigned long flags, int pc);
 434 void tracing_sched_switch_trace(struct trace_array *tr,
 435                                 struct task_struct *prev,
 436                                 struct task_struct *next,
 437                                 unsigned long flags, int pc);
 438
 439 void tracing_sched_wakeup_trace(struct trace_array *tr,
 440                                 struct task_struct *wakee,
 441                                 struct task_struct *cur,
 442                                 unsigned long flags, int pc);
 443 void trace_special(struct trace_array *tr,
 444                    struct trace_array_cpu *data,
 445                    unsigned long arg1,
 446                    unsigned long arg2,
 447                    unsigned long arg3, int pc);
 448 void trace_function(struct trace_array *tr,
 449                     unsigned long ip,
 450                     unsigned long parent_ip,
 451                     unsigned long flags, int pc);
 452
 453 void trace_graph_return(struct ftrace_graph_ret *trace);
 454 int trace_graph_entry(struct ftrace_graph_ent *trace);
 455 void set_graph_array(struct trace_array *tr);
 456
 457 void tracing_start_cmdline_record(void);
 458 void tracing_stop_cmdline_record(void);
 459 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 460 void tracing_stop_sched_switch_record(void);
 461 void tracing_start_sched_switch_record(void);
 462 int register_tracer(struct tracer *type);
 463 void unregister_tracer(struct tracer *type);
 464
 465 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 466
 467 #ifdef CONFIG_TRACER_MAX_TRACE
 468 extern unsigned long tracing_max_latency;
 469 extern unsigned long tracing_thresh;
 470
 471 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 472 void update_max_tr_single(struct trace_array *tr,
 473                           struct task_struct *tsk, int cpu);
 474 #endif /* CONFIG_TRACER_MAX_TRACE */
 475
 476 #ifdef CONFIG_STACKTRACE
 477 void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
 478                         int skip, int pc);
 479
 480 void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags,
 481                             int pc);
 482
 483 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 484                    int pc);
 485 #else
 486 static inline void ftrace_trace_stack(struct trace_array *tr,
 487                                       unsigned long flags, int skip, int pc)
 488 {
 489 }
 490
 491 static inline void ftrace_trace_userstack(struct trace_array *tr,
 492                                           unsigned long flags, int pc)
 493 {
 494 }
 495
 496 static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
 497                                  int skip, int pc)
 498 {
 499 }
 500 #endif /* CONFIG_STACKTRACE */
 501
 502 extern cycle_t ftrace_now(int cpu);
 503
 504 extern void trace_find_cmdline(int pid, char comm[]);
 505
 506 #ifdef CONFIG_DYNAMIC_FTRACE
 507 extern unsigned long ftrace_update_tot_cnt;
 508 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 509 extern int DYN_FTRACE_TEST_NAME(void);
 510 #endif
 511
 512 extern int ring_buffer_expanded;
 513 extern bool tracing_selftest_disabled;
 514 DECLARE_PER_CPU(local_t, ftrace_cpu_disabled);
 515
 516 #ifdef CONFIG_FTRACE_STARTUP_TEST
 517 extern int trace_selftest_startup_function(struct tracer *trace,
 518                                            struct trace_array *tr);
 519 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 520                                                  struct trace_array *tr);
 521 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 522                                           struct trace_array *tr);
 523 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 524                                              struct trace_array *tr);
 525 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 526                                                  struct trace_array *tr);
 527 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 528                                          struct trace_array *tr);
 529 extern int trace_selftest_startup_nop(struct tracer *trace,
 530                                          struct trace_array *tr);
 531 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 532                                                struct trace_array *tr);
 533 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 534                                                struct trace_array *tr);
 535 extern int trace_selftest_startup_branch(struct tracer *trace,
 536                                          struct trace_array *tr);
 537 extern int trace_selftest_startup_hw_branches(struct tracer *trace,
 538                                               struct trace_array *tr);
 539 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 540
 541 extern void *head_page(struct trace_array_cpu *data);
 542 extern unsigned long long ns2usecs(cycle_t nsec);
 543 extern int
 544 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 545 extern int
 546 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 547 extern int
 548 trace_array_vprintk(struct trace_array *tr,
 549                     unsigned long ip, const char *fmt, va_list args);
 550 int trace_array_printk(struct trace_array *tr,
 551                        unsigned long ip, const char *fmt, ...);
 552
 553 extern unsigned long trace_flags;
 554
 555 extern int trace_clock_id;
 556
 557 /* Standard output formatting function used for function return traces */
 558 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 559 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 560 extern enum print_line_t
 561 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 562
 563 #ifdef CONFIG_DYNAMIC_FTRACE
 564 /* TODO: make this variable */
 565 #define FTRACE_GRAPH_MAX_FUNCS          32
 566 extern int ftrace_graph_count;
 567 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 568
 569 static inline int ftrace_graph_addr(unsigned long addr)
 570 {
 571         int i;
 572
 573         if (!ftrace_graph_count || test_tsk_trace_graph(current))
 574                 return 1;
 575
 576         for (i = 0; i < ftrace_graph_count; i++) {
 577                 if (addr == ftrace_graph_funcs[i])
 578                         return 1;
 579         }
 580
 581         return 0;
 582 }
 583 #else
 584 static inline int ftrace_trace_addr(unsigned long addr)
 585 {
 586         return 1;
 587 }
 588 static inline int ftrace_graph_addr(unsigned long addr)
 589 {
 590         return 1;
 591 }
 592 #endif /* CONFIG_DYNAMIC_FTRACE */
 593 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 594 static inline enum print_line_t
 595 print_graph_function(struct trace_iterator *iter)
 596 {
 597         return TRACE_TYPE_UNHANDLED;
 598 }
 599 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 600
 601 extern struct pid *ftrace_pid_trace;
 602
 603 #ifdef CONFIG_FUNCTION_TRACER
 604 static inline int ftrace_trace_task(struct task_struct *task)
 605 {
 606         if (!ftrace_pid_trace)
 607                 return 1;
 608
 609         return test_tsk_trace_trace(task);
 610 }
 611 #else
 612 static inline int ftrace_trace_task(struct task_struct *task)
 613 {
 614         return 1;
 615 }
 616 #endif
 617
 618 /*
 619  * trace_iterator_flags is an enumeration that defines bit
 620  * positions into trace_flags that controls the output.
 621  *
 622  * NOTE: These bits must match the trace_options array in
 623  *       trace.c.
 624  */
 625 enum trace_iterator_flags {
 626         TRACE_ITER_PRINT_PARENT         = 0x01,
 627         TRACE_ITER_SYM_OFFSET           = 0x02,
 628         TRACE_ITER_SYM_ADDR             = 0x04,
 629         TRACE_ITER_VERBOSE              = 0x08,
 630         TRACE_ITER_RAW                  = 0x10,
 631         TRACE_ITER_HEX                  = 0x20,
 632         TRACE_ITER_BIN                  = 0x40,
 633         TRACE_ITER_BLOCK                = 0x80,
 634         TRACE_ITER_STACKTRACE           = 0x100,
 635         TRACE_ITER_SCHED_TREE           = 0x200,
 636         TRACE_ITER_PRINTK               = 0x400,
 637         TRACE_ITER_PREEMPTONLY          = 0x800,
 638         TRACE_ITER_BRANCH               = 0x1000,
 639         TRACE_ITER_ANNOTATE             = 0x2000,
 640         TRACE_ITER_USERSTACKTRACE       = 0x4000,
 641         TRACE_ITER_SYM_USEROBJ          = 0x8000,
 642         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 643         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 644         TRACE_ITER_LATENCY_FMT          = 0x40000,
 645         TRACE_ITER_SLEEP_TIME           = 0x80000,
 646         TRACE_ITER_GRAPH_TIME           = 0x100000,
 647 };
 648
 649 /*
 650  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 651  * control the output of kernel symbols.
 652  */
 653 #define TRACE_ITER_SYM_MASK \
 654         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 655
 656 extern struct tracer nop_trace;
 657
 658 /**
 659  * ftrace_preempt_disable - disable preemption scheduler safe
 660  *
 661  * When tracing can happen inside the scheduler, there exists
 662  * cases that the tracing might happen before the need_resched
 663  * flag is checked. If this happens and the tracer calls
 664  * preempt_enable (after a disable), a schedule might take place
 665  * causing an infinite recursion.
 666  *
 667  * To prevent this, we read the need_resched flag before
 668  * disabling preemption. When we want to enable preemption we
 669  * check the flag, if it is set, then we call preempt_enable_no_resched.
 670  * Otherwise, we call preempt_enable.
 671  *
 672  * The rational for doing the above is that if need_resched is set
 673  * and we have yet to reschedule, we are either in an atomic location
 674  * (where we do not need to check for scheduling) or we are inside
 675  * the scheduler and do not want to resched.
 676  */
 677 static inline int ftrace_preempt_disable(void)
 678 {
 679         int resched;
 680
 681         resched = need_resched();
 682         preempt_disable_notrace();
 683
 684         return resched;
 685 }
 686
 687 /**
 688  * ftrace_preempt_enable - enable preemption scheduler safe
 689  * @resched: the return value from ftrace_preempt_disable
 690  *
 691  * This is a scheduler safe way to enable preemption and not miss
 692  * any preemption checks. The disabled saved the state of preemption.
 693  * If resched is set, then we are either inside an atomic or
 694  * are inside the scheduler (we would have already scheduled
 695  * otherwise). In this case, we do not want to call normal
 696  * preempt_enable, but preempt_enable_no_resched instead.
 697  */
 698 static inline void ftrace_preempt_enable(int resched)
 699 {
 700         if (resched)
 701                 preempt_enable_no_resched_notrace();
 702         else
 703                 preempt_enable_notrace();
 704 }
 705
 706 #ifdef CONFIG_BRANCH_TRACER
 707 extern int enable_branch_tracing(struct trace_array *tr);
 708 extern void disable_branch_tracing(void);
 709 static inline int trace_branch_enable(struct trace_array *tr)
 710 {
 711         if (trace_flags & TRACE_ITER_BRANCH)
 712                 return enable_branch_tracing(tr);
 713         return 0;
 714 }
 715 static inline void trace_branch_disable(void)
 716 {
 717         /* due to races, always disable */
 718         disable_branch_tracing();
 719 }
 720 #else
 721 static inline int trace_branch_enable(struct trace_array *tr)
 722 {
 723         return 0;
 724 }
 725 static inline void trace_branch_disable(void)
 726 {
 727 }
 728 #endif /* CONFIG_BRANCH_TRACER */
 729
 730 /* set ring buffers to default size if not already done so */
 731 int tracing_update_buffers(void);
 732
 733 /* trace event type bit fields, not numeric */
 734 enum {
 735         TRACE_EVENT_TYPE_PRINTF         = 1,
 736         TRACE_EVENT_TYPE_RAW            = 2,
 737 };
 738
 739 struct ftrace_event_field {
 740         struct list_head        link;
 741         char                    *name;
 742         char                    *type;
 743         int                     filter_type;
 744         int                     offset;
 745         int                     size;
 746         int                     is_signed;
 747 };
 748
 749 struct event_filter {
 750         int                     n_preds;
 751         struct filter_pred      **preds;
 752         char                    *filter_string;
 753         bool                    no_reset;
 754 };
 755
 756 struct event_subsystem {
 757         struct list_head        list;
 758         const char              *name;
 759         struct dentry           *entry;
 760         struct event_filter     *filter;
 761         int                     nr_events;
 762 };
 763
 764 struct filter_pred;
 765
 766 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 767                                  int val1, int val2);
 768
 769 struct filter_pred {
 770         filter_pred_fn_t fn;
 771         u64 val;
 772         char str_val[MAX_FILTER_STR_VAL];
 773         int str_len;
 774         char *field_name;
 775         int offset;
 776         int not;
 777         int op;
 778         int pop_n;
 779 };
 780
 781 extern void print_event_filter(struct ftrace_event_call *call,
 782                                struct trace_seq *s);
 783 extern int apply_event_filter(struct ftrace_event_call *call,
 784                               char *filter_string);
 785 extern int apply_subsystem_event_filter(struct event_subsystem *system,
 786                                         char *filter_string);
 787 extern void print_subsystem_event_filter(struct event_subsystem *system,
 788                                          struct trace_seq *s);
 789 extern int filter_assign_type(const char *type);
 790
 791 static inline int
 792 filter_check_discard(struct ftrace_event_call *call, void *rec,
 793                      struct ring_buffer *buffer,
 794                      struct ring_buffer_event *event)
 795 {
 796         if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) {
 797                 ring_buffer_discard_commit(buffer, event);
 798                 return 1;
 799         }
 800
 801         return 0;
 802 }
 803
 804 extern struct mutex event_mutex;
 805 extern struct list_head ftrace_events;
 806
 807 extern const char *__start___trace_bprintk_fmt[];
 808 extern const char *__stop___trace_bprintk_fmt[];
 809
 810 #undef TRACE_EVENT_FORMAT
 811 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)      \
 812         extern struct ftrace_event_call event_##call;
 813 #undef TRACE_EVENT_FORMAT_NOFILTER
 814 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt)
 815 #include "trace_event_types.h"
 816
 817 #endif /* _LINUX_KERNEL_TRACE_H */