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_SYSCALL_ENTER,
  38         TRACE_SYSCALL_EXIT,
  39         TRACE_KMEM_ALLOC,
  40         TRACE_KMEM_FREE,
  41         TRACE_POWER,
  42         TRACE_BLK,
  43
  44         __TRACE_LAST_TYPE,
  45 };
  46
  47 /*
  48  * Function trace entry - function address and parent function addres:
  49  */
  50 struct ftrace_entry {
  51         struct trace_entry      ent;
  52         unsigned long           ip;
  53         unsigned long           parent_ip;
  54 };
  55
  56 /* Function call entry */
  57 struct ftrace_graph_ent_entry {
  58         struct trace_entry              ent;
  59         struct ftrace_graph_ent         graph_ent;
  60 };
  61
  62 /* Function return entry */
  63 struct ftrace_graph_ret_entry {
  64         struct trace_entry              ent;
  65         struct ftrace_graph_ret         ret;
  66 };
  67 extern struct tracer boot_tracer;
  68
  69 /*
  70  * Context switch trace entry - which task (and prio) we switched from/to:
  71  */
  72 struct ctx_switch_entry {
  73         struct trace_entry      ent;
  74         unsigned int            prev_pid;
  75         unsigned char           prev_prio;
  76         unsigned char           prev_state;
  77         unsigned int            next_pid;
  78         unsigned char           next_prio;
  79         unsigned char           next_state;
  80         unsigned int            next_cpu;
  81 };
  82
  83 /*
  84  * Special (free-form) trace entry:
  85  */
  86 struct special_entry {
  87         struct trace_entry      ent;
  88         unsigned long           arg1;
  89         unsigned long           arg2;
  90         unsigned long           arg3;
  91 };
  92
  93 /*
  94  * Stack-trace entry:
  95  */
  96
  97 #define FTRACE_STACK_ENTRIES    8
  98
  99 struct stack_entry {
 100         struct trace_entry      ent;
 101         unsigned long           caller[FTRACE_STACK_ENTRIES];
 102 };
 103
 104 struct userstack_entry {
 105         struct trace_entry      ent;
 106         unsigned long           caller[FTRACE_STACK_ENTRIES];
 107 };
 108
 109 /*
 110  * trace_printk entry:
 111  */
 112 struct bprint_entry {
 113         struct trace_entry      ent;
 114         unsigned long           ip;
 115         const char              *fmt;
 116         u32                     buf[];
 117 };
 118
 119 struct print_entry {
 120         struct trace_entry      ent;
 121         unsigned long           ip;
 122         char                    buf[];
 123 };
 124
 125 #define TRACE_OLD_SIZE          88
 126
 127 struct trace_field_cont {
 128         unsigned char           type;
 129         /* Temporary till we get rid of this completely */
 130         char                    buf[TRACE_OLD_SIZE - 1];
 131 };
 132
 133 struct trace_mmiotrace_rw {
 134         struct trace_entry      ent;
 135         struct mmiotrace_rw     rw;
 136 };
 137
 138 struct trace_mmiotrace_map {
 139         struct trace_entry      ent;
 140         struct mmiotrace_map    map;
 141 };
 142
 143 struct trace_boot_call {
 144         struct trace_entry      ent;
 145         struct boot_trace_call boot_call;
 146 };
 147
 148 struct trace_boot_ret {
 149         struct trace_entry      ent;
 150         struct boot_trace_ret boot_ret;
 151 };
 152
 153 #define TRACE_FUNC_SIZE 30
 154 #define TRACE_FILE_SIZE 20
 155 struct trace_branch {
 156         struct trace_entry      ent;
 157         unsigned                line;
 158         char                    func[TRACE_FUNC_SIZE+1];
 159         char                    file[TRACE_FILE_SIZE+1];
 160         char                    correct;
 161 };
 162
 163 struct hw_branch_entry {
 164         struct trace_entry      ent;
 165         u64                     from;
 166         u64                     to;
 167 };
 168
 169 struct trace_power {
 170         struct trace_entry      ent;
 171         struct power_trace      state_data;
 172 };
 173
 174 enum kmemtrace_type_id {
 175         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
 176         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
 177         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
 178 };
 179
 180 struct kmemtrace_alloc_entry {
 181         struct trace_entry      ent;
 182         enum kmemtrace_type_id type_id;
 183         unsigned long call_site;
 184         const void *ptr;
 185         size_t bytes_req;
 186         size_t bytes_alloc;
 187         gfp_t gfp_flags;
 188         int node;
 189 };
 190
 191 struct kmemtrace_free_entry {
 192         struct trace_entry      ent;
 193         enum kmemtrace_type_id type_id;
 194         unsigned long call_site;
 195         const void *ptr;
 196 };
 197
 198 struct syscall_trace_enter {
 199         struct trace_entry      ent;
 200         int                     nr;
 201         unsigned long           args[];
 202 };
 203
 204 struct syscall_trace_exit {
 205         struct trace_entry      ent;
 206         int                     nr;
 207         unsigned long           ret;
 208 };
 209
 210
 211 /*
 212  * trace_flag_type is an enumeration that holds different
 213  * states when a trace occurs. These are:
 214  *  IRQS_OFF            - interrupts were disabled
 215  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 216  *  NEED_RESCED         - reschedule is requested
 217  *  HARDIRQ             - inside an interrupt handler
 218  *  SOFTIRQ             - inside a softirq handler
 219  */
 220 enum trace_flag_type {
 221         TRACE_FLAG_IRQS_OFF             = 0x01,
 222         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 223         TRACE_FLAG_NEED_RESCHED         = 0x04,
 224         TRACE_FLAG_HARDIRQ              = 0x08,
 225         TRACE_FLAG_SOFTIRQ              = 0x10,
 226 };
 227
 228 #define TRACE_BUF_SIZE          1024
 229
 230 /*
 231  * The CPU trace array - it consists of thousands of trace entries
 232  * plus some other descriptor data: (for example which task started
 233  * the trace, etc.)
 234  */
 235 struct trace_array_cpu {
 236         atomic_t                disabled;
 237         void                    *buffer_page;   /* ring buffer spare */
 238
 239         /* these fields get copied into max-trace: */
 240         unsigned long           trace_idx;
 241         unsigned long           overrun;
 242         unsigned long           saved_latency;
 243         unsigned long           critical_start;
 244         unsigned long           critical_end;
 245         unsigned long           critical_sequence;
 246         unsigned long           nice;
 247         unsigned long           policy;
 248         unsigned long           rt_priority;
 249         cycle_t                 preempt_timestamp;
 250         pid_t                   pid;
 251         uid_t                   uid;
 252         char                    comm[TASK_COMM_LEN];
 253 };
 254
 255 /*
 256  * The trace array - an array of per-CPU trace arrays. This is the
 257  * highest level data structure that individual tracers deal with.
 258  * They have on/off state as well:
 259  */
 260 struct trace_array {
 261         struct ring_buffer      *buffer;
 262         unsigned long           entries;
 263         int                     cpu;
 264         cycle_t                 time_start;
 265         struct task_struct      *waiter;
 266         struct trace_array_cpu  *data[NR_CPUS];
 267 };
 268
 269 #define FTRACE_CMP_TYPE(var, type) \
 270         __builtin_types_compatible_p(typeof(var), type *)
 271
 272 #undef IF_ASSIGN
 273 #define IF_ASSIGN(var, entry, etype, id)                \
 274         if (FTRACE_CMP_TYPE(var, etype)) {              \
 275                 var = (typeof(var))(entry);             \
 276                 WARN_ON(id && (entry)->type != id);     \
 277                 break;                                  \
 278         }
 279
 280 /* Will cause compile errors if type is not found. */
 281 extern void __ftrace_bad_type(void);
 282
 283 /*
 284  * The trace_assign_type is a verifier that the entry type is
 285  * the same as the type being assigned. To add new types simply
 286  * add a line with the following format:
 287  *
 288  * IF_ASSIGN(var, ent, type, id);
 289  *
 290  *  Where "type" is the trace type that includes the trace_entry
 291  *  as the "ent" item. And "id" is the trace identifier that is
 292  *  used in the trace_type enum.
 293  *
 294  *  If the type can have more than one id, then use zero.
 295  */
 296 #define trace_assign_type(var, ent)                                     \
 297         do {                                                            \
 298                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 299                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 300                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 301                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 302                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 303                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 304                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 305                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 306                           TRACE_MMIO_RW);                               \
 307                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 308                           TRACE_MMIO_MAP);                              \
 309                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 310                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 311                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 312                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 313                           TRACE_GRAPH_ENT);             \
 314                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 315                           TRACE_GRAPH_RET);             \
 316                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 317                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 318                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 319                           TRACE_KMEM_ALLOC);    \
 320                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 321                           TRACE_KMEM_FREE);     \
 322                 IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
 323                           TRACE_SYSCALL_ENTER);                         \
 324                 IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
 325                           TRACE_SYSCALL_EXIT);                          \
 326                 __ftrace_bad_type();                                    \
 327         } while (0)
 328
 329 /*
 330  * An option specific to a tracer. This is a boolean value.
 331  * The bit is the bit index that sets its value on the
 332  * flags value in struct tracer_flags.
 333  */
 334 struct tracer_opt {
 335         const char      *name; /* Will appear on the trace_options file */
 336         u32             bit; /* Mask assigned in val field in tracer_flags */
 337 };
 338
 339 /*
 340  * The set of specific options for a tracer. Your tracer
 341  * have to set the initial value of the flags val.
 342  */
 343 struct tracer_flags {
 344         u32                     val;
 345         struct tracer_opt       *opts;
 346 };
 347
 348 /* Makes more easy to define a tracer opt */
 349 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 350
 351
 352 /**
 353  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 354  * @name: the name chosen to select it on the available_tracers file
 355  * @init: called when one switches to this tracer (echo name > current_tracer)
 356  * @reset: called when one switches to another tracer
 357  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 358  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 359  * @open: called when the trace file is opened
 360  * @pipe_open: called when the trace_pipe file is opened
 361  * @wait_pipe: override how the user waits for traces on trace_pipe
 362  * @close: called when the trace file is released
 363  * @read: override the default read callback on trace_pipe
 364  * @splice_read: override the default splice_read callback on trace_pipe
 365  * @selftest: selftest to run on boot (see trace_selftest.c)
 366  * @print_headers: override the first lines that describe your columns
 367  * @print_line: callback that prints a trace
 368  * @set_flag: signals one of your private flags changed (trace_options file)
 369  * @flags: your private flags
 370  */
 371 struct tracer {
 372         const char              *name;
 373         int                     (*init)(struct trace_array *tr);
 374         void                    (*reset)(struct trace_array *tr);
 375         void                    (*start)(struct trace_array *tr);
 376         void                    (*stop)(struct trace_array *tr);
 377         void                    (*open)(struct trace_iterator *iter);
 378         void                    (*pipe_open)(struct trace_iterator *iter);
 379         void                    (*wait_pipe)(struct trace_iterator *iter);
 380         void                    (*close)(struct trace_iterator *iter);
 381         ssize_t                 (*read)(struct trace_iterator *iter,
 382                                         struct file *filp, char __user *ubuf,
 383                                         size_t cnt, loff_t *ppos);
 384         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 385                                                struct file *filp,
 386                                                loff_t *ppos,
 387                                                struct pipe_inode_info *pipe,
 388                                                size_t len,
 389                                                unsigned int flags);
 390 #ifdef CONFIG_FTRACE_STARTUP_TEST
 391         int                     (*selftest)(struct tracer *trace,
 392                                             struct trace_array *tr);
 393 #endif
 394         void                    (*print_header)(struct seq_file *m);
 395         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 396         /* If you handled the flag setting, return 0 */
 397         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 398         struct tracer           *next;
 399         int                     print_max;
 400         struct tracer_flags     *flags;
 401         struct tracer_stat      *stats;
 402 };
 403
 404
 405 #define TRACE_PIPE_ALL_CPU      -1
 406
 407 int tracer_init(struct tracer *t, struct trace_array *tr);
 408 int tracing_is_enabled(void);
 409 void trace_wake_up(void);
 410 void tracing_reset(struct trace_array *tr, int cpu);
 411 void tracing_reset_online_cpus(struct trace_array *tr);
 412 void tracing_reset_current(int cpu);
 413 void tracing_reset_current_online_cpus(void);
 414 int tracing_open_generic(struct inode *inode, struct file *filp);
 415 struct dentry *trace_create_file(const char *name,
 416                                  mode_t mode,
 417                                  struct dentry *parent,
 418                                  void *data,
 419                                  const struct file_operations *fops);
 420
 421 struct dentry *tracing_init_dentry(void);
 422 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 423
 424 struct ring_buffer_event;
 425
 426 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
 427                                                     int type,
 428                                                     unsigned long len,
 429                                                     unsigned long flags,
 430                                                     int pc);
 431 void trace_buffer_unlock_commit(struct trace_array *tr,
 432                                 struct ring_buffer_event *event,
 433                                 unsigned long flags, int pc);
 434
 435 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 436                                                 struct trace_array_cpu *data);
 437
 438 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 439                                           int *ent_cpu, u64 *ent_ts);
 440
 441 void tracing_generic_entry_update(struct trace_entry *entry,
 442                                   unsigned long flags,
 443                                   int pc);
 444
 445 void default_wait_pipe(struct trace_iterator *iter);
 446 void poll_wait_pipe(struct trace_iterator *iter);
 447
 448 void ftrace(struct trace_array *tr,
 449                             struct trace_array_cpu *data,
 450                             unsigned long ip,
 451                             unsigned long parent_ip,
 452                             unsigned long flags, int pc);
 453 void tracing_sched_switch_trace(struct trace_array *tr,
 454                                 struct task_struct *prev,
 455                                 struct task_struct *next,
 456                                 unsigned long flags, int pc);
 457
 458 void tracing_sched_wakeup_trace(struct trace_array *tr,
 459                                 struct task_struct *wakee,
 460                                 struct task_struct *cur,
 461                                 unsigned long flags, int pc);
 462 void trace_special(struct trace_array *tr,
 463                    struct trace_array_cpu *data,
 464                    unsigned long arg1,
 465                    unsigned long arg2,
 466                    unsigned long arg3, int pc);
 467 void trace_function(struct trace_array *tr,
 468                     unsigned long ip,
 469                     unsigned long parent_ip,
 470                     unsigned long flags, int pc);
 471
 472 void trace_graph_return(struct ftrace_graph_ret *trace);
 473 int trace_graph_entry(struct ftrace_graph_ent *trace);
 474
 475 void tracing_start_cmdline_record(void);
 476 void tracing_stop_cmdline_record(void);
 477 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 478 void tracing_stop_sched_switch_record(void);
 479 void tracing_start_sched_switch_record(void);
 480 int register_tracer(struct tracer *type);
 481 void unregister_tracer(struct tracer *type);
 482
 483 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 484
 485 extern unsigned long tracing_max_latency;
 486 extern unsigned long tracing_thresh;
 487
 488 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 489 void update_max_tr_single(struct trace_array *tr,
 490                           struct task_struct *tsk, int cpu);
 491
 492 void __trace_stack(struct trace_array *tr,
 493                    unsigned long flags,
 494                    int skip, int pc);
 495
 496 extern cycle_t ftrace_now(int cpu);
 497
 498 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 499 typedef void
 500 (*tracer_switch_func_t)(void *private,
 501                         void *__rq,
 502                         struct task_struct *prev,
 503                         struct task_struct *next);
 504
 505 struct tracer_switch_ops {
 506         tracer_switch_func_t            func;
 507         void                            *private;
 508         struct tracer_switch_ops        *next;
 509 };
 510 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 511
 512 extern void trace_find_cmdline(int pid, char comm[]);
 513
 514 #ifdef CONFIG_DYNAMIC_FTRACE
 515 extern unsigned long ftrace_update_tot_cnt;
 516 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 517 extern int DYN_FTRACE_TEST_NAME(void);
 518 #endif
 519
 520 #ifdef CONFIG_FTRACE_STARTUP_TEST
 521 extern int trace_selftest_startup_function(struct tracer *trace,
 522                                            struct trace_array *tr);
 523 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 524                                                  struct trace_array *tr);
 525 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 526                                           struct trace_array *tr);
 527 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 528                                              struct trace_array *tr);
 529 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 530                                                  struct trace_array *tr);
 531 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 532                                          struct trace_array *tr);
 533 extern int trace_selftest_startup_nop(struct tracer *trace,
 534                                          struct trace_array *tr);
 535 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 536                                                struct trace_array *tr);
 537 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 538                                                struct trace_array *tr);
 539 extern int trace_selftest_startup_branch(struct tracer *trace,
 540                                          struct trace_array *tr);
 541 extern int trace_selftest_startup_hw_branches(struct tracer *trace,
 542                                               struct trace_array *tr);
 543 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 544
 545 extern void *head_page(struct trace_array_cpu *data);
 546 extern unsigned long long ns2usecs(cycle_t nsec);
 547 extern int
 548 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 549 extern int
 550 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 551
 552 extern unsigned long trace_flags;
 553
 554 /* Standard output formatting function used for function return traces */
 555 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 556 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 557 extern enum print_line_t
 558 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 559
 560 #ifdef CONFIG_DYNAMIC_FTRACE
 561 /* TODO: make this variable */
 562 #define FTRACE_GRAPH_MAX_FUNCS          32
 563 extern int ftrace_graph_count;
 564 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 565
 566 static inline int ftrace_graph_addr(unsigned long addr)
 567 {
 568         int i;
 569
 570         if (!ftrace_graph_count || test_tsk_trace_graph(current))
 571                 return 1;
 572
 573         for (i = 0; i < ftrace_graph_count; i++) {
 574                 if (addr == ftrace_graph_funcs[i])
 575                         return 1;
 576         }
 577
 578         return 0;
 579 }
 580 #else
 581 static inline int ftrace_trace_addr(unsigned long addr)
 582 {
 583         return 1;
 584 }
 585 static inline int ftrace_graph_addr(unsigned long addr)
 586 {
 587         return 1;
 588 }
 589 #endif /* CONFIG_DYNAMIC_FTRACE */
 590 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 591 static inline enum print_line_t
 592 print_graph_function(struct trace_iterator *iter)
 593 {
 594         return TRACE_TYPE_UNHANDLED;
 595 }
 596 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 597
 598 extern struct pid *ftrace_pid_trace;
 599
 600 static inline int ftrace_trace_task(struct task_struct *task)
 601 {
 602         if (!ftrace_pid_trace)
 603                 return 1;
 604
 605         return test_tsk_trace_trace(task);
 606 }
 607
 608 /*
 609  * trace_iterator_flags is an enumeration that defines bit
 610  * positions into trace_flags that controls the output.
 611  *
 612  * NOTE: These bits must match the trace_options array in
 613  *       trace.c.
 614  */
 615 enum trace_iterator_flags {
 616         TRACE_ITER_PRINT_PARENT         = 0x01,
 617         TRACE_ITER_SYM_OFFSET           = 0x02,
 618         TRACE_ITER_SYM_ADDR             = 0x04,
 619         TRACE_ITER_VERBOSE              = 0x08,
 620         TRACE_ITER_RAW                  = 0x10,
 621         TRACE_ITER_HEX                  = 0x20,
 622         TRACE_ITER_BIN                  = 0x40,
 623         TRACE_ITER_BLOCK                = 0x80,
 624         TRACE_ITER_STACKTRACE           = 0x100,
 625         TRACE_ITER_SCHED_TREE           = 0x200,
 626         TRACE_ITER_PRINTK               = 0x400,
 627         TRACE_ITER_PREEMPTONLY          = 0x800,
 628         TRACE_ITER_BRANCH               = 0x1000,
 629         TRACE_ITER_ANNOTATE             = 0x2000,
 630         TRACE_ITER_USERSTACKTRACE       = 0x4000,
 631         TRACE_ITER_SYM_USEROBJ          = 0x8000,
 632         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 633         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 634         TRACE_ITER_LATENCY_FMT          = 0x40000,
 635         TRACE_ITER_GLOBAL_CLK           = 0x80000,
 636         TRACE_ITER_SLEEP_TIME           = 0x100000,
 637         TRACE_ITER_GRAPH_TIME           = 0x200000,
 638 };
 639
 640 /*
 641  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 642  * control the output of kernel symbols.
 643  */
 644 #define TRACE_ITER_SYM_MASK \
 645         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 646
 647 extern struct tracer nop_trace;
 648
 649 /**
 650  * ftrace_preempt_disable - disable preemption scheduler safe
 651  *
 652  * When tracing can happen inside the scheduler, there exists
 653  * cases that the tracing might happen before the need_resched
 654  * flag is checked. If this happens and the tracer calls
 655  * preempt_enable (after a disable), a schedule might take place
 656  * causing an infinite recursion.
 657  *
 658  * To prevent this, we read the need_resched flag before
 659  * disabling preemption. When we want to enable preemption we
 660  * check the flag, if it is set, then we call preempt_enable_no_resched.
 661  * Otherwise, we call preempt_enable.
 662  *
 663  * The rational for doing the above is that if need_resched is set
 664  * and we have yet to reschedule, we are either in an atomic location
 665  * (where we do not need to check for scheduling) or we are inside
 666  * the scheduler and do not want to resched.
 667  */
 668 static inline int ftrace_preempt_disable(void)
 669 {
 670         int resched;
 671
 672         resched = need_resched();
 673         preempt_disable_notrace();
 674
 675         return resched;
 676 }
 677
 678 /**
 679  * ftrace_preempt_enable - enable preemption scheduler safe
 680  * @resched: the return value from ftrace_preempt_disable
 681  *
 682  * This is a scheduler safe way to enable preemption and not miss
 683  * any preemption checks. The disabled saved the state of preemption.
 684  * If resched is set, then we are either inside an atomic or
 685  * are inside the scheduler (we would have already scheduled
 686  * otherwise). In this case, we do not want to call normal
 687  * preempt_enable, but preempt_enable_no_resched instead.
 688  */
 689 static inline void ftrace_preempt_enable(int resched)
 690 {
 691         if (resched)
 692                 preempt_enable_no_resched_notrace();
 693         else
 694                 preempt_enable_notrace();
 695 }
 696
 697 #ifdef CONFIG_BRANCH_TRACER
 698 extern int enable_branch_tracing(struct trace_array *tr);
 699 extern void disable_branch_tracing(void);
 700 static inline int trace_branch_enable(struct trace_array *tr)
 701 {
 702         if (trace_flags & TRACE_ITER_BRANCH)
 703                 return enable_branch_tracing(tr);
 704         return 0;
 705 }
 706 static inline void trace_branch_disable(void)
 707 {
 708         /* due to races, always disable */
 709         disable_branch_tracing();
 710 }
 711 #else
 712 static inline int trace_branch_enable(struct trace_array *tr)
 713 {
 714         return 0;
 715 }
 716 static inline void trace_branch_disable(void)
 717 {
 718 }
 719 #endif /* CONFIG_BRANCH_TRACER */
 720
 721 /* set ring buffers to default size if not already done so */
 722 int tracing_update_buffers(void);
 723
 724 /* trace event type bit fields, not numeric */
 725 enum {
 726         TRACE_EVENT_TYPE_PRINTF         = 1,
 727         TRACE_EVENT_TYPE_RAW            = 2,
 728 };
 729
 730 struct ftrace_event_field {
 731         struct list_head        link;
 732         char                    *name;
 733         char                    *type;
 734         int                     offset;
 735         int                     size;
 736         int                     is_signed;
 737 };
 738
 739 struct event_filter {
 740         int                     n_preds;
 741         struct filter_pred      **preds;
 742         char                    *filter_string;
 743 };
 744
 745 struct event_subsystem {
 746         struct list_head        list;
 747         const char              *name;
 748         struct dentry           *entry;
 749         void                    *filter;
 750 };
 751
 752 struct filter_pred;
 753
 754 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event,
 755                                  int val1, int val2);
 756
 757 struct filter_pred {
 758         filter_pred_fn_t fn;
 759         u64 val;
 760         char str_val[MAX_FILTER_STR_VAL];
 761         int str_len;
 762         char *field_name;
 763         int offset;
 764         int not;
 765         int op;
 766         int pop_n;
 767 };
 768
 769 extern void print_event_filter(struct ftrace_event_call *call,
 770                                struct trace_seq *s);
 771 extern int apply_event_filter(struct ftrace_event_call *call,
 772                               char *filter_string);
 773 extern int apply_subsystem_event_filter(struct event_subsystem *system,
 774                                         char *filter_string);
 775 extern void print_subsystem_event_filter(struct event_subsystem *system,
 776                                          struct trace_seq *s);
 777
 778 static inline int
 779 filter_check_discard(struct ftrace_event_call *call, void *rec,
 780                      struct ring_buffer *buffer,
 781                      struct ring_buffer_event *event)
 782 {
 783         if (unlikely(call->filter_active) && !filter_match_preds(call, rec)) {
 784                 ring_buffer_discard_commit(buffer, event);
 785                 return 1;
 786         }
 787
 788         return 0;
 789 }
 790
 791 #define DEFINE_COMPARISON_PRED(type)                                    \
 792 static int filter_pred_##type(struct filter_pred *pred, void *event,    \
 793                               int val1, int val2)                       \
 794 {                                                                       \
 795         type *addr = (type *)(event + pred->offset);                    \
 796         type val = (type)pred->val;                                     \
 797         int match = 0;                                                  \
 798                                                                         \
 799         switch (pred->op) {                                             \
 800         case OP_LT:                                                     \
 801                 match = (*addr < val);                                  \
 802                 break;                                                  \
 803         case OP_LE:                                                     \
 804                 match = (*addr <= val);                                 \
 805                 break;                                                  \
 806         case OP_GT:                                                     \
 807                 match = (*addr > val);                                  \
 808                 break;                                                  \
 809         case OP_GE:                                                     \
 810                 match = (*addr >= val);                                 \
 811                 break;                                                  \
 812         default:                                                        \
 813                 break;                                                  \
 814         }                                                               \
 815                                                                         \
 816         return match;                                                   \
 817 }
 818
 819 #define DEFINE_EQUALITY_PRED(size)                                      \
 820 static int filter_pred_##size(struct filter_pred *pred, void *event,    \
 821                               int val1, int val2)                       \
 822 {                                                                       \
 823         u##size *addr = (u##size *)(event + pred->offset);              \
 824         u##size val = (u##size)pred->val;                               \
 825         int match;                                                      \
 826                                                                         \
 827         match = (val == *addr) ^ pred->not;                             \
 828                                                                         \
 829         return match;                                                   \
 830 }
 831
 832 extern struct mutex event_mutex;
 833 extern struct list_head ftrace_events;
 834
 835 extern const char *__start___trace_bprintk_fmt[];
 836 extern const char *__stop___trace_bprintk_fmt[];
 837
 838 #undef TRACE_EVENT_FORMAT
 839 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)      \
 840         extern struct ftrace_event_call event_##call;
 841 #undef TRACE_EVENT_FORMAT_NOFILTER
 842 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt)
 843 #include "trace_event_types.h"
 844
 845 #endif /* _LINUX_KERNEL_TRACE_H */