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 enum trace_type {
  16         __TRACE_FIRST_TYPE = 0,
  17
  18         TRACE_FN,
  19         TRACE_CTX,
  20         TRACE_WAKE,
  21         TRACE_STACK,
  22         TRACE_PRINT,
  23         TRACE_BPRINT,
  24         TRACE_SPECIAL,
  25         TRACE_MMIO_RW,
  26         TRACE_MMIO_MAP,
  27         TRACE_BRANCH,
  28         TRACE_BOOT_CALL,
  29         TRACE_BOOT_RET,
  30         TRACE_GRAPH_RET,
  31         TRACE_GRAPH_ENT,
  32         TRACE_USER_STACK,
  33         TRACE_HW_BRANCHES,
  34         TRACE_SYSCALL_ENTER,
  35         TRACE_SYSCALL_EXIT,
  36         TRACE_KMEM_ALLOC,
  37         TRACE_KMEM_FREE,
  38         TRACE_POWER,
  39         TRACE_BLK,
  40
  41         __TRACE_LAST_TYPE,
  42 };
  43
  44 /*
  45  * The trace entry - the most basic unit of tracing. This is what
  46  * is printed in the end as a single line in the trace output, such as:
  47  *
  48  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  49  */
  50 struct trace_entry {
  51         unsigned char           type;
  52         unsigned char           flags;
  53         unsigned char           preempt_count;
  54         int                     pid;
  55         int                     tgid;
  56 };
  57
  58 /*
  59  * Function trace entry - function address and parent function addres:
  60  */
  61 struct ftrace_entry {
  62         struct trace_entry      ent;
  63         unsigned long           ip;
  64         unsigned long           parent_ip;
  65 };
  66
  67 /* Function call entry */
  68 struct ftrace_graph_ent_entry {
  69         struct trace_entry              ent;
  70         struct ftrace_graph_ent         graph_ent;
  71 };
  72
  73 /* Function return entry */
  74 struct ftrace_graph_ret_entry {
  75         struct trace_entry              ent;
  76         struct ftrace_graph_ret         ret;
  77 };
  78 extern struct tracer boot_tracer;
  79
  80 /*
  81  * Context switch trace entry - which task (and prio) we switched from/to:
  82  */
  83 struct ctx_switch_entry {
  84         struct trace_entry      ent;
  85         unsigned int            prev_pid;
  86         unsigned char           prev_prio;
  87         unsigned char           prev_state;
  88         unsigned int            next_pid;
  89         unsigned char           next_prio;
  90         unsigned char           next_state;
  91         unsigned int            next_cpu;
  92 };
  93
  94 /*
  95  * Special (free-form) trace entry:
  96  */
  97 struct special_entry {
  98         struct trace_entry      ent;
  99         unsigned long           arg1;
 100         unsigned long           arg2;
 101         unsigned long           arg3;
 102 };
 103
 104 /*
 105  * Stack-trace entry:
 106  */
 107
 108 #define FTRACE_STACK_ENTRIES    8
 109
 110 struct stack_entry {
 111         struct trace_entry      ent;
 112         unsigned long           caller[FTRACE_STACK_ENTRIES];
 113 };
 114
 115 struct userstack_entry {
 116         struct trace_entry      ent;
 117         unsigned long           caller[FTRACE_STACK_ENTRIES];
 118 };
 119
 120 /*
 121  * trace_printk entry:
 122  */
 123 struct bprint_entry {
 124         struct trace_entry      ent;
 125         unsigned long           ip;
 126         const char              *fmt;
 127         u32                     buf[];
 128 };
 129
 130 struct print_entry {
 131         struct trace_entry      ent;
 132         unsigned long           ip;
 133         char                    buf[];
 134 };
 135
 136 #define TRACE_OLD_SIZE          88
 137
 138 struct trace_field_cont {
 139         unsigned char           type;
 140         /* Temporary till we get rid of this completely */
 141         char                    buf[TRACE_OLD_SIZE - 1];
 142 };
 143
 144 struct trace_mmiotrace_rw {
 145         struct trace_entry      ent;
 146         struct mmiotrace_rw     rw;
 147 };
 148
 149 struct trace_mmiotrace_map {
 150         struct trace_entry      ent;
 151         struct mmiotrace_map    map;
 152 };
 153
 154 struct trace_boot_call {
 155         struct trace_entry      ent;
 156         struct boot_trace_call boot_call;
 157 };
 158
 159 struct trace_boot_ret {
 160         struct trace_entry      ent;
 161         struct boot_trace_ret boot_ret;
 162 };
 163
 164 #define TRACE_FUNC_SIZE 30
 165 #define TRACE_FILE_SIZE 20
 166 struct trace_branch {
 167         struct trace_entry      ent;
 168         unsigned                line;
 169         char                    func[TRACE_FUNC_SIZE+1];
 170         char                    file[TRACE_FILE_SIZE+1];
 171         char                    correct;
 172 };
 173
 174 struct hw_branch_entry {
 175         struct trace_entry      ent;
 176         u64                     from;
 177         u64                     to;
 178 };
 179
 180 struct trace_power {
 181         struct trace_entry      ent;
 182         struct power_trace      state_data;
 183 };
 184
 185 enum kmemtrace_type_id {
 186         KMEMTRACE_TYPE_KMALLOC = 0,     /* kmalloc() or kfree(). */
 187         KMEMTRACE_TYPE_CACHE,           /* kmem_cache_*(). */
 188         KMEMTRACE_TYPE_PAGES,           /* __get_free_pages() and friends. */
 189 };
 190
 191 struct kmemtrace_alloc_entry {
 192         struct trace_entry      ent;
 193         enum kmemtrace_type_id type_id;
 194         unsigned long call_site;
 195         const void *ptr;
 196         size_t bytes_req;
 197         size_t bytes_alloc;
 198         gfp_t gfp_flags;
 199         int node;
 200 };
 201
 202 struct kmemtrace_free_entry {
 203         struct trace_entry      ent;
 204         enum kmemtrace_type_id type_id;
 205         unsigned long call_site;
 206         const void *ptr;
 207 };
 208
 209 struct syscall_trace_enter {
 210         struct trace_entry      ent;
 211         int                     nr;
 212         unsigned long           args[];
 213 };
 214
 215 struct syscall_trace_exit {
 216         struct trace_entry      ent;
 217         int                     nr;
 218         unsigned long           ret;
 219 };
 220
 221
 222 /*
 223  * trace_flag_type is an enumeration that holds different
 224  * states when a trace occurs. These are:
 225  *  IRQS_OFF            - interrupts were disabled
 226  *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 227  *  NEED_RESCED         - reschedule is requested
 228  *  HARDIRQ             - inside an interrupt handler
 229  *  SOFTIRQ             - inside a softirq handler
 230  */
 231 enum trace_flag_type {
 232         TRACE_FLAG_IRQS_OFF             = 0x01,
 233         TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
 234         TRACE_FLAG_NEED_RESCHED         = 0x04,
 235         TRACE_FLAG_HARDIRQ              = 0x08,
 236         TRACE_FLAG_SOFTIRQ              = 0x10,
 237 };
 238
 239 #define TRACE_BUF_SIZE          1024
 240
 241 /*
 242  * The CPU trace array - it consists of thousands of trace entries
 243  * plus some other descriptor data: (for example which task started
 244  * the trace, etc.)
 245  */
 246 struct trace_array_cpu {
 247         atomic_t                disabled;
 248         void                    *buffer_page;   /* ring buffer spare */
 249
 250         /* these fields get copied into max-trace: */
 251         unsigned long           trace_idx;
 252         unsigned long           overrun;
 253         unsigned long           saved_latency;
 254         unsigned long           critical_start;
 255         unsigned long           critical_end;
 256         unsigned long           critical_sequence;
 257         unsigned long           nice;
 258         unsigned long           policy;
 259         unsigned long           rt_priority;
 260         cycle_t                 preempt_timestamp;
 261         pid_t                   pid;
 262         uid_t                   uid;
 263         char                    comm[TASK_COMM_LEN];
 264 };
 265
 266 struct trace_iterator;
 267
 268 /*
 269  * The trace array - an array of per-CPU trace arrays. This is the
 270  * highest level data structure that individual tracers deal with.
 271  * They have on/off state as well:
 272  */
 273 struct trace_array {
 274         struct ring_buffer      *buffer;
 275         unsigned long           entries;
 276         int                     cpu;
 277         cycle_t                 time_start;
 278         struct task_struct      *waiter;
 279         struct trace_array_cpu  *data[NR_CPUS];
 280 };
 281
 282 #define FTRACE_CMP_TYPE(var, type) \
 283         __builtin_types_compatible_p(typeof(var), type *)
 284
 285 #undef IF_ASSIGN
 286 #define IF_ASSIGN(var, entry, etype, id)                \
 287         if (FTRACE_CMP_TYPE(var, etype)) {              \
 288                 var = (typeof(var))(entry);             \
 289                 WARN_ON(id && (entry)->type != id);     \
 290                 break;                                  \
 291         }
 292
 293 /* Will cause compile errors if type is not found. */
 294 extern void __ftrace_bad_type(void);
 295
 296 /*
 297  * The trace_assign_type is a verifier that the entry type is
 298  * the same as the type being assigned. To add new types simply
 299  * add a line with the following format:
 300  *
 301  * IF_ASSIGN(var, ent, type, id);
 302  *
 303  *  Where "type" is the trace type that includes the trace_entry
 304  *  as the "ent" item. And "id" is the trace identifier that is
 305  *  used in the trace_type enum.
 306  *
 307  *  If the type can have more than one id, then use zero.
 308  */
 309 #define trace_assign_type(var, ent)                                     \
 310         do {                                                            \
 311                 IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);     \
 312                 IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);        \
 313                 IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);   \
 314                 IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 315                 IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);   \
 316                 IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
 317                 IF_ASSIGN(var, ent, struct special_entry, 0);           \
 318                 IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,          \
 319                           TRACE_MMIO_RW);                               \
 320                 IF_ASSIGN(var, ent, struct trace_mmiotrace_map,         \
 321                           TRACE_MMIO_MAP);                              \
 322                 IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
 323                 IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
 324                 IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
 325                 IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,      \
 326                           TRACE_GRAPH_ENT);             \
 327                 IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,      \
 328                           TRACE_GRAPH_RET);             \
 329                 IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
 330                 IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 331                 IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry,       \
 332                           TRACE_KMEM_ALLOC);    \
 333                 IF_ASSIGN(var, ent, struct kmemtrace_free_entry,        \
 334                           TRACE_KMEM_FREE);     \
 335                 IF_ASSIGN(var, ent, struct syscall_trace_enter,         \
 336                           TRACE_SYSCALL_ENTER);                         \
 337                 IF_ASSIGN(var, ent, struct syscall_trace_exit,          \
 338                           TRACE_SYSCALL_EXIT);                          \
 339                 __ftrace_bad_type();                                    \
 340         } while (0)
 341
 342 /* Return values for print_line callback */
 343 enum print_line_t {
 344         TRACE_TYPE_PARTIAL_LINE = 0,    /* Retry after flushing the seq */
 345         TRACE_TYPE_HANDLED      = 1,
 346         TRACE_TYPE_UNHANDLED    = 2,    /* Relay to other output functions */
 347         TRACE_TYPE_NO_CONSUME   = 3     /* Handled but ask to not consume */
 348 };
 349
 350
 351 /*
 352  * An option specific to a tracer. This is a boolean value.
 353  * The bit is the bit index that sets its value on the
 354  * flags value in struct tracer_flags.
 355  */
 356 struct tracer_opt {
 357         const char      *name; /* Will appear on the trace_options file */
 358         u32             bit; /* Mask assigned in val field in tracer_flags */
 359 };
 360
 361 /*
 362  * The set of specific options for a tracer. Your tracer
 363  * have to set the initial value of the flags val.
 364  */
 365 struct tracer_flags {
 366         u32                     val;
 367         struct tracer_opt       *opts;
 368 };
 369
 370 /* Makes more easy to define a tracer opt */
 371 #define TRACER_OPT(s, b)        .name = #s, .bit = b
 372
 373
 374 /**
 375  * struct tracer - a specific tracer and its callbacks to interact with debugfs
 376  * @name: the name chosen to select it on the available_tracers file
 377  * @init: called when one switches to this tracer (echo name > current_tracer)
 378  * @reset: called when one switches to another tracer
 379  * @start: called when tracing is unpaused (echo 1 > tracing_enabled)
 380  * @stop: called when tracing is paused (echo 0 > tracing_enabled)
 381  * @open: called when the trace file is opened
 382  * @pipe_open: called when the trace_pipe file is opened
 383  * @wait_pipe: override how the user waits for traces on trace_pipe
 384  * @close: called when the trace file is released
 385  * @read: override the default read callback on trace_pipe
 386  * @splice_read: override the default splice_read callback on trace_pipe
 387  * @selftest: selftest to run on boot (see trace_selftest.c)
 388  * @print_headers: override the first lines that describe your columns
 389  * @print_line: callback that prints a trace
 390  * @set_flag: signals one of your private flags changed (trace_options file)
 391  * @flags: your private flags
 392  */
 393 struct tracer {
 394         const char              *name;
 395         int                     (*init)(struct trace_array *tr);
 396         void                    (*reset)(struct trace_array *tr);
 397         void                    (*start)(struct trace_array *tr);
 398         void                    (*stop)(struct trace_array *tr);
 399         void                    (*open)(struct trace_iterator *iter);
 400         void                    (*pipe_open)(struct trace_iterator *iter);
 401         void                    (*wait_pipe)(struct trace_iterator *iter);
 402         void                    (*close)(struct trace_iterator *iter);
 403         ssize_t                 (*read)(struct trace_iterator *iter,
 404                                         struct file *filp, char __user *ubuf,
 405                                         size_t cnt, loff_t *ppos);
 406         ssize_t                 (*splice_read)(struct trace_iterator *iter,
 407                                                struct file *filp,
 408                                                loff_t *ppos,
 409                                                struct pipe_inode_info *pipe,
 410                                                size_t len,
 411                                                unsigned int flags);
 412 #ifdef CONFIG_FTRACE_STARTUP_TEST
 413         int                     (*selftest)(struct tracer *trace,
 414                                             struct trace_array *tr);
 415 #endif
 416         void                    (*print_header)(struct seq_file *m);
 417         enum print_line_t       (*print_line)(struct trace_iterator *iter);
 418         /* If you handled the flag setting, return 0 */
 419         int                     (*set_flag)(u32 old_flags, u32 bit, int set);
 420         struct tracer           *next;
 421         int                     print_max;
 422         struct tracer_flags     *flags;
 423         struct tracer_stat      *stats;
 424 };
 425
 426 struct trace_seq {
 427         unsigned char           buffer[PAGE_SIZE];
 428         unsigned int            len;
 429         unsigned int            readpos;
 430 };
 431
 432 static inline void
 433 trace_seq_init(struct trace_seq *s)
 434 {
 435         s->len = 0;
 436         s->readpos = 0;
 437 }
 438
 439
 440 #define TRACE_PIPE_ALL_CPU      -1
 441
 442 /*
 443  * Trace iterator - used by printout routines who present trace
 444  * results to users and which routines might sleep, etc:
 445  */
 446 struct trace_iterator {
 447         struct trace_array      *tr;
 448         struct tracer           *trace;
 449         void                    *private;
 450         int                     cpu_file;
 451         struct mutex            mutex;
 452         struct ring_buffer_iter *buffer_iter[NR_CPUS];
 453
 454         /* The below is zeroed out in pipe_read */
 455         struct trace_seq        seq;
 456         struct trace_entry      *ent;
 457         int                     cpu;
 458         u64                     ts;
 459
 460         unsigned long           iter_flags;
 461         loff_t                  pos;
 462         long                    idx;
 463
 464         cpumask_var_t           started;
 465 };
 466
 467 int tracer_init(struct tracer *t, struct trace_array *tr);
 468 int tracing_is_enabled(void);
 469 void trace_wake_up(void);
 470 void tracing_reset(struct trace_array *tr, int cpu);
 471 void tracing_reset_online_cpus(struct trace_array *tr);
 472 int tracing_open_generic(struct inode *inode, struct file *filp);
 473 struct dentry *trace_create_file(const char *name,
 474                                  mode_t mode,
 475                                  struct dentry *parent,
 476                                  void *data,
 477                                  const struct file_operations *fops);
 478
 479 struct dentry *tracing_init_dentry(void);
 480 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 481
 482 struct ring_buffer_event;
 483
 484 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
 485                                                     unsigned char type,
 486                                                     unsigned long len,
 487                                                     unsigned long flags,
 488                                                     int pc);
 489 void trace_buffer_unlock_commit(struct trace_array *tr,
 490                                 struct ring_buffer_event *event,
 491                                 unsigned long flags, int pc);
 492
 493 struct ring_buffer_event *
 494 trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
 495                                   unsigned long flags, int pc);
 496 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
 497                                         unsigned long flags, int pc);
 498 void trace_nowake_buffer_unlock_commit(struct ring_buffer_event *event,
 499                                         unsigned long flags, int pc);
 500
 501 struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 502                                                 struct trace_array_cpu *data);
 503
 504 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 505                                           int *ent_cpu, u64 *ent_ts);
 506
 507 void tracing_generic_entry_update(struct trace_entry *entry,
 508                                   unsigned long flags,
 509                                   int pc);
 510
 511 void default_wait_pipe(struct trace_iterator *iter);
 512 void poll_wait_pipe(struct trace_iterator *iter);
 513
 514 void ftrace(struct trace_array *tr,
 515                             struct trace_array_cpu *data,
 516                             unsigned long ip,
 517                             unsigned long parent_ip,
 518                             unsigned long flags, int pc);
 519 void tracing_sched_switch_trace(struct trace_array *tr,
 520                                 struct task_struct *prev,
 521                                 struct task_struct *next,
 522                                 unsigned long flags, int pc);
 523 void tracing_record_cmdline(struct task_struct *tsk);
 524
 525 void tracing_sched_wakeup_trace(struct trace_array *tr,
 526                                 struct task_struct *wakee,
 527                                 struct task_struct *cur,
 528                                 unsigned long flags, int pc);
 529 void trace_special(struct trace_array *tr,
 530                    struct trace_array_cpu *data,
 531                    unsigned long arg1,
 532                    unsigned long arg2,
 533                    unsigned long arg3, int pc);
 534 void trace_function(struct trace_array *tr,
 535                     unsigned long ip,
 536                     unsigned long parent_ip,
 537                     unsigned long flags, int pc);
 538
 539 void trace_graph_return(struct ftrace_graph_ret *trace);
 540 int trace_graph_entry(struct ftrace_graph_ent *trace);
 541
 542 void tracing_start_cmdline_record(void);
 543 void tracing_stop_cmdline_record(void);
 544 void tracing_sched_switch_assign_trace(struct trace_array *tr);
 545 void tracing_stop_sched_switch_record(void);
 546 void tracing_start_sched_switch_record(void);
 547 int register_tracer(struct tracer *type);
 548 void unregister_tracer(struct tracer *type);
 549
 550 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 551
 552 extern unsigned long tracing_max_latency;
 553 extern unsigned long tracing_thresh;
 554
 555 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu);
 556 void update_max_tr_single(struct trace_array *tr,
 557                           struct task_struct *tsk, int cpu);
 558
 559 void __trace_stack(struct trace_array *tr,
 560                    unsigned long flags,
 561                    int skip, int pc);
 562
 563 extern cycle_t ftrace_now(int cpu);
 564
 565 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
 566 typedef void
 567 (*tracer_switch_func_t)(void *private,
 568                         void *__rq,
 569                         struct task_struct *prev,
 570                         struct task_struct *next);
 571
 572 struct tracer_switch_ops {
 573         tracer_switch_func_t            func;
 574         void                            *private;
 575         struct tracer_switch_ops        *next;
 576 };
 577 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 578
 579 extern void trace_find_cmdline(int pid, char comm[]);
 580
 581 #ifdef CONFIG_DYNAMIC_FTRACE
 582 extern unsigned long ftrace_update_tot_cnt;
 583 #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func
 584 extern int DYN_FTRACE_TEST_NAME(void);
 585 #endif
 586
 587 #ifdef CONFIG_FTRACE_STARTUP_TEST
 588 extern int trace_selftest_startup_function(struct tracer *trace,
 589                                            struct trace_array *tr);
 590 extern int trace_selftest_startup_function_graph(struct tracer *trace,
 591                                                  struct trace_array *tr);
 592 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 593                                           struct trace_array *tr);
 594 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 595                                              struct trace_array *tr);
 596 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 597                                                  struct trace_array *tr);
 598 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 599                                          struct trace_array *tr);
 600 extern int trace_selftest_startup_nop(struct tracer *trace,
 601                                          struct trace_array *tr);
 602 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 603                                                struct trace_array *tr);
 604 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 605                                                struct trace_array *tr);
 606 extern int trace_selftest_startup_branch(struct tracer *trace,
 607                                          struct trace_array *tr);
 608 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 609
 610 extern void *head_page(struct trace_array_cpu *data);
 611 extern unsigned long long ns2usecs(cycle_t nsec);
 612 extern int
 613 trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
 614 extern int
 615 trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 616
 617 extern unsigned long trace_flags;
 618
 619 /* Standard output formatting function used for function return traces */
 620 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 621 extern enum print_line_t print_graph_function(struct trace_iterator *iter);
 622 extern enum print_line_t
 623 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
 624
 625 #ifdef CONFIG_DYNAMIC_FTRACE
 626 /* TODO: make this variable */
 627 #define FTRACE_GRAPH_MAX_FUNCS          32
 628 extern int ftrace_graph_count;
 629 extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
 630
 631 static inline int ftrace_graph_addr(unsigned long addr)
 632 {
 633         int i;
 634
 635         if (!ftrace_graph_count || test_tsk_trace_graph(current))
 636                 return 1;
 637
 638         for (i = 0; i < ftrace_graph_count; i++) {
 639                 if (addr == ftrace_graph_funcs[i])
 640                         return 1;
 641         }
 642
 643         return 0;
 644 }
 645 #else
 646 static inline int ftrace_trace_addr(unsigned long addr)
 647 {
 648         return 1;
 649 }
 650 static inline int ftrace_graph_addr(unsigned long addr)
 651 {
 652         return 1;
 653 }
 654 #endif /* CONFIG_DYNAMIC_FTRACE */
 655 #else /* CONFIG_FUNCTION_GRAPH_TRACER */
 656 static inline enum print_line_t
 657 print_graph_function(struct trace_iterator *iter)
 658 {
 659         return TRACE_TYPE_UNHANDLED;
 660 }
 661 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 662
 663 extern struct pid *ftrace_pid_trace;
 664
 665 static inline int ftrace_trace_task(struct task_struct *task)
 666 {
 667         if (!ftrace_pid_trace)
 668                 return 1;
 669
 670         return test_tsk_trace_trace(task);
 671 }
 672
 673 /*
 674  * trace_iterator_flags is an enumeration that defines bit
 675  * positions into trace_flags that controls the output.
 676  *
 677  * NOTE: These bits must match the trace_options array in
 678  *       trace.c.
 679  */
 680 enum trace_iterator_flags {
 681         TRACE_ITER_PRINT_PARENT         = 0x01,
 682         TRACE_ITER_SYM_OFFSET           = 0x02,
 683         TRACE_ITER_SYM_ADDR             = 0x04,
 684         TRACE_ITER_VERBOSE              = 0x08,
 685         TRACE_ITER_RAW                  = 0x10,
 686         TRACE_ITER_HEX                  = 0x20,
 687         TRACE_ITER_BIN                  = 0x40,
 688         TRACE_ITER_BLOCK                = 0x80,
 689         TRACE_ITER_STACKTRACE           = 0x100,
 690         TRACE_ITER_SCHED_TREE           = 0x200,
 691         TRACE_ITER_PRINTK               = 0x400,
 692         TRACE_ITER_PREEMPTONLY          = 0x800,
 693         TRACE_ITER_BRANCH               = 0x1000,
 694         TRACE_ITER_ANNOTATE             = 0x2000,
 695         TRACE_ITER_USERSTACKTRACE       = 0x4000,
 696         TRACE_ITER_SYM_USEROBJ          = 0x8000,
 697         TRACE_ITER_PRINTK_MSGONLY       = 0x10000,
 698         TRACE_ITER_CONTEXT_INFO         = 0x20000, /* Print pid/cpu/time */
 699         TRACE_ITER_LATENCY_FMT          = 0x40000,
 700         TRACE_ITER_GLOBAL_CLK           = 0x80000,
 701         TRACE_ITER_SLEEP_TIME           = 0x100000,
 702         TRACE_ITER_GRAPH_TIME           = 0x200000,
 703 };
 704
 705 /*
 706  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
 707  * control the output of kernel symbols.
 708  */
 709 #define TRACE_ITER_SYM_MASK \
 710         (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
 711
 712 extern struct tracer nop_trace;
 713
 714 /**
 715  * ftrace_preempt_disable - disable preemption scheduler safe
 716  *
 717  * When tracing can happen inside the scheduler, there exists
 718  * cases that the tracing might happen before the need_resched
 719  * flag is checked. If this happens and the tracer calls
 720  * preempt_enable (after a disable), a schedule might take place
 721  * causing an infinite recursion.
 722  *
 723  * To prevent this, we read the need_resched flag before
 724  * disabling preemption. When we want to enable preemption we
 725  * check the flag, if it is set, then we call preempt_enable_no_resched.
 726  * Otherwise, we call preempt_enable.
 727  *
 728  * The rational for doing the above is that if need_resched is set
 729  * and we have yet to reschedule, we are either in an atomic location
 730  * (where we do not need to check for scheduling) or we are inside
 731  * the scheduler and do not want to resched.
 732  */
 733 static inline int ftrace_preempt_disable(void)
 734 {
 735         int resched;
 736
 737         resched = need_resched();
 738         preempt_disable_notrace();
 739
 740         return resched;
 741 }
 742
 743 /**
 744  * ftrace_preempt_enable - enable preemption scheduler safe
 745  * @resched: the return value from ftrace_preempt_disable
 746  *
 747  * This is a scheduler safe way to enable preemption and not miss
 748  * any preemption checks. The disabled saved the state of preemption.
 749  * If resched is set, then we are either inside an atomic or
 750  * are inside the scheduler (we would have already scheduled
 751  * otherwise). In this case, we do not want to call normal
 752  * preempt_enable, but preempt_enable_no_resched instead.
 753  */
 754 static inline void ftrace_preempt_enable(int resched)
 755 {
 756         if (resched)
 757                 preempt_enable_no_resched_notrace();
 758         else
 759                 preempt_enable_notrace();
 760 }
 761
 762 #ifdef CONFIG_BRANCH_TRACER
 763 extern int enable_branch_tracing(struct trace_array *tr);
 764 extern void disable_branch_tracing(void);
 765 static inline int trace_branch_enable(struct trace_array *tr)
 766 {
 767         if (trace_flags & TRACE_ITER_BRANCH)
 768                 return enable_branch_tracing(tr);
 769         return 0;
 770 }
 771 static inline void trace_branch_disable(void)
 772 {
 773         /* due to races, always disable */
 774         disable_branch_tracing();
 775 }
 776 #else
 777 static inline int trace_branch_enable(struct trace_array *tr)
 778 {
 779         return 0;
 780 }
 781 static inline void trace_branch_disable(void)
 782 {
 783 }
 784 #endif /* CONFIG_BRANCH_TRACER */
 785
 786 /* set ring buffers to default size if not already done so */
 787 int tracing_update_buffers(void);
 788
 789 /* trace event type bit fields, not numeric */
 790 enum {
 791         TRACE_EVENT_TYPE_PRINTF         = 1,
 792         TRACE_EVENT_TYPE_RAW            = 2,
 793 };
 794
 795 struct ftrace_event_field {
 796         struct list_head        link;
 797         char                    *name;
 798         char                    *type;
 799         int                     offset;
 800         int                     size;
 801 };
 802
 803 struct ftrace_event_call {
 804         char                    *name;
 805         char                    *system;
 806         struct dentry           *dir;
 807         int                     enabled;
 808         int                     (*regfunc)(void);
 809         void                    (*unregfunc)(void);
 810         int                     id;
 811         int                     (*raw_init)(void);
 812         int                     (*show_format)(struct trace_seq *s);
 813         int                     (*define_fields)(void);
 814         struct list_head        fields;
 815         struct filter_pred      **preds;
 816
 817 #ifdef CONFIG_EVENT_PROFILE
 818         atomic_t        profile_count;
 819         int             (*profile_enable)(struct ftrace_event_call *);
 820         void            (*profile_disable)(struct ftrace_event_call *);
 821 #endif
 822 };
 823
 824 struct event_subsystem {
 825         struct list_head        list;
 826         const char              *name;
 827         struct dentry           *entry;
 828         struct filter_pred      **preds;
 829 };
 830
 831 #define events_for_each(event)                                          \
 832         for (event = __start_ftrace_events;                             \
 833              (unsigned long)event < (unsigned long)__stop_ftrace_events; \
 834              event++)
 835
 836 #define MAX_FILTER_PRED 8
 837
 838 struct filter_pred;
 839
 840 typedef int (*filter_pred_fn_t) (struct filter_pred *pred, void *event);
 841
 842 struct filter_pred {
 843         filter_pred_fn_t fn;
 844         u64 val;
 845         char *str_val;
 846         int str_len;
 847         char *field_name;
 848         int offset;
 849         int not;
 850         int or;
 851         int compound;
 852         int clear;
 853 };
 854
 855 int trace_define_field(struct ftrace_event_call *call, char *type,
 856                        char *name, int offset, int size);
 857 extern void filter_free_pred(struct filter_pred *pred);
 858 extern void filter_print_preds(struct filter_pred **preds,
 859                                struct trace_seq *s);
 860 extern int filter_parse(char **pbuf, struct filter_pred *pred);
 861 extern int filter_add_pred(struct ftrace_event_call *call,
 862                            struct filter_pred *pred);
 863 extern void filter_free_preds(struct ftrace_event_call *call);
 864 extern int filter_match_preds(struct ftrace_event_call *call, void *rec);
 865 extern void filter_free_subsystem_preds(struct event_subsystem *system);
 866 extern int filter_add_subsystem_pred(struct event_subsystem *system,
 867                                      struct filter_pred *pred);
 868
 869 static inline void
 870 filter_check_discard(struct ftrace_event_call *call, void *rec,
 871                      struct ring_buffer_event *event)
 872 {
 873         if (unlikely(call->preds) && !filter_match_preds(call, rec))
 874                 ring_buffer_event_discard(event);
 875 }
 876
 877 #define __common_field(type, item)                                      \
 878         ret = trace_define_field(event_call, #type, "common_" #item,    \
 879                                  offsetof(typeof(field.ent), item),     \
 880                                  sizeof(field.ent.item));               \
 881         if (ret)                                                        \
 882                 return ret;
 883
 884 void event_trace_printk(unsigned long ip, const char *fmt, ...);
 885 extern struct ftrace_event_call __start_ftrace_events[];
 886 extern struct ftrace_event_call __stop_ftrace_events[];
 887
 888 #define for_each_event(event)                                           \
 889         for (event = __start_ftrace_events;                             \
 890              (unsigned long)event < (unsigned long)__stop_ftrace_events; \
 891              event++)
 892
 893 extern const char *__start___trace_bprintk_fmt[];
 894 extern const char *__stop___trace_bprintk_fmt[];
 895
 896 /*
 897  * The double __builtin_constant_p is because gcc will give us an error
 898  * if we try to allocate the static variable to fmt if it is not a
 899  * constant. Even with the outer if statement optimizing out.
 900  */
 901 #define event_trace_printk(ip, fmt, args...)                            \
 902 do {                                                                    \
 903         __trace_printk_check_format(fmt, ##args);                       \
 904         tracing_record_cmdline(current);                                \
 905         if (__builtin_constant_p(fmt)) {                                \
 906                 static const char *trace_printk_fmt                     \
 907                   __attribute__((section("__trace_printk_fmt"))) =      \
 908                         __builtin_constant_p(fmt) ? fmt : NULL;         \
 909                                                                         \
 910                 __trace_bprintk(ip, trace_printk_fmt, ##args);          \
 911         } else                                                          \
 912                 __trace_printk(ip, fmt, ##args);                        \
 913 } while (0)
 914
 915 #undef TRACE_EVENT_FORMAT
 916 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)      \
 917         extern struct ftrace_event_call event_##call;
 918 #include "trace_event_types.h"
 919
 920 #endif /* _LINUX_KERNEL_TRACE_H */